Genetics Quiz

What is the definition of "genetics"?

• The study of genes and their variation in organisms

• The study of observable traits like color and size

• The study of the environment's effect on organisms

• The study of recessive traits in plants only

What is an allele?

• A variant form of a gene

• The genetic makeup of an organism

• The physical appearance of an organism

• A gene that is always expressed

What does the term "phenotype" refer to?

• The genetic makeup of an organism

• The observable traits or characteristics of an organism

• A genetic trait that is expressed only in homozygotes

• A variant form of a gene

What is a homozygote?

• An organism with two different alleles for a particular gene

• An organism that expresses only dominant traits

• An organism with two identical alleles for a particular gene

• An organism that can only pass on recessive traits

What is a recessive trait?

• A trait expressed when at least one dominant allele is present

• A trait that is always expressed in homozygotes

• A trait expressed only when two copies of the recessive allele are present

• A trait that can never be passed on by heterozygotes

Which of the following best describes a "dominant trait"?

• A trait that is only expressed when two recessive alleles are present

• A trait that is expressed even if only one dominant allele is present

• A trait that can only be expressed in heterozygotes

• A trait that is always masked by a recessive trait

What is a heterozygote?

• An organism that has two identical alleles for a particular gene

• An organism that has two different alleles for a particular gene

• An organism with one dominant allele and one recessive allele, but only expresses the dominant trait

• An organism that does not carry any alleles for a specific trait

What does "genotype" refer to in genetics?

• The observable characteristics of an organism

• The specific sequence of alleles an organism has for a particular gene

• The study of heredity in humans only

• The physical traits expressed by the environment

What is the relationship between genotype and phenotype?

• Genotype determines the physical appearance of an organism, which is its phenotype

• Phenotype refers to the alleles an organism inherits

• Phenotype is unrelated to genotype and is only influenced by the environment

• Genotype and phenotype have no connection

Which of the following is an example of a "recessive trait"?

• A person with brown eyes (if brown eyes are dominant)

• A person who can roll their tongue (if tongue-rolling is dominant)

• A person with blue eyes (if blue eyes are recessive)

• A person with a widow's peak (if widow's peak is recessive)