Heredity Flashcards
what is a gene?
stretch of DNA that encodes for traits located on chromosomes (category)
what is an allele?
different versions of the same gene (specific outcome within the category of trait)
how many alleles are there usually per gene? what is the exception?
2
when an X-linked gene is on a male (because there would only be one allele)
what is a geneotype?
lists the alleles of an individual
ex: BB or bb
what is a phenotype?
describes the trait
ex: colorblindness/ freckles
what does homozygous mean?
genotype has two of the same alleles for a gene
what does heterozygous mean?
genotype has two different alleles for a gene
what are dominant alleles?
capital letters
determine if trait is present
can hide recessive alleles
what are recessive alleles?
lowercase letters
only determine trait if dominant allele doesn’t
can be hidden
using B and/or b write a homozygous dominant genotype
BB
using B and/or b write a homozygous recessive genotype
bb
using B and/or b write a heterozygous genotype
Bb
what is a Punnett square?
used to determine probability of genotype/phenotype
what are the three degrees of dominance?
complete dominance
incomplete dominance
codominance
what is complete dominance? what does this mean for the phenotype? ex?
dominant completely hides recessive
phenotype is the same for homozygous dominant and heterozygous
ex: red or white flowers
