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1.2 Alleles, Dominance & Multiple Alleles — Test 1
Q1. When two alleles each contribute independently and fully to the phenotype of the heterozygote, they are said to be:✓ Co-dominant
Q2. Inheritance of flower colour in the four o'clock plant (red × white → pink) is an example of:✓ Incomplete dominance
Q3. ABO blood group inheritance in humans is a classic example of:✓ Multiple allelism and codominance
Q4. The C(ch)C(ch) genotype for coat colour in rabbits represents which phenotype?✓ Chinchilla — light grey, near-white with black tips
Q5. The Rh blood group system in humans is best described as an example of:✓ Multiple alleles
Q6. Lucien Cuénot crossed yellow mice and never obtained all-yellow offspring; the ratio was always 2 yellow : 1 non-yellow. This is a case of:✓ Recessive lethal allele
Q7. The phenotype of the heterozygote that includes the phenotypes of BOTH homozygotes is seen in:✓ Codominance
Q8. Multiple alleles of a gene are located:✓ At the same locus on homologous chromosomes
Q9. A mother of blood group O has a child of group O. The father could be of group:✓ A or B or O
Q10. A child has blood group O and the mother is also group O. What could be the father's blood group?✓ A or B (heterozygous) or O
Q11. In a marriage between a universal-donor mother and a universal-recipient father, the possible blood groups of children are:✓ 50% A and 50% B
Q12. In humans, blue eye colour is recessive to brown. A brown-eyed boy has a blue-eyed mother. The father's eye phenotype could be:✓ Brown eye
Q13. The degree of effect produced by a given genotype under a given set of environmental conditions is called:✓ Expressivity
Q14. A single gene having more than one phenotypic effect on apparently unrelated traits is said to show:✓ Pleiotropy
Q15. Which inherited human disease is an example of pleiotropy?✓ Lesch-Nyhan syndrome
Q16. In a hypothetical diploid species a locus has two codominant alleles A and B. How many different phenotypes are possible?✓ 3
Q17. The inheritance of yellow coat colour in mice is a classic example of:✓ Lethal genes
Q18. If two related organisms have regions of conserved synteny, it means their orthologous genes are:✓ In the same order on the chromosome
Q19. A normal functional allele of a gene that predominates in a wild population is called the:✓ Wild-type allele
Q20. Match each inheritance pattern with its example and select the correct option.✓ A-iv, B-i, C-ii, D-iii