Chapter 14: Mendel and the Gene Idea Flashcards Preview

Bio 93: Exam 3 > Chapter 14: Mendel and the Gene Idea > Flashcards

Flashcards in Chapter 14: Mendel and the Gene Idea Deck (23):
1

What is true-breeding?

Completely homozygous parents passing on

2

What is hybridization?

Cross between two true-breeding varieties

3

Versions of genes are called _______.

Alleles

4

What is a locus?

Area of chromosome that holds the gene

5

What is the genotype?

The actual genetic ratio

6

What is the phenotype?

The visual ratio

7

What is the Law of Segregation?

When heritable traits are hidden and then reappear

When a heterozygous crosses with another heterozygous

(When two alleles in a pair segregated into different gametes during gamete formation)

8

What is the law of independent assortment?

Hereditary alleles assort randomly during gamete production

Alleles assort independently of each other, such as round/wrinkled vs yellow/green

9

What is testcrossing?

Do either:

PP x pp
Pp x pp

This is to figure out if the dominant gene is homozygous or heterozygous

10

To determine the genotype of a round pea plant it should be crossed with ____________________.

Homozygous recessive plant

11

What is a dihybrid cross?

Looking at two traits simultaneously

Eg, peas

12

What is incomplete dominance?

Neither gene is dominant, but there is a blend.

Pink is considered the "intermediate phenotype"

Red + white = pink

13

What is codominance?

Neither gene is dominant, but there is a mixture of the two.

Black + white = black and white spots

14

For incomplete dominance and codominance, how do you write the punnet squares?

Red: C^r
White: C^w
Pink: C^r C^w

15

Which of the following represents a gamete that the dihybrid plant (YyRr) could form?

A. Yy
B. Rr
C. YR
D. YyRr

C. YR

Because YyRr would give one trait from the mother and one trait from the father, which would be:

YR
Yr
yR
yr

16

What are multiple alleles and what's an example of them?

3 or more alleles for a specific gene

Eg, blood groups

17

What are the genotypes for blood group A, B, AB, and O?

A - IA IA or IA i

B - IB IB or IB i

AB - IA IB

O - ii

18

True or false:

The blood type of a child who's parents blood types are A and B could be A, B, AB, or O.

True

Do a punnet square

19

What is epistasis?

When one gene affects the expression of another gene

Gene 1: lab fur colour
Gene 2: permission of pigment

20

What does this mean:

The gene for pigment deposition is epistatic to the gene for lab colour.

The gene for pigment disposition is more important (dominant) than the gene for fur colour

21

What is pedigree analysis?

Chart of traits in humans

22

What is significant about having a recessive disorder?

If you're heterozygous for a recessive disorder, you will not have that disorder. If you are heterozygous you only "carry" it.

DD = you do not have the disorder
Dd = you carry the disorder
dd = you have the disorder

23

What is significant about having a dominant disorder?

If you are heterozygous for a dominant disorder, you will have that disorder.

DD = you have the disorder
Dd = you have the disorder
dd = you do not have the disorder