1. Genetic drift
3. Human Genome Project.
4. (b) 14th day
5. Edward Wilson
6. Propionibacterium sharmani
7. (a) Turner’s syndrome. Genetic constitution: 44A + X0
(b) Sterile, Ovaries are rudimentary. Lack of secondary sexual characters. Dwarf. Mentally retarded (Any 2).
8. (a) Yes. Methanogens are the microbes that can be used for biogas production.
(b) Rhizobium, Azotobacter, Cyanobacterium, Mycorrhiza etc. (any 2)
10. (a) An antibody. It is produced by B-lymphocytes (B-cells).
(b) These are the proteins to fight the pathogens. i.e., gives immunity.
11. (a) It states that life came out of decaying and rotting matter like straw, mud etc.
(b) Louis Pasteur disproved this theory.
12. (a) Implantation
(d) Corpus luteum
13. (a) Test cross. It is the cross between F1 hybrid with a recessive parent.
(b) It is used to find out the unknown genotype of a character.
14. (a) Warning signs:
· Drop in academic performance and absence from school.
· Lack of interest in personal hygiene.
· Withdrawal and isolation.
· Depression, fatigue, aggressive and rebellious behaviour.
· Change in sleeping and eating habits.
(b) Prevention and control:
· Avoid undue peer pressure.
· Education and counselling.
· Seeking help from parents and peers.
· Looking for danger signs.
· Seeking professional and medical help.
15. (a) T.H Morgan
(b) • They can grow on simple synthetic medium.
• Short generation time.
• Breeding can be done throughout the year.
• Hundreds of progenies per mating.
(c) Tightly linked genes show low recombination. Loosely linked genes show high recombination.
16. (a) Extinction of the parasites when the host is extinct.
In co-evolved plant-pollinator mutualism, extinction of one causes the extinction of the other.
(b) Biodiversity (species richness) is highest in tropics because
· Tropics had more evolutionary time.
· Relatively constant environment (less seasonal).
· They receive more solar energy which contributes to greater productivity.
(c) Hotspots are the regions with very high species richness, high degree of endemism but most threatened.
17. Divergent evolution: It is the evolution by which related species become less similar to survive and adapt in different environmental condition.
Convergent evolution: It is the evolution by which unrelated species become more similar to survive and adapt in similar environmental condition.
18. a. (i) Digestion of DNA by restriction endonucleases. (ii) Hybridization by radioactive VNTR probe.
b. DNA carries non-coding repeated sequences called variable number tandem repeats (VNTR). VNTR is specific in each person.
c. Yes. It is a forensic tool to solve paternity, rape, murder etc.
19. (a) Central Dogma of Molecular Biology:
(b) Salient features of genetic code:
• Triplet code. 61 codons code for amino acids. UAA, UAG & UGA are stop codons (Termination codons).
• Genetic code is universal.
• No punctuation b/w adjacent codons.
• An amino acid is coded by many codons. So the code is degenerate.
(c) AUG is the initiator codon. Methionine is the amino acid coded by it.
20. (a) Vasectomy
(c) Easily available, reversible, prevent STDs, gives privacy to the user.
(d) (i) Gamete Intrafallopian Transfer (ii) Intracytoplasmic Sperm Injection.