Simple Genetics

What is the significance of the dominant allele in a heterozygous genotype?

• It has no effect on the phenotype.

• It determines the phenotype by masking the effect of the recessive allele.

• It is always expressed in the phenotype regardless of the recessive allele.

• It can only be expressed in a homozygous genotype.

What does heterozygous mean?

• Having two identical alleles for a particular gene (e.g., AA)

• Having two different alleles for a particular gene (e.g., Aa)

• Having one allele for a gene and no allele for another gene

• Having multiple alleles for a single gene

What is the difference between phenotype and genotype?

• Genotype refers to the observable traits of an organism, while phenotype refers to the genetic makeup.

• Genotype refers to the genetic makeup of an organism, while phenotype refers to the observable traits resulting from that genotype.

• Phenotype and genotype are the same and can be used interchangeably.

• Phenotype refers to the DNA sequence, while genotype refers to the physical appearance.

What are genotypes?

• The physical appearance of an organism

• The genetic makeup of an organism, represented by the combination of alleles (e.g., Aa, DD, bB, yy)

• The environmental factors affecting an organism

• The process of cell division in organisms

What does homozygous mean?

• Having two identical alleles for a particular gene (e.g., AA or aa).

• Having two different alleles for a particular gene (e.g., Aa).

• Having one allele for a gene and no allele for another gene.

• Having multiple alleles for a single gene.

What is homozygous recessive?

• Having two copies of a dominant allele (e.g., AA or BB).

• Having one copy of a dominant allele and one copy of a recessive allele (e.g., Aa or Bb).

• Having two copies of a recessive allele (e.g., xx or qq).

• Having two different alleles (e.g., AB or XY).

What is the expected genotypic ratio for a monohybrid cross?

• 1:2:1 (AA:Aa:aa)

• 3:1 (AA:Aa:aa)

• 1:1 (AA:aa)

• 2:1 (AA:Aa)

What is a dominant allele?

• An allele that is only expressed in homozygous genotypes.

• An allele that expresses its trait in the phenotype even when only one copy is present in a heterozygous genotype.

• An allele that is always recessive in its expression.

• An allele that can only be inherited from one parent.

What is a recessive allele?

• An allele that expresses its trait in the phenotype only when two copies are present in a homozygous recessive genotype.

• An allele that always expresses its trait in the phenotype regardless of the genotype.

• An allele that can mask the expression of a dominant allele in the phenotype.

• An allele that is only found in the heterozygous genotype.

What is a Punnett square?

• A diagram used to predict the outcome of a genetic cross by showing the possible combinations of alleles from the parents.

• A tool for measuring the height of plants in genetics studies.

• A method for calculating the age of fossils in paleontology.

• A chart used to track the migration patterns of animals.