TRB PG Assistant - Mendelian principles, alleles, multiple alleles One Line Questions & Answers

1. In a monohybrid cross between two heterozygous parents (Aa x Aa), what is the expected genotypic ratio of the offspring? — 1:2:1

2. In a monohybrid cross between two heterozygous parents (Aa x Aa), what is the expected phenotypic ratio of the offspring, assuming complete dominance? — 3:1

3. In a dihybrid cross between two individuals heterozygous for two traits (e.g., AaBb x AaBb), assuming independent assortment and complete dominance, what is the expected phenotypic ratio of the offspring? — 9:3:3:1

4. Which of the following scenarios best demonstrates Mendel's Law of Segregation? — A cross between two heterozygous individuals for a single trait

5. The Law of Segregation applies to the inheritance of alleles for: — A single gene

6. What does the term 'multiple alleles' refer to? — A single gene having many different alleles

7. The position of a gene on a chromosome is called its: — Locus

8. What is the term for a gene that influences the expression of another gene? — Epistatic gene

9. The concept of 'alleles' is fundamental to understanding genetic variation within a population because: — Different alleles at a locus lead to different traits.

10. What type of alleles are responsible for the different blood types A, B, AB, and O in humans? — Multiple alleles

11. If a trait is determined by multiple alleles, how many alleles for that trait can an individual diploid organism possess at any given time? — Only two alleles

12. What is the term for a gene that is located on a sex chromosome? — Sex-linked gene

13. Which of the following is an example of a trait exhibiting complete dominance? — Flower color in pea plants (purple dominant to white)

14. Who is considered the father of modern genetics? — Gregor Mendel

15. In snapdragons, crossing a red-flowered plant (RR) with a white-flowered plant (WW) produces pink-flowered offspring (RW). This is an example of: — Incomplete dominance

16. The gene for sickle-cell anemia is an example of: — Pleiotropy

17. Gregor Mendel's work laid the foundation for genetics by establishing principles of heredity based on: — Particulate inheritance and discrete units of heredity

18. A cross between two individuals that are heterozygous for a single trait is called a: — Monohybrid cross

19. The allele whose effect is masked by a dominant allele in a heterozygous individual is called: — Recessive allele

20. In codominance, such as in the ABO blood system (alleles I^A and I^B), both traits are: — Expressed and neither masks the other

21. What term did Mendel use to describe the hereditary units that are passed from parents to offspring? — Factors

22. In Mendelian genetics, what term describes different versions of the same gene? — Alleles

23. What is the term for the observable physical characteristics of an organism, determined by its genotype and environmental influences? — Phenotype

24. What is the term for an organism that has two identical alleles for a particular trait? — Homozygous

25. An organism with two different alleles for a particular trait is described as: — Heterozygous

26. In a test cross, an individual with a dominant phenotype is crossed with an individual that is: — Homozygous recessive

27. In the ABO blood group system, the alleles are I^A, I^B, and i. Which allele is recessive? — i

28. A person with blood type AB has which combination of alleles? — I^A I^B

29. A person with blood type O has which genotype? — ii

30. What is the term for a situation where both alleles in a heterozygous individual contribute to the phenotype? — Codominance

31. Which of Mendel's principles states that during gamete formation, the alleles for each gene segregate from each other so that each gamete carries only one allele for each gene? — Law of Segregation

32. Which of Mendel's principles states that alleles of different genes assort independently of one another during gamete formation? — Law of Independent Assortment

33. Which of Mendel's principles explains how traits for different genes are inherited independently, provided they are on different chromosomes? — Law of Independent Assortment

34. Which term describes the interaction between different genes where one gene masks the expression of another gene at a different locus? — Epistasis

35. What is the primary difference between Mendelian inheritance and non-Mendelian inheritance patterns? — Non-Mendelian inheritance includes codominance, incomplete dominance, and multiple alleles.

36. Pleiotropy refers to the phenomenon where: — One gene controls multiple traits

37. A dihybrid cross involves the inheritance of: — Two traits

38. The Law of Independent Assortment is best illustrated by crosses involving: — Two traits (dihybrid cross)

39. If a father has blood type A and a mother has blood type B, what are the possible blood types of their children? — A, B, AB, or O

40. Mendel's experiments were primarily conducted on which plant species? — Pea plants (Pisum sativum)

41. The genetic makeup of an organism, represented by the combination of alleles it possesses, is called its: — Genotype

42. If a gene has three or more alleles in a population, this is an example of: — Multiple alleles

43. In a heterozygous individual, the allele that is expressed and masks the effect of the other allele is called: —

44. In the ABO blood group system, alleles I^A and I^B are: — Codominant to each other

45. Which human blood group system is a classic example of multiple alleles? — ABO blood group system

46. If gene A is epistatic to gene B, then the phenotype of gene A will be expressed regardless of: — The genotype of gene B

47. What is a test cross used for? — To determine the genotype of an individual showing a dominant phenotype

48. In the context of alleles, the term 'heterozygous' means an individual has: — Two different alleles for a trait

Mendelian principles, alleles, multiple alleles - One Line Questions