maintanence of genetic variation

Question 1

distinct genetic trait

Answer 1

a trait that shows a limited number of distinct categories

e.g sex

Question 2

phenotype

Answer 2

outward, physical manifestation of an organisms genetic code

Question 3

character

Answer 3

a heritable feature ( e.g flower colour )

Question 4

trait

Answer 4

a varient of each character ( e.g purple or white where flower colour is the character )

Question 5

Hardy-Weinberg principle

Answer 5

the genetic variation in a population will remain constant from one generation ( under certain conditions )

• new allele frequencies are the same as the
  old allele frequencies
• the rarer allele doesnt get increasingly rare
  over time
• the frequency of the allele has nothing to
  do with whether its dominant or recessive

If our observed frequencies match our expected frequencies we say that our populations is in Hardy Weinberg Equilibrium

Question 6

assumptions : genotype frequiencies stable over time

Answer 6

• infinate population size
• random mating
• no mutations
• no selection
• equal allele frequencies among males and
  females

Question 7

quantitative ( = polygenic ) traits

Answer 7

a characteristic, such as height or skin color, that is influenced by two or more genes

• controlled by several loci, each with small effect ( phenotypes are often continous )
• the substitution of one allele for another is often undetectable
• environment often has a substantial influence
• different genotypes can produce the same phenotype

Question 8

phenotypic plasticity

Answer 8

when a genotype expresses differnent phenotypes, depending on the environment

Question 9

genotype environment interaction

Answer 9

if different genotypes have different kinds of phenotypic plasticity