Mule is sterile and cannot yield its offsprings because it is born from the cross made between different species like Male Donkey and Female Horse.

1. PUFA or Polyunsaturated fatty acids have one or more double bonds.
2. The clotting property of blood decreases due to high proportion of PUFA. Thus chances of blockage or blood clots are reduced.

1. Yes. Reducing sugars have a free aldehyde or ketone group. They reduce cupric ions of Benedicts or Fehling's solution to form cuprous ions. Eg: Glucose.
2. Non Reducing sugar do not have a free aldehyde or ketone group. They do not respond to Benedicts / Fehling's solution. Eg: Sucrose.

1. It is a RNA which translates the code from mRNA and transfers amino acids to the ribosome to build proteins.
2. It is highly folded into an elaborate 3D structure and comprises about 15% of total RNA

1. mRNA (messenger RNA)
2. tRNA (transfer RNA)
3. rRNA (ribosomal RNA)

1. Amino acids condense to form peptide. In this process, the carboxylic group of one amino acid joins with the amino group of another amino acid with a loss of water molecule.
2. The bond thus formed is called amide or peptide bond. A chain of two amino acids is called dipeptide, that of three is tripeptide and so on.

S.No	Reducing Sugars	non-reducing Sugars
1	The sugars have a free aldehyde or ketone group The sugars can reduce cupric ions of Benedict's or Fehling's solution to forming brick red precipitate cuprous ions	A free aldehyde or ketone group is absent. They do not reduce cupric ions of Benedict's or Fehling's solution to cuprous ions
2	Eg: Glucose.	Eg: Sucrose.

Nitrogenous base	Inorganic base
In nitrogenous base the basic character is because of lone pair electron called lewis base	Inorganic base is because of hydroxyl ion that is Arrhenius base
Eg: Pyridine, Pyrimidine	Eg: NaOH

Category	Compound
Nucleoside	Uracil

A Nitrogenous base is linked to pentose sugar through a n-Glycosidic linkage and forms a nucleoside.

(i) Watson and Crick shared the Nobel Prize in 1962 for their discovery, along with Maurice Wilkins, who. had produced the crystallographic data supporting the model. Rosalind Franklin (1920-1958) had earlier produced the first clear crystallographic evidence for a helical structure. James Watson and Francis Crick of Cavendish laboratory in Cambridge built a scale model of double helical structure of DNA which is the most prevalent form of DNA, the B-DNA. This is the secondary structure of DNA.
(ii) As proposed by James Watson and Francis Crick, DNA consists of right-handed double helix with 2 helical polynucleotide chains that are coiled around a common axis to form right-handed B form of DNA. The coils are held together by hydrogen bonds which occur between complementary pairs of nitrogenous bases. The sugar is called 2'. A deoxyribose because there is no hydroxyl at position 2'. Adenine and thiamine base pairs -has two hydrogen bonds while guanine and cytosine base pairs have three hydrogen bonds.
Chargaff's Rule:
(a) A = T; G = C
(b) A + G = T + C
(c) A: T = G: C = 1
(iii) As published by Erwin Chargaff in 1949, a purine pairs with pyrimidine and vice versa. Adenine (A) always pairs with Thymine (T) by double bond and Guanine (G) always pairs with Cytosine (C) by triple bond. 

(i) Many enzymes require non-protein components called cofactors for their efficient activity. Cofactors may vary from simple inorganic ions to complex organic molecules. They are of three types: inorganic ions, prosthetic groups and coenzymes.
(ii) Holoenzyme: Active enzyme with its non-protein component.
(iii) Apoenzyme: The inactive enzyme without its non-protein component.
(iv) Inorganic ions help to increase the rate of reaction catalysed by enzymes. Example: Salivary amylase activity is increased in the presence of chloride ions.
(v) Prosthetic groups are organic molecules that assist in catalytic function of an enzyme. Flavin adenine dinucleotide (FAD) contains riboflavin (Vit B2), the function of which is to accept hydrogen. 'Haem' is an iron-containing prosthetic group with an iron atom at its centre.
(vi) Coenzymes are organic compounds which act as cofactors but do not remain attached to the enzyme. The essential chemical components of many coenzymes are vitamins. ego NAD, NADP, Coenzyme A, ATP.

(i) The word biology itself is a greek word where bios means life and logos means study.
(ii) The role for latin and greek words are used in classification especially in Binomial classification.
(iii) Named to understand and remember the scientific names of organisms.
(iv) The Binomial nomenclature (L.Bio-two; Nomen-Name) Vector animals and Plants is largely derived from latin and Greek words.
(v) Binomial nomenclature was originally codified in the works of Carolus Linnaeus (1753), Species Plantarum.
(vi) Latin is now used by classical scholars, certain purpose in botany and in the medicine field.
(vii) The purpose is to give every species a distinct name which will be recognized everywhere became common names abundant species vary from country to country or even from region to region within a country.
(viii) using latin and greek forms simply refresh the main language of science when this system was invented.
(ix) Other languages words now used are given grammatical endings derived from the classical languages. Ex: Blakea atton boroaghi.

Structure of DNA:
1. Watson and Crick shared the Nobel Prize in 1962 for their discovery, along with Maurice Wilkins, who had produced the crystallographic data supporting the model.
2. Rosalind Franklin (1920-1958) had earlier produced the first clear crystallographic evidence for a helical structure.
3. James Watson and Francis Crick of Cavendish built a scale model of double helical structure of DNA which is the most prevalent form of DNA, the B-DNA. This is the secondary structure of DNA.
4. DNA consists of right handed double helix with 2 helical polynucleotide chains that are coiled around a common axis to form right handed B form of DNA. .
5. The coils are held together by hydrogen bonds which occur between complementary pairs of nitrogenous bases. The .sugar is called 2'-deoxyribose because there is no hydroxyl at position 2'.
6. Adenine and thymine base pairs has two hydrogen bonds while guanine and cytosine base pairs have three hydrogen bonds. As published by Erwin Chargaff in 1949, a purine pairs with pyrimidine and vice versa.
7. Adenine (A) always pairs with Thymine (T) by double bond and Guanine (G) always pairs with Cytosine (C) by triple bond.
Chargaff 's Rule:
A = T; G=C
A + G =T+ C
A : T=G:C = l  
Features of DNA:
1. If one strand runs in the 5'-3' direction, the other runs in 3'-5' direction and thus are antiparallel (they run in opposite direction). The 5' end has the phosphate group and 3'end has the OR group.
2. The angle at which the two sugars protrude from the base pairs is about 120°, for the narrow angle and 240° for the wide angle.
3. Each base is 0.34 nm apart and a complete turn of the helix comprises 3.4 nm or 10 base pairs per turn in the predominant B form of DNA
4. DNA helical structure has a diameter of 20 A and a pitch of about 34 A. X-ray crystal study of DNA takes a stack of about 10 bp to go completely around the helix (360°).
5. Thermodynamic stability of the helix and specificity of base pairing includes
(i) The hydrogen bonds between nitrogenous boxes.
(ii) Stacking interaction between bases of electron cloud interactions (IT - IT) between the bases

6. The phosphodiester linkages gives an inherent polarity to the DNA helix. They form strong covalent bonds, gives the strength and stability to the polynucleotide chain.
7. Plectonemic coiling - the two strands of the DNA are wrapped around each other in a helix, making it impossible to simply move them apart without breaking the entire structure. Where as in paranemic coiling the two strands simply lie alongside one another, making them easier to pull apart.
8. Based on the helix and the distance between each turns, the DNA is of three forms - A DNA, B DNA and Z DNA.

Many enzymes require non-protein components called cofactors for their efficient activity. Cofactors may vary from simple inorganic ions to complex organic molecules. They are of three types: Inorganic ions, Prosthetic groups and Coenzymes.

1. Holoenzyme - Active enzyme with its non protein component.
2. Apoenzyme - The inactive enzyme without its non-protein component.
3. Inorganic ions help to increase the rate of the reaction catalysed by enzymes. Eg: Salivary amylase activity is increased in the presence of chloride ions.
4. Prosthetic groups are organic molecules that assist in the catalytic function of an enzyme. Flavin adenine dinucleotide (FAD) contains riboflavin(vit B2), the function of which is to accept hydrogen. ";
5. Coenzymes are organic compounds which act as cofactors but do not remain attached to the enzyme. The essential chemical components of many coenzymes are vitamins. Eg. NAD, NADP, Coenzyme A, ATP.

Certain substances present in the cells may react with the enzyme and lower the rate of reaction. These substances are called inhibitors. It is of two types competitive and non-competitive inhibitors.

Competitive Inhibitor:
1. Molecules that resemble the shape of the substrate and may compete to occupy the active site of enzyme are known as competitive inhibitors.
2. Eg: The enzyme that catalyses the reaction between carbon dioxide and the CO2 acceptor molecule in photosynthesis, known as ribulose bisphosphate carboxylase oxygenase (RUBISCO) is competitively inhibited by oxygen/carbon-di-oxide in the chloroplast. The competitive inhibitor is malonate for succinic dehydrogenase.
Non-competitive Inhibitors:
1. There are certain inhibitors which may be unlike the substrate molecule but still combines with the enzyme.
2. This either blocks the attachment of the substrate to active site or change the shape so that it is unable to accept the substrate. Eg: The effect of the amino acids alanine on the enzyme pyruvate kinase in the final step of glycolysis.
(i) Certain non-reversible / irreversible inhibitors bind tightly and permanently to an enzyme and destroy its catalytic properties entirely. These could also be termed as poisons. Eg: Cyanide ions which blocks cytochrome oxidase in terminal oxidation in cell aerobic respiration.

Properties of enzymes:
1. All are globular proteins.
2. They act as catalysts and effective even in small quantity.
3. They remain unchanged at the end of the reaction.
4. They are highly specific.
5. They have an active site where the reaction takes place.
6. Enzymes lower activation energy of the reaction they catalyse.

1. Based on the R group amino acids are classified as acidic, basic, polar, non-polar.
2. The amino group of one amino acid reacts with carboxyl group of other amino acid, forming a peptide bond.
3. Two amino acids can react together with the loss of water to form a dipeptide. Long strings of amino acids linked by peptide bonds are called polypeptides. In 1953 Fred Sanger first sequenced the Insulin protein.
Structure of Protein:

1. Protein is synthesised on the ribosome as a linear sequence of amino acids which are held together by peptide bonds.
2. After synthesis, the protein attains conformational change into a specific 3D form for proper functioning.
3. According to the mode of folding, four levels of protein organisation have been recognised namely primary, secondary, tertiary and quaternary
(i) The primary structure is linear arrangement of amino acids ill a polypeptide chain.
(ii) Secondary structure arises when various functional groups are exposed on outer surface of the molecular interaction by forming hydrogen bonds. This causes the amino acid chain to twist into coiled configuration called a-helix or to fold into a flat \(\beta \) -pleated sheets.
(iii) Tertiary protein structure arises when the secondary level proteins fold into globular structure called domains.
(iv) Quaternary protein structure may be assumed by some complex proteins in which more than one polypeptide forms a large multi-unit protein. The individual polypeptide chains of the protein are called subunits and the active protein itself is called a multimer. Eg: Enzymes serve as catalyst for chemical reactions in cell and are non-specific. Antibodies are complex glycoproteins with specific regions of attachment for various organisms.

Hydrogen Bond:
1. It is formed between some hydrogen atoms of oxygen and nitrogen in a polypeptide chain. The hydrogen atoms have a small positive charge and oxygen and nitrogen have small negative charge. Opposite charges attract to form hydrogen bonds.
2. Though these bonds are weak, large number of them maintains the molecule in 3D shape.
Ionic Bond:
1. It is formed between any charged groups that are not joined together by peptide bond. It is stronger than hydrogen bond and can be broken by changes in pH and temperature.
Disulfide Bond:
1. Some amino acids like cysteine and methionine have sulphur.
2. These form disulphide bridge between sulphur atoms and amino acids.
Hydrophobic Bond:
1. This bond helps some protein to maintain structure.
2. When globular proteins are in solution, their hydrophobic groups point inwards away from water.

(i) Yes we can use recent molecular tools to identify and classify organisms.
(ii) Eg: Automated species identification tools electron microscopy (for cellular organelles and molecular structures by neo taxonomical tools) behaviour of organisms by ethology of taxonomical tools and development of electronic digital images and description by INOTAXA or e- Taxonomic resources.

Probiotics	Pathogenic bacteria
Probiotic bacteria are beneficial.	Pathogenic bacteria are harmful.
Probiotic bacteria may be decomposers, photosynthetic and few may be pathogenic.	All are pathogenic and causing diseases.