exam 3 ppt 1

Question 1

definition of genetic variation

Answer 1

genetic differences that exist among individuals in a population at a particular point in time

Question 2

definition of genotype

Answer 2

the genetic makeup of a cell or organism- what combination of alleles is present

Question 3

exps of genotypes

Answer 3

PP, Pp, pp

Question 4

definition of phenotype

Answer 4

an individual’s observable characteristics (i.e. height, eye color, weight, color blindness, etc)

Question 5

exp of phenotype

Answer 5

purple vs. white flowers

Question 6

definition of alleles

Answer 6

the different forms of any gene

Question 7

what do alleles correspond to?

Answer 7

changes in the DNA sequence

Question 8

do we all have the same genes?

Answer 8

yes, we all have the same genes, but just different alleles of them

Question 9

how many copies of every gene do we have? why?

Answer 9

we have 2 copies of every gene, because we’re diploid

Question 10

what does it mean if an individual is homozygous?

Answer 10

it means that both alleles are the same (either homozygous dominant or recessive)

Question 11

what does it mean if an individual is heterozygous?

Answer 11

it means that their two alleles for a gene are different

Question 12

exp of a homozygous genotype

Answer 12

BB or bb

Question 13

exp of a heterozygous genotype

Answer 13

Bb

Question 14

who is Gregor Mendel?

Answer 14

he is the father of modern genetics

Question 15

what did Mendel study?

Answer 15

he studied the results of hybridization, where two different varieties of pea plants were interbred

Question 16

what plants did Mendel work with?

Answer 16

pea plants

Question 17

what strains did the pea plants have that Mendel worked with?

Answer 17

these strains were true breeding (pure line)

Question 18

what does it mean if a strain is true breeding (pure line)?

Answer 18

it means that every offspring is identical to the parent

Question 19

what were the two different types of fertilization involved in pea plant hybridization?

Answer 19

self-fertilization and cross-fertilization

Question 20

explain the self-fertilization in pea plant hybridization

Answer 20

the male organs of the plant produce pollen grains which produce sperm cells, and the female organ receives the pollen

Question 21

explain the cross-fertilization in pea plant hybridization

Answer 21

plant with greed seeds crossed with plant with yellow seeds; collect pollen from one individual and transfer it to the female organ of a flower on another plant whose male organs have been removed

Question 22

definition of a trait

Answer 22

variation in physical appearance of a heritable characteristic = phenotype

Question 23

what is the trait called that appears in the F1?

Answer 23

the dominant trakt

Question 24

what is the trait called that does NOT appear in the F1?

Answer 24

recessive

Question 25

what were the results of Mendel’s single-trait (monohybrid) cross with the round vs. wrinkled seed trait?

Answer 25

in the parental generation, male parents produce round seeds while female parents produce wrinkled seeds; the F1 generation all produce round seeds (all heterozygote)->. plant, grow, and allow to self-fertilize; the F2 generation produce a 3:1 phenotypic ratio with 75% round seeds, 25% wrinkled seeds

Question 26

when does segregation occur in Mendel’s monohybrid cross of round vs. wrinkled seeds?

Answer 26

segregation occurs in the F2 generation at a ratio of 3:1

Question 27

list of all of Mendel’s monohybrid crosses

Answer 27

seed shape, seed color, pod shape, pod color, flower color, flower and pod position, stem length

Question 28

what are yellow and green seeds the result of?

Answer 28

they’re the result of two different alleles of the same gene

Question 29

what does true breeding mean for the cross for seed color?

Answer 29

it means that these lines are homozygous

Question 30

what are the genotypes used in the seed color Mendel experiment?

Answer 30

yellow= YY, green= yy (same trait, same letter)

Question 31

is the dominant allele capitalized or lower case when written out?

Answer 31

the dominant allele is a capital letter, the recessive allele is a lowercase letter

Question 32

what results in the F1 generation of the monohybrid cross for seed color?

Answer 32

the trait that appears, yellow seeds, is dominant and green seeds are recessive; due to crossing two true-breeders in the parental generation, all children in F1 generation are heterozygote (Yy) but still exhibit yellow seed color

Question 33

what does the principle of segregation talk about?

Answer 33

it discusses the separation of alleles into different gametes

Question 34

what happens to the alleles in a heterozygote individual?

Answer 34

in a heterozygote, both alleles are present and expressed, but observe dominant phenotype

Question 35

explanation of Mendel’s parental cross between two homozygotes

Answer 35

homozygous father (RR) and homozygous mother (rr) -> make gametes that go into punnett square- male is R, female is r; the F1 generation results in all Rr offspring (heterozygotes) and all round seeds (dominant phenotype)

Question 36

explanation of Mendel’s parental cross between two heterozygotes

Answer 36

this explains the F2 generation; heterozygous mother from F1 (Rr) with heterozygous father from F1 (Rr), both have gametes of R and r; offspring in F2 generation have genotypes of 25% RR, 50% Rr, and 25% rr and have phenotypes of 75% round (dominant), 25% wrinkled

Question 37

what are the phenotypic and genotypic ratios always seen in F2 generations?

Answer 37

1:2:1 genotypic ratio, 3:1 phenotypic ratio

Question 38

how does segregation occur in the breeding of heterozygous plants?

Answer 38

Aa plants produce gametes A and a, 50% each = segregation

Question 39

when does the segregation of alleles occur?

Answer 39

this occurs during meiosis

Question 40

what does segregation reflect (a part of meiosis)?

Answer 40

segregation reflects the separation of homologous chromosomes during anaphase I of meiosis

Question 41

when did Mendel discover the principle of segregation?

Answer 41

he discovered this in his monohybrid cross with true breeding parents

Question 42

what can you use punnett squares to explain?

Answer 42

you can use them to explain how gametes form (equally possible to produce all gamete combinations)

Question 43

what characteristic are the principles of transmission genetics?

Answer 43

these principles are statistical

Question 44

what can the principles of transmission genetics be stated as?

Answer 44

they can be stated as probabilities

Question 45

what must the probability of any genotype be between?

Answer 45

it must be between 0 and 1 (add up to 100%)

Question 46

what is the probability of getting the genotype aa as a result in a cross between AA x Aa?

Answer 46

0

Question 47

what is the probability of getting the genotype aa in a cross between Aa x Aa?

Answer 47

1/4 (25%)

Question 48

is each genetic event unique?

Answer 48

yes

Question 49

what are the expected progeny (resulting genotypes and phenotypes) from a cross of an AA plant with an Aa plant?

Answer 49

1:1 genotypic ratio (1/2 AA, 1/2 Aa); 1:0 phenotypic ratio (all have dominant phenotype)

Question 50

what are the gametes that each parent produces in a cross between AA x Aa?

Answer 50

1/2 AA, 1/2 Aa

Question 51

how does a genotype become a phenotype?

Answer 51

through DNA -> RNA -> protein