chapter 5 genetics and heredity Flashcards
why did mendel use pea plants
they use sexual repr. he forced them to cross polinate
differnt forms of a gene
allels
what does the principal of dominance state
some alleles are dominant while others are recessive
what does a dominat trait look like and when is it expressed
capital letter if 1 copy is inherited
when does a recessive allele show
when the dominat trait isnt present
what does a recessive trait look like and when is it expressed
lower case letter and if 2 copies are inherited
which trait do heterozygous pairs get
dominant
what does the law of segregation state
copies seperate from eachother during gamete formation
both alleles are the same form
homozygous
what does a homozygous dominat look like (t)
TT
what does a homozygous recessive look like (t)
tt
alleles are differnt forms
heterozygous
what does a dominat heterozygous look like (t)
Tt
what are genotypes
the letters (genetic makeup)
what are phenotypes
words(physical descriptions)
what is codominance
Heterozygote displays BOTH alleles at same time
3 phenotypes
what is incomplete dominace
Heterozygote is a BLEND of both parent’s alleles
3 phenotypes
what are multiple alleles
Several different phenotype possibilities
what are polygenic traits
Involves 2 or more genes influencing the expression of one trait
what are sex-linked traits
Genes are located on the sex chromosomes
23rd pair, usually inherited on the “X”
what are the 2 gender symbols in a pedigree
o=female
square= male
what does shading mean in a pedigree and what does half shading mean
shading means its affected, half shading means its a carrier
what does it mean if theres shading in every generation
its dominate
how do u decide if its autosomal or sex linked
if males and females are shaded, its autosomal
