Ch 14: Mendelein Genetics

Question 1

heredity

Answer 1

passing of traits to offspring by parents

Question 2

blending hypothesis

Answer 2

genetic material from 2 parents blends together

Question 3

particulate hypothesis

Answer 3

parent pass on discrete heritable units (genes)

Question 4

advantages of pea plants

Answer 4

• many distinct heritable features
• mating can be controlled
• each plant has both sperm/egg producing organs
• cross pollination

Question 5

stamen

Answer 5

sperm producing organ

Question 6

carpel

Answer 6

egg producing organ

Question 7

cross pollination

Answer 7

fertilization between different plants

Question 8

P generation

Answer 8

true breeding parents

Question 9

F1 generation

Answer 9

hybrid offspring of P gen

Question 10

F2 generation

Answer 10

when F1 individuals self pollinate

Question 11

hybridization

Answer 11

mating of 2 contrasting, true breeding varieties

Question 12

law of segregation

Answer 12

P = pure white & purple
F1 = all purple
F2 = 3 purple & 1 white

3:1 ratio

Question 13

what id Mendel call a “heritable factor”

Answer 13

gene

Question 14

3:1 inheritance pattern

Answer 14

4 related concepts

Question 15

Concept #1

Answer 15

alternative versions of genes account for variations in inherited characters

• diff genes have same location (locus) in homologous chromosome

Question 16

Concept #2

Answer 16

for each gene an organism inherits 2 alleles; one from each parent

homozygous & heterozygous

Question 17

what generation is homozygous

Answer 17

P gen

Question 18

what generation is heterozygous

Answer 18

F1 hybrids

Question 19

Concept #3

Answer 19

if 2 alleles at a locus differ, the dominant one determines the organism’s appearance & the recessive one has no effect on appearance

F1 had purple flowers bc purple is dominant

Question 20

Concept #4

Answer 20

2 alleles for a heritable character separate (segregate) during meiosis & end up in diff gametes

Question 21

what is concept #4 also known as

Answer 21

law of segregation

Question 22

homozygous

Answer 22

2 identical alleles

Question 23

heterozygous

Answer 23

2 alleles are different
- not true breeding

Question 24

phenotype

Answer 24

organism’s physical appearence

Question 25

genotype

Answer 25

organism's genetic makeup

Question 26

Genotype ratio in F1

Answer 26

1 : 2 : 1 PP : Pp : pp

Question 27

testcross

Answer 27

to tell the genotype of an individual with the dominant phenotype

Question 28

what is the dominant individual crossed with

Answer 28

homozygous recessive (pp)

Question 29

what does it mean if the offspring has recessive phenotype (testcross)

Answer 29

mystery parent is heterozygous

Question 30

law of independent assortment cross

Answer 30

crossing 2 true-bred parents differing in 2 characteristics produces dihybrids in F1

Question 31

what is the F1 generation in law of independent assortment

Answer 31

heterozygous for both characters

Question 32

what does a dihybrid cross between F1 dihybrids determine

Answer 32

whether 2 characters are transmitted to offspring as a package or independently

Question 33

dihybrid cross ratio

Answer 33

9 : 3 : 3 : 1 9 = homozygous dominant 3 = heterozygous 3 = heterozygous 1 homozygous recessive

Question 34

law of independent assortment

Answer 34

each pair of alleles segregates independently of other pairs of alleles during gamete formation

Question 35

what does law of independent assortment apply to

Answer 35

genes on different, nonhomologous chromosomes

Question 36

genes located near each other on the same chromosome

Answer 36

tend to be inherited together

Question 37

when does inheritance deviate from Mendelian patterns

Answer 37

- alleles are not completely dominant or recessive - gene has more than 2 alleles - gene produces multiple phenotypes

Question 38

complete dominance

Answer 38

phenotypes of heterozygote & dominant homozygote are identical

Question 39

codominance

Answer 39

2 dominant alleles affect the phenotype in separate, distinguishable ways

Question 40

incomplete dominance

Answer 40

the phenotype of F1 hybrids is somewhere between the phenotype of the 2 parental varieties

Question 41

most genes exist in populations in ____ allelic forms

Answer 41

more than 2

Question 42

pleiotropy

Answer 42

multiple phenotypic effects

Question 43

epistasis

Answer 43

traits determined by 2 or more genes

Question 44

a gene at one locus alters...

Answer 44

the phenotypic expression of a gene at a second locus

Question 45

polygenic inheritance

Answer 45

additive effect of 2 or more genes on a single phenotype

Question 46

norm of reaction

Answer 46

phenotypic range of a genotype influenced by the environment

Question 47

multifactorial

Answer 47

genetic & environmental factors collectively influence phenotype

Question 48

pedigree

Answer 48

family tree that describes the interrelationships of parents & children across generations