Chapter 12

Question 1

Early botanists produced

Answer 1

Hybrids

Question 2

Hybrids

Answer 2

crosses between two true-breeding plants

Question 3

In the 1900’s,

Answer 3

Mendel studied pea plants

Question 4

List 4 reasons of why Mendel studied pea plants

Answer 4

1. Hybrids could be produced
2. Many “varieties” were
   available
3. They were small and easy
   to grow
4. They can self-fertilize or
   be cross-fertilized

Question 5

Mendel produced ___ -___ ___ for many traits

Answer 5

True Breeding Strains

Question 6

cross true-breeding strains having alternate
forms of a trait to produce ___

Answer 6

Hybris

Question 7

Mendel produced true-breeding pea strains
for _ diffrent traits,each trait with _ alternate forms

Answer 7

7,2

Question 8

Explain Mendel’s Monohybrid Cross

Answer 8

studies 2 forms of a trait

Question 9

Describe Mendel’s F1 Generation

Answer 9

“hybrid”
offspring produced by crossing 2 true-breeding
strains

Question 10

Monohybrid Cross, Dominant ( explain )

Answer 10

the form of each trait seen in the
F1 plants (e.g, blue flower color)

Question 11

Monohybrid Cross, Recessive

Answer 11

the form of the trait that
“disappeared” in the F1 plants (e.g., white
flower color)

Question 12

gene

Answer 12

section of a chromosome that codes for a
particular trait

Question 13

alleles

Answer 13

alternate forms genes that occur on
homologous chromosomes

Question 14

homozygous

Answer 14

having all of the same allele

Question 15

heterozygous

Answer 15

having different alleles

Question 16

Genotype

Answer 16

the alleles carried by an individual

Question 17

RR is ___ ___

Answer 17

heterozygous dominant

Question 18

Rr is ___

Answer 18

heterozygous

Question 19

rr is __

Answer 19

homozygous recessive

Question 20

phenotype is also known as

Answer 20

outside appearance

Question 21

If an individual is heterozygous, half of its gametes
will have the

Answer 21

dominant allele, other half is recessive

Question 22

If an individual is homozygous, all of its gametes
will have the

Answer 22

same form of the allel

Question 23

Punnett squares
can be used to

Answer 23

predict offspring genotypes

Question 24

In a monohybrid cross, one
parent is

Answer 24

homozygous recessive, and one is homozygous dominant

Question 25

F1s are all

Answer 25

heterozygous

Question 26

F2s are

Answer 26

25% homozygous
dominant
50% heterozygous
25% homozygous
recessive

Question 27

Dihybrid cross examines

Answer 27

2 separate traits in a
single cross (e.g., RRYY x rryy)

Question 28

Alleles assort

Answer 28

independently

Question 29

Testcross is used to determine
the

Answer 29

the genotype of an
individual with the dominant
phenotype (is it
homozygous dominant or
heterozygous?)

Question 30

Mendel’s model of inheritance assumes that

Answer 30

-each trait is controlled by a single gene
-each gene has only 2 alleles
-there is a clear dominant-recessive
relationship between the alleles

Question 31

Polygenic
inheritance is where

Answer 31

multiple genes
control phenotype

Question 32

Polygenic inheritance is also known as

Answer 32

quantitative

Question 33

Pleiotropy

Answer 33

one allele has more than one
effect on the phenotype