Chapter 9 Genetics

Question 1

What does “true breeding” mean?

Answer 1

Repeated self-fertilization always yields the same phenotype

Question 2

A fly has small wings (vv) and a black body (bb). What is it’s phenotype?

Answer 2

black body, small wings

Question 3

If we did a cross ad expected to see 25% of each possible phenotype and we instead saw that 90% were of two of the types and only 10% were the other two, what can we tell about these genes?

Answer 3

They are linked

Question 4

If you mate a hairy plant with a smooth plant and obtain a slightly hairy plant, this an example of ______?

Answer 4

Incomplete Dominance

Question 5

If the distance between genes P and Q is 30 units, the distance between P and Y is 20 units, and the distance between Q and Y is 10 units, which gene is between the other two?

Answer 5

Y

Question 6

IF two alleles are both expressed in the presence of each other, they are ______?

Answer 6

Codominant

Question 7

What is polygenic inheritance?

Answer 7

One trait, many genes

Question 8

Genetics

Answer 8

The study of how traits are passed down from generation to generation

Question 9

True or False - A Punnett square will always tell you exactly how many offspring of each type to expect from a cross.

Answer 9

False - it provides the probability of a particular outcome

Question 10

The Generation resulting from mating the P Generation

Answer 10

F1

Question 11

You are crossing GgHh x gghh. What goes on the sides of the Punnett Square?

Answer 11

One side GH, Gh, gH, gh; other side: gh

Question 12

Principle of Independent Assortment

Answer 12

Alleles of different genes assort randomly with respect to each other.

Question 13

Which more reliably characterizes a probabilistic process like inheritance; large samples or small samples?

Answer 13

Large Samples

Question 14

Statistical Test

Answer 14

A method of determining if a particular experimental result matches a Punnett square prediction closely enough to be attributed to chance.

Question 15

When you see a trait which varies continuously from very small to very large within a population, this is most likely a ______?

Answer 15

Quantitative (polygenic) traits

Question 16

In a cross where we expected to see equal representation of all four possible phenotypes, we observed; 5 rough purple, 45 rough red, 45 smooth purple, 5 smooth purple. Which are the parental types?

Answer 16

Rough red and smooth purple

Question 17

In a cross where we expected to see equal representation of all four possible phenotypes, we observed:
5 rough purple
45 rough red
45 smooth purple
5 smooth purple
What is the recombination frequency?

Answer 17

10%

Question 18

How many copies of each gene on the x chromosome does a male human have?

Answer 18

One

Question 19

Is an individual with a “tt” genotype homozygous or heterozygous?

Answer 19

Homozygous

Question 20

Why would you do a test cross?

Answer 20

To determine the genotype of an unknown which has a dominant phenotype

Question 21

If the chance of being tall was 1/3 and the chance of being green-eyes is 1/3, what is the chance of being tall OR green-eyed?

Answer 21

2/3

Question 22

How can you identify a sex-linked trait?

Answer 22

Disproportionate effect on one gender

Question 23

If two individuals don’t have a trait, but their offspring does have the trait, is the trait dominant or recessive?

Answer 23

Recessive

Question 24

The chromosome theory of inheritance combines two different ideas…What are they?

Answer 24

Mendel’s genetic work with movement of chromosomes during cell division

Question 25

What is pleiotropy?

Answer 25

One gene, many traits

Question 26

What gametes can be made form a AABb individual?

Answer 26

AB, Ab

Question 27

Who is the father of modern genetics?

Answer 27

Gregor Mendel

Question 28

The true-breeding parental generation

Answer 28

P

Question 29

The generation that results when the F1 generation is mated?

Answer 29

F2

Question 30

Principle of segregation

Answer 30

Alleles within one gene separate when gametes are formed combined when fertilization occurs

Question 31

If the probably of being green is 1/3 and the probability of being soft is 1/9, what is the probability of being both green and soft?

Answer 31

1/27