Genetics Questions

Objective questions

What is the law of segregation?

A) Genes are located on chromosomes. B) Alleles separate during gamete formation. C) Two alleles for each trait are inherited from each parent. D) Alleles are exchanged during crossing over.

Correct Answer: B) Alleles separate during gamete formation.

Which of the following represents a homozygous genotype?

A) Aa B) AA C) Ab D) Bb

Correct Answer: B) AA

What is a phenotype?

A) The genetic makeup of an organism. B) The observable traits of an organism. C) The environment's influence on genes. D) The location of a gene on a chromosome.

Correct Answer: B) The observable traits of an organism.

A cross between two heterozygous individuals (Aa) for a trait governed by simple dominance will result in which genotype ratio?

A) 1:1 B) 1:2:1 C) 3:1 D) 9:3:3:1

Correct Answer: B) 1:2:1

Which of the following traits did Mendel not study?

A) Seed shape B) Flower color C) Pod size D) Plant height

Correct Answer: C) Pod size

In a monohybrid cross, the recessive trait will appear in what percentage of the offspring in the F2 generation?

A) 25% B) 50% C) 75% D) 100%

Correct Answer: A) 25%

What does the term "allele" refer to in genetics?

A) A different form of a gene. B) The observable traits of an organism. C) The chromosomes in a cell. D) The dominant trait in a population.

Correct Answer: A) A different form of a gene.

What does a test cross determine?

A) If an individual is heterozygous or homozygous. B) The number of offspring produced. C) The location of a gene. D) The likelihood of crossing over occurring.

Correct Answer: A) If an individual is heterozygous or homozygous.

The principle of independent assortment states that:

A) Alleles for different traits segregate independently of each other. B) All traits are inherited together. C) Alleles for one gene influence the alleles for another gene. D) Genetic information from the father is dominant over the mother’s.

Correct Answer: A) Alleles for different traits segregate independently of each other.

If a true-breeding yellow pea plant is crossed with a true-breeding green pea plant, and yellow is dominant, what will the offspring be?

A) All green B) All yellow C) Half green, half yellow D) 3 yellow, 1 green

Correct Answer: B) All yellow

What is incomplete dominance?

A) A dominant allele masks a recessive allele. B) Both alleles contribute equally to the phenotype. C) The heterozygote has an intermediate phenotype. D) Alleles blend together in the phenotype.

Correct Answer: C) The heterozygote has an intermediate phenotype.

Which of the following is an example of incomplete dominance?

A) Red and white flowers producing pink offspring. B) Black and white chickens producing a black and white speckled chicken. C) A and B blood types both being expressed. D) Pea plants with both tall and short traits.

Correct Answer: A) Red and white flowers producing pink offspring.

In a dihybrid cross between two heterozygous individuals (AaBb), what is the expected phenotypic ratio?

A) 1:2:1 B) 3:1 C) 9:3:3:1 D) 1:1:1:1

Correct Answer: C) 9:3:3:1

Which of the following is a polygenic trait?

A) Pea plant height B) Blood type C) Human skin color D) Purple flower color in pea plants

Correct Answer: C) Human skin color

A man with type AB blood and a woman with type O blood have a child. What is the probability that the child will have type B blood?

A) 0% B) 25% C) 50% D) 100%

Correct Answer: C) 50%

Which of the following describes co-dominance?

A) One allele is completely dominant over the other. B) Neither allele is completely dominant; both alleles are expressed equally. C) The phenotype is a blend of both alleles. D) One gene influences the expression of another gene.

Correct Answer: B) Neither allele is completely dominant; both alleles are expressed equally.

Which of the following is an example of co-dominance?

A) Red and white flowers producing pink offspring. B) A person with type AB blood. C) Pea plants producing either purple or white flowers. D) A person with type O blood.

Correct Answer: B) A person with type AB blood.

In co-dominance, if a red cow is crossed with a white cow, the offspring will likely:

A) Be red B) Be white C) Have red and white patches D) Be a blend of red and white (pink)

Correct Answer: C) Have red and white patches

In blood type inheritance, which blood types are co-dominant?

A) A and O B) A and B C) O and B D) AB and O

Correct Answer: B) A and B

In a cross between a black chicken and a white chicken that shows co-dominance, what would the offspring look like?

A) Black B) White C) Black and white D) Gray

Correct Answer: C) Black and white

Theory Questions

An albino man marries a normal woman (homozygous) for skin pigmentation). What is the probability the couple could have an albino child?
Gene for albinism = aa Gene for the Normal pigmentation = AA

Explain how blood group can be used to determine the paternity of a child.

List 4 characteristics that can passed from parent to offspring in man

State five application of genetics in medicine and agriculture

What is a chromosome?