Mendelian& Non mendelian Genetics Flashcards
alleles
The different forms of a gene. Y and y are different alleles of the gene that determines seed color. Alleles occupy the same locus, or position, on chromosomes.
autosome
Any chromosome that is NOT a sex chromosome. humans have 23 pairs of autosomes
Allosomes/sex chromosomes
Humans have one pair of sex chromosomes
co-dominant alleles
Two different alleles at a locus are responsible for different phenotypes, and both alleles affect the phenotype of the heterozygote.
dominant trait
A trait expressed in the phenotype if the dominant allele is present in the genotype.
F1 generation
Offspring of a cross between the parental (P1) generation.
F2 generation
Offspring of a cross involving the F1 generation.
genotype
The genetic constitution of an organims with respect to a trait. For a single trait on an autosome, an individual can be homozygous for the dominant trait, heterozygous, or homozygous for the recessive trait. Yellow seeds are dominant, but yellow seeded plants could have a genotype of either YY or Yy.
heterozygous
differing alleles for a trait in an individual such as Rr.
homologous chromosomes
The pair of chromosomes in a diploid individual that have the same overall genetic content. One member of each homologous pair of chromosomes inherited from each parent.
homozygous
Both alleles for a trait are the same in an individual. They can be homozygous dominant (YY), or homozygous recessive (yy).
Incomplete dominance
Intermediate phenotype in F1, parental phenotypes reappear in F2.
Mendel’s law of independent assortment of alleles
Alleles of different genes are assorted independently of one another during the formation of gametes.
Mendel’s law of segregation
Alleles segregate from one another during the formation of gametes.
monohybrid cross
a cross in which only one trait is being studied.
