Flashcards in Equations Deck (10):

1

## Coefficient of coincidence

### CoC = # double crosses / # expected double crosses

2

##
Recombination frequency (st - ss - e)

Rf (st - ss) =

Rf (ss - e) =

This is the distance between genes

###
Rf (st - ss) = [ (Sum double cross) + (Sum single st-ss) / (total progeny) ] *100

Rf (ss - e) = [ (Sum double cross) + (Sum single ss-e) / (total progeny) ] *100

3

## Recombination frequency (st - ss - e) meaning

### This is the distance between genes

4

##
Recombination frequency (st - ss - e)

Rf (st - e) =

### Rf (st - e) = Rf (st - ss) + Rf (ss - e)

5

## What is the probability that 2 girls and 2 boys will be born?

###
P = { n! / (s! t!) } x (p^s) (q^t)

Now using this equation, calculate the probability (P) that in 4 delivery rooms (n=4), two boys and two girls will be born (s=2 and t=2). Remember, p= 1⁄2 boys and q= 1⁄2 girls .

P = (24/4) x (1/4) (1/4) = 24/64 = 0.375

6

##
Two carriers of the recessive allele for cystic fibrosis have six children. What is the probability that:

Two will be normal and four will have the disease?_

###
P = { n! / (s! t!) } x (p^s) (q^t)

n = 6, s = 2, t = 4

p(normal) = 3/4

q (CF) = 1/4

P = 0.03

7

## Interference equation

### I = 1 - CoC (CoC coefficient of coincidence)

8

## Coefficient of coincidence CoC =

### CoC = Observed DCO / Expected DCO

9

## Expected DCO =

###
Expected DCO = RF seg1 x RF seg2 x Total # progeny

Expected DCO = distance seg1 x distance seg2 x Total # progeny

10