Inheritance Flashcards
what is a genotype?
genetic constitution of an organism
what is a phenotype?
expression of this genetic constitution and its interaction with the environment
what kinds of alleles are there?
- dominant
- recessive
- codominant
what are genes?
a gene is a sequence of bases on a DNA molecules that codes for a protein which results in a characteristic
what are alleles?
different versions of the same gene
what is a locus?
- fixed position that the gene is found on and allele
what are dominant alleles?
- always expressed in the phenotype, even when there’s only one copy of it(Aa)
what are recessive alleles?
- only expressed in the phenotypes if there are two copies present (aa)
what are codominant alleles?
- both alleles are equally expressed in the phenotypes
what is homozygous?
- an organism carries two copies of the same allele
= homozygous at that locus
what is heterozygous?
- if an organisms carries two different alleles
what is sex-linkage?
- alleles that code for the characteristics are located on a sex chromosome
what is autosomal linkage?
- any chromosome which is not a sex chromosome
- two or more genes are on the same autosomal chromosme
what is epistasis?
- may different genes can control the same characteristics
- this can be due to the allele of one gene masks the expression of alleles of other genes
what is chi squared test?
- statistical test (difference between observed and expected results)
what criteria is needed to use the chi squared test?
- sample size is large enough(over20)
- data uses discrete categories
- raw counts used (not percentages)
what is the formula for chi squared?
x2 = sum of (observed - expected)2 divided by expected
what is the critical value for chi squared?
- 0.05
when is the null hypothesis accepted?
- value obtained is greater than or equal to the critical value
- difference is likely due to chance
