Q: In a trihybrid cross ($AaBbCc \times AaBbCc$), what is the probability of obtaining an offspring with genotype $Aabbcc$?

$(1/2) \times (1/4) \times (1/4) = 1/32$

Question 1

Which of the following best describes Mendel's Law of Segregation?

Accepted Answer

During gamete formation, paired unit factors separate randomly so each gamete receives one factor from each pair.

Question 2

In a monohybrid cross between two heterozygous pea plants for seed shape ($Ss 	imes Ss$), what is the expected phenotypic ratio in the F2 generation?

Accepted Answer

$3:1$ (round:wrinkled)

Question 3

A test cross is performed between a purple-flowered plant of unknown genotype and a white-flowered plant ($pp$). If all offspring are purple, what is the genotype of the unknown parent?

Accepted Answer

Homozygous dominant ($PP$)

Question 4

Which of the following statements is TRUE regarding Mendel’s Law of Independent Assortment?

Accepted Answer

Genes for different traits are sorted separately from one another during gamete formation.

Question 5

In a dihybrid cross ($YyRr 	imes YyRr$), what is the expected phenotypic ratio for the F2 generation?

Accepted Answer

$9:3:3:1$

Question 6

If a pea plant with genotype $Ss$ is self-fertilized, what is the probability that an offspring will be homozygous recessive ($ss$)?

Accepted Answer

$1/4$

Question 7

A plant with genotype $AaBb$ is crossed with another $AaBb$ plant. What is the probability that an offspring will have genotype $AABB$?

Accepted Answer

$1/16$

Question 8

Which of the following is a key observation from Mendel’s monohybrid crosses?

Accepted Answer

The trait not shown in the F1 reappeared in the F2 in about 25% of the offspring.

Question 9

In a dihybrid cross between $YyRr$ plants, what is the probability of obtaining an offspring with genotype $yyrr$?

Accepted Answer

$1/16$

Question 10

Which of the following best explains why the wrinkled seed trait reappears in the F2 generation after disappearing in the F1 generation?

Accepted Answer

The wrinkled trait is recessive and only appears when both alleles are recessive in F2.

Question 11

If you cross $AABb$ with $Aabb$, what is the probability that the offspring will have genotype $AaBb$?

Accepted Answer

$1/4$

Question 12

Which statement about reciprocal crosses in Mendel’s experiments is correct?

Accepted Answer

Reciprocal crosses produced the same results, indicating that inheritance was not sex-dependent.

Question 13

In a trihybrid cross ($AaBbCc 	imes AaBbCc$), what is the probability of obtaining an offspring with genotype $Aabbcc$?

Accepted Answer

$(1/2) 	imes (1/4) 	imes (1/4) = 1/32$

Question 14

Which of the following is NOT a principle derived from Mendel’s experiments?

Accepted Answer

Law of Blending Inheritance

Question 15

A plant with genotype $Yy$ (yellow seed, yellow dominant over green) is self-fertilized. What fraction of the offspring will have green seeds?

Accepted Answer

$1/4$

Question 16

In a dihybrid cross ($GgWw 	imes GgWw$), what is the probability of obtaining an offspring with genotype $GGww$?

Accepted Answer

$(1/4) 	imes (1/4) = 1/16$

Question 17

Which of the following best describes a heterozygous genotype?

Accepted Answer

Two different alleles for a trait

Question 18

If a plant with genotype $Ss$ is crossed with a plant with genotype $ss$, what is the expected genotypic ratio of the offspring?

Accepted Answer

$1 Ss : 1 ss$

Question 19

In a dihybrid cross, what is the probability of obtaining an offspring that is heterozygous for both traits ($YyRr$) from parents $YyRr 	imes YyRr$?

Accepted Answer

$1/4$

Question 20

Which of the following is a real-world application of Mendel’s Law of Independent Assortment?

Accepted Answer

Predicting the inheritance of two unlinked genetic diseases in humans.

Monohybrid and Dihybrid Inheritance: Mendelian Principles and Genetic Crosses

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