Question 1

Which of the following best describes Mendel’s First Law (Law of Segregation)?

Accepted Answer

Pairs of alleles separate during gamete formation, and each gamete receives one allele randomly.

Question 2

A pea plant with genotype Rr is self-fertilized. What is the expected genotypic ratio in the F2 generation?

Accepted Answer

$$1 \; RR : 2 \; Rr : 1 \; rr$$

Question 3

In a dihybrid cross between two heterozygous pea plants (YyRr x YyRr), what is the expected phenotypic ratio in the F2 generation?

Accepted Answer

$$9:3:3:1$$

Question 4

Which experimental innovation was NOT a part of Mendel’s methodology?

Accepted Answer

Blending inheritance to explain results

Question 5

A test cross is performed between a plant with genotype Bb and a homozygous recessive plant (bb). What is the expected phenotypic ratio among the offspring?

Accepted Answer

$$1:1$$

Question 6

Which stage of meiosis explains Mendel’s Law of Segregation?

Accepted Answer

Anaphase I

Question 7

If a woman is heterozygous for an autosomal recessive condition (Aa), what proportion of her gametes will carry the dominant allele?

Accepted Answer

$$50\%$$

Question 8

Which of the following statements about reciprocal crosses is TRUE?

Accepted Answer

They are used to determine if a trait is sex-linked.

Question 9

In Mendel’s experiments, what was the significance of using pure-breeding strains?

Accepted Answer

They ensured no variation in phenotype over generations, allowing clear interpretation of inheritance patterns.

Question 10

Which of the following best explains the 3:1 phenotypic ratio observed in Mendel’s F2 generation from a monohybrid cross?

Accepted Answer

The dominant allele masks the recessive allele in heterozygotes.

Question 11

Which process during meiosis is responsible for the independent assortment of alleles for different genes?

Accepted Answer

Random alignment of homologous chromosomes during Metaphase I

Question 12

A plant with genotype GG is crossed with a plant with genotype Gg. What is the expected genotypic ratio among the offspring?

Accepted Answer

$$1 \; GG : 1 \; Gg$$

Question 13

Which of the following is a direct result of crossing-over during meiosis?

Accepted Answer

Recombination of alleles between homologous chromosomes

Question 14

In a dihybrid test cross (YyRr x yyrr), what is the expected phenotypic ratio among the offspring if the genes assort independently?

Accepted Answer

$$1:1:1:1$$

Question 15

Which of the following best describes the concept of 'particulate inheritance' as concluded by Mendel?

Accepted Answer

Traits are determined by discrete units (genes) that are inherited unchanged from each parent.

Question 16

A true-breeding tall pea plant (TT) is crossed with a true-breeding short pea plant (tt). What will be the phenotype of the F1 generation?

Accepted Answer

All tall

Question 17

Which of the following is NOT a source of genetic variation in meiosis?

Accepted Answer

Replication of DNA during S phase

Question 18

If a plant with genotype RrYy is crossed with a plant with genotype rryy, what proportion of the offspring will have round, yellow seeds (dominant for both traits)?

Accepted Answer

$$1/4$$

Question 19

Which of the following statements about Mendel’s Second Law (Law of Independent Assortment) is correct?

Accepted Answer

It applies only to genes located on different chromosomes or far apart on the same chromosome.

Question 20

A biologist performs a reciprocal cross and observes identical results in both directions. What can be inferred from this observation?

Accepted Answer

The trait is likely not sex-linked.

Mendelian Genetics I: Foundations of Transmission Genetics

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