Genetics & Heredity Quiz

A segment of DNA found on a chromosome that codes for a specific trait.

Different versions of a gene that result in variations of a trait. For example, blue and brown eye color are different alleles for the eye color gene.

The physical characteristics of an organism, like hair color or height, that are determined by the alleles we inherit.

The combination of alleles an individual possesses for a specific trait, represented by letters like "AA" or "Aa" for example.

A change in the DNA sequence, which can introduce new alleles. These can be beneficial, harmful, or neutral in their effects.

The study of how traits are passed from parents to offspring, involving genes, chromosomes, and the mechanisms of inheritance.

The allele that masks the other allele in a heterozygote. Only one copy of the dominant allele is required to express the trait.

The allele that is masked by the dominant allele. Two copies of the recessive allele are required to express the trait.

The genetic makeup of an organism that describes the combination of alleles for a specific trait.

The observable physical characteristics or traits of an organism. These are determined by the genotype and can be influenced by the environment.

A genotype where both alleles for a particular trait are the same. Example: TT (both alleles are dominant) or tt (both alleles are recessive).

A genotype where the two alleles for a particular trait are different. Example: Tt (one allele is dominant, and the other is recessive).

The likelihood of a specific event happening.

During meiosis, the two alleles for each trait separate and each gamete (sperm or egg) receives only one allele from the pair.

A diagram used to predict the probability of different offspring genotypes and phenotypes based on the genotypes of the parents.

A cross involving only one trait.

Different genes are passed on independently of each other.

A cross involving two traits.

A situation where neither allele is completely dominant.

Many genes, with more than two alleles, control a single characteristic.

Two dominant alleles are fully expressed at the same time, resulting in a third phenotype. The alleles do not blend together, but both are visible in the offspring.

Erminette chickens exhibit codominance. They have black (BB) and white (WW) alleles, resulting in a third phenotype called Erminette (BW), where both black and white feathers are present.

Human blood types A, B, AB, and O are determined by multiple alleles. A and B are codominant, while O is recessive.

The Rh factor in blood is determined by a separate gene from the ABO blood type. Rh positive is dominant, while Rh negative is recessive.

A heterozygous Type A man (IAi) and a heterozygous Type B woman (IBi) can have children with blood types A, B, AB, and O because of the different combinations of their alleles.

In sex-linked traits, genes are located on the X chromosome. Males have only one X chromosome and are more likely to inherit recessive traits. For example, color blindness is an X-linked recessive trait.