CGP Inheritance Flashcards
Define gene
A sequence of bases on a DNA molecule that codes for a protein which results in a characteristic (e.g. gene for eye colour)
Define allele.
One of a number of forms of genes.
Define genotype.
The genetic constitution of an organism - the alleles an organism has (eg BB, Bb).
Define phenotype.
The expression of the genetic constitution and its interaction with the environment - the characteristics eg brown eyes.
Define dominant.
An allele whose characteristic appears in the phenotype even when there’s only one copy.
Define recessive.
An allele whose characteristic appears in the phenotype of two copies are present.
Define codominant.
Alleles that are both expressed in the phenotype - neither one is recessive.
Define locus.
The fixed position of a gene on a chromosome.
Define homozygote.
An organism that carries two copies of the same allele (eg BB or bb).
Define heterozygote.
An organism that carries two different alleles eg Bb.
Define carrier.
A person carrying an allele which is not expressed in the phenotype but that can be passed on to offspring.
What type of chromosomes do females have?
Two X chromosomes.
What types of chromosomes do males have?
One X and one Y.
What is an autosome?
Any chromosome that isn’t a sex chromosome.
Why are genes on the same autosome said to be linked?
Because they’re on the same autosome, they’ll stay together during the independent assortment of chromosomes in meiosis I, and their alleles will be passed onto offspring together.
