1styear BIOLOGY Notes Chapter-11

Chapter-11
BIO-ENERGETICS

DEFINITION
The capturing and conversion of energy from one form to another in the living system and its utilization in metabolic activities is called Bioenergetics.
Bio-energetics is the quantitative study of energy relationships and conversion into biological system. Biological energy transformation always obey the laws of thernodynamic.

ROLE OF ATP AS ENERGY CURRENCY
ATP is adenosine triphosphate. Adenosine is made of adenosine and ribose sugar. Among the three phosphate groups two are energy rich PO4 bonds. So ATP is a high energy compound it gives its PO4 groups easily. When 1 ATP is converted into ADP, 7.3 K cal/mole or 31.81 KJ/mole energy is released. ATP -> ADP + Pi + Energy
Living organisms use organic food for generation of energy. These food usually contain carbohydrates which degrade to produce CO2, H2O and energy. Which is usually in the form of ATPs. ATP plays role in several endergonic and exergonic reactions.

ENDERGONIC REACTIONS
Those chemical reactions which accompanied by the absorption of the energy are known as endergonic reactions. The products have a higher free energy than reactants. Examples of endergonic reaction in human are
1. Synthesis of proteins
2. Synthesis of lipids
3. Synthesis of cholestrol
4. Synthesis of glycogen

EXERGONIC REACTIONS
Those reactions which complete along with the liberation of free energy are known as Exergonic reaction. The products have a lower free energy than the reactants.
EXAMPLE
An aerobic glycolysis, Kreb’s cycle, oxidative phosphoylation.

PIGMENTS
Substances in plants that absorb the visible light are called Pigments. Different pigments absorb light of different wavelength. They are involved in the conversion of light energy to chemical energy. Important plant pigments are chlorophyls, carotenoids, phycobilin, xanthophylls, phaelophytin.

PHOTOSYSTEM
Each photosystem is a highly organized unit consisting of chlorophyll accessory pigment molecules and electron carrier molecules present on the thylakoids of chloroplast. Each thylakoid contains many units of two photosystems the photosystem I and photosystem II. So chloroplast contains thousands of photosystem.
The photosystem consists of chlorophyll “a” and “b” and carotenoids. Chlorophyll having empirical formula of C55H72O5N4Mg is almost identical to “Chlorophyll b” of empirical formula C55H70O6N4Mg. But the slight structural difference between them is enough to give 2 pigments slightly different absorption spectra and hence different colours “Chlorophyll a” is blue green while “b” is yellow green.
Hundreds of chlorophyll a, chlorophyll b and carotenoids cluster together in a photosystem. But only a single molecule of chlorophyll a acts like a reaction centre the rest of others absorbs a photon, the energy is transmitted from pigment, molecules to pigment molecules until it reaches a particular chlorophyll a located in the region of reaction centre, where it gives electrons to primary electron acceptor
FIGURE 11.3 PAGE 260
Hundreds of carotenoids are admixed with 2 types of chlorophyll molecules in photosystem, giving yellow and orange shades. Carotenoids can absorb wavelength of light that chlorophyll cannot transfer to chlorophyll a. Some times excess energy can damage chlorophyll a, so carotenoids accept energy from them, thus providing a function known as Photoreceptor.

ROLE OF LIGHT
Light has a dual nature, can behave like a wave or like a particle. It is composed of packets of energy called photons (hu). Light energy captured in the light harvesting complexes is efficiently and rapidly transferred to the chlorophyll molecules present in the photosynthetic reaction centre. When a photon of light hits these chlorophyll a molecules. The energy of these photons is absorbed and results in the elevation of an e- from the ground state to an excited state, level depends upon the energy and incident photon.
A photon of red light has enough energy to raise an electron to excited state I and this energy is sufficient to carryout all the chemical reactions of photosynthesis.
The energy transferred by blue light raise the electron to excited state –2. However the energy transmitted by red or blue photons to photosynthetic electron transport chain is exactly the same. This is because that extra energy is lost (from absorption of blue photon) by radiationless de-excitation.
The excitation energy can be used in
1. Photochemistry (i.e. it enter the photosynthetic electron transport chain)
2. Lost as heat.
3. Give fluorescence etc.

PHOTOSYNTHESIS
Photosynthesis is an anabolic process in which chloroplast of the plants take up CO2 and H2O and using light energy to synthesize carbohydrates. In photosynthesis, the light energy is converted to chemical energy. It is an oxidation reduction process in which water is oxidized and CO2 is reduced
6CO2 + 12H2O -> C6H12O6 + 6H2O + 6O2 ?
In simple
6CO2 + 6H2O -> C6H12O6 + 6O2 ?
This process divides into
1. Light reaction
2. Dark reaction

1. LIGHT REACTION
In the light dependent reactions, light energy is absorbed by chlorophyll and other photosynthetic pigment molecules. It is then converted into chemical energy. Due to this energy conversion, NADPH+ and ATP are produced.
Components of light reaction
1. Light capturing chlorophyll molecules.
2. Membrane bound protein complexes
3. Mobile electron carriers


CHLOROPHYLL MOLECULES AND PHOTOSYSTEM
Each photosystem consists of a light gathering “antenna complex” and a “reaction centre”. The antenna complex has many molecules of chlorophyll a, chlorophyll b and carotenoids most of them channeling the energy to reaction centre. Reaction centre of photosystem I and II has one or two “chlorophyll a” molecules, primary electron acceptor, associated electron carriers of electron transport system and certain specific proteins known as chlorophyll-bound proteins which differs them from other “chlorophyll a” molecules of the same system. The “chlorophyll a” molecules at the reaction centre of photosystem I (PSI) has a maximum absorbance at 700 nm, while those of PS II absorb at 680 nm. Therefore these reaction centre are called P700 and P680 where P simply stands for pigment.


COMPLEXES
There are 4 major groups of complexes.
1. PS I
2. PS II
3. Cytochrome b/f complex
4. ATPase complex
The PS I and ATPase or ATP synthase complex are present on non-appressed region of thylakoid. While PS II and light harvesting complexes (LHC II) are present on appressed side. The cyt b/f complex is randomly distributed throughout the mambrane.

MOBILE ELECTRON CARRIERS
Transport the excited electrons between the complexes. These are plastoquinone (PQ) plastocyanin (PC), ferredoxin (FD)

ELECTRON TRANSPORT
This process occurs in several steps.

(1) EXCITATION OF PS II
When chlorophyll a of reaction centre of PS II is striked by a photon, the energy of photon absorbs in it. This results in the elevation of an electron from the ground state to an excited state. The excited electrons produced within P680 is rapidly transferred to the primary electrons acceptors phaelophytin. So 2 electrons which are transformed has to be replaced which is done by water.

(2) PHOTOLYSIS OF WATER
In the presence of light a water splitting enzyme complex extracts 4 electrons from two water molecules. Removal of electrons splits the water into two hydrogen ions 2H+ and oxygen atoms. The extracted electrons from water are supplied to PS II (P680) while the oxygen atom immediately combines with another oxygen atom to form O2. Which is released during photosynthesis. The hydrogen ions or proton (H+) are stored in thylakoid space. The overall reaction will be
2H2O -> 4 H+ + 4e- + O2

(3) FLOW OF ELECTRONS FROM PS II TO PS I
Photoexcited electrons accepted by phaelophytin from PS II are transferred to plastoquinone molecules QA and QB which accept two electrons and takes up two protein from the stroma. PQ carries electrons from PS II to cytochrome b/f complex containing FeS protein. This is thought to be the rate limiting step of electron transport. Electrons from PQ are taken up by Cyt b/f complex through FeS and releasing protons (2H+) to the lumen. The second mobile electron carrier plastocyanin (PC) takes the electrons and delivered to the photosystem I.

(4) FLOW OF ELECTRONS FROM PS I TO NADP+ REDUCTASE
A second excitation event within PS I leads to the transfer of electrons to the primary electron acceptor. The primary e- acceptor of PS I passes the photoexcited electrons to a second electron transport chain, which transmit then to ferredoxin, an iron containing protein. An enzyme called NADP reductase then transfer the electrons from Fd to NADP+ (oxidized form)

(5) REDUCTION OF NADP+ TO NADPH+ H+
This is the redox reaction that stores the high energy electrons in NADP+ to reduced it to NADPH + H+.
NADP+ + 2H+ -> NADPH + H+
Hydrogen ions are taken from stroma which is being pumped from thylakoid space to stroma by ATPase.

PHOTOPHOSPHORYLATION
Hydrogen ions are pumped into thylakoid space by cyt b/f and also 2H+ ions are collected there from photolysis of one water molecule. This large no. of H+ ions in thylakoid space compared to stroma, creates an electrochemical gradient, when these hydrogen ions flow out of the thylakoid space by way of a channel protein present in membrane called the ATP synthase complex, energy is prvided to it. The transport of 3 protons (H+ ions) through the ATPase complex are normally required to produce 1 ATP from ADP and inorganic phosphate Pi.
ADP + Pi -> ATP
This is called chemiosmotic ATP synthesis because chemical and osmatic events join to permit ATP synthesis. The linear flow of electrons from H2O to NADP+, coupled to ATP syntheses is non-cyclic photophosphorylation because the electrons pass on to a terminal acceptor.
In cyclic photophosphorylation the electrons are cycled from PS I back to PQ. So only ATP is produced but not NADPH + H+. This occurs under following conditions to meet increased ATP demand for e.g. CO2 fixation
1. Protein synthesis
2. Synthesis of starch

EVENTS OF LIGHT REACTION
1. Photolysis of water.
2. Reduction of NADP+ to NADPH + H+
3. Synthesis of ATP by photophosphorylation.
So during light reaction ATP and NADPH + H+ are produced which are used in Dark reaction, O2 is evolved as a by product.

2. DARK REACTION
The dark reaction consist of a series of light independent reactions which can proceed even in the absence of light. During dark reaction, energy is produced by ATP and NADPH+ H+ and CO2 is fixed in carbohydrates. This cyclic series of enzymatic catalyzed reaction in the stroma of the chloroplasts is called Calvin-Benson Cycle. During this cycle CO2 is reduced to triose-PO4 sugars, therefore this pathway is also known as C3 pathray (reductive pentose phosphate cycle) and the plants undergo this cycle are known as C3 plants. The calvin or C3 cycle is divided into 3 phases.

CARBOXYLATION (CARBON FIXATION)
The calvin cycle begins when a molecule of CO2 reacts with a highly reactive phosphorylated five carbon sugar named ribulase 1.5 bisphosphate (RuBP). This reaction is catalyzed by the enzyme ribulase biphosphate carboxylase or Rubisco (it is the most abundant protein in chloroplast). The product of this reaction is a highly unstable, six carbon intermediate that immediately breakdown into two molecules of three carbon compound called 3-phosphoglycerate (G3P).
3CO2 + 3RuBP -> G3P

REDUCTION
Each molecule of the PGA or G3P receives an additional phosphate from ATP of light reaction, forming 1,3-bisphosphoglycerate (G1,3P) which is then reduced to glyceraldehydes 3-phosphate (GA3P) and Dihydroxyacetone phosphate (DHAP) by NADPH+ H+GA3P and DHAP are intercovertible and the reaction don’t require any energy. These products are also formed during glycolysis and links dark reaction with sugar synthesis pathway.
6G3P + 6ATP + 6NADPH + H+ -> 6GA3P + 6ADP + 6NADP+ + 6Pi

REGENERATION
Three carbon compounds are rearranged to form five carbon units ribulose 1,5-bisphosphate (RuBP), which is the primary carbon acceptors in the cycle.
5 GA3P + 3ATP -> 3 RuBP + 3 ADP + 3Pi
Again more molecules of ATP are used for phosphorylation of RuBP, which then starts the cycle again.

CONCLUSION
For every 3 molecules of CO2 entering the cycle and combining with 3 mole of RuBP (5C), six molecules of three carbon G3P is produced. Out of six G3P only one G3P molecule leaves the cycle and can be used for synthesis of glucose, starch, cellulose, sucrose or other compounds. The other 5 molecules are recycled to regenerate 5C RuBP’s three molecules, the CO2 acceptor.

CONSUMPTION
For the net synthesis of one G3P molecule, the calvin cycle consumes a total of nine ATP’s and six NADPH + H+

PHOTORESPIRATION
In presence of light (photon), oxygen is taken up by RuBP and CO2 is evolved.
RuBP + O2 -> PGA + Phosphoglycolate ® CO2
It occurs when CO2 is deficient, Rubisco works like an oxygenase rather than carboxylase in presence of O2, produce phosphoglycerate (phosphoglyceric acid-PGA) and Phosphoglycolate, where phosphoglycolate rapidly breaks down to release CO2. Alternative mechanisms of carbon fixation in hot, arid climate.
In hot temperature the concentration of CO2 begins to fall in leaves due to closing of stomata, increase yield of photosynthesis etc. These conditions in leaves may cause a wasteful process called photorespiration in which precious products are lost and less energy is generated. In certain plant species alternate mode of CO2 fixation have evolved even in very hot and arid environment.

These two photosynthetic adaptations are

1. C4 PHOTOSYNTHESIS (C4 PATHWAY)
This process occurs in C4 plants. Those which prefer calvin cycle with an alternate mode of carbon fixation are known as C4 plants. CO2 reacts with PEP in presence of PEP carboxylase to produce oxaloacetate, a four carbon compound which converts into malate. Malate transfers from mesophyll cell to bundle sheath cell where it breaks down to pyruvate and releases CO2. This CO2 is fixed in calvin cycle by Rubsico and so the cycle continues.
E.g. Family poaceae especially sugar cane, corn.

2. CAM
Plants of hot, arid environment, open their stomata during the night and close them during the day. Closing stomata during the day helps deserts plants to conserve water but it also prevents CO2 from entering the leaves. During the night, when their stomata are open, these plants take up CO2 and incorporate it into a variety of organic acids because of lack of energy (ATPs and NADPH+ H+). This mode of carbon fixation is called crassulacean acid metabolism (CAM). They store these organic acids in vacuoles. During day time organic acids release CO2 for dark reaction because light reaction can supply ATP and NADPH+ H+ on which the calvin cycle depends.
E.g. Cactus, Pinapple, Succulent plants.

CELLULAR RESPIRATION
Aerobic breakdown of glucose molecules into CO2 and water with synthesis of ATP is called Cellular Respiration.
C6H12O6 +6O2 -> 6CO2 + 6H2O + 673 Kcal/mole
Respiration is an oxidation reduction process because the carbon of substrate, mostly glucose is oxidized to form CO2, while the atmospheric O2 is reduced to form the water.

There are two types of cellular respiration.

(A) AEROBIC RESPIRATION
The breakdown of sugar, in presence of oxygen [molecular O2] and release of carbondioxide and water with sufficient amount of energy. This type of respiration is known as Aerobic respiration, and the organisms performed this are known as Aerobes.

(B) ANAEROBIC RESPIRATION
The break down of sugar in absence of oxygen is known as Anaerobic respiration, and this type of respiration is performed by Anaerobs.
E.g. Yeast, some bacteria, gut parasites (e.g. tapeworm). Some species of annelids, roots of plants growing in water logged area. Anaerobes are of two types. Those which never need of O2 at all are Obligate anaerobes. Those which respire aerobically but can also respire in absence of O2 are known as Facultative aerobes.

CATEGORIES OF AEROBIC RESPIRATION
The process of aerobic respiration is divided into three main categories.
1. Glycolysis
2. Kreb’s cycle
3. ETC

(1) GLYCOLYSIS
Glycolysis is the first and common step in both aerobic and anaerobic respiration. It consists of a complex series of enzymatically catalyzed reactions in which a 6 carbon molecule “Glucose” breaks down into 3 carbon “Pyruvic acid”. These reactions occur in Cytoplasm and doesn’t require oxygen. Following are the different steps of Glycolysis.

(I) PHOSPHORYLATION
Phosphorylation is the addition of phosphate groups to the sugar molecules. Glucose is phosphorylated by a molecule of ATP to form an activated molecule, the glucose 6 phosphate. ATP is converted to ADP.

(II) ISOMERIZATION
Glucose -6-phosphate is converted to fructose -6-phosphate, an isomer of it by an enzyme.

(III) SECOND PHOSPHORYLATION
Another molecules of ATP is invested which transfers its phosphate group to carbon no.1 of fructose –6-phosphate, forming fructose 1,6-bisphosphate and ADP.

(IV) CLEAVAGE
The 6-carbon, fructose 1,6 bisphosphate molecule is break down into 2; three carbon molecules, 3-phosphoglyceraldehyde PGAL and dihydroxyacetone phosphate (DHAP). These two sugar molecules are isomers and are interconvertible. This is the reaction from which glycolysis derives its name. DHAP is converted to its isomer PGAL and then 2 PGAL will be converted to 2 pyruvic acid molecules. Since at this stage 2 ATPs are used, therefore this phase is known as Energy investment phase.
In the subsequent reactions, energy is produced therefore this half is also known as Energy yielding phase

(V) DEHYDROGENATION (OXIDATION)
In the next step, PGAL is acted upon by an enzyme dehydrogenase along with a co-enzyme nicotine amide adenine dinucleotide (NAD+), which convert PGAL into phosphoglyceric acid PGA or phosphoglycerate by the loss of two hydrogen atoms (2e- + 2H+). These H atoms are captured by NAD+. This is a redox reaction in which PGAL oxidized by removal of electrons and NAD is reduced by the gaining of electrons. Now phosphoglyceric acid PGA picks up phosphate group (Pi) present in cytoplasm and becomes 1,3-bisphosphoglyceric acid (DPGA)

(VI) PHOSPHORYL TRANSFER
1,3-bisphosphoglyceric acid loses its phosphate group to ADP forming ATP and 3-phosphoglyceric acid.

(VII) ISOMERIZATION
The PO4 group of PGA, attaches with carbon no,3 changes its position to carbon no.2 forming an isomer 1-phosphoglyceric acid.

(VIII) DEHYDRATION
A water molecule is removed from the substrate and forming phosphoenal pyruvate (PEP)

(IX) PHOSPHORYL TRANSFER
ADP removes the high energy PO4 from PEP producing ATP and Pyruvic acid. OVERALL REACTION of glycolysis can be summarized as Glucose + 2ADP + 2NAD+ -> 2 Pyruvic acid + 2ATP + 2NADH+ H+ + 2H2O

ENERGY YIELD
Since when PGAL is produced, the cycle is counted twice because DHAP also converts into PGAL and enter the same cycle. 4ATP molecules are produced at Substrate level phosphorylation because PO4 groups are transferred directly to ADP from another molecule. 2 ATP are used in the first phase. Thus there is a net gain of 2 ATPs. 2 NADH+ H+ are produced and each gives 2 ATPs (a total of 6 ATPs). Therefore net production of ATP during glycolysis is 8 ATPs

FATE OF PYRUVIC ACID
There are 3 major pathways by which it is further processed under anaerobic conditions, pyruvic acid either forms, ethyl alcohol or lactic acid or produces CO2 and H2O from kreb’s cycle under aerobic conditions.

FERMENTATION
Fermentation the alternative term for Anaerobic respiration was used by W.Pasteur and defined as respiration in absence of oxygen (air). The production of ethyl alcohol from glucose is alcoholic fermentation and that of lactic acid is lactic acid fermentation.

ALCOHOL FERMENTATION
Each pyruvic acid molecule is converted to ethyl alcohol also known as Ethanol in two steps. In the first pyruvic acid is decarboxylated to acetaldehyde under the action of enzyme.
Pyruvic acid CH3.CO.COOH -> CH3CHO + CO2
In the next step NADH+ H+ reduces acetaldehyde to ethyl alcohol
CH3.CHO + NADH+ H+ -> CH3.CH2OH + NAD+
Ethyl alcohol is toxic, plants can never use it because it cannot be converted to carbohydrates or breaks up in presence of O2. When accumulation is more than tolerable limits, plants will be poisoned and subsequently they died.

LACTIC ACID FERMENTATION
When NADH+ H+ transfer its hydrogen directly to pyruvic acid, it results in formation of lactic acid.
Pyruvic acid + NADH + H+ -> CH3.CH.OH. COOH
During extensive exercise such as fast running muscle cells of animals and man respire anaerobically. Due to inadequate supply of O2, pyruvic acid is converted to lactic acid. Blood circulation removes lactic acid from muscle cells. When lactic acid accumulates inside cells, it causes Muscle futigue. This forces person to stop work, until normal O2 levels are restored.

ECONOMIC IMPORTANCE OF FERMENTATION
1. It is the source of ethyl alcohol in wines and beers Wines are produced by fermenting fruits like grapes, dates etc. Beers are produced by fermenting malted cereals such as Barley.
2. Yeast is used to prepare bread from wheat.
3. Milk is converted to curd (yoghurt) by bacteria.
4. Preparation of cheese and other dairy products.
5. Production of lactic acid, propionic acid, and butanol.
6. Flavour of pickles is due to lactic and acetic acid.
7. Addition of lactic and acetic acids prevent foods from spoilage and also give sour flavours to yoghurt and cheese.
8. Acetone is also formed as a by-product.

(2) KREB’S CYCLE
FORMATION OF ACETYL-CO
Before entering the Kreb’s cycle, each molecule of pyruvic acid undergoes oxidative decarboxylation. During this process one of the three carbons of pyruvic acid molecule is removed to form CO2 by enzymatic reactions. Simultaneously pyruvic acid is oxidized and a pair of energy rich Hydrogen atoms are passed on to a H acceptor NAD+ to form NADH+H+. The remaining 2-carbon component is called acetyle which combines with coenzyme A to form an activated two carbon compound called acetyle CoA. “Acetyle CoA connects Kreb’s cycle with glycolysis.” For each molecule of glucose that enters glycoilysis, two molecules of acetyle CoA produced, which enter in a cyclic series of enzymatically catalyzed reactions known as Kreb’s Cycle, which occurs in Mitochondria.
Pyruvic acid (3C) + CoA + NAD+ -> Acetyle CoA + CO2 + NADH+H+

SERIES OF REACTIONS IN KREB’S CYCLE
Sir Hans Kreb was working over these cyclical series of reactions therefore the cycle was given the name as Kreb’s cycle. The first molecule formed during the cycle is citric acid, so it is also called as “Citric Acid cycle.” This cycle is a multi step process and the steps are given below:

1. FORMATION OF CITRIC ACID
In this first step of the Kreb’s cycle, bond between acetyl and CoA is broken by the addition of water molecule. The acetyl (2C) reacts with 4 carbon compound (oxalo acetic) acid to form 6-carbon compound, citric acid, and the CoA is set free. This citric acid possess 3 carboxyl groups, therefore the cycle is also recommended as Tricarboxylic Acid Cycle (TCA cycle).

2. ISOMERIZATION
A molecule of water is removed and another added back so that cirtic acid is isomerized to isocitric acid through an intermediate, Cis-aconitic acid.

3.FIRST OXIDATIVE DECARBOXYLATION
First time the sugar molecules are oxidized, therefore it is also called first oxidation of the cycle. Isocitric acid is oxidized yielding a pair of electrons (2H+) that reduces a molecule of NAD+ to NADH+H+. The reduced sugar molecule is decarboxylated with the removal of CO2. It now converts into a 5 carbon compound a-Ketoglutaric acid (aKG).

4. SECOND OXIDATIVE DECARBOXYLATION
aKG is oxidatively decarboxylated. A CO2 molecule is lost. The remaining 4-C compound is oxidized by transfer of a pair of electrons (2H+) reducing NAD+ to NADH+H+. This 4-C compound accepts CoA forming succinyl CoA.

5. SUBSTRATE LEVEL PHOSPHORYLATION
Bond between succinyl and CoA is broken. CoA is replaced by PO4 group, which is then transferred to Guanosine diphosphate (GDP) to form Guanosine Triphosphate (GTP). GTP then transfers its phosphate group to ADP, forming ATP and with addition of 1 water molecule, succinic acid is formed.

6. THIRD OXIDATION
With loss of two electrons (2H+)succinic acid is oxidized to fumaric acid and FAD+ is reduced to FADH2.

7. HYDRATION
One water molecule is added to fumaric acid to convert it to Malic acid.

8. FOURTH OXIDATION AND REGENERATION OF OXALO-ACETIC ACID
Oxidation of malic acid leads to the production of 1 more NADH+H+ and oxaloacetic acid is regenerated.

ENERGY YIELD
Glucose molecule breaks down into 2 pyruvic acid molecules and each will enter the Kreb’s cycle.

For each pyruvic acid molecule, 3CO2 molecules are produced, four NADH+H+ are produced and 1 FADH2.

Pyruvic Acid + 3H2O + 4NAD+ + FAD+ -> 3CO2 + 4NADH+H+ + 1FADH2

Four calculation of energy (ATPs) we will multiply the products with 2 as 2 acetyle CoA enters the Kreb’s cycle.

Pyruvic Acid to Acetyl CoA..............1NADH2 -> 3ATP x 2 = 6 ATP

Kreb’s Cycle......................................3NADH+H + -> 9ATP x 2 = 18 ATP

.................................................. ....1FADH2 -> 2ATP x 2 = 4 ATP

.................................................S ubstrate Level Phosphorylation -> 1ATP x 2 = 2ATP


--------------------------------------------------------------------------------

Total..................................... = 30 ATP



OVERALL ENERGY YIELD OF AEROBIC RESPIRATION
Glycolysis..............................8ATP

Pyruvic Acid to Acetyl CoA..............6ATP

Kreb’s Cycle............................24 ATP


--------------------------------------------------------------------------------
Total...................................38 ATP

But actually 2 ATPs are utilizing in transporting cytoplasmic NADH+H+ to Mitochondria, which are produced during Glycolysis, so overall energy yield is only 36 ATPs.

3. ELECTRON TRANSPORT CHAIN/ ETC OR ET SYSTEM
The last of all steps is ETC. It consists of a series of electron acceptors which are located in the cristae of mitochondria. In respiration there are 6 steps at which hydrogen atoms are released (one in glycolysis, 5 in Kreb’s cycle). A pair of hydrogen atoms are dissociated into a pair of electrons and a pair of protons.
2H -> 2H+ + 2e
These electrons are accepted by Nicotinamide adenine dinucleotide (NAD) and Flavin Adenine Dinucleotide (FAD) from where they are passed along a chain of electron carriers such as cytochrome b, cytochrome c; cytochrome a, cytochrome a3.While passing from one carrier to another, these cytochromes are alternatively reduced and oxidized. During this, the energy released is used in the formation of ATP (adenosine triphosphate) from ADP and Pi. The final electron acceptor is atmospheric oxygen, which also picks up protons, and form the water molecule. The formation of ATP in mitochondria is called Oxidative Phosphorylation.
From every NAD, 3ATPs and from 1 FADH2, 2 ATPs are produced.

1styear BIOLOGY Notes Chapter-10

Chapter-10
KINGDOM ANAMALIA

Phylum Porifera (Sponges)

MAIN CHARACTERISTICS
Animals of this phylum show following important characters.

NATURE
Most simple multicellular organisms. From evolutionary point of view they occupy a position between protozoa and true metazoa

HABIT AND HABITAT
• Mostly marine but few in fresh water habitat.
• They are sessile, living attached to rocks, coral and other hard surfaces

SHAPE AND STRUCTURE
• Their shape may be cylindrical, branching, globular, flat, bell shaped or cup shaped
• Some are dull in colour and most are brightly coloured
• The body is perforated by pores and canals

MICROSCOPIC STRUCTURE
Most of sponges contain following types of cell:

(A) PINACOCYTES
Forming the epidermis.

(B) POROCYTES
Form pores of the body wall

(C) CHOANOCYTES
These are flagellated cells, form the internal lining of the body. These cells are strikingly similar to the choano flagellates.
• Much of the body is composed of jelly like matrix containing a skeleton made of Protein, CaCO3 or silica.
• Sponges are organized on cellular level, instead of a single cell carring on all the life activities.
• Sponges show cellular differentiation but little or no coordination of cells to form tissues.
• They usually have an endoskeleton of separate spicules.
• They do not posses a head, an interior end, a mouth or gut cavity.
• They are sedentary organisms ranging in size from 1 to 200cm.

DIGESTION
Digestion takes place with in the cell. (Intracellular)

PROCESS OF FEEDING, EXCRETION AND RESPIRATION
• Sponges feed by filtering out bacteria and fine particles of organic matter from water.
• The flagella of “Choanocytes” beat and create a current of water.
• The water current also helps in respiration, removal of waste products and dispersal of gametes.

REPRODUCTION
• Reproduction is of both type a***ual and ***ual
• A***ual reproduction is by means of “Buds” and “Gemmules formation”.
• ***ual reproduction is by means of sperm and ova.
• All sponges appear to be diploid and have the usual metazoan process of “Oogenesis” and “Spermatogenesis”.
• The eggs retained just beneath the choanocytes where they are fertilized by sperm from another sponge brought in with the current of water.
• Fertilization is internal.

LARVA
• After cleavage, the larva escape from the parent to the open sea as a free swimming “Amphiblastula larva”.
• It finally becomes attached to the bottom by its anterior end.
• Reproduction is also by fragmentation.

BODY CAVITY
Body cavity is known as “Spongocoel”.
EXAMPLES
Common examples are
1. Sycon
2. Euplectella
3. Euspongia 

1styear BIOLOGY Notes Chapter-9

Chapter-9
KINGDOM PLANTAE

Kingdom Plantae
INTRODUCTION
• Includes all eukaryotic multicellular and chlorophyllous living organisms, which have cell wall made up of true cellulose.
• Majority of members are autotrophic but few are parasite e.g.: “Cuscuta”
• They have localized growth, regions of growth lying primarily at the extremities that is root and stem apices.

CLASSIFICATION OF KINGDOM PLANTAE
Kingdom planatae is divided into tow sub-kingdom on the basis of presence or absence of vascular tissue (xylem and phloem).
A - SUB-DIVISION - BRYOPHYTES (NON-VASCULAR)
• Class Hepatica (Liverworts)
• Class Musci (Mosses)
• Class Anthroccrota (Hornworts)

B- SUB-DIVISION - TRACHEOPHYTES
• Class Psilopsida (Psilopsids)
• Class Lycopsida (Club Mosses)
• Class Sphenopsida (Horse Tails)
• Class Pteropsida (Ferns)
• ClassSpermopsida (Seed Plants)

SUB –DIVISION BRYOPHYTA (AMPHIBIAN PLANTS) OR (NON-VASCULAR PLANTS)
• Absence of lignin-fortified tissue to support tall plants on land.
• Members of this sub-division usually sprawl horizontally as mats over a large surface.
• Always have a low profile (1-2cm-20cm tall).
Regular heteromorphic alternation of generation is present w/t gametophytes dominancy (Gametophytes large and long lived).
• Sporophyte stage of bryophytes is generally smaller and shorter lived, and it depends on gametophyte for water and nutrients.
• The diploid sporophyte produces haploid spores via meiosis in a structure called “sporangium”
• The tiny, spores, protected by sporopollenim, disperse and give rise to new gametophytes.
• All members of bryophytes need water to reproduce.
• Gametes produce within reproductive structures “Gametangia” (Male-Antheridia and Female-Archer- gonium)
• Antheridium produces flagellated sperm while female archegonium contains one egg (ovum).
• Fertilization occurs w/t in the archegonium
• Zygote develops into an embryo within the protective jacket of Archegonium.
• Windblown spores disperse the speies.
• All bryophytes belong to Silurian/Devonian period (345-395Million yrs. Ago.)

ADAPTATION OF BRYOPHYTES TO LAND HABITAT
All Bryophytes show amphibious form of land plants. Following are main adaptations exhibited by them.
a. Rhizoid for water absorption
b. Conservation of water
c. Absorption of CO 2
d. Heterogamy
e. Protection of reproductive cells
f. Formation of embryos

CLASSES OF BRYOPHYTES
1-MUSCI (MOSSES)
• Plants grow in a tight pack, in the form of mat, in order to hold one another up.
• Mat of moss possess spongy quality and enables it to absorb and retain water.
• Rhizoids are elongated cells or cellular filaments of mats which grip the substratum.
• Photosynthesis occurs in upper part of the plant w/c has many small stem like and leaf like appendages. • E.g Funaria.

2-HEPATICAE (LIVERWORTS)
• Usually present in tropical areas
• Plant body is divided into lobes somewhat of the lobed liver, of an animal.
• These plants are less fimiliar than Mosses.
• E.g Marchantia

3- ANTHROCERATAE:- (HORNWORTS)
• These plants resemble w/t liverworts, but are differentiated by their sporophytes plants.
• Sporophyte are elongated capsules that grow like horn from mat like gametophyte.
• Sporophyte has stomata and chloroplast, performs photosynthesis
• Sporophyte plant can survive even often the death of gametophyte due to presence of Meristem.
• Meristem is a specialized tissue, which keeps on adding new cells in sporophyte plant.
• Hornworts are the most advanced members of bryophytes.
• E.g Arthroceros

SUB-DIVISION TRACHEOPHYTA (VASCULAR PLANTS)
Main characters are as follow,
• Conducting vessels Xylem and Phloem are present in plant body.
• A protective layer of sterile “Jacket” cells around reproductive organs are present.
• Multicellular embryos retained within the archegonia.
• On aerial parts protective covering “Cuticles” is present w/c prevents excessive loss of water during hot climate.
• In life cycle Sporophyte stage is dominant.

CLASSES OF TRACHEOPHYTES
1-PSILOPSIDA
• These are the fossil representatives of the vascular plants, belonging to “Silurain period” and “Devonian Period”
• Sporophytes are simple dichotomously branching plants.
• True leaves and true roots absent.
• Underground stems that contain unicellular rhizoid similar to root hairs.
• The aerial stems are green and carry out photosynthesis.
• Lacking secondary growth due to absence of “Cambium”
• Reproductive structure “Sporangia” develop at the tips of some of the aerial branches.
• Meiosis produces haploid spores, within the sporangia.
• E.g. Rhynia, Psilotum Temesipteris

(A) RHYNIA (FIRST VASCULAR PLANT)
• One of the most primitive vascular plant
• It is an extinct genus, was named often the village “Rhynia of Scotland where the first fossils of Rhynia were discovered.
• It belongs to Devonian period, which started about 400 million years ago.
• The fossils of this plant are so well preserved that the stomata are still intact.
STRUCTURE
• The plant body (Sporophyte) was simple.
• It consisted of slender, dichotomously branched creeping rhizome, bearing erect, dichotomously branched aerial stem.
• Instead of roots, rhizoids were given out from rhizome.
• The aerial branches were leaf-less having terminal fusiform naked sporangia.
MICROSCOPIC STRUCTURE
• The internal structure of branches show a solid central core of vascular tissues surrounded by Cortex.
• The outer most layer is Epidermis having stomata.
• The vascular tissue is differentiated into centrally placed xylem and surrounded phloem
(B) PSILOTUM AND TEMESIPTERIS (LIVING SPECIES OF PSILOPSIDA)
• Sporophyte plant produce spores, which give rise to minute subterranean gametophytes.
• Each gametophyte bears both female reproductive organ Archegonia and male reproductive organ Antheridia w/c produce both egg and sperm respectively.
• As a result of fertilization a diploid zygote is formed which develops into sporophyte plant.
• Sporophyte stage of life cycle is dominant, but haploid gametoplyte stage is still relatively large.

EVOLUTION OF LEAF
The leaf is the most important organ of a green plant because of its photosynthetic activity. Leaves are of tow types
1. Single veined leaves- Contain only one vein
2. Poly veined leaves- Contain two or more veins

1- EVOLUTION OF SINGLE-VEINED LEAF
• It is assuming that a thorn like out growth emerged on the surface of the naked stem.
• With an increase in size of the leaf, the vascular tissues were also formed for the supply of water and support to the leaf.
• Another possibility is that a single veined leaf originated by a reduction in size of a part of the leafless branching system of the primitive vascular plants.

- EVOLUTION OF POLY-VEINED LEAF
• These are the evolutionary modifications of the forked branching in the primitive plants.
• The first step in the evolution of this leaf was the restriction of forked branches to a single plane.
• The branching system become flat.
• The next step in the evolution was filling the space b/w the branching and the vascular tissues.
• The leaf so formed looked like the webfoot of a duck.

2-LYCOPSIDA(THE CLUB MOSSES)
• These plants belong to middle Devonian and carboniferous periods.
• They were very large trees that formed the earth’s first forests.
• Only five living genera of this group are present.
• Two members, selaginella and lycopodium are common in many areas of Pakistan
• These plants have true branched underground roots.
• True leaves also present w/c have arisen as simple scale like outgrowth (emergence) from the outer tissues of the stem.
• Specialized reproductive leaves bearing sporangia on their surfaces, are present, such type of leaves are known as “Sporophylls”.
• In some members, the sporophylls are collected on a short length of stem and form cone like structure “Strobilus”.
• The cone is rather club-shaped; hence name “Club-Mosses” for the lycopsids.
• Gametophytes plant may be homosporous or heterosporous .

(A) HOMOSPOROUS GAMETOPHYTES
• Spores produced by sporophyte plant are all alike, and each give rise to a gametophytes that bear both archegonia (female reproductive structure) and antheridia (male reproductive structure)
• Example Lycopodium (Running pine or ground pine)

(B) HETEROSPOROUS GAMETOPHYTES
• Sporophyte (2n) plant produces two types of sporangia, which produced different kinds of spores.
• One type of sporangium produces very large spores called “Megaspores,” which develop in female gametophytes bearing archegonia.
• Other type of sporangium produces small spores called “Microspores, which develop into male gametophytes bearing antheridia.
• That’s mean ***es are separate in the gametophytes generation (Heterosporous).
• Example: Selaginella.

EVOLUTION OF SEED
Seeds are evolved from primitive spores.

STEPS OF EVOLUTION
1. PRIMITIVE SPORES
All spores of specie are nearly identical in size, structure and function.

2. HETEROSPORES
• There are many vascular plants that form two kinds of spores, these plants are said to be “Heterosporous” and spores are called “Heterospores.”
• These spores on germination give rise to two different types of plants.
(A) MALE SPORE: It produces sperm forming gametophyte plant.
(B) FEMALE SPORE: It grows into egg forming gametophyte.

3. PROTECTION OF HETEROSPORES
• The two different kinds of spores are formed in two different kinds of sporangia.
• Various enveloping structures develop in order to protect these spores.
• Certain fern like plants first developed seed like structures, each of their sporangia, containing one or more female spores, was surrounded by little branch like out growth structure forming “Integument.”

4. PERSISTANCE OF FEMALE SPORES
• Instead of being shed from the sporangium, the female spores are retained and protected inside the integument.
• The female spore develops into a tiny female gametophyte protected by the integuments.

5. FORMATION AND STRUCTURE OF SEED
• Seed is formed as the result of fertilization of male spore with this protected female spore.
Immature seed is called “Ovule.”
• Ovule is protected by integuments and it contains great quantities of food.
• Ovule not only protects the female gametophyte from the environment but also provides food for the new off springs that is produced when the seed matures and germinate. The development of seed has given the vascular plants better adaptations to their environment.

3. SPHENOPSIDA (THE HORSE TAILS)
• These plants belong to late Devonian and Carboniferous period.
• Only one living member “Equisetum” commonly called “Horse-tail” exists today.
• Ancient sphenopsids were large trees but now most of these are small (Less than one meter).
• Coal deposits of today was formed from the dead bodies of those plants.
• These plants possess true roots, stems and leaves.
• Stems are hollow and are jointed, whorls of leaves occur at each joint.
• Secondary growth absent, because modern species do not possess cambium.
• Spore are born in terminal cones (Strobili) and all are alike (i.e. plants are homosporous) and give rise to small gametophytes that bear both archegonia and antheridia (i.e. the ***es are not separate).

4. PTEROPSIDA (THE FERNS)
• These plants belong to Devonian and Carboneferous Period and then decline in Paleozoid Period.
• They are very well developed plants having vascular system with true roots, stem and leaves.
• Leaves are probably arisen from flattened web branched stems. They are large and provide much greater surface area for photosynthesis.
• Leaves of Ferns are sometimes simple, but more often they are compound, being divided into numerous leaflets.
• In most modern ferns of temperate regions, the stems are prostrate on or in the soil, and the large leaves are only part normally seen.

SPOROPHYTIC STAGE
• The large leafy plant (fern) is diploid sporophytic phase.
• Spores are produced in sporangia (Reproductive structure) located in clusters on the underside of some modified leaves “Sporophyll.”
• Most modern ferns are homosporous i.e. all these spores are alike.
• Vascular sporophytes can live in drier places and grow bigger.

GAMETOPHYTE STAGE
• After germination, the spores develop into gametophytes that bear both archegonia and antheridia.
• These gametophytes are tiny (less than one centimeter wide), thin and often more or less heart-shaped.
• Free-living, non-vascularized gametophytes can survive only in moist places, their sperms are flagellated and water is required for fertilization.Young sporophyte develops directly from the zygote without passing through any protected seed like stage.

ALTERNATION OF GENERATION
• In Kingdom Plantae, life cycle of many plants is completed in two stages or generations known as Gametophyte and Sporophyte.
• The two generations normally differ from each other in morphology, reproduction and number of chromosomes.
• The gametophyte is haploid and reproduces ***ually by forming the gametes, while the sporophyte is diploid and reproduces a-***ually by forming the spores.
• The two generations regularly alternate with each other and therefore, the phenomenon is called “Alternation of generation” (Heteromorphic).
• In Bryophytes, the main plant itself is the Gametophyte while the sporophyte is reduced.
• In Tracheophytes, the main plant is “Sporophyte” and the “Gametophyte” is reduced.

5. SPERMOSIDA (THE SEED PLANTS)
• First appeared in late Devonian and became dominant in Carboniferous Period.
• Gametophyte stage is even more reduced than in the ferns, and non-photosynthetic or free-living.
• The sperms of most modern species are not independent free-swimming flagellated cells.
• Young embryo, is enclosed within a seed coat and can remain dormant for long periods.
• Spermosida can be divided into two main sub-groups, which are as follows:
(i) Gymnosperms
(ii) Angiosperms

(I) GYMNOSPERM
• These plants have naked seed because ovules are not covered by ovary i.e. fruit is absent.
• Sub-divisions of Gymnosperms are
a) Cycads
b) Gnetae
c) Ginkgo
d) Conifers

(A) CYCADS'
• They have arisen from the seed ferns.
• These plants appeared in “Permian Period” and Mesozoic Period and declined in Cretaceous Period.
• They possessed large palm like leaves with short height stems.
• Living species commonly found in tropical regions and also known as “Sago Palms.”
• Nine living genera with over a hundred species exist today.
• Cycads and its relatives.

(B) GINKGOAE'
• Mostly contains extinct species, only one living specie, “the Ginkgo” which is also known as “Maiden Hair Tree.”
• Ginkgo often planted as lawn tree.
• E.g: Ginkgo Biloba.

(C) CONIFERS
• Most familiar and best-known group of gymnosperms.
• Leaves are small evergreen needles or scales with an internal arrangement of tissues.
• Reproductive organs are cone like modified leaves.
• E.g: Pinus.

PINUS
This plant belongs to Gymnosperms. It includes about 90 species.

HABIT AND HABITAT
• It is distributed world-wide mostly in northern hemisphere. 30 species are found in the Himalayas. Some are reported in the planes of Punjab.

MORPHOLOGY
• The pinus plant belongs to the “Sporophytic Phase.”
• It is a tall tree, pyramidal in form and gives a conical appearance and therefore commonly grouped under “Conifers.”
• It is well differentiated into stem, root and leaves.

STEM
It is erect, cylindrical, solid and covered with thick, rough and brownish bark. The branches are dimorphic,
• Branches of unlimited growth or long shoot.
• Branches of limited growth or dwarf shoot.

ROOTS
Underground root system is formed by “Tap Roots” which disappear early and only lateral roots persist later on.

LEAVES
It bears two types of leaves (dimorphic condition)
(a) Scale leaves
(b) Foliage leaves

(A) SCALE LEAVES
• Thin, membranous small scale like structures.
• Provide protection and do not help in photosynthesis.

(B) FOLIAGE LEAVES
• Only develop on dwarf shoots.
• Number of foliage leaves is fixed for particular specie.
• Each leave is needle shaped, simple green therefore also known as “Needles.”
• They have smooth surface and are evergreen and persistent.

LIFE CYCLE OF PINUS
• The adult plant of Pinus represents the “Sporophytic Phase” of life cycle.
• The sporophytic plant body of pinus reproduces a***ually by means of spores and after passing through “Gametophytic Phase” of the life cycle again produce Sporophytic plant, showing distinct Alternation of Generation.

1. SPOROPHYTIC PHASE
• The sporophytic plants of Pinus are mostly monoecious i.e. male and female cones are found on same plant.
• Special reproductive organs called “Cones,” developed on it.

(A) MALE CONE OR O-STROBILUS
• The male cones occur in clusters near the end of long branches at the place of dwarf shoot. (Dwarf shoots are replaced by male cone).
• Each male cone is simple ovoid structure 3-4 cm in length.
It has got single centrally located cone axis around which are arranged spirally, many scaly microsporophylls (60-135).
• Each microsporophyll has an expanded triangular central part and a stalk like base.
• Each microsporangium, which is born on the lower side bears numerous “Pollen grain mother cells.”
• When the microsporangium matures, on its lower side a horizontal slit is formed through which numerous Pollen grains are liberated and dispersed by wind.
• Each pollen grain is winged structure and yellow in colour.

(B) FEMALE CONE OR O-STROBILUS
• The female cones are developed laterally in the axis of scale leaves.
• The female cones are much bigger, woody, dry and hard structure.
• The young female cone is reddish green structure. Each female cone consists of a central axis to which are attached the “Megasporophyll.”
• Each megasporophyll on its surface has two ovules.
• Each ovule is orthosporous and consists of a central mass of tissue, surrounded by a single integument, made up of 3 layers.
• The integument bears a wide gap, the microphyle.
• Within the megasporangium, megaspore mother cells are present, which undergoes reduction division to produce a “Megaspore.”
• Only one megaspore is functional, however the other three degenerate.

2. GAMETOPHYTE PHASE
• The spores are the units of gametophytic phase of life cycle.
• In case of Pinus the spores are of two types, microspores and megaspores.

(A) MALE GAMETOPHYTES
• Microspore is a unit of male gametophyte.
• Each microspore or pollen grain is a unicellular body, covered with an outer layer, “Exine,” thick and heavily culticularized, while the inner layer, the “Intine” is very thin.
• The Exine forms the balloon shaped wings on either side, which help in pollination.
• The microspore is at this, four celled stage (consisting of one generative cell and two prothalial cells and a tube cell).

(B) FEMALE GAMETOPHYTE
• The Megaspore is the first cell of female gametophyte.
• The functional megaspore increases in size and forms a complete cellular female gametophyte, also known as “Endosperm.”
• The “Archegonia” are formed towards micropylar side.
• The cells of the endosperm or Archegonia initial cell divides and forms the central cell.
• The central cell forms the venter canal cell and a large egg cell.

POLLINATION
In case of Pinus, Pollination is effected by wind (Anemophyllous).

FERTILIZATION
1. The pollen grains reach the apex of the Archegonium.
2. The pollen tube carrying the two male gametes and the tube nuclei comes in contact with the archegonium.
3. The tip ruptures, discharging its contents into the egg.
4. One of the male gamete fuses with the egg nucleus and unites forming the oospore or zygote.
5. The second male gamete along with the tube and tube nuclei disintegrate.

PINUS SEED
• Fertilized ovules get transformed into seeds.
• Seeds are small elongated and winged.

GERMINATION OF SEED
The seed undergoes into a condition of dormancy when the conditions are favourable, the seed absorbs moisture and the embryo resume growth.

STRUCTURE OF OVULE
• Ovules are female part of flower, form seed after fertilization.
• Microscopic study of an ovule reveals following structural features of an ovule.

1. FUNICLE
It is slender stalk of ovule through which it attaches to the placenta.

2. HILUM
It is the point of attachment of the body of the ovule to its funicle.

3. RAPHE
In the inverted ovule, the funicle continues beyond the hilum along side of the body of the ovule forming a sort of ridge, which is called the “Raphe.”

4. CHALAZA
The distal end of the raphe, which is the junction of integuments and the nucellus is called the “Chalaza.”

5. NUCELLUS
It is the main body of ovule.

6. INTEGUMENTS
Nucellus is surrounded by two coats called the “Integuments.”

7. MICROPYLE
It is the small opening at the apex of integuments.

8. EMBRYO-SAC
It is a large, oval cell lying embedded in the nucellus towards the micropyle end. It is the most important part of the ovule as it bears the embryo. It is further developed, and in the mature embryo sac following cells can be seen:

(A) EGG APPARATUS
• It is the group of three cells lying towads the micropyle.
• One cell of the group is the female gamete, the ovum/egg, and the other two are called “Synergids.”
• The ovum or egg-cell on fertilization gives the embryo, synergids get disorganized soon after fertilization.

(B) ANTIPODAL CELLS
This is the group of three cells lying at the opposite end of egg apparatus. These have no definite function.

(C) DEFINITIVE NUCLEUS
In the middle of the embryo-sac there is a distinct nucleus known as a definitive nucleus, which is the fused product of the two polar nuclei.

STRUCTURE OF POLLEN GRAIN
• Pollen grains are male part of flowers, and are contained in the “Pollen-Sac.”
• They are very small in size, usually varying from 10 to 200 µm.
• Microscopic study of a pollen grain shows following features:

1. EXINE
• It is the outer coat of the pollen grain.
• It is tough, cutinized layer, which is often provided with spinous out growths or markings of different patterns, sometimes smooth.
• It has one or more weak slits or pores called “Germopores.”

2. INTINE
• It is the inner coat of the pollen grain.
• It is thin, delicate, cellulose layer lying internal to the exine.
• During fertilization in time grows to form pollen-tube.

3. INTERNAL STRUCTURE
• Each pollen grain contains a bit of cytoplasm on a nucleus.
• During germination of pollen grain nucleus further divides to form a “Tube Nucleus,” and a smaller one the “Generative Nucleus.”
• The generative nucleus soon divides into two male gametes.

PLANT FAMILIES

1- CAESAL PINIOIDEAE/CASIA FAMILY
CLASSIFICATION
• DIVISION : ANGIOSPERMS
• CLASS : DICOTYLEDON
• SUBCLASS : POLYPETALAE
• SERIES : CALCIFLORAE
• ORDER : ROSALES
• FAMILY : LEGUMINOSAE
• SUB-FAMILY : CAESALPINIOIDEAE OR CAESALPINIACEAE.

GENERAL CHARACTERS
Majority of these plants are trees or shrubs, about 135 genera and 5800 species are known .

VEGETATIVE CHARACTERS
ROOT
Usually, Taproot with nodules and primary, secondary and tertiary divisions.

STEM
Usually, Climbing stem or erect herbaceous or woody, Some plants show xerophytic character.

LEAVES
Usually, Compound leaves bipinnate, stipulate.

INFLORESCENCE
Usually, Racemose.

FLORAL CHARACTER
Usually, Complete, bi***ual, perigynous, zygomorphic, pentamerous.

CALYX
5 sepals, polysepalous, imbricate or valvate, Green in colour.

COROLLA
5 petals, poly petalous, imbricate aestivation.

ANDROECIUM
Usually, 10 stamens, polyanderous, exerted, extrose.

GYNOECIUM
Usually Monocarpillary, perigynous, placentational marginal, unilocular with many ovules.

FLORAL FORMULA
+ , Q , K(5) , C(5) , A10 , G1/

POLLINATION
Usually, Cross pollination by insects (entomophilly)

SEEDS
Usually, Both endospermic and non-endospermic.

FRUIT
Legume pod.

ECONOMICAL IMPORTANCE
MEDICINAL PLANS
• Amaltas
• Kachnar
• Tamarindus Indica
• Panwar. e.t.c.

ORNAMENTALS
• Parkinsonia
• Gul-e-mohar
• Cacia sophera

DYES AND STAINING
Haemotoxylin is obtained from haemotoxylon campechianom.

EDIBLE FRUIT
• Lomentum (Imli)

FIBER
Suitable fiber for paper making is obtained from parkinsonia Aculeata.

FAMILIAR PLANTS
Botanical name............Common Name...............Local Names
1-Tamarindus indica.........Tamarind.................Imli
2-Cassia fistula............Amaltus.
3-Bauninia verigata.........Camel’s foot.............Kachnar
4-Poinciana regia...........Flame of Forest .........Gul-e-Mohar
5-Parkinosia roxburgai......VilayatiKikar

FLORAL DIAGRAM
(From Book)

2 MIMOSACEAE
ALTERNATE NAME
It is also known as “Acacia family”.

CLASSIFICATION
• DIVISION : ANGIOSPERMS
• CLASS : DICOTYLEDON
• SUBCLASS: POLYPETALAE
• SERIES : CALCIFLORAE
• ORDER : ROSALES
• FAMILY : LEGUMINOSAE
• SUBFAMILY : MIMOSACEAE / ACACIA

GENERAL CHARACTERS
It is the smallest group among the 3 groups of family legume. It contains about 40 genera and 1450 species.

HABITAT
Mostly plants are distributed in tropical and subtropical regions. Great variation inhabit, usually these trees are perinial or binnial shrubs, some are herbs and climbing.

VEGETATIVE CHARACTERS
1. ROOT
Usually, Tap root with side branches, nodules are present.

2. STEM
Usually, Erect and woody stem, rarely herbacious, tannin and gums may also present.

3. LEAVES
Usually, Compound, bipinnate, stipule are modified into spines. In many plants leaves show sleeping movement or after having a shock.

INFLORESCENCE
Mostly, racemose.

FLORAL CHARACTERS
Usually, Complete, bi***ual actinomorphic, perigynous, pentamerous.

1. CALYX
Usually, 5 sepals, gamosepalous, valvate.

2. COROLLA
Usually, 5 petals, polypetalous, valvate aestivation, small size.

3. ANDROCEIUM
Usually, numerous stamens, exerted, extrose, basifixed anther.

4. GYNOECIUM
Usually, Monocarpillary, perigynous, unilocular, placentation marginal, many ovules in locule.

POLLINATION
Usually, cross pollination by insects (entomophilly).

SEEDS
Usually, Non-endospermic or with very little endosperm.

FRUIT
Usually, It is called legume.

FLORAL FORMULA
+ ,Q , K(5) , C(5) , Aa , G1/

ECONOMICAL IMPORTANCE
1.WOOD YIELDING PLANTS
e.g-prosopis
• Acacia species
• Albizzia
• Xyliaet

2. ORNAMENTALS
e.g-Mimosa pudica (chuimoi)
• Austratian Acacia
• Neptunia

3. FOODER
From leaves of prosopis,
• Acacia
• Dicrostachys e.t.c.

4. SOAP POPS
Acacia concinna pods have (soponim), a substance can be used as Soap.

5. CATECHU (KATHA)
Piece of hard wood

6. MEDICINAL USE
• Katha
• Siah Kanta
• Entada
• Acacia senegal
e.t.c.

7. GUMS & DYES
• Katha
• Safed Babul
• Sada Babul

IMPORTANT FAMILY MEMBERS
BOTANICAL NAME..............COMMON NAME................LOCAL NAME
1-Acacia nilotica................Gum tree.................Bauble, Kikar
2-Albizzia lebbek................Siris
3-Mimosa pudica.................Touch-me-not..............Chhui mui
4-Prosopis glandulosa............Prosopis.................Dev i
5-Acacia catechu.................Katha plant

FLORAL DIAGRAM
(FROM BOOK)

3- ROSACEAE
CLASSIFICATION
• Division
• Class
• Subclass
• Series
• Order
• Family: Rosaceae / Rose family.

GENERAL CHARACTERS
It has about 100 genera and 2000 species.

HABITAT
These plants are found growing all over the world 213 species of about 29 genera are reported from Pakistan.

VEGETATIVE CHARACTERS
1. ROOT
Usually, Tap root with its usual branching.

2. STEM
Usually, Green herbaceous, cylindrical, small spines are also present.

3. LEAVES
Usually, Simple leaves with or without petiole, Opposite or alternate.

INFLORSCENCE
Usually Racemose

FLORAL CHARACTERS
Usually, Complete, bi***ual, actinomorphic, perigynous, pentamerous.

1. CALYX
Usually, Sometime epicalyx may also be present, of variable number, 5 sepals are present, Gamosepalous, green, pubescent.

2. COROLLA
Usually, 5 petals or multiple of 5 petals, polypetalous, aestivation, imbricate, shape-rosaceous, full of colour.

3. ANDROCEIUM
Usually, Nomerous stamen,ditheous, anther, enerted, extrose, dorsi fixed.

4. GYNOECIUM
Usually, Monocarpillary or multiple capillary with formation of a single compound pistil. Ovary perigynous, unilocular two or more ovules are present, placentation axile when the carpels are many and syncarpous

FLORAL FORMULA
+ , Q , K(5) , C(a) , Ax , G1/ (2-5) or x

ECONOMICAL IMPORTANCE
FRUIT
Economical importance of this family is great in providing the pleasure and welfare of mankind. Plants of many famous fruits belong to this family for e.g. Apple, pear, peach, e.t.c. Perhaps they rank 3rd in commercial importance in the temperate, zone among the families of flowering plants.

ORNAMENTALS
A large no. of ornamental plants of this family are grown in parks and gardens the most widely cultivated plant for this purpose is Rosa. Many others genera are also grown for their beautiful flowers in homes and gardens.

OTHERS
Branches of crataegus and cotoneaster provide excellent walking stick and wood. The wood of pyruspastia is used for making tobacco pipes. In Asian countries rose petals are used in making Gul Khand and are also used in extraction of an essential oil, Rose oil, used as perfume or may be used as eye cleaner in certain diseases.

FAMILIAR PLANTS
BOTANICAL NAME...................COMMON NAME..............LOCAL NAME
Malva silvestis............................Apple........ ............Seb
Pyrus pyrifolia............................Pear......... ............Nashpati
Prunus amygdalus...........................Almond........ ............Badam
Rosa indica................................Rose........ ..............Gulab
Prunus persica.............................Peach......... ............Aru

FLORAL DIAGRAM
(FROM BOOK)

4- SOLANACEAE
ALTERNATE NAME
Night shade or Potato family

HABIT AND HABITAT
• It is widely distributed in temperate region and very abundant in tropical countries.
• The plants are usually herbs or climbing vines but may be shrub.

VEGETATIVE CHARACTERS
1-ROOT
Tap root and branched

2-STEM
Herbacious, erect or underground(Potato)

3-LEAF
Alternate in vegetative and opposite in floral region

FLORAL CHARCTERS
1-INFLORESCENCE
Cyme sometimes helicoids

2-FLOWER
Pentamerous, Bi***ual, Regular, Actinomorphic, Hypogynous.

3-CALYX
Five, united sepals

4-COROLLA
Five petals, united, valvate aestivation

5-ANDROCIEUM
Five stamens, Inserted on Corolla

6-GYNOECIUM
Bicarpellary, Syncarpous (Carpels fused), Placentaion axile.

7-FRUIT
Capsule Berry or Xanthium.

8-SEED
Minute with abundant endosperm.

FLORAL FORMULA
+ , O , K(5) , A5, C(5) ,

ECONOMIC IMPORTANCE
Members of this family provide drugs and food. Some plants are poisonous and other are ornamental. This family is of great economic importance as it provides food, fodder, drugs and ornamentals.

1-FOODER
• Solanum tuberosum (Potato)
• Lycopersicum esculentum (Tomato)
• Solanum melongena (Brinjal)

2-CONDIMENTS
• Fruit of capsicum
• Capsicum frutenscens

3-EDIBLE FRUIT
• Physalis (Cherry or Rasbhari)

4-DRUG YIELDING
• Atropa belladonna (atropine)
• Dotura (Daturine)
• Used in severe cold and in eye diseases.
• Sap of hanbane is used in dilating the pupils, white cherry is used an nerve tonic.

5-ORNAMENTAL
• Cultivated in gardens
• Petunaia
• Nicotiana
• Cestrum Schizanthus
• Brunfelsia solanum

6-CIGARETTE MAKING
• Nicotiania tobacum (Tobacco)

IMPORTANT FAMILY MEMBERS
BOT-NAME........................COMMON NAME.........................LOC-NAME
1-Solanum Tuberosum..................Potato................. .............Aaloo
2-Solanum Melongena..................Bringal................ .............Bengan
3-Lycoperscum Escalentum.............Tomato..................... .........Temater
4-Capsicum Annum.....................Red-Pepper..........................Lal-mirch
5-Petunia Alba.......................Petunia
6-Solanum Nigrum.....................Black Night shade
7-Datura Alba........................Thorn apple
8-Nicotiana Tobaccum.................Tobacco.................. ...........Tambako
9-Atropa Belladonna..................Deadly night shade
10-Cestrum nocturnum.................Lady of night.......................Raat ki Rani

FLORAL DIAGRAM
FROM TEXT BOOK (BIO-XI FAMILY SOLANACEAE )

5-FABACEAE
ALTERNATE NAME
• Papilionaceae or Pea family

HABIT AND HABITAT
Plants are herbs, shrubs or trees. Climbers, aquatic plants or xerophytes. World wide distributed.

VEGETATIVE CHARACTERS
1-ROOTS
Tap root, branched bearing tubercle containing nitrogen fixing bacteria.

2- STEM
Herbecious or woodi, erect or climber.

3-LEAF
Simple or commonly compound alternate, stipulate

FLORAL CHARACTERS
1- INFLORESCENCE
Racemose, rarely solitary.

2- FLOWER
Bi***ual, irregular, zygomorphic, hypogynous.

3- CALYX
Five sepals, united

4- COROLLA
Five petals, usually free.
Corolla is papilionaceous (Butterfly shaped). In this form the petals are 5, one of them is usually large and clawed. This petal is called standard or “Vexillum” The two lateral ones, which are free are called as “Wings” and two anterior inner most fuse to form a boat shaped structure called the “Keel” or “Carina”.

5- ANDROCIEUM
Stamens (9) +1 i.e 9 fuse to form a round sheath around the pistil while tenth is free.

6-GYNOECIUM
Monocarpellary, ovary unilocular, ovule numerous on marginal placenta.

7-FRUIT
Legume or pod.

8-SEED
EX-albuminous.

FLORAL FORMULA
+ , Q , K(5) , C 1+2+(2) , A(9)+1 , G1

ECONOMIC IMPORTANCE
The family is of considerable importance, as a source of high protein food, oil and forage as well as for ornamental purposes. Chief importance lies in the pulses, belonging to this family. All types of pulses (Dalls) are actually the seeds of this family which are rich in protein.

1- FOOD & FORAGE
• Cicer arietinum (Gram)
• Pisum sativum (Pea)
• Lens esculanta (Masure)
• Phaseolus aureus (Mung)
• Phaseolus mung (Urad/Mash)
• Phaseolus vulgaris (kidney bean/Lobia)
• Medicago sativa alfalfa (Lusan)
• Vicia
• Melilotus & Trifolium

2- FURNITURE & BUILDING PURPOSE
• Butea
• Dilburgia

3- OIL EXTRACTION
Arachis hypogea (Peanut/Moongphali)

4- DYES
• Indigofera tinctoria (Neel)
• Butea monosperma (Yellow dye)

5-MEDICINAL PURPOSE
• Glycyrrhiza glabra (Cough & cold treatment)
• Clitoria termatea (Snake bite treatment)

6- ORNAMENTAL PLANTS
• Lathyrus
• Lupinus
• Clitoria
• Butea
• Abrus precatorious, used by jewellars as weights called “Ratti”.

IMPORTANT FAMILY MEMBERS
BOT-NAME...................COMMON NAME....................LOCAL-NAME
1- Lathyrus Odoratus...........Sweet pea......................Matter
2- Arachis Hypogea.............Peanut........................ .Moongphali
3- Cicer Arietinum.............Gram........................ ...Channa
4- Dalbergia Sisso.............Red-wood.......................Shesham
5- Pisum Sativum...............Edible pea
6- Sesbania aegyptica..........Sesbania

FLORAL DIAGRAM
FROM TEXT BOOK

6- POACEAE
ALTERNATE NAME
GRAMINAE/ GRASS FAMILY

HABIT AND HABITAT
• The species are most numerous in the tropics but they are also abundant in temperate region.
• This family is monocot (one cotyledon in seed)
• Mostly annual or perennial herbs or shrubs.

VEGETATIVE CHARACTERS
1- ROOTS
Adventitious, fibrous or fascicled.

2- STEM
Cylindrical, Conspicuous nodes and hollow, although solid stems are also found as sugar cane.

3- LEAF
Legulate, alternate leaf sheath mostly open sessile, lamina narrow and ribbon shaped.

FLORAL CHARACTERS
1- INFLORESCENCE
Compound spikes.

2- FLOWER
Sessile, bracteate, incomplete, bi***ual or uni***ual and zygomorphic.

3- PERIANTH
It is combined structure instead of calyx and corolla. Number 2 or 3 membranous scales called “ Lodicules”

4- ANDROECIUM
Usually 3 stamens, filaments long, free anther versatile.

5- GYNOECIUM
Tricarpellary, syncarpous though only one is functional, unilocular, single ovule, style short 2-3, stigma feather like.

6- FRUIT
Grain or coryposis.

7- SEED
Endospermic, monocotyledonous.

FLORAL FORMULA
+ or O , O or O or O , P2 (lodicules) , A3 or 0 , G1 or 0

ECONOMIC IMPORTANCE
The family poaceae has great importance than any other family of flowering plants.

1- FODDER AND FOOD STUFF
• Triticum indicum
• Avena sativa
• Zea mays
• Oryza sativa
• Hordeum vulgare
• Pennisetum typhoideum

2- SUGAR MAKING
Saccharum officinarum (sugar cane)

3-PAPER MANUFACTURING
Certain species of Grasses

4- VEGETABLES & SOUP DISH
• Sugar cane
• Bamboo-shoots

IMPORTANT FAMILY MEMBERS
BOT-NAME..............................COM-NAME.........................LOC-NAME
Triticum Indicum..........................Wheat............ ................****um
Avena Sativa..............................Oats
Zea Mays..................................Indian corn......................Makai
Oryza Sativa..............................Rice.......... ...................Chawal
Saccharum Officinarum.....................Sugar cane.......................Ganna
Hordeum Vulgare...........................Barly........... .................Joo
Pennisetum Typhoideum.....................Bajra
Bambusa Arundinacea.......................Bamboo.......... .................Banns
Cymbopogon Jawarancuza....................................... ..............Lemon Grass
Cynodon dactylon.......................................... .................Lawn Grass

DOUBLE FERTILIZATION
• After pollination, the tube nucleus of the pollen grain forms pollen tube, while generative nucleus divides into two male (sperm) gametes.
• When pollen tube reaches the embryo sac through micropyle, one of the male gametes fuses w/t egg cell and forms “oospore (zygote)”,it develops into seed. Another male gamete fuses with definitive nucleus and forms “Endospermic nucleus”, w/c develop into endosperm of seed or food storage tissue of seed.
• Because two times fertilization occurs so it is called “Double fertilization”.

THE FLOWERS
The flower is a modified shoot and meant for ***ual reproduction. It is collection of four different kinds of floral members, arranged in four separate whorls. The upper two whorls are essential or reproductive whorls whereas lower two are helping or accessory whorls. The flower is born on an axis which consists of two parts the pedicel or stalk of flower and the thalamus is swollen end of the axis on which the floral leaves are inserted. The floral whorls are arranged on the thalamus in a particular order one just above the other. These four whorls are as follows.

CALYX
It is the first or lower most whorl of the flower, the calyx is generally green is colour. Each member of calyx is known as sepal. Sometimes sepals become coloured called petaloid. Such as in gold mohur. The calyx is non essential or accessory part of flower.
FUNCTIONS
1- Protection of floral bud
2- Assimilation when green in colour
3- Attraction when coloured and showy
4- Modified into papus which helps in dispersal

COROLLA
It is the second non essential floral whorl of flower. It is brightly colored. Each member of its known as petal. However there is no differentiation of calyx and corolla in some flowers. It is called perianth.
FUNCTIONS
1- The corolla attracts insects and hence help in pollination.
2- It encloses stamens and carpels.
3- It protect the stamens and carpels from external heat rain and insects attack.

ANDROCIEUM
It is the third essential floral whorl and each member of it is known as stamen. The stamen is a male reproductive body and consists of filament, anther and connective. The anther bears four chambers of pollen sacs, each chamber is filled with granular mass of small cells called pollen grains. Each pollen grain consists of two walls, the outer exine and inner intine.
FUNCTIONS
It is the male reproductive body and hence possess male gametes which take part in reproduction.

GYNOECIUM
It is the fourth essential floral whorl and its component parts are called carpals. The carpel is a female reproductive body, it may be one or more than one, and may be united or free. Each carpel consists of stigma, style and ovary. The stigma is terminal end which receives the pollen grain. It may be smooth or hairy and becomes sticky on maturity, The style is slender projection of ovary, It helps in pollination and later on dries up. The ovary is swollen basal portion, which encloses minute egg like bodies called ovules. The ovule possess egg cells.
FUNCTIONS
The gynoecium is a female reproductive body. It possess the egg cells which take parts in reproduction.

AESTIVATION
It is the arrangement of floral whorls i.e. the sepals or petals in a floral bud, it is of following types:

(A) VALVATE
The members of a whorl lie close to each other and do not overlap e .g Calatropis.

(B) TWISTED
One margin of a floral whorl overlaps that of the next one. It may be clockwise or anti clockwise e.g. China rose.

(C)VEXILLARY
When petals are five, two internal are overlaped on both margins by two petals, these two are overlaped by a single largest posterior petal e.g. Pea bean etc.

(D)IMBRICATE
When one of the sepal or petal is internal and other external and each or remaining one is overlaped on one margin and it overlaps the next one on other margin e.g Gold mohur .
A. Velvate.
B. Twisted
C. Vexillary
D. Imtricate.

INSERTION OF FLORAL LEAVES ON THE THALAMUS
The floral leaves are inserted on the thalamus in a particular order, it is of following types:

(A) HYPOGYNOUS
In some flowers the thalamus is convex or conical and ovary occupies the highest position on it. However other floral whorls are inserted below the ovary, such flower is known as hypogynous and ovary as superior. E.g. Mustard.

(B) PERIGYNOUS
In certain flowers thalamus forms a flattened circular disc due to the fact that sises of thalamus grows up to the same level. The apex of thalamus is in the middle of the disc at which gynoecium develops, whereas at the rim or margin sepals, petals and androecium are inserted. They are round about it and hence are called perigynous, such as in pea. Sometimes the apex of thalamus grows up in conical shape as in raspberry. Whereas in some cases the calyx forms a cup shaped structure called calyx tube such as in wild rose.

(C) EPIGYNOUS
In some flowers the concave receptacle surrounds the ovary and is fused with it. The sepals, petals and stamens apparently arise from the tip of the ovary such ovary is said to be inferior. E.g. Sunflower, apple, guava, pear etc.

IMPORTANT TERMS TO DESCRIBE A FLOWER
COMPLETE : When all the four floral whorls are present.
INCOMPLETE : When any of the whorl is absents.
BI***UAL : The stamen and carpel both are present.
UNI***UAL :The flower possess either stamen or carpel.
STAMINATE : Only stamens are present (male).
PISTILATE : When flower possess only carpels (female).
NEUTER : The stamens and carpels both are absent.

SYMMETRY
+ACTINOMORPHIC
When a flower can be divided into two equal halves by any vertical section passing through centre.

+ ZYGOMORPHIC
When it can be divided into two similar halves by only one vertical section.

+ IRREGULAR
The flower can not be divided into two similar halves by any vertical plane.

COHESION OF STAMEN
+ MONOADELPHOUS
When filaments are united in a bundle and anthers are free e.g. China rose.

+ DIADELPHOUS
The filaments are united into two bundles and anthers are free e.g. Pea.

+ POLYADELPHOUS
The filaments are united into more than two bundles and anthers are free.

+ SYNGENECIOUS
The anthers are united together and filaments are free e.g. Sunflower.

ADHESION OF STAMENS
+ EPIPETALOUS
The stamens adhere to corolla, wholly or partially by their filaments.

+ GYNANDROUS
When stamens adhere to carpels e.g. Calatropis.

LENGTH OF STAMENS
+DIDYNAMOUS
The stamens are four, two of them short and two long e.g. Nerium.

+TETRADYNAMOUS
The stamens are six but two short and four long e.g. mustard.

GYNOECIUM
+ MONOCARPELLARY
The pistil consists of only one carpel, it is also known as simple pistil e.g. Pea, Bean

+ POLYCARPELLARY
The pistil consists of two or more carpels, it is also known as compound pistil e.g. Rose.

+ SYNCARPOUS
The carpels are united into one ovary e.g. Mustard.

STIGMA
+ CAPITATE
When stigma is rounded and knob like. Bi, tri or Multified: when stigma is branched into two , three or many.

+ FEATHERY
When stigma is feather like.

+ FLATTENED
When sitgma is flat.

+ POINTED
When stigma is pointed.

+ LINEAR
When it is long and narrow.

STYLE
+ TERMINAL
When style arise from top of ovary; such as in Mustard.

+ GYNOBASIC
When it arise between the lobes of the ovary from its base;such as in Salvia.

+ PEDICILLATE
When flower is born on a stalk or pedicel. (STALKED)

+ SESSILE
When stalk is absent

+ BRACTEATE
When flower is developed in the axil of a bract

+ EBRACTEATE
When bract is absent.

+ DIMEROUS
When each floral whorl has two floral leaves (Dicot)

+ TRIMEROUS
When floral whorl has three floral leaves (Monocot)

+ TETRAMEROUS
When each floral whorl has four floral leaves; and so the pentamerous Dicots)

CALYX
+ PETALOID
The calyx having other then green colour.

+ CAMPANULATE
Sepals fused to form bell shaped structure.

+ POLYSEPALOUS
When sepals are free from one another.

+ GAMOSEPALOUS
When sepals are fused or united with one another.

PETALS
+SEPALOID
The petals are green in colour.

+CRUCIFORM
Petals are arranged in form of a cross.

+POLYPETALOUS
When petals are free from one another.

+GAMOPETALOUS
When petals are united with one another.

+PERIANTH
When calyx and corolla can not be distinguished with one other due to similar shape and colour.

PERIANTH
+SEPALOID
When perianth leaves are green.

+POLYPHYLLOUS
When perianth leaves are free from one another.

+GAMOPHYLLOUS
When perianth leaves are fused.

FLORAL FORMULA
The floral formula is represented by various symlols. The symbols used in floral formula are as follows.

SYMMETRY OF THE FLOWER
• Zygomorphic = +
• Actinomorphic = O

***UALITY
• Bi***ual = Q+
• Uni***ual (male)
• Uni***ual (female)
• Neuter =

PERIANTH
• Perianth = P
• Polyphyllous = Pn n=number of perianth leaves.
• Gamophyllous = (n) “ “ “

CALYX
• Epicalyx = Epi K
• Petals = C
• Calyx = K
• Polypetalous = Cn,
• Polysepalous = Kn, n= number
• Gamopetalous = C(n)
• Gamosepalous = K (n) of sepals

ANDROECIUM
• Androecium = A
• Androecium free = An n= number of stamens
• Androecium United = A (n)
• Epipetalous = C-A

GYNOECIUM
• Gynoecium = G
• Apocarpous = Gn
• Syncarpous = G (n)
• Ovary inferior = G
• n= number of carpels
• Ovary Superior = G

FLORAL DIAGRAM
The features of flower in flora formula are represented by symbols, while in floral diagram by the diagram of its various floral leaves alongwith actual number and position.

MOTHER AXIS:
It is represented by a Dot above the floral diagram. It actually shows the position how a flower is born. The position of it can be seen from upperside. It may be between two adjacent sepals or a single sepal.