Genetics/Inheritance Flashcards
What is the genotype of an organism?
The term given to the genetic constitution of an organism (e.g. TT)
What is the phenotype of an organism?
The term given to the expression of this genetic constitution and its interaction with the environment. In other words, the observable characteristics of an organism (e.g. tongue-roller)
What is an allele?
A version of a gene
What is meant by a dominant allele?
An allele which is always expressed in the phenotype, no matter what the other allele is
What is meant by a recessive allele?
An allele which is only expressed in the phenotype if no other allele is present
What is meant by a co-dominant allele?
An allele which is expressed jointly with another allele
What is meant by heterozygous?
Two alleles for the same gene which are different (e.g. Bb)
What is meant by homozygous?
Two alleles for the same gene which are the same (e.g. BB or bb)
What is meant by diploid?
A diploid organism has two of each chromosome
What is meant by haploid?
A haploid organism or cell (e.g. a gamete) has one of each chromosome
What is a locus?
The location of a gene on a particular chromosome
What is a sex-linked allele?
An allele which appears on the X and Y chromosome. The phenotype varies depending on the gender as the organism will get one, two or no copies depending on gender
What are multiple alleles?
Genes which have more than two versions e.g. blood groups A,B, and O
What is epistasis?
The interaction of the genes at two or more loci, resulting in one gene or allele masking the phenotypic expression of the other genes or alleles
What is the statistical analysis used to see if phenotypic ratios are as expected?
Chi Squared
