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It is chromosome and not the individual gene which segregate during gamete formation.

23 Pairs of chromosomes, present in human egg cells.

(i) Male, because there is a Y-chromosome and an X-chromosome.

(ii) (a) A female would have two X-chromosomes and no Y-chromosome.

(b) A sperm cell would have half the number of chromosomes. 23 instead of 46. There would be only one sex chromosome which could be either Y or X.

1. Ovule

2. Inflorescence

3. Blackman law of limiting factor

4. Night blindness

(i) Axial round

(ii) Axial round, axial wrinkled, terminal round, terminal wrinkled.

(iii) 9:3:3:1

(iv) Law of independent assortment: When there are two pairs of contrasting characters, the distribution of factors of each pair in the gametes is independent of the distribution of other pair of characters.

Any change in genetic composition of an individual brought about by internal or external factors is called mutation. Mutation play a significant role in the evolution and speciation because they cause variability. However, some harmful mutations cause diseases.

Monohybrid: Crosses involving a single pair of alleles. It yields a phenotypic ratio of 3 : 1 in F₂ generation.

Dihybrid: Crosses involving two pairs of alleles. It yields a phenotypic ratio of 9 : 3 : 3 : 1 in F₂ generation.

The phenomenon of inheritance of a group of genes together through some generations.

The regions where crossing-over takes place are called Chiasmata. 

The individual having similar pair of genes is Homozygous.

Transmits characteristics from parents to offsprings is Genes.

Pair of genes responsible for a particular characteristic is Alleles.

The individuals having dissimilar pair of genes is Heterozygous.

Heterosome: Chromosome found in reproductive cell and which are responsible for the sex of a child.

Retro virus with DNA as heredity material. e.g. HIV

Nucleus Cell organelle directly involved in genetics.

When an individual has both the genes of a contrasting character, it is said to be Heterozygous.

The phenomenon of the exchange of genetic material between two non-sister chromatids.

When two individuals differing in at least one character are crossed, the process is known as Hybridization. 

Dominance: The character expressed in first generation when any two individuals of contrasting characters breed is dominant and the phenomenon is called dominance.

1. The number of chromosomes in human is pairs /46.

2. The physical expression of genes is called Phenotype.

3. The small differences among individuals are called Variations.

4. The dissimilar pairs of genes present in an individual are known as Heterozygous.

5. Autosomes chromosomes do not take part in sex determination.

1. Alleles are the alternative forms of a gene producing different effects.

2. 9 : 3 : 3 : 1 is the ratio of dihybrid cross.

3. A character that is supressed is Recessive.

4. Upon Fertilization the diploid condition is restored.

Cells having a single set of chromosomes Haploid.

The ratio of offspring on F₂ generation in a dihybrid cross is 9 : 3 : 3 : 1.

The genetic composition of any organism is called genotype.

Genotype: It designates the genetic constitution of an individual which determines the characters. The individuals of the same genotype interbreed and have the same phenotype if they are present in the same environment.

Phenotype: It designates the external appearance of an individual. The individual of the same phenotype may appear alike but may not interbreed if genetically different.

Transmission of characters through generations is Heredity.

Cataract: It is a condition in which the lens turns opaque and the vision is cut down even to total blindness. It can be corrected by surgically removing the lens and by using spectacles with highly convex lense.

The correct answer is (A) catabolic

1. Respiration provides energy for biosynthesis of biomolecules. 

2. It is also a source of energy for cell division, growth, repairs and replacement of worn out parts, movements, locomotion etc. 

3. Various intermediates of Krebs cycle are used as building blocks for synthesis of other complex compounds. 

4. Coupled with photosynthesis, it helps to maintain the balance between CO₂ and O₂ in the atmosphere. 

5. Anaerobic respiration (fermentation) is used in various industries such as dairies, bakeries, distilleries, leather industries, paper industries etc. It is used in the commercial production of alcohol, organic acids, vitamins, antibiotics etc.

Significance of ETS: 

1. Major amount of energy is generated through ETS or terminal oxidation in the form of ATP molecules. 

2. Per glucose molecule 38 ATP molecules are formed, out of which 34 ATP molecules are produced through ETS. 

3. Oxidized coenzymes such as NAD and FAD are regenerated from their reduced forms (NADH+H⁺ and FADH₂ ) for recycling. 

4. In this process, energy is released in a controlled and stepwise manner to prevent any damage to the cell. 

5. ETS produces water molecules.

Phosphorylation occurs in three different ways as – photophosphorylation, substrate-level phosphorylation and oxidative phosphorylation.

The correct answer is (D) malate dehydrogenase

ATP is hydrolysed whenever energy is required for any metabolic reactions.

The correct answer is (B) inner membrane of mitochondria.

Oxidative phosphorylation: It is a metabolic pathway that uses energy released by the oxidation of substrates to produce ATP. 

1. Oxidative phosphorylation takes place in the mitochondrial membrane. 

2. Many intermediate products during respiration are oxidised and release 2H⁺ . 

3. The released hydrogen is trapped by NAD⁺ or FAD⁺ . 

4. Electrons pass through electron transport system to produce ATP and metabolic water.

Phosphorylation occurs in three different ways as – photophosphorylation, substrate-level phosphorylation and oxidative phosphorylation.

It is the formation of ATP, by addition inorganic phosphate to ADP. ADP + Pi → ATP

The primary lymphoid organs are those organs in which B-lymphocytes and Tlymphocytes undergo maturation. For example, bone marrow and thymus.

In oxidative phosphorylation ATP is synthesize by using the energy released during the oxidation of substrates like NADH + H⁺ and FADH₂ . This occurs on the inner mitochondrial membrane only.

B-cells and T-cells.

(i)

ii. Two chromosomal aberration-associated disorders are Down’s syndrome and Klinefelter’s syndrome. 

iii. a. Down’s syndrome: The individuals have overall masculine development but they express feminine development like development of east, i.e., gynaecomastia. They are sterile. 

b. Klinefelter’s syndrome: The females are sterile as ovaries are rudimentary. Other secondary sexual characters are also lacking.

(a)

(b) Human height or skin colour are examples of polygenic inheritance. Height trait is controlled by at least three gene pairs. Additive effect allele contributes to the phenotypic expression of the trait. The dominant alleles more are, more pronounced is the phenotypic expression or more in other word. The recessive alleles less pronounced is the phenotypic expression.

Clot is formed inside an intact vessel. Such a clot is called thrombus and its formation is thrombosis.

RBCs are formed in bone marrow and spleen.

Eosinophils (Acidophils) and Basophils.

Muscles forming cells are myoblast.

Tendon joins a skeleton muscles to a bone and ligament joins a bone to another bone.