Chapter 2

Question 1

What happens during Mitosis?

Answer 1

1 progenitor cell divides into 2 genetically identical daughter cells
-2n–>2n

Question 2

What type of cell does mitosis happen in?

Answer 2

somatic cells

Question 3

What happens in meiosis?

Answer 3

1 progenitor cell divides into 4 daughter cells, in which only have half of the gene content of the mother cell
-2n–>1n

Question 4

What type of cell does meiosis happen in?

Answer 4

germline cells: eggs, sperm/pollen

Question 5

What is a controlled genetic cross?

Answer 5

a cross where the parental genotypes are known

Question 6

What is a characteristic of using pure-breeding strains in experimental crosses?

Answer 6

they consistently produce the same phenotype even after many generations of crossing

Question 7

What are discrete traits?

Answer 7

when each single trait has two forms(dichotomous) that are easily distinguishable and that have no intermediate forms

Question 8

what is a reciprocal cross?

Answer 8

made when the same crosses are made but from different sexes

Question 9

what is a test cross?

Answer 9

made when a plant is crossed with the recessive pure-breeding parent, which can help determine the genetic make-up (genotype) of individuals

Question 10

What ratio of gametes is found in a diploid (homozygous recessive) monohybrid (heterozygous) testcross?

Answer 10

1:1

Question 11

What is the trait shown by the F1 offspring?

Answer 11

the dominant phenotype

Question 12

What is the trait that is not apparent in the F1 offspring?

Answer 12

the recessive phenotype

Question 13

What did mendel find when the F1 pea plants were crossed?

Answer 13

75% had the dominant trait, but the recessive trait reappeared in the other 25%

Question 14

what is a monohybrid cross?

Answer 14

when an F1 individual is crossed with another F1 individual(both are heterozygous)

Question 15

what was the phenotypic ratio of the F2 phenotypes/when a diploid monohybrid is selfed?

Answer 15

3:1

Question 16

What was the theory of particulate inheritance?

Answer 16

Mendel’s theory that plants carry two discrete hereditary units for each trait; a plant receives one of these in the egg and the second in pollen

Question 17

What genotypic ratio is predicted for the F2 generation produced by the monohybrid cross?

Answer 17

1:2:1

Question 18

What is the Law of Segregation?

Answer 18

alleles separate during meiosis

Question 19

What is Autosomal inheritance?

Answer 19

refers to transmission of traits carried on autosomes, chromosomes found in both males and females

Question 20

What is a pedigree?

Answer 20

a family tree, and is a way of tracing the inheritance of traits in humans and some animals

Question 21

What trait is commonly expressed in every generation?

Answer 21

autosomal dominant traits

Question 22

What are 5 ways of identifying autosomal dominant inheritance?

Answer 22

1. Affected individuals have at
   least one affected parents.
2. Both males and females are
   affected in equal numbers, and
   both sexes transmit the trait
   equally.
3. When only one parent is affected,
   about half the offspring will be affected.
4. Two unaffected parents will have
   unaffected children.
5. Two affected parents can have
   unaffected children.

Question 23

What are 5 ways to identify autosomal recessive inheritance?

Answer 23

1. Affected individuals are often
   born to unaffected parents.
2. Both males and females are
   affected in equal numbers, and
   both transmit the trait equally.
3. When both parents have the
   trait, all children will have the trait.
4. The trait is often not seen in every
   generation.
5. If the trait is rare in the population,
   then the unaffected parents of affected
   individuals are more likely to be related.

Question 24

what is chromosomal sex?

Answer 24

the presence
of sex chromosomes associated
with males and females

Question 25

what is phenotypic sex?

Answer 25

he internal
and external morphology
found in each sex

Question 26

In mammals, what is sex determined by?

Answer 26

the presence or absence of the Y chromosome

Question 27

Which gender is heterogametic sex in mammals, and which is homogametic sex?

Answer 27

males are heterogametic sex and females are homogametic

Question 28

What are 4 characteristics found in a X-linked recessive pedigree?

Answer 28

1. More males than females
   have the traits because of
   hemizygosity
2. If a male with the recessive trait
   mates with a homozygous
   dominant female, all progeny will
   have the dominant phenotype
3. Mating of male with the
   recessive trait with a carrier
   female will produce offspring of
   which half will have the trait
4. Mating of a homozygous recessive female
   with an unaffected male produces males
   with the trait and carrier females

Question 29

What are 3 characteristics found in a X-linked dominant pedigree?

Answer 29

1. Affected males mated to a normal
   female (homozygous recessive) transmit the trait to all daughters but none of the sons
2. The trait will be equally frequent in males and females, but some crosses are biased toward having affected female offspring.
3. Heterozygous females mated with a normal male passes on the trait to half the progeny of each sex.

Question 30

Characteristics of Y-linked inheritance?

Answer 30

-the y chromosome is transmitted in a male-to-male fashion
-pseudoautosomal because their inheritance resembles autosomal inheritance in that there are two copes→one x and one y

Question 31

What was The Blending Theory of Inheritance?

Answer 31

previous thought that viewed traits in offspring as a mixture of the parental traits

Question 32

what is monohybrid another word for?

Answer 32

heterozygous

Question 33

what is diploid another name for?

Answer 33

homozygous recessive

Question 34

What is wild-type another name for?

Answer 34

homozygous dominant