Untitled Flashcards Set

Trait

Physical characteristic of an organism, e.g., hair or eye color.

Gene

Portion of DNA that determines a trait, e.g., gene for hair or eye color.

Alleles

Different versions of genes for the same trait, e.g., for the gene for eye color, there are blue and brown eyes.

Phenotype

The variation of a trait that shows in an individual, e.g., blue eyes.

Genotype

The combination of alleles that an individual has, e.g., (1,1), (1,2), (2,2).

Dominant

The allele that will always show when present, e.g., purple flower.

Recessive

The allele that will only show if no dominant allele is present, e.g., white flower, white mouse.

Homozygous

A genotype in which the two alleles are the same.

Heterozygous

A genotype in which the two alleles are different, e.g., (1,2).

What are alleles?

Different versions of genes for the same trait.

What does phenotype refer to?

The variation of a trait that shows in an individual.

How are traits inherited across sexually reproducing organisms?

Traits are usually inherited independently from one another.

What is a dominant allele?

An allele that will always show when present.

Fill in the blank: Sexually reproducing organisms have two factors that determine each trait (inherited characteristics) __________ from each parent.

one from each parent.

Genes from a trait can occur in different versions ______

called alleles. 

If there are two variations of a trait in a population and there are two alleles (1 and 2) then there can be _____ combinations of alleles (1,1) (1,2) and (2,2).

three

Idea 3

Traits are _______ inherited independently from one another.

USUALLY