genetic terminology Flashcards
(11 cards)
What is a genotype?
The genetic constitution of an organism - for a gene this refers to the allele present.
What is a phenotype?
The appearance of a characteristic due to the expression of the genotype and its interaction with the environment.
What are alleles?
Different forms of the same gene; they may be dominant, codominant, or recessive.
What is a dominant allele?
Always expressed in the phenotype.
What is a recessive allele?
Only expressed when the genotype is homozygous recessive.
What is a codominant allele?
Both alleles are expressed in the phenotype.
What is a locus?
The position of a gene on a chromosome.
What is homozygous?
Refers to both alleles being the same.
What is heterozygous?
Refers to both alleles differing.
What happens when there are multiple alleles?
More than two alleles for a gene; however, only two can be present in the genotype.
What is a sex linked gene?
Where the gene is carried on only one type of sex linked chromosome.
