Quiz 3

Question 1

gene

Answer 1

inherited factor that determines a character

Question 2

allele

Answer 2

different variations of a gene

Question 3

locus

Answer 3

place on a chromosome where an allele is found

Question 4

genotype

Answer 4

the set of alleles an organism has

Question 5

phenotype

Answer 5

manifestation/appearance

Question 6

homozygous

Answer 6

diploid organism with two identical alleles at a given locus

Question 7

heterozygous

Answer 7

diploid organism with two different alleles at a given locus

Question 8

Mendel’s Conclusions

Answer 8

1. each F1 plant must possess two alleles encoding a character
2. the two alleles in each plant separate and each gamete gets only one
3. two alleles of a plant separate with equal probability
4. concept of dominance

Question 9

concept of dominance

Answer 9

trait that remained unchanged in F1=dominant
trait that disappears in F1=recessive

Question 10

Principle of Segregation

Answer 10

two alleles from each parent separate and each gamete gets only one
each allele has a 50% of being found in any of the 4 gametes produced

Question 11

Multiplication rule

Answer 11

the probability of 2+ independent events occurring together is calculated by multiplying their probabilities
“and”=multiplication

Question 12

Addition Rule

Answer 12

the probability of any one of two or more mutually exclusive events is calculated by adding their probabilities
“or”=addition

Question 13

Principle of independent assortment

Answer 13

when two alleles separate their separation is independent of the separation of other alleles at other loci

Question 14

Branch Diagram Method

Answer 14

Break cross down into two monohybrid crosses
use multiplication rule to figure out total probability

Question 15

test cross

Answer 15

one individual of unknown genotype is crossed with another individual with a homozygous recessive genotype
this reveals the genotype of the unknown

Question 16

Chi-Square

Answer 16

goodness-of-fit test
used to predict the probability that genes are expressed following Mendel

Question 17

Lethal Alleles

Answer 17

Extreme of genetic variation where phenotypes are bad
cause death, usually in early development

Question 18

dominant

Answer 18

heterozygote is the same as one parent

Question 19

incomplete dominance

Answer 19

heterozygote as an intermediate
range of different phenotypes
intermediate is highest ratio and doesn’t match parent

Question 20

codominance

Answer 20

heterozygote exhibits both phenotypes

Question 21

epistasis

Answer 21

one gene hides/masks the effect of another gene at a different locus

Question 22

recessive epistasis

Answer 22

presence of two recessive alleles inhibits the expression of allele at a different locus
Ex. Bombay phenotype

Question 23

dominant epistasis

Answer 23

presence of a single copy of an allele can inhibit the expression of an allele at a different locus

Question 24

epistatic gene

Answer 24

gene that does the masking

Question 25

hypostatic gene

Answer 25

gene whose effect is masked

Question 26

What is CFTR?

Answer 26

Cystic fibrosis transmembrane conducted regulator

Question 27

What is the function of CFTR?

Answer 27

maintains fluidity of mucus and other secretions forms channels that transport Cl ions through the cell membrane, this controls the movement of water

Question 28

How does CFTR cause disease?

Answer 28

failed ion transport leads to failed movement of water, producing an abnormally thick and sticky mucus - clogs lungs -obstructs pancreas - blocks bile ducts in liver - blacks vas deferens

Question 29

pleiotropy

Answer 29

single gene impacts many characteristics

Question 30

penetrance

Answer 30

percentage of individuals with a particular genotype that expressed the expected phenotype

Question 31

incomplete penetrance

Answer 31

genotype does not produce expected phenotype

Question 32

expressivity

Answer 32

degree to which a character is expressed (range)

Question 33

sex-linked

Answer 33

genes on X or Y chromosome ex. colorblindness

Question 34

sex-influenced

Answer 34

genes on autosomes are more readily expressed in one sex ex. bearded goats (females don't fully express)

Question 35

sex-limited

Answer 35

autosomal genes expressed in only one sex ex. rooster feathering

Question 36

genomic imprinting

Answer 36

genes whose expression is influenced by sex of transmitting parent