Flashcards in Test 2 Deck (22):

1

## What do you get if you cross a monohybrid or dihybrid homozygote x homozygote?

### a heterozygote

2

## For monohybrid crosses, what ratio do you get if you cross a heterozygote x heterozygote?

### 3:1 ratio

3

## For monohybrid crosses, what ratio do you get if you cross a heterozygote x homozygous recessive?

### 1:1 ratio

4

## For dihybrid crosses, what ratio do you get if you cross a heterozygote x heterozygote?

### 9:3:3:1 ratio

5

## For dihybrid crosses, what ratio do you get if you cross a heterozygote x homozygous recessive?

### 1:1:1:1 ratio

6

## Do reciprocal crosses matter? If you have a male red eyed fly X brown female or brown-eyed X red female?

###
RR X rr = Rr

rr X RR = Rr

Only matters for sex-linked genes

7

##
What kind of cross is this and what would the ratio be?

Aa X Aa

###
Monohybrid

3:1

8

##
What kind of cross is this and what would the ratio be?

Aa X aa

###
Monohybrid

1:1

9

##
What kind of cross is this and what would the ratio be?

AaBb X AaBb

###
Dihybrid

9:3:3:1

10

##
What kind of cross is this and what would the ratio be?

AaBb X aabb

###
Dihybrid

1:1:1:1

11

##
What kind of cross is this and what would the ratio be?

AaBbCc X AaBbCc

###
Trihybrid

27:9:9:9:3:3:3:1

12

##
What kind of cross is this and what would the ratio be?

AaBbCc X aabbcc

###
Trihybrid

1:1:1:1:1:1:1:1

13

## What were Mendel's four postulates?

###
1. Unit Factors in Pairs

2. Dominance/Recessiveness

3. Random Segregation

4. Independent Assortment

14

## What is Mendel's postulate, Unit Factors in Pairs?

###
Homologous Chromosomes contain the same genes

-each chromosome has a copy of the same gene called an allele

-humans are diploid

15

## What is Mendel's postulate, Dominance/Recessiveness?

###
One copy of the gene, an allele, may be dominant to the other copy

-heterozygotes express the phenotype of the dominant allele

16

## What is Mendel's postulate, Random Segregation?

###
Homologous chromosomes segregate into different gametes during meioisis

-Aa -> 1/2 A & 1/2 a

17

## What is Mendel's postulate, Independent Assortment?

###
Genes on NON-homologous chromosomes sort independently of eachother during meioisis

-can get any combination

-AaBb -> AB & Ab & aB & ab

18

## When does the sum rule apply? What is it's clue word?

###
When looking for EITHER of 2 or more outcomes of ONE event

-Clue word is "or"

eg. What is the probablility of rolling a 1 or a 2 when rolling a die?

1/6 + 1/6 = 2/6 = 1/3

19

## When does the product rule apply? What is the clue word?

###
When looking at more than one event

-Clue word is "and"

eg. What is the probability of landing on heads each time when flipping a coin 3 times?

1/2 x 1/2 x 1/2 = 1/8

20

## How is PKU inherited?

###
recessive allele

PP = Normal

Pp = Carrier

pp = No enzyme; PKU

21

##
What do the letters of the binomial expansion equation stand for?

P = ( n! / s!t! ) (p^s) (q^t)

###
P = probablity

n = number of events (usually number of offspring)

s = outcome 1

t = outcome 2

p= probability of outcome 1

q= probability of outcome 2

22