Question 1

A plant with genotype $Tt$ (where $T$ is tall and $t$ is short) is crossed with another plant with genotype $Tt$. What is the expected phenotypic ratio of tall to short plants in the offspring?

Accepted Answer

3:1

Question 2

Which of the following best describes the law of segregation?

Accepted Answer

Each individual has two alleles for each gene, and these alleles separate during gamete formation so that each gamete receives only one allele.

Question 3

A woman who is heterozygous for an autosomal recessive disorder ($Aa$) marries a man who is homozygous dominant ($AA$). What is the probability that their child will be affected by the disorder?

Accepted Answer

$0$

Question 4

In a dihybrid cross between two individuals heterozygous for both traits ($RrYy 	imes RrYy$), what is the expected phenotypic ratio in the F2 generation, assuming independent assortment?

Accepted Answer

9:3:3:1

Question 5

Which of the following scenarios best illustrates the rule of multiplication in genetics?

Accepted Answer

Calculating the probability of getting a child with genotype $aa$ from two heterozygous parents ($Aa 	imes Aa$).

Question 6

A pedigree shows a trait that appears in every generation and affects both males and females equally. What is the most likely mode of inheritance?

Accepted Answer

Autosomal dominant

Question 7

If a true-breeding purple-flowered pea plant is crossed with a true-breeding white-flowered pea plant, and all the F1 offspring have purple flowers, what can be concluded about the purple flower allele?

Accepted Answer

It is a dominant allele.

Question 8

Which of the following best defines a locus?

Accepted Answer

A specific location on a chromosome where a gene is found.

Question 9

A couple has a child with a rare autosomal recessive disorder. Neither parent shows symptoms. What are the most likely genotypes of the parents?

Accepted Answer

Both are heterozygous carriers.

Question 10

Which of the following is an example of a monohybrid cross?

Accepted Answer

Crossing $Aa 	imes aa$

Question 11

If two individuals with the genotype $Bb$ (where $B$ is brown eyes and $b$ is blue eyes) have children, what is the probability that their first two children will both have blue eyes? (Assume blue eyes are recessive.)

Accepted Answer

$\frac{1}{16}$

Question 12

Which of the following statements about a hybrid organism is correct?

Accepted Answer

It is the result of a cross between two true-breeding parents with different traits.

Question 13

A Punnett square is used to:

Accepted Answer

Predict the possible genotypes and phenotypes of offspring from a genetic cross.

Question 14

Which of the following best describes a phenotype?

Accepted Answer

The observable physical or physiological traits of an organism.

Question 15

In a family pedigree, a trait skips generations and appears only when both parents are unaffected carriers. What is the most likely inheritance pattern?

Accepted Answer

Autosomal recessive

Question 16

Which of the following is an example of the rule of addition in genetics?

Accepted Answer

Calculating the probability of getting either $Aa$ or $aA$ genotype from a cross between $Aa 	imes Aa$.

Question 17

If a gene has two alleles, $A$ and $a$, and an individual is $Aa$, which term best describes this genotype?

Accepted Answer

Heterozygous

Question 18

Which generation is produced by crossing two individuals from the F1 generation?

Accepted Answer

F2 generation

Question 19

A geneticist is studying two genes located on different chromosomes. According to the law of independent assortment, what is expected during gamete formation?

Accepted Answer

The alleles of the two genes will assort independently into gametes.

Question 20

A man with genotype $Dd$ (where $D$ is dominant and $d$ is recessive) marries a woman with genotype $dd$. What is the probability that their child will be homozygous recessive?

Accepted Answer

$\frac{1}{2}$

Patterns of Inheritance: Key Terms and Concepts

Study Guide - Practice Questions

Study Guide - Flashcards