Genetics — Problem Solving

Grade 10 Science — Genetics — Problem Solving: 25 practice questions with instant scoring and explanations.

1. In a monohybrid cross Aa × Aa, what is the phenotypic ratio of offspring?
2. If two heterozygous tall plants (Tt) are crossed, how many homozygous tall offspring will be produced?
3. A person with blood type AB marries someone with blood type O. What are possible blood types of offspring?
4. In a dihybrid cross AaBb × AaBb, what is the phenotypic ratio?
5. In a monohybrid cross, if phenotypic ratio is 1:1, the parents must be:
6. If both parents are carriers of a recessive disease (Aa), probability of affected child is:
7. In humans, male hemophilia is X-linked recessive. If an affected male (XᵃY) marries a normal woman (XᴬXᴬ), their daughters will be:
8. In sex-linked inheritance, color blindness (Xᵇ) is recessive. What is probability of color-blind female?
9. For a gene with alleles A and a, if frequency of A = 0.6, frequency of a =?
10. In Hardy-Weinberg equation p² + 2pq + q² = 1, what does 2pq represent?
11. A Punnett square for Aa × Aa shows:
12. If a test cross (Aa × aa) produces 100 offspring, expected ratio is:
13. In a cross AaBb × aabb, number of phenotypic classes expected is:
14. If a man with genotype AaBb has children, maximum number of different gamete types he can produce is:
15. Two parents with blood type AB and B can have child with blood type:
16. In a dihybrid cross, if both parents are AaBb, probability of aabb offspring is:
17. An X-linked dominant trait (Xᴰ) in a heterozygous female (XᴰXᵈ) crossed with normal male (XᵈY) will produce:
18. Crossing over increases genetic variation by:
19. If both parents are TtPp (heterozygous for two traits), probability of one specific phenotype like TTPP is:
20. In incomplete dominance, red flowers (RR) × white flowers (WW) produce:
21. Codominance example: Blood type AB person has:
22. A person is heterozygous for sickle cell (AS). Their phenotype is:
23. If allele frequency of recessive trait is 0.2, frequency of dominant phenotype is:
24. In testcross of AaBbCc × aabbcc, total number of possible offspring phenotypes is:
25. A heterozygous black cow (B) is crossed with homozygous recessive brown cow (b). Ratio of phenotypes is: