chapter 11 Flashcards
what is a gene?
discrete region of DNA
what are alleles?
different versions of a gene
what are chromosomes?
double stranded DNA molecules
what is a genotype?
combination of alleles (RrYy/ RRYY/rryy/etc.)
homozygote is?
2 identical alleles
heterozygote is?
2 different alleles
what is a phenotype?
physical differences between alleles.
who is the father of modern genetics?
Gregor Mendel
who was Gregor Mendal before he learned about genetics?
he was a monk and later became an abbot
what plant did Mendal study ?
Pea plants
how many traits did he examine?
7 different traits
what type of crossing over did Mendal do?
artificial pollination
what type of breeding did Mendal use?
he only used true breeding
what type of crosses did he use?
monohybrid and dihybrid crosses.
what is monohybrid?
2 individuals that differ from 1 trait
What is dihybrid?
2 individuals that differ from 2 traits
Monohybrid always get what ratio?
3:1 phenotypic ratio
Dihybrid always get what type of ratio?
9:3:3:1 phenotypic ratio
what is a testcross?
a cross used to determine the genotype of an individual with dominant phenotypes
what is a punnet square?
visual representation of a mathematical process
traits are determined by what?
discrete genes
what is Mendel’s first law?
Law of segregation of alleles
what is the law of segregation of alleles mean?
when gametes form the pairs separate: while each gamete carries 1 version for each trait
what is Mendel’s 2nd law?
Law of independent assortment
what is the Law of independent assortment?
different traits are inherited independently
what is codominance?
when heterozygote has phenotypes of both homozygotes.
what is incomplete dominance?
heterozygote has intermediate phenotype
what’s another name for incomplete dominance?
semi dominance
what is overdominance?
heterozygotes has neither phenotypes of homozygotes.
what’s another name for overdominance?
heterozygote advantage
multiple alleles mean what?
more than 2 alleles within a population
