DNA replication

DNA replication

The process of synthesis of DNA molecule from preexisting dna is called dna replication.

DNA replication may occur by following process:

1     1.semi-conservative replication

         2.conservative replication

         3.dispersive replication

Semi-conservative mode of DNA replication

Enzymes involved in semi conservative DNA replication:

Helicase- helicase enzyme breaks the hydrogen bonds formed between bases of nucleotides

Topoisomerase- topoisomerase enzyme breaks and reseals one strand of DNA

DNA polymerase- it connects the nucleotides to form DNA polymer nucleotides. It forms RNA primer in DNA strand which is like a knot formed o thread. Due to its formation, newly formed DNA strands cannot separate.

Ligase- ligase binds the fragments of DNA strand together

Repair enzyme- this enzyme cuts off wrong base of nucleotide and rejoin correct base in newly formed DNA

Process:

DNA replication in  eukaryotes may begin at several points. in replication ,the helicase enzyme breaks the hydrogen bond between the bases of nucleotides. due to breaking of hydrogen bonds of nucleotides, the two strands separate. The process of separation of DNA strands also supported by enzyme topoisomerase. This enzyme breaks and reseals one strand of dna molecule.

Now the bases of DNA strands become exposed and joins with the free nucleotides present in nucleoplasm only in 5’-3’ direction. This process or formation of polynucleotide chain takes place in the presence of enzyme DNA polymerase. The four types of nucleotides are present in nucleus in the form of datp, dgtp; dttp and dctp.THESE molecules are triphosphates and break down into monophosphates damp, dtmp, dcmp and dgmp with the release of energy. These monophosphates nucleotides make hydrogen bonds with the complementary nucleotides of DNA strand.

According to base pairing rule the nucleotides are arranged. As DNA strand formation occurs only in 5’-3’ direction,in on strand of DNA a continuous strand is formed called leading strand ehereas in other strand of DNA,fragments of strands are formed,these fragments are called okazaki fragments named after Japanese scientist okazaki.the strand with okazaki fragments is called lagging strand.

Here,both DNA strands take part in replication process,so they are called as templates.the segments of strands are joined by the help of enzyme ligase.at the beginning of strand formation, RNA primer is formed at the DNA strand and it is due to the enzyme primase.sometime a wrong base maybe linked with the DNA nucleotide. When it occurs,the  repair enzyme replaces the wrong base by correct base.

In the above process,newly formed DNA have one strand of old DNA and one of new formed polynucleotide chain. Hence the process is called as semi conservative process of DNA replication.

It means half of parent DNA is conserved in new formed DNA.

Introduction Kalazar

Kalazar ( leishmania donovani)


Systematic position

Phylum-Protozoa
Class- flagellate
Order- kinetoplostidia
Genus- Leishmania
Species- donovani

The pathogenic flagellate parasite found in reticulo- endothelial system (liver, spleen bone-marrow)

History-
Biologist leishman reported the parasite from London in 1903.Another biologist Donovan reported the parasite in spleen smears of patient in Madras in same year. So the name of parasite became Leishmania Donovani.

Mode of infection - Sand Fly (Phlebotomus argentipes). There are the two types of parasites of the leishmania donovani.

1. Amastigote :

-Found in human
-It is round-oval 2 to 4μm covered by thin pellicle.
-Nucleus is also oval round.
-Kinetoplast (a DNA containing body and mitochondrial structure) lies at right angle to nucleas.
-Axoneme (rhizoplast) a filament extends from kinetoplast to margin of the body.

2. Promastigote:

-Found in sand fly and by culturing.
-It is pear shaped and slender-shaped in maturity.
-Nucleus is more oval.
-Kinetoplast lies transversely near anterior end.
-Axoneme extends outward to forma long flagellum.




Symptoms :

• Recurrent fever intermittent or remittent with often double rise
• loss of appetite, pallor and weight loss with progressive emaciation
• weakness
• Splenomegaly – spleen enlarges rapidly to massive enlargement, usually soft and nontender
• Liver – enlargement not to the extent of spleen, soft, smooth surface, sharp edge
• Lymphadenopathy 
• Skin – dry, thin and scaly and hair may be lost. Light coloured persons show grayish discolouration of the skin of hands, feet, abdomen and face which gives the Indian name Kala-azar meaning “Black fever”
• Anaemia – develops rapidly

 Diagnosis: 

Clinical:
A case of fever of more than 2 weeks duration not responding to antimalarials and antibiotics. Clinical laboratory findings may include anaemia, progressive leucopenia thrombocytopenia and hypergammaglobulinemia

Laboratory:
K39 test

Treatment :
By using drugs like:

• Sodium Stibogluconate
• Pentamidine Isethionate
• Amphotericin B
• Liposomal Amphotericin B
• Miltefosine 

Socially significant disease

    DRUG ABUSE 

Drugs are the chemical substance that modifies one or more functions of living organism.

Drug abuse
Misuse of drug is called drug abuse.

The disease that brings abnormal changes or mental illness due to smoking, drug, alcohol etc known as mental diseases. One percent of world population suffers from mental illness and ten percentages from mild mental disorders. A condition of habit or feeling compelled to take certain drugs is called drug addiction.
Drugs are either depressants or stimulants.
Depressants slow down the activity of brain. Stimulants excite the activity of brain.

Types and effects
i) Tranquilizers and depressants-
These lower the activities of CNS. These do not affect the working efficiency. Examples are- Equanil, Valium (diazepam) calm pose etc. Their excessive use causes addiction.
ii) Narcotics-These are used to free from anxiety (nervous and worried).These produce sleep and relieve
pain. Examples are Opium, Morphine, caffeine and Heroin.
iii) Psychedelic or vision producing drugs-
These effect on sense organ and cerebrum strongly. Individual may see strange colour and sound for nothing. Examples are LSD (Lysergic Acid diethylamide) Marijuana and Hashish.


Effects on health

Depressant and hypnotic:
Depressed brain and deep sleep.
Stimulants: Restless, and BP, heart beat appetite are affected.
Narcotics: Reduce respiratory and cardio-vascular activities, Cause nausea and vomiting. Supress brain activity, anxiety and fever.
Psychedelics hallucinogens: Damage CNS leading to suicide.

Reasons of drug addiction

• curiosity
• Family history
• Peer pressure ( pressure of friend)
• Relief from pain
• To do more work
• Frustration

Control measures

• Hospitalization of sick or addict
• Counseling
• Banning of smuggling of drugs
• Strictly implementation of law
• Education

Alcohol addiction (Alcoholism)

Alcohol is obtained through the fermentation (decaying) of different food ( rice, millets, potati, molasses and fruits) by yeast or fungi.

Two kinds of alcohols
Less concentration- beer, wine etc. these are not distilled.
More concentrated- whiskey, brandy rum gin, vodka, etc. Distilled well

The prolonged use ( long time ) of alcohol causes dependence of body called alcohol addiction or alcoholic. Alcohol is a depressant drug.

Effects of alcoholism (symptoms)

• CNS- loss of sensation, emotional control, visual problems, neuritis ( any projection from cell body) Amnesis (loss of memory)
• Gastrilitis
• Liver is highly affected 
• Increase blood pressure and mal-function of heart
• On kidney- hyper-osmotic ( less concentration) urine 
• Lower the blood sugar level.
• Affect on ovulation and unborn baby in women.
• Cause family and social problems.
• Crimes( rape, kill)

Reasons of alcohol addiction

• feeling of independence
• Frustrations
• To increases confidence
• Social pressure 
• curiosity

Controls
a. Treatment and hospitalization
b. Rehabilitation
c. psychological treatment
d. strict on laws
e. Education

Smoking

Regular consumption of tobacco in different forms (cigarette, chewing) is called smoking.
It is made from leaves of tobacco plant ( Nicotiana tobaccum and N. ristica)

Tobacco smoking contains 4000 different chemicals. Major are nicotine cyanide, formaldehyde, tar, co etc.

Effect off nicotine

1. If nicotine is injected intravenously can kill a human.
2. stimulates the conduction of nerve impulse, secrete adrenaline.
3. BP and heart beat increase
4. Decrease the breathing capacity

Hemp Plant ( cannabis indica c. sativa)
1. Charas- resinc of c. indica
2. Bhang- Leaf and seed of c.indica
3. Marijuana (hashish) - leaves and flowers tops of c. sativa

Effects (short term)
1. Senseless, confusion and fears.
2. Intense in color and sound.
3. BP and heart beat increase.
4. Red eye and dry mouth.

Long term effects

1. cancer- tobacco is carcinogenic c to form cancerous cell). It cause oral cancer and lung cancer
2. Bronchitis- Reduce lung is gaseous exchange capacity.
3. Emphysema- breakdown of wall of alveolar wall during coughing so reduce the gaseous exchange.
4. Heart diseases- Nicotine constrict blood vessel result increase of heart beats.
5. Birth defects- In a pregnant woman it causes 10w birth weight, metal disability and damage of internal organ.
6. Duodenal ulcers, tuberculosis and lack of o2 in blood.

Controls

a. Treatment and hospitalization
b. Rehabilitation
c. psychological treatment
d. strict on laws
e. Education

Osmoregulation and Homeostasis

Osmoregulation  and  Homeostasis

In case of human hypertonic urine is excreted. This minimizes the water loss from their body. The filtrate fluid in Bowman's capsule (isotonic) passes through the tubules of nephrones. Then a large amount of water and solutes are reabsorbed during this course.
During cold month, hypotonic urine is excreted but in warmer month hypertonic urine is excreted due to sweating.

ADH and regulation of water reasbsorption
Antidiuretic hormone (ADH) or vasopressin is the hormone released by posterior part of pituitary gland. The main function of ADH is to increase permeability of distal convoluted tubule (DCT) and collecting duct (CD) due to which reabsorption of water increases. There are two conditions to balance water:

1. When a person takes small amount of water: In this condition large amount of salt is ingested in diet or excessive sweating then solute potential of the body fluids become more negative (Osmotic pressure rises in the blood). The change in the osmotic potential is detected by osmoreceptors in the hypothalamus and carried to the brain. The brain detects such changes in the body and pituitatory gland releases ADH in the blood.
A large amount of water is reabsorbed rapidly from the filtrate into the cortex and medulla and passes back into the blood capillaries to maintain osmotic pressure normal. So that urine becomes highly concentrated and reduced volume of urine is released from kidney. It is generally called anti-diuresis.

2. When a person takes large amount of water: When a person takes large amount of water or little sweating or extremely low salt intake in diet then the solid potential of the blood becomes less negative. (Osmotic pressure becomes low in blood) This condition is detected by osmoreceptors and carried to the brain. It sends the message to the pituitary gland to inhabit the
In absence of ADH walls of DCT and CD are impermeable to water and less water is reabsorbed as the osmotic pressure of filtrate is normal and large volume of diluted urine is excreted. It is generally called diuresis.
The regulation of water by ADH is an example of homeostatic feedback mechanism.

Other functions of kidney
1. Regulation of fluid balance: The kidney controls osmotic pressure of extra cellular body fluids by regulating the amount of water lost from body.
2. Regulation of electrolyte concentrations: The concentration of electrolytes like Sodium, Potassium, Chloride Bicarbonates etc in blood also regulated. It is performed by selective tubular reasbsorption process in proximal tubule.
3. Maintenance of acid-base balance
4. Removal of other substances like mineral salts, iodides, drugs, arsenic and bacteria are recovered of the blood by kidney only.
5. Kidney secretes rennin which is an enzyme but acts as hormone which changes the plasma protein.
6. Kidney secretes erythropoietin which stimulates the formation of RBC.

Homeostasis

The regulation or maintenance of a constant body fluid or internal environment is called homeostasis. The temperature, amount of water and glucose concentration are at almost constant in homeostasis. At the temperature of 37 oC enzymes work perfectly, division of cell and metabolism is also perfect.
The term homeostasis was first put forward by French biologist Claude Bernard in 1859. In 1929, American physiologist Walter Cannon first used the term homeostasis and studied about it.
Homeostatic organs are skin, liver, kidney lungs, endocrine glands etc.
Skin as homeostatic organ: Skin helps in temperature regulation. It possesses pigment cells (chromatophores and melanophores), sweat glands and sebaceous glands which help in controlling the heat and fluid balance. The melanin pigment helps to absorb solar heat and increase body temperature.
Kidney as homeostatic organ: Kidneys are the chief excretory and osmoregulatory organs. These also play key role in homeostasis. For example,
(a) Regulation of water content by ADH
(b) Regulation of salt or ion concentration in blood
(c) Maintain acid base balance in body (Lactic acid, ketones, sulphuric acid etc)
(d) Blood volume is regulated by the kidney

Liver as homeostatic organ: Liver is a key homeostatic organ due to the following reasons:
(a) Regulation of Carbohydrate, lipid and amino acid metabolism.
(b) Regulation of amount of glucose in blood by gluconeogenesis process.
(c) It maintains the optimum temperature
(d) Liver produces the bile. Bilirubin and Biliverdin, by products of dead RVC are excreted from the liver.

Lungs as homeostatic organ: It balances the concentration of O2 and Co2 in blood at the best level for the cells’ chemical reaction.

Biomolecules

Biomolecules

Living cell are made up of many kinds of molecules. These molecules are basic and essential to
the life. Therefore, they are considered as bio-molecules.

Carbohydrate

Carbohydrates are the organic compounds of carbon, hydrogen and oxygen. Where the h ydrogen
and oxygen are present in the ratio of 2:1 as in water. Thus known as hydrates of carbon.
The general formula of carbohydrate can be written as
C(HO)
 If carbohydrate containing aldehydes groups –CHO are called Aldoses 
and carbohydrates containing ketons groups C=O are called Ketoses

Classification of carbohydrate.

Carbohydrate are classified into 3 groups on the basic of complexity of chemical substance.

i. Monosaccharides ii. Oligosaccharides iii. Polysaccharides.

i. Monosaccharides:
a. These are chemically simplest form of carbohydrate.
b. They can’t hydrolysed into smaller carbohydrate.
c. They are highly soluble in water.
d. They are sweet in test.
e. They are compose of 3-7 carbon atoms.
Example: glucose, fructose, riboses, deoxyribose etc

  ii. Oligosaccharides

Oligosaccharides are those which contain 2-10 molecules of monosaccharides. These
monosaccharides are joined by glycosidic linkage. Common oligosaccharides found in nature are
disaccharides.

Disaccharides

a. Disaccharides are simplest oligosaccharides. They are made up of 2 similar or dissimilar
monosaccharides.
b. They are joined by glycosidic bond.
c. On hydrolysis, it gives monosaccharides. They are soluble in water and sweet in taste.

Example: Maltose, Lactose, Sucrose etc Glucose + Glucose =Maltose
 Glucose + Glactose =Lactose
 Glucose + Fructose =Sucrose



Glycosidic bond:
it is a type of bond which is formed by joint of 2 monosaccharides
releasing one molecules of water.

iii. Polysaccharides:

a. Polysaccharides are the complex molecules made up of more than 10 molecules of
monosaccharides.
b. Monosaccharides are linked together by glycosidic bonds.
c. On hydrolysis polysaccharides release many monosaccharides.
d. They are insoluble in water and not sweet in teste.
Example: starch, cellulose, glycogen etc.

Function of carbohydrate:

1. Carbohydrate as source of energy.
2. Carbohydrate as building blocks.
3. Carbohydrate as structure components.
4. Carbohydrate as reserve foods.
5. They help in synthesis of fat and amino acids.

Amino acid

Amino acids are the basic units of proteins.
All amino acids have at least one acidic (-COOH) carboxylic group and one basic amino
group (NH).
These are soluble in water and insoluble in organic solvent.
20 amino acid found in natures.

Formation of peptide bond

When two amino acid are joined together by the union of carboxylic group (-COOH) of an
amino acid with the amine group of other amino acid, a peptide bond is formed (-CO-NH) and a
molecule of water is released out.


Types of amino acid

20 types of amino acid divided into 2 categories
1.Essential amino acid:

these are the amino acids which are
not synthesized in the body.
These are 8 in number. Eg: Leucine, Valine, Lysine etc

2.Non-essential amino acid:

these are the amino acids which are synthesized in the body.
These are 12 in number. Eg: alanine, serine, glycine etc.

Function of amino acid

1. Amino acids are building block of protein.
2. Tryptophan is the precursor of plant hormones IAA (Indole acetic acid).
3. - alanine takes part in the formation of co-enzyme A.

Protein

Proteins are polymers of different kind of amino acid. In protein amino acid are linked by
peptide bond. Proteins are most complex chemical compounds formed of C, H, O, N, S and P.

Classification of protein

1.Simple proteins:
these are formed of peptide chain and give in only amino acid on
hydrolysis. Eg: albumins, globulin, histones etc.
2.Conjugated protein:
conjugated protein formed in the combination of simple protein
and non-protein substances. Eg:
Glucose + Protein =glycoprotein
Lipid + Protein =Lipoprotein
Nucleic acid + Protein =Nucleoprotein
3.Derived protein :
protein which are formed by the partial hydrolysis of simple and
conjugated protein. Eg:peptones, proteoses etc.

  On the basic of shape protein are divided into 2 types
1.Fibrous proteins:
they are thread like shape. They are insoluble in water. Fibrous
proteins are 2 º- structures. Eg: Keratine, Collagens Elastin etc

2.Globular proteins:

they are oval or spherical shape. They are mostly soluble in water.
Eg:egg albumin, gluten of seed, myoglobin of muscles etc.

  Function of proteins

1. Protein as building block.
2. Protein as source of energy.
3. Protein as enzyme.
4. Protein as hormones.
5. Protein as defensive.

  Lipids

Lipids are the ester of fatty acid and glycerol. Lipids are the group of fats and fat like substance.
Lipids are heterogenous group of organic compounds. They are made up of C, H and O. they
have less amount of oxygen. They are insoluble in water but soluble in organic solvents such as
alcohol, ether, benzene, acetone etc.


Types of fatty acid

a.Saturated fatty acid:
they do not have double bond between carbon atoms.
Eg: palmiti acid , Stearic acid.

b. Unsaturated fatty acid:

they have one or more double bond between two carbon atom.
Eg: Oleic acid ( One double bond)

Classification of lipid

Lipids are grouped into 3 categories.

1.Simple lipids :

simple lipids are the ester of fatty acid and glycerol. These are no
additional compounds. On hydrolysis of simple lipids gives fatty acid and glycerol.

2.Complex lipids:
these lipids are conjugated types. When a simple lipids combines with
other compound forms compound lipids.
Glycolipids: Lipids + Carbohydrate
Phospholipids: Lipids + Phosphate
Lipoprotein: Lipids + Proteins Molecules

3.Derived lipids:
these are derived from simple and compound lipid.
Eg: Cholesterol.

  Function of lipids:

1. Lipids as a rich source of energy.
2. Lipid as heat insulator.
3. Lipid as food reserve.
4. Lipids as solvent ( fat soluble vitamins ADEK)
5. Lipid act as cushions.
6. Lipoprotein can prevent bacterial disease.

Nucleic acids

Nucleic acid is the most essential molecules of the life. They contain C, H, O, N and P. They
found in genetic material of all organisms including virus. Nucleotides are the monomers of
nucleic acids. Basically nucleotides compose of three components. i.e.
1.Pentose sugar :
two types of pentose sugar found in nucleic acid. RNA contains ribose
sugar and DNA contains deoxyribose sugar.

2.Nitrogenous bases:

two types of nitrogen base are found in nucleic acid.
i. Purine : they are two ring structural compound. Purine are Adenine (A) and Guanine (G)
ii. Pyrimidine: they are one ring structure. Pyrimidines are C ytosine (C) , Thymine
(T) and Uracil (U). ( Uracil is present in RNA only in place of Thymine)

 3.Phosphoric acid:
it contains a phosphate group.

Formation of nucleotides

Nucleotide

is formed b y a combination of a sugar, a base and a phosphoric acid.

Nucleoside
is formed by combination of a sugar and a base.

Types of nucleic acid.

Two types of nucleic acid are: -

I. Deoxyribonucleic acid (DNA):

Occurrence : DNA is located in the nucleus, mitochondria and plastids.
Structure:
DNA is a macromolecule, formed of several thousand monomers. These monomers
are called nucleotides. Watson and crick (1953) have proposed the possible model for the DNA
molecule for which they were awarded the Nobel Prize.

DNA contains followings characters.
1. DNA consists of deoxyribose sugar.
2. Both the strands are spirally coiled.
3. Two stands are antiparallel.
4. These helical stands have sugar-phosphate chain on outer side and purine and pyrimidine
bases on the inner side of helix.
 5. The distance between two strands is 20ºA.
6. The distance between two base pairs is 3.4ºA.
7. These are 10 base pairs on a complete turn (34ºA)
8. Purine base is attached to its pyrimidine base. i.e. A=T, C=G
9. Nucleotides in a helix are joined together by phosphodiester bonds.

  Function of DNA

1. It carries genetic character from one generation to other.
2. It controls all the biological activities of cells.
3. It synthesizes RNA.
4. It can replicate to form new DNA molecules.

II. Ribonucleic acid (RNA)

Occurrence:
RNA found in nucleolus, cytoplasm and ribosome.
Characters:

1. It is single stranded.
2. Each nucleotide consists of a ribose sugar, phosphate and nitrogen base.
3. The nitrogen bases in RNA are Adenine, Guanine, cytosine and Uracil.
4. No of purine is not equal to no of pyrimidine.

Types of RNA

On the basis of molecular size and function, rna dividing into 3 types
a.Messanger RNA (mRNA): it carries the genetic information.
b.Ribosomal RNA (rRNA): it is assiociated with ribosomes.
c.Transfer RNA (tRNA): it carries amino acid molecules to the site of protein synthesis.

Function
1. It plays an important role in protein synthesis.
2. It is the hereditary material in some virus.


Minerals

Organisms need different types of elements for proper life functions. Minerals are the elements
which are present in small amount. Depending upon their concentration required, essential
minerals are categorized into 2 types.
a.Micronutrients: these are required in small amounts (less than 1 gm)
eg: copper(Cu), cobalt (Co), Zinc (Zn), Iron (Fe), Iodine (I) etc.
b. Macronutrients : macronutrients are those which are required in large amounts (more
than 1 gm) eg: calcium (Ca), magnesium (Mg), Potassium (K), Sodium (Na), Chlorine
(Cl), Nitrogen (N), phosphorus (P) etc.

Function of minerals
Nitrogen
N is necessary for the synthesis of amino acid, protein, nucleic acid , vitamins, hormones, co-
enzymes, ATP and Chlorophyll.
Phosphorous (P)
P is the structural components of ATP, DNA, RNA, NADP (Nicotinamide adenine diphosphate)
It helps in trans location of food and therefore maintains proper growth of the root system.

Potassium (K) :
K involves in balance of salt in body, opening and closing of stomata, synthesis of nucleic acid
and chlorophyll.

Calcium (Ca) : Calcium provides rigidity and strength of bone and teeth. It activates many enzymes. It is the
component of exoskeleton of many invertebrates. It is necessary for cell division and cell
elongation.

Water

Water is most abundant substance. 60-90% of weight of organism contains water. Water
compose of 2 atoms of hydrogen and one atoms of oxygen, bond angle is 104.5º.
Biological role of water
 1. Solvent: water is commonly called universal solvent. It has power to dissolve a number of
solutes.
2. Digestion: water is necessary for digestion of complex compounds into simple compounds.
3. Source of electron: water provides electron to chlorophyll molecules during photosynthesis.
4. Excretion: excretion of waste matter takes place in dissolved state.
5. Movements: plants movements such as opening and closing of stomat a are due to loss and gain
of water.
6.Habitat : a number of aquatic organisms inhabit in water.

Lichens And their Economical importance

Lichens

Lichens are the organisms produced by the permanent association of algae and fungi. The algae
in lichen belongs to either cyanobacteria (Nostoc, Rivularia etc) or chlorophyceae (Cladophora,
Protococcus etc). Fungi in lichens belong to ascomycetes and basidiomycetes. About 400 genera
and 1600 species of lichen have been reported.

Habit and habitat
They are commonly found on the walls, house, trunks of trees, rock etc.
Structure
Body of lichen consists of thallus. The size of thallus varies from 1 mm to one meter diameter.
According to external morphology, lichens are divided into three types.
1. Crustose lichens: The thallus of lichens is closely attached to substratum. Therefore it
can’t be separated without damaging it. Eg: Graphis, Lecanora,dermatocarpon etc.

2. Foliose lichens: These have flat, leaf like, lobed thallus, attached to the substratum by
rhizoid. The lobes of thallus are with irregular margin. Eg: Peltigera, parmelia,physcia,Collema etc.

3. Fructicose lichens: They are branched, cylindrical or ribbon like thallus, which is
upright or pendulous. The thallus is attached to the substratum by its basal portion
composed by densely packed hyphae. Eg: Usnea, Evernia,cladoniaetc.



                               


Reproduction of lichen
 Lichen reproduces by asexual and sexual methods:

Asexual reproduction
It occurs by the following methods:
1. Fragmentation: In fragmentation methods, the lichen thallus breaks into small
fragments and each fragment gives rise to new thallus.

2. Soredia: These are special small bud-like out growths developed on the thallus. Each
soredium consists of few algal cells surrounded by fungal hyphae. In suitable
condition, soredia germinate to produce new thallus.

3. Isidia: They are small projections on the upper surface of the thallus. They consist of an
external cortical layer and an internal algal layer. When the thallua become dry they
break off and develop into new thallus.

Sexual reproduction
Sexual reproduction in lichens is performed by its fungal partner. Most of the fungal partners
are ascomycetes. So sexual reproduction takes place by formation of ascospore in asci.
Female reproductive organs is carpogonium and male reproductive organs are called
spermogonia which produce the spermatia.
Economic important of lichens

1. Pioneers of vegetation: crustose lichens aries first on the bare rocks. They secrete acids
and disintegrate rocks into soil particles, where moss and higher plants are established.
2. Food: some species of lichen are also used as food. Eg: Parmelia.
3. Medicines: some species of lichens are used in treatment of some disease.
i) Lobaria pulmonaria are used in lungs disease.
ii) Xanthoria sp are used in jaundice etc
4. Perfumes: Several species of lichens are used in preparation of cosmetic perfumes.
5. Bio-indicators of air pollution: Lichens grow in pollution free places. As the level of
pollution increase, their number decrease. By this trend, degree of air pollution can be
predicated.
6. Dyes: Lichens are used to manufacture high quality dyes of various colors. Litmus is also
obtained from lichens.
7. Forest fire: Dry thalli of lichens in forest from the thick mat on tree branches and easily
catch fire. So there is high risk of forest fire due to lichens.
8. Damaging buildings: Lichens can grow on the walls of buildings. As they secret acids,
they can damage the plasters and shining beauty of buildings.
9. Shading of leaf: lichens can grow on the plant leaves and block the sunlight, so that
photosynthesis of plant is badly affected.

Economical importance of Fungi

Economical importance of Fungi 

                 

                     

 Fungi include many species which are of economic importance to man . We are harmed and benefited by Fungi directly or indirectly. Some account for beneficial and harmful activities of Fungi is as under:

Useful activities of Fungi:

(1) Destruction of organic waste: Saprophytic Fungi decompose plant and animal remains by acting as natural scavengers. Carbon dioxide released in the process is used by green plants. By some workers saprophytic Fungi have been designated as vegetative vultures.

(2) In Industry:

(A)       Many fungi are used in the commercial preparation of many organic acids and some vitamin preparation. Aspergillus miger, A. glaucus, A. clavatus, citronyces citricus have been recommended for preparation citric acid. Many fungi also prepare gluconic acid lactic acid.

Aspergillus and Fusaruim are source riboflavin, a constituent of vitamin B. Yeasts are also rich in vitamin B.

(B)       Recently Fungi have been founded to be the basis of entire alcoholic industry. The basis of alcoholic industry is production of ethyl alcohol by fermentation of sugar solutions by yeast. Yeasts are source of complex enzyme zymase which is responsible for the process of fermentation. Yeasts are used in making wines, bear and ciders.

(C)       Certain yeasts Saccharamyces cerevisiaes form important basis of baking industries.

(D)       Some fungi such as species of Penicillium are used in preparation of certain cheese.

(3) As food: Many fungi like mushroom (Agaricus), Puffballs (Lycoperdon), Morels (Morchella) are edible. They are important as protein sources. They are regarded as delicacies of table.

Large scale production of yeast is used in conversion of carbohydrates and in organic nitrogen salts in to edible and nutritional forms. Yeast food supplies a number of vitamins like thiamine, riboflavin, micotomic acid, Panthothenic acid, biotin etc. Yeast food is there fore supplement of human food requirements.

(4)        In Medicines or Medicinal value: Recently many fungi have been founded to be responsible for producing certain antibiotic drugs which inhibit the growth of pathogenic micro-organisms. Some medicines formed from Fungi are Penicillin to kill bacteria that cause Pnemonia streptomycin. Auroemoycin, chloromycetin and Ephedrine from yeast.

(5)        In plastic manufacture: Certain Fungi like odium lactis is widely used in plastic industry.

(6)        Control and insect pest: Many Fungi like Ascherronia deyroides, Isaria ferinosa, Empusa sepulchralis help in controlling the infection of insect pests of the plants.

(7)        Phytohormone or Auxins: Many growth promoting substances like Gibberellins are synthesized from the fungi like Fusarium maniforma and Dematium pullulans.

(8)        Nutrition of plant: Many members of Phycomycetes, Ascomycetes, Basidiomycetes and fungi imerfecii are involved in the formation of mycorrhizae which are of fundamental importance in nutrition of tree like Cycas, Zamia and Pinus.

Harmful activities:

Fungi cause diseases to human, animals and plants. They cause destruction to clothes, paper, jute, leather, rubber, Paints, petroleum products, good grains and other bakery products. Harmful effects are:

(1)        Many fungi cause very much loss to our timber trees by causing wood rot. Armillaria mellea, the honey mushroom causes red rot of apple and many forest trees. Many species of Polypores attack forest trees causing wood rot.

(2)        Some would fungi like Rhizopus, Mucor, Aspergillus spoil our food. Their spores are always in the air and settle down on exposed jams, pickles, jelly, bread and fruits and develop mycelia and make food articles unfit for human use.

(3)        Some parasitic fungi are causative agents of diseased of our cops, fruits and other economic plants. In them fungi like Puccimia and ustilago cause rusts and smuts. They are great enemies of crops and cause loss by reducing crop yield. The rusts reproduce yellow, orange or black pustules on the stem and leaves of cereal plants while smuts attack forests and produces a black powdery mass of smut spores in the place of seed and fruits. Damage caused to cereals (wheat, maize, oat and barley) by rust and smuts amounts to several hundred millions of rupees annually. Fungi diseases in plants are:

(i)         While rust of crucifers by crystopus cindidus.

(ii)        Powdery mildew by Erisiphae species.

(iii)       Fruit root of apple by Rhizopus arrhizus.

(iv)       Late blight of Potato by Phytopora infestans.

(v)        Red rot of sugar came by colletorichum falcatum.

(vi)       Some parasitic fungi cause diseases to animals.

Saprolegnia which occurs as saprophyte on dead fish or flies behave as facultative parasite producing serious diseases to crops and gold fishes.

(4)        Some fungi are also cause some important diseases in human beings. Asperigillus as A.miger, A.fiavus, A.fumigatus are common human pathogens. Disease caused in aspergilloses of lungs and ears. Some parasitic fungi live in mucous membrane of throad, bronchii and lungs. Few fungi cause skin discoloration. A well known skin disease rung worm or “Dead” is also a fungus disease.

Economical importance of Bacteria

Helpful Bacteria :

(1) Samitation value: Some bacteria bring about decomposition of proteins, fats, carbohydrates and other complex organic compound in the bodies of plants and animals and in their waste products. In this way they clear the earth of organic debris and return to the soil and air, the simple substances which are necessary for manufacture of food by green plants and maintenance of soil fertility.

(2) Soil fertility: Some bacteria increase soil fertility. Nitrogen is an essential ingredient of all having protoplasm. All growing plants therefore require it in their metabolism. Nitrogen is most abundant of all minerals. It makes up about 80% of atmospheres composition. They are of two kinds:

(i) Nitrogen fixing bacteria: Some live free in soil and others in root modules of leguminous plants. These bacteria are able to make use of atmospheric nitrogen and change it into nitrogenous compounds. This process is called nitrogen fixation e.g. Bacillus radicicola.

(ii) Nitrifying bacteria: These bacteria covert free nitrogen into ammonium compounds. They are converted into nitrates.

(iii) Nitrogen Cycle: Cycle of changes by which nitrogen passes wing to activities of bacteria and other living organisms is called nitrogen cycle.

(3) Industrial Value: The metabolic process and products of bacteria are important in many industries like vinegar, Dairies, Alcohols, Tea, tobacco, textile and Tanneries.

(4) Medicinal Values: Antibiotics and Vitamins are obtained by bacterial activities. Stroptomycin is obtained from streptomyces grisens.

Harmful Bacteria:

Most harmful activities of bacteria include epidermis and ailment of human beings, animals and plants. They take highest tool of human life.

(1) Human Diseases: Bacteria causes many serious diseases of man e.g. Tuberculosis meningitis, pleumonia, lock jaw, typhoid, cholera, diphtheria, leprosy and dysentery.

(2) Animal diseases: Tuberculosis of cattle, anthrax of sheep, chicken, cholera, pneumonia, in horses, sheep and goats and various serious diseases are caused by bacteria.

(3) Plant diseases: Fire blight of pears, citrus canker, cotton root rot, potato blackleg, soft rot of carrot, cabbage and cucumber, plants. Pine apple rot and wild diseases of tomatoes, potatoes, cucumbers, squash, are serious plant diseases caused by bacteria.

(4) Food spoiling: Several species of bacteria infect food stuffs and spoil then by producing poisons. Most common poisoning bacteria are clostridium botulinum.

Digestion of Food in Frog

Digestion of Food in Frog

In stomach: The actual digestion begin from stomach where food remain for 2 to 3 hrs. Here, food get mixed with pepsinogen and H.C.L produced by gastrice gland and oxyntic gland respectively. The inactive pepsinogen changes into active pepsin in presence of hydrochloric acid and pepsin acts upon protein to cover into peptones and proteases. Hydrochloric acid provides acidic medium and kills bacteria and fungi. Hcl also makes food soft. The the muscular contraction of wall of stomach help in mixing of digestive enzymes with done and converts done in semi solid paste like form called as chyme. The chyme passes to duodenum from pyloric valves.

In intestine: In small intestine three substances, bile, pancreatic juice and intestinal juice mixed up with food.
Bile is alkaline fluid produced by liver which neutralizes acidic food, emulsifies fat and activates pancreatic lipase. 
The pancreatic juice contains different enzymes which acts in alkaline medium. It contains trypsinogen, amylase and lipase. The inactive trypsinogen changes into active trypsin by internal enterokinase. The trypsin acts upon protein, proteoses, peptones etc. And converts them into aminoacids. The amylase converts carbohydrate into gulcose. The lipase converts emulsified fat into fatty acids and glycerol. 
The intestinal juice of succus entericus contains different enzymes besides enterokinase and acts upon all types of foods. tripsin acts upon protein and converts it into aminoacids. Maltase converts maltose into gulcose. Sucrase converts sucrose to gulcose. Lipase converts fat into fatty acids and glycerol.
Simple form of food materials are absorbed by goods lining of intestine. Presence of folds like villi make the profess of absorption faster. Gulcose and amino acids pass into alone capillaries of folds. While fatty acids and glycerol pass into lymphatic vessels or lacteal in folds.

Undigested food pass into rectum for storage and preparation re faeces. The faecal matter pass into cloaca and pass out through cloacal aperture. The passing out of feacal matter through cloacal aperture is called as egestion.

Venous system of Frog

Venous system of Frog

The venous system includes veins or those blood vessele in which blood of body returns to the blood. In frog it consists of three parts :

(1) pulmonary veins

(2) caval veins and

(3) portal veins.

1. Pulmonary veins: Oxygenated blood from two lungs is collected by right and left pulmonary veins which unite to form a common pulmonary vein opening directly into the left auricle on the dorsal side.
2. Caval veins: Deoxygenated blood from rest of the body travels towards heart in three large vessels, two anterior precavals and single posterior postcaval, all the three opening into shots venosus.

A. Anterior vanacava or precavals: The right and left precavals or anterior vanae cave collect venous blood from the anterior part of body. Each precaval is formed by the union of three major veins which are:
i. External jugular: It is formed by the union of lingual form tongue and mandibular from outer margin of lower law.

ii. Innominate: It is formed by the union of internal jugular from cranial cavity and orbit and subscapular form shoulder and back of arm.

iii. Subclavian: It is formed by the union of brachial form fore limb and the musculo-cutaneous form muscles and skin of side of body and head.

B. Posterior venacave or postcaval: The single postcaval is a large, dark coloured vein lying ventral to dorsal aorta. It is posterior end is formed between the two kidneys form which it drains blood by 5-6 pairs of renal veins. It also receives a pair of genital veins (spermatic in male, overian in female ) from gonads. The postcaval then runs forwards, dorsally to the liver and receiving from it a pair of short hepatic veins, before opening into the posterior part of sinus venosus.

3. Portal veins : a vein which collects blood form one organ of body and supplies alone to another organ instead of going to heart is called as postal vein. Thus a portal vein is bicapillary vein. All veins associated with a portal vein forms portal system. Frog consists of two postal system.

A. Renal postal system : the veins which carry alone to a capillary system in kidneys constitute the penal postal system. Blood of each hind leg is collected by two veins, an outer fermoral and an inner sciatic. On entering the abdominal cavity the femoral divides into a dorsal renal portal and ventral pelvic vein. The renal postal unites with the sciatic of its side and while running along there outer border of kidney of its side it receives alone from lumbar region by a dorso-lumbar vein. Renal postal vein enters the kidney by several branches which break up into capillaries.

B. Hepatic postal system : it consist of hepatic portal vein and anterior abdominal vein.
A large hepatic portal vein is formed by the union of several branches form stomach, intestine, spleen and pancreas. It carrier blood form alimentary canal, laden with digested food stuffs, to the liver into which it brakes up into capillaries.
Anterior abdominal vein : the pelvic veins of both sides unite to form a median ventral or anterior abdominal vein. It receives blood form urinary bladder and ventral abdominal wall and runs forwards to enter liver into which it brakes up into capillaries. Before entering liver the anterior abdominal and hepatic postal veins are connected by small loop.

Male reproductive system of Frog

Male reproductive system (urinogenital) of Frog

Male reproductive system consists of two testis attached to kidneys, several tara efferentia and two urinogeniteal ducts. Copulatory organs are absent IN frog.

1. Testis: A pair of testis are present. Each testis is an elongated or ovoid, light-yellow body attached to the antero-ventral surface of each kidney by a double dole of peritoneum, called mesorchium. Never the anterior end of testis arise several branched finger like fat bodies which provide reserve food to nourish developing spermatozoa and during seprmatogenesis.
Histologically each testis is a compact mass of much boiled seminiferous tubules, the epithelial lining of which produces spermatozoa by spermatogenesis.between two seminiferous tubules,there lies ledig's cell ehich produce male sex hormone testosterone.

fig- a pair of testis

T.s of testis 

# A mature sperm is microscopic, elongated about 0.03 mm long structure. It consists of a small rounded anterior acrosome, a long cylindrical head containing nucleus, a short middle piece containing controls and mitochondria, and a much elongated posterior motile tail terminating in a flagellum.

2. Vasa efferentia:All the seminiferous tubules in a testis are connected to form 10 or 12 narrow tubes, the tara efferentia. They leave form the margin of testis run through mesorchium and enter the  margin of kidney to open into the bidder's cannal. The bidder's canal is connected to the tues through collecting tubules of kidney. Thus vasa efferentia conduct nature spermatozoa from testis to the ureter of kidney.

3. Urinogenital duct: Ureter in make frog is both a urinary duct and vas deferens, hence it is called urinogenital duct. The ducts of both the side open into roof of cloaca separately on urinogenital papillae. In some species of frog, the urinogenital ducts are enlarged near kidney or cloaca forming seminal vesicles for temporary storage of spermatozoa until needed.

Arterial system of Frog

Arterial system of Frog

it includes all the arteries. Arteries carry bloods away from heart. The artericl system in frog beings with truncus arterious. The trumats divides into left and right branches or trunks, each of which subdivides into three major vessels or aortic arches:

1) common carotid

2) systemic and

3) pulmocutaneous.

Common barnchial arch: It is a short vessel running forward and outward, but soon divides into 2 branches: external and internal carotides. 

A. External carotid: It is the smaller inner branch carrying blood to the tongue and adjacent parts. It is also called lingual.

B. Internal carotid: It is the larger attes branch. At its base it forms a little swelling. The carotid labyrinth. Its lumen is converted into a labyrinth by folding of the walls. It is probably a sense organ and controls blood pressure in the internal barntie artery. The internal carotid divides into 3 branches - a palatine to the some of mouth, a cerebral to the brain and an ophthalmic to the eye.

Systemic arch: It is the longest of the three arches and with greatest distribution of blood. The two systemic archer curve dorsally around the oesophagus and join with each other behind the heart to form the dorsal aorta. In its course each systemic arch gives off 3 arteries:
a. Oesophageal. A small artery to oesophagus.

b. Occipition-vertebral. It immediately sends an occipital branch to occiput or posterior part of head, and a vertebral branch to vertebral column and spinal cord.


c. Subcalvian: It is a large supplying the shoulder region and extending into the forelimb as brachial artery.

Dorsal aorta: As already said, it is formed by the union of both the systemic arches. It stop posteriorly lying mid.dorsally just beneath the vertebral coloun. It gives off the following arteries :

a. Coeliaco-mesentric. It is a single large artery arising from the junction of the two systemic arches. It has two main branches : the coeliac to stomach, pancrease and liver; and the anterior mesentric to spleen and intestine.

b. Gonadial. A pair of short arteries to gonads. Called spermatic. In male frog and overian in female frog.
c. Renal. While passing between the two kidneys, dorsal costa sends off 5-6 pairs of small renal arteries in a series into both the kidneys.

d. Posterior mesentric. It arises from the posterior end of dorsal aorta, or sometimes from anterior mesentric. It goes to large intestine or rectum.

e. Commo iliacs. The dorsal costa finally bifurcates posteriorly into two common liliacs, each supplying an epigastric to ventral body wall, rectovesciluar to rectum and urinary bladder, femoral to hip and upper thigh, and sciatic to lower leg.

 Pulmocutaneous arch: It divides into main arteries, pulmonary to the lung and cutaneous to skin of dorsal and lateral sides.

Structure and working of Frog's heart

Structure and working of  Frog's heart

Structure of  Frog's Heart


It is a muscular organ and acts as pumping station and pumps blood.

External structure

it lies mid-ventrally in the anterior region of body cavity. It is reddish in colour and is triangular in shape with broad anterior and narrow prosterior end.
It lies inside thin, transparnent, two layered sac called as pericardium. The cavity between two pericardial layers contains pericardial fluid which postects heart from friction or shocks and keeps it moist.
It consists of 3 chambers, two auricles and one ventricle. The auricles are two anterior dark coloured chambers and are right auricle and left auricle. Two auricles remain demarcated by a longitudinal inter-auricular groove. The ventricle is posterior, comical pink colour chamber. The auricles and ventricle remain demarcated with each other by transverse auricular-ventricular groove or coronary sulcus.
The frog's heart has two additional chambers, sinus venosus and truncus arterious. The sinus venosus is dark coloured, thin walled and triangular chamber present on dorsal surface of heart. It is formed by union of two anterior precavels and one posterior postcarvel. The truncus arterious arises from anterior right ventral side of ventricle and is a tubular structure. It bifurcates anteriorly into two branches or trunks, each further divides into three arches; carotid, systemic and pulmocutaneous.

Internal structure



its internal structure is studied with the help of vertical section. It is hollow, muscular with different chambers. The different chambers remain seperated by values to keep one way flow of blood.
The two auricles are thin walled and remain separated from each other by a thin vertical inter-auricular septum. Right buriale is larger than left. The sinus venosus opens into dorsal wall of right buriale by a large oval aperture, sinu auricular aperture. It kids at middle close to inter-auricular septum and remains guarded by a pair of flap like values. The common pulmonary vein opens into left auricle, near inter-auricular septum, by a small opening without values. Both auricles open into ventricle by a common large auriculo ventricular aperture guarded by two pairs of flap like auriculo-ventricular values.
The ventricle is thick walled, muscular and spongy in nature. Its inner surface has irregular ridges or folds, the columnae carneae with depressions called as fissures. These folds reduce cavity of ventricle. The flaps of auriculo-ventricular values remain connected with wall of ventricle by thread like chordae tendineae.
The opening of ventricle into truncus anteriosus is guarded by 3 semilunar values (4 according to sharma) which prevent back flow of blood from truncus into ventricle. The spirally twisted cavity of truncus anteriosus remains divided by 3 semilunar values into a long thick walled proximal conus arteriosus or pylangium and a short distal, thin walled bulbous aorta or synangium. A longitudinal spiral valve is present on pylangium which remain attached dorsally while free ventrally. It divides cavity of pylangium into left dorsal cavum pulmoutaneum and right ventral cavum aorticum. The common opening of two pulmocutaneous arches lies in cavum pulmocutaneum while seperate openings of carotid and systemic arches lie in synangium. Sharma describes a joint opening of carotid and systemic. All there openings are guarded by values.


Working of heart
Heart constantly beats during life time under nervous control to pump blood into blood vessels. Contraction of heart is called systole, while relaxation is called as diastole. When shots venosus contracts, its non oxygencted blood passes into right auricle through sinu auricular aperture the blood from lungs come into left auricle through pulmonary vein. The two auricles now contract almost simultanadously forcing their blood into ventricle through auriculo-ventricular aperture.

A ) old view : according to the older they the ventricle contained only deoxygenated blood in its right side received from right auricle and only oxygencted blood in its left side received from left auricle, with some mixed blood in the middle region. The two lines of blood could not mix to any great extent because of their viscous nature and also because of the network of columnae carneane. When ventricle starts contraction, first the deoxygenated blood from the right side being nearer flows into the truncus arterious and directed by the spiral valve into the common opening of pulmocutaneous arches and carried to lungs and skin for oxygenction. Spiral valve now closes the opening of pulmocutaneous arches. Next follows the mixed blood which is pushed through cavum aorticum into the systemic arches and sent to the body and limbs. Finally enters the oxygeneated blood of left side and directed through carotid arches to the head. Thus, spiral value in truncus plays an important sold in directing blood into different arches.

B ) modern view: Recent experimental studies conducted mostly by vandervael and foxon show trav it is actually campelety mixed blood in ventricle and truncus which flows simultaneously through the three pairs of arches to all parts of the body. The blood received from skin an buccal cavity into sinus venosus and right buriale is in fact more oxygencted than that received from lungs to left auricle. According to this view he interauricular serum and spiral value in truncus have become functionless in frogs. Studies by delong indicate that the carotid arches receive highly oxygencted blood, the pulmocuataneous archer with atleast oxygen, and the systemic arches mixed blood. The precise mechanism is not understood.

Ecosystem

Ecosystem:the system resulting from the interaction of all the living and non living factors of the environment is called the ecosystem.

Types of ecosystem:

Natural
  Terrestrial
      Grassland
        Forest
        desert
  aquatic
      freshwater
           running water(lotic)
           stable water(lentic)
  marine
artificial(aquarium)
Here we have to study only lentic (pond) and grassland ecosystem.


Pond ecosystem:
It is a type of lentic freshwater ecosystem with complex interaction between its biotic and abiotic component. Upper part of pond is called littoral zone having shallow water , central is called limentic zone and lower part of pond is called as profundal zone with less biodiversity. Pond ecosystem consists of two major components:
abiotic components:
the abiotic component of pond includes:
Inorganic compounds like water, oxygen, carbon dioxide, carbon, calcium, phosphorus and their compounds.
Organic compounds like carbohydrates, protein, lipids, and amino acids. Only small amount of these are found in dissolved form rather they are found in base as sediment.
Ecological factors such as light, temperature, wind, rainfall etc regulates the functioning of pond ecosystem.
Biotic components: the living components of a pond are:
Producers: these are autotrophic aquatic green plants, photosynthetic bacteria etc. they fix solar energy during photosynthesis and make organic food from co2 and water. They are:
Emergent hydrophytes: it includes rooted emergent plants like ranunculus, typha etc.
Floating hydrophytes: it includes freely floating plants like pistia and azolla.
Submerged hydrophytes: it includes hydrilla and vallisnaria.
Phytoplanktons: it includes tiny plants like spirogyra and volvox.

Consumers: they are heterotrops which depends on their nutrients on producers. the consumers of pond are:
Primary: these are herbivores which feed on plants. They are microscopic animals like Cyclopes, daphria and other larger animals like insects, larvae, small fish etc.
Secondary: these are carnivores that feed on primary consumers. They are mainly crab, frog and snake.
Tertiary: these are some large fish, water birds etc.

Decomposers: after death of aquatic plants and animals; their bodies are acted upon by microorganism like bacteria and fungi(asprrgillus,rhizopus) etc. they are called decomposers. They convert complex organic substance into simple inorganic form; which can be utilized by green plants in nutrition.

Figure of pond ecosystem:

Grassland ecosystem:
The grassland ecosystem is a type of terrestrial ecosystem with open land grasses in which there is constant interaction between biotic communities and abiotic factors.
The grassland ecosystem consists of two major components:
Abiotic: the nonliving component of grassland ecosystem includes:
Inorganic compounds like carbondioxide, water, minerals, nitrate, phosphate, sulphate etc present in soil.
Organic compounds such as carbohydrates, proyein, lipid and amminoacids.
Environmental factors include light, temperature, wind, rainfall etc.

Biotic: the living factors of grassland ecosystem includes:
Producers: producers are those living organisms that can prepare food from inorganic substance .they are different types of species of grasses like cyanodon, imperata, oxalis, agropyron etc. In addition to this many herbs, shrubs are found in grassland.
Consumer: these are mainly heterotrophic animal which feed on producer. They are of following types:
Primary: they are herbivores feeding on grasses. They include mainly grazing animals like cow, buffalo, rabbit etc.
Secondary: they are primary carnivores like snake, frog, lizard, toad etc who feed on herbivores.
Tertiary: these are animals that depend upon secondary consumers for food. In grassland ecosystem, hawk, vulture are tertiary consumers.
Decomposers: these are saprophytic organism like bacteria and fungi. They decompose the dead bodies of plant and animal and convert the organic substance into simple form which is reused by green plants.

Functional aspects of ecosystem:
Functional aspects of ecosystem include flow of energy and the cycling of nutrients. The green plants fix solar energy in presence of CO2 and water to make organic food. From green plants, these organic compounds are passed into herbivores and from herbivore it transfer to carnivores.
All the living organisms have definite life span after which they die. The dead bodies provide food for saprophytic bacteria and fungi. During decomposition, energy is lost into environment as heat. Thus energy flow in ecosystem is noncyclic from sun to decomposers. Minerals from decomposed body are withdrawn by the root of plants and deposited in tissue of plants and again return to soil when plant dies. All the energy in ecosystem is recycled.