Question

Q 11. Which of the following statements is TRUE about Sickle cell anemia? (A) It is caused by a genetic mutation in the beta-hemoglobin gene. (B) It confers heterozygote advantage against malaria (C) It results in abnormal, sickle-shaped erythrocytes. (D) All of the above. Q 12. Which of the following explains why a deleterious allele may persist in a population? (A) Random genetic drift (B) Balancing selection (C) Negative selection (D) Random genetic drift or balancing selection Q 13. Which statement is TRUE? (A) Individuals with trisomy of a chromosome with only a few genes will likely survive. (B) Most of the aneuploid embryos will survive. (C) Individuals with monosomy have only one chromosome in their genomes. (D) Autosomes and sex chromosomes in Indian muntjac are fused. Q 14. Which statement regarding Evolution is FALSE? (A) Evolution is an outcome of natural processes. (B) Evolutionary patterns make predictions, (C) Evolution is an assumption made by scientists (D) Evolution applies to all species. Q 15. Which of the following statements is TRUE? (A) GWAS can identify variants (SNPs) associated with the disease. (B) GWAS is for discovering Mendelian disease genes only. (C) GWAS does not require follow-up studies to determine causation (D) False positives in GWAS studies are rare.

Answer 1

11) The answer will be all of the above (option D).

Explanation: Sickle cell anemia caused sickle shaped red blood cell (Erythrocyte), which die earlier than normal RBC due to the mutation in beta-hemoglobin gene. Further, carrier of sickle cell disease (Heterozygote) provide protection against malaria, i.e., heterozygote advantage. Thus, correct answer will be option D.

12) The answer will be random genetic drift or balancing selection (option D).

Explanation: In negative selection, deleterious allele will be removed. Thus, we can ignore option C. In balancing selection, deleterious allele can persist due to heterozygote advantage. Genetic drift doesn't take account beneficial or harmful effect of an allele & can fixed a deleterious allele purely by chance. Thus, correct answer will be option D.