Sets 1-2 Flashcards
what is natural selection ?
individuals with traits that will survive and reproduce in a given environment
what was the goal for fox domestication experiment?
for tameness
when and who did the fox experiment ?
Dmitry Belyaev in 1950s
who is gregor mendel?
an augustinian monk and plant breeder who experiment with garden peas
what is pure breeding lines?
offspring that have the same traits as parents everytime they are crossed
what is a phenotype
observable characteristic also know as a trait
what is a genotype ?
the genetic info of an individual
what is an allele?
different forms of a single gene
what is an example of an allele
brown or blue eyes
what is polymorhpic?
a gene that may have several alleles that normally occur in a population
ex. the gene eye pigment and within the population theres green,brown,blue,hazel eyes
what is monomorphic?
a gene that has only one allele which is normal within a population
ex. a cheetahs skin coat will be the same with rare
what is a monohybrid cross?
a cross between two organism that differ in trait (ex colour)
what is mendels law of segregation ?
it is when two alleles are seperated at gamete formation and come together at random for each parent during fertilization
what is the PHENOTYPIC for simple dominant/ressesive traits (TRAIT THAT IS SHOWN) ratio for a monohybrid cross?
3:1
if you were given a yellow pea to determine it genotype what are you crossing it with an why
a homozygous recessive yy as if it a yellow pea with YY or Yy, the Yy x yy will give us both a yellow and green pea meanwhile YY x yy will give us only yellow peas and will allow us to tell what the genotype of the original pea is
what is the law of product ?
the probability of two or more independent events occurring at the same time can be calculated by multiplying the probability of each individual event eg getting a 6 on a dice three time
what is the genotypic ratio for monohybrid crossses
1:2:1
what is the law of sum
the probability of getting two or more events that cannot occur at the same time is the sum of their individual probabilities eg wanting to get either a 2 or 3 or 5 in a 1 time die roll
what are dihybrids?
different alleles of two genes eg green or yellow & round or wrinkled
what is the phenotypic ratio for dihybrid crosses?
9:3:3:1
what is the law of independent assortment?
explains how different alleles of different genes behave
what genotype should be used for test crosses?
homozygous ressesive
what is multiple alleles
more than 2 alleles for a gene
how is blood type made ?
a gene encodes an enzyme that adds a terminal sugar (A or B or nothing) onto polymer chain
what does blood type A look like
iA iA or iA i or iA Hh
what does blood type B look like
iB iB or iB i or iB Hh
what does blood type AB
iA iB
what can blood type O look like ?
i i or iA hh or iB hh
what is the dominance series with blood types
iA=iB> i
what is co-dominance ?
contributions from both alleles are visible in the phenotype
what is the genotype from incomplete dominence and co-dominance?
1:2:1
what is the phenotype from incomplete dominence and co-dominance)?
1:2:1
what is the different between co dominance and incomplete dominance
just how they appear , co dominance is like both colour visibly showing
incomplete dominance is where there is an intermediate colour that is not like the parents
what is incomplete dominance?
a heterozygote with an intermediate phenotype
red+ white = pink
what is pleiotropy?
one gene influences multiple phenotypic traits
what is an example of pleiotropy?
Sickle cell
what is sickle cell caused by ?
a single mutation in the HBB gene
what are lethal alleles ?
a dominant or recessive allele that can kill the organism
what is the phenotypic ratio for recessive lethal alleles ?
the phenotypic ratio is 2:1 as in the 3:1 the 1 ressesive one will die.
what are additive genes ?
two or more genes influence 1 trait
what is epistasis ?
one gene will hide the effect of another gene
what is the dominant epistasis phenotypic ratio?
12:3:1
what is the recessive epistasis phenotypic ratio?
9:3:4
what is recessive epistatsis
where the ressesive homoygous GG ee will always be visible no matter what the dominant is
what is dominant epistastis
where a homo or heterozygous with a dominant C (CC or Cc) will mask the other allele no matter if it homo or hetero zygous Cc GG or CC gg or Cc Gg etc
can two blood type o parents have a type a child ?
yes bc they can have recessive epistasis where they have and A polymer but its is being hiding and not being expressed
what is complementary gene action ?
two or more genes that can work together in the same biochemical pathway that produce a trait
what is an example of gene complementry action
a type a blood type gene ex. IA Hh
what is a heterogeneous trait ?
a mutation at any one out of number of genes can give us the same penotype , two parent can lack the trait but i will show in the next generation.
what is a complementry gene action phenotypic ratio ?
9:7
what is complementation testing ?
testing to see if 1 or 2 genes can produce of certain phenotype or have the mutation
what is complex traits ?
a trait which is determined by many genes or by the interaction between genes and the enviroment
what is multifactorial inheritance ?
a new phenotype coming from two or more genes or the genes or eniviroment
what is penetrance ?
a percentage of the population with a particular genotype , that demontates an expected trait CAN BE INCOMPLETE , not all in population have the expected trait or COMPLETE all have the trait
what is expressivity ?
the degree or intensity of a particular genotype that is expressed in a phenotype in a population, NOT PREDICTABLE, like skin tone different shades of brown like olive dark, born, light degrees of skin tone constant , same colour varible, multiple
what are sex linked traits ?
genes on the X or Y chromosomes
what are sex limitied traits ?
limited to only one sex male or female
what are sex influced
in both sexes , on the autosomal traits , expression may be differeent so like bald head on men but it doesnt happen to women
tempurature,light altitude environment can affect the expression of a phenotype etc skin colour
what is conditional lethality ?
where an allele is lethal under certain conditions
what is permissive vs restrictiive
permissive they live restrictive they die
what is true breeding ?
they are genetically & phenotypically identical to both parents
With multiple alleles how do you figure out dominance series?
by crossing using homozygotes
