7.1 Inheritance Flashcards
(9 cards)
What is a genotype
Genetic constitution of an organism
What is a phenotype
Expression of the genetic constitution and its interaction with the environment
What are alleles and How do they arise
Variations of a gene (same locus)
Arise by mutation (changes in DNA base sequence)
Diffrent types of alleles
Dominant
Recessive
Co-dominant : both alleles are expressed
What do monohybrid and dihybrid crosses show
Mono-inheritance of 1 phentypic characteristic coded by 1 gene
Di-inheritance of 2 phenotypic characteristics coded by 2 genes
How does autosomal linkage affect inheritance
2 genes located on same autosome (non-sex chromosome)
Alleles inherited together
But crossing over can create new combination of alleles
If genes are close together they are less lightly to be split by crossing over
What is epistasis
Interaction of non-linked genes where one masks/suppresses the expression of the other
Why is observed frequency’s diffrent from expected
Fertilisation/fusion of gametes is random
Autosomal linkage (sex-linkage)
Small sample size
Some genotypes may be lethal
What stats test is used
Chi^2 (observed vs expected)
