Complementation

Question 1

there can be many ___ at the same ___ and many ___ acting on the same ___

Answer 1

alleles, locus

loci, trait

Question 2

+ means

Answer 2

wild-type

Question 3

different alleles are indicated how?

Answer 3

superscripts

Question 4

2 homozygous individuals w/ different recessive alleles at the same locus will…

Answer 4

have heterozygous offspring with a recessive phenotype

Question 5

often mutations at different loci can give….

Answer 5

identical or nearly identical phenotypes

Question 6

suppose you have 2 recessive mutant strains w/ same phenotype. they could be due to…

Answer 6

mutations at the same locus

2 different loci acting on the same trait

Question 7

double heterozygote offspring

Answer 7

2 individuals with recessive homozygotes at different loci can fix each other

normal phenotype

Question 8

how to tell if the mutation is caused by one locus or different loci?

Answer 8

cross them

Question 9

offspring of the mutant phenotype caused by 2 mutations at the same locus…

Answer 9

will have the same mutant phenotype

Question 10

offspring of the mutant phenotype caused by mutations at 2 different loci…

Answer 10

will be wild type

Question 11

complementation

Answer 11

when 2 recessive homozygotes produce wild-type offspring

Question 12

when complementation occurs how many loci are involved?

Answer 12

2

Question 13

noncomplementation is when the offspring…

Answer 13

look like the recessive parents

Question 14

alleles at the same locus are called

Answer 14

complementation group

Question 15

complementation group

Answer 15

mutations that don’t complement eachother

mutants lying within the same cistron (noncomplementation group)

Question 16

mutant screen asks

Answer 16

how many different loci are involved when all these lines have the same phenotype?

Question 17

how to do a mutant screen?

Answer 17

mutate many flies (make grandchildren homozygous by inbreeding)

keep looking for same recessive phenotype

Question 18

pleiotropy

Answer 18

multiple traits caused by the same gene

one mutation w/ multiple effects

Question 19

examples of pleiotropy

Answer 19

Waardenburg Syndrome

Nail-Patella Syndrome

Cystic Fibrosis

Question 20

incomplete penetrance

Answer 20

does the effect show up at all?

Question 21

variable expressivity

Answer 21

how much does it show up? is it mild or severe?

Question 22

epistasis

Answer 22

the effect of alleles of one gene may depend on the alleles of another gene

multiple loci working together to control a trait

ex. mouse fur color

Question 23

exception to complementation

Answer 23

interallelic complementation