17 inherited change Flashcards
define gene
a section of DNA that codes for a specific polypeptide
define genotype
the genetic constitution of an organism and all the alleles that an organism possesses
define gene pool
all alleles within an interbreeding population
define population
all the individuals of the same species that occupy the same area at the same time
what 3 things can alleles be?
dominant, recessive or codominant
define multiple alleles
more than 2 alleles for the same gene
define locus
different alleles for the same gene are found at the same position on the homologous chromosome
define homozygous
two copies of the same gene being the same allele
define heterozygous
if the two copies of a gene are different alleles
define dominant allele
always expressed in the phenotype
define recessive allele
only expressed when the genotype is homozygous
define codominant allele
equally expressed in the phenotype
define diploid
cells with two copies of a gene
what kind of cells are haploid?
gametes
what offspring phenotype ratio is expected for monohybrid inheritance?
3:1
what offspring phenotype ratio is expected for dihybrid inheritance?
9:3:3:1
what offspring phenotype ratio is expected from codominant inheritance?
1:2:1
what offspring phenotype ratio is expected from epistasis?
9 : 4 : 3 or 15 : 1 or 9 : 7
(ratio adds up to 16 but isn’t 9:3:3:1)
what is allelic frequency?
the number of times an allele occurs in a gene pool
what does the hardy weinberg principle predict?
the allelic frequencies (of a particular gene) from one generation to the next will remain constant
what 5 things have to be in place for the hardy weinberg principle to be true?
- no migration
- no gene mutations
- no selection for or against a particular allele
- large population
- mating should be random
