Statement I: | The peptide chain of the haemoglobin molecule that gets mutated leading to the disease is the alpha chain. |
Statement II: | The mRNA codon X can be GAG and the mRNA codon Y can be GUG. |
Statement I: | It is an autosome-linked recessive blood disease transmitted from parents to the offspring when both partners are the unaffected carriers for the gene (or heterozygous). |
Statement II: | The defect could be due to either mutation or deletion which ultimately results in a reduced rate of synthesis of one of the globin chains (α and β chains) that make up haemoglobin. |
Statement I: | α Thalassemia is controlled by a single gene HBB on chromosome 11 of each parent and occurs due to mutation of one or both the genes. |
Statement II: | β Thalassemia is controlled by two closely linked genes HBA1 and HBA2 on chromosome 16 of each parent. |
1. | The former is a quantitative problem of synthesising too few globin molecules while the latter is a qualitative problem of synthesising an incorrectly functioning globin. |
2. | The former is a qualitative problem of synthesising too few globin molecules while the latter is a quantitative problem of synthesising an incorrectly functioning globin. |
3. | Both disorders are qualitative problems of synthesising too few globin molecules. |
4. | Both disorders are quantitative problems of synthesising too few globin molecules. |
Statement I: | Part A shows the common clinical features of Down’s syndrome. |
Statement II: | Part B shows the characteristic karyotype of Down’s Syndrome. |
Chromosomal disorder | Karyotype | |
A | |
|
B | |
|
1. | Only A | 2. | Only B |
3. | Both A and B | 4. | Neither A nor B |
1. | Autosomal recessive | 2. | Autosomal dominant |
3. | Sex-linked recessive | 4. | Sex-linked dominant |
1. | Autosomal recessive | 2. | Autosomal dominant |
3. | Sex-linked recessive | 4. | Sex-linked dominant |
Pedigree Symbol | Meaning | |
1. | |
Mating between relatives (consanguineous mating) |
2. | |
Parents above and children below(in order of birth – left to right) |
3. | |
Parents with a male child affected with the disease |
4. | Five affected offspring |
I. | The sex determination in honey bee is based on the number of sets of chromosomes an individual receives. |
II. | An offspring formed from the union of a sperm and an egg develops as a female (queen or worker), and an unfertilised egg develops as a male (drone) by means of parthenogenesis. |
III. | The males have double the number of chromosomes than that of a female, therefore, the females are haploid having 16 chromosomes and the males are diploid, i.e., having 32 chromosomes. |
IV. | This is called a haplodiploid sex-determination system. |
V. | The males produce sperms by mitosis, they do not have a father and thus cannot have sons, but have a grandfather and can have grandsons. |
1. | 2 | 2. | 3 |
3. | 4 | 4. | 5 |