genetic variation at the population level, multifactorial genetics

Question 1

short tandem repeat

Answer 1

2-3 nucliotide tandem microsatellite repeats that can be detected by PCR

Question 2

VNTR (variable number tandem repeat)

Answer 2

10-100 nucliotide variable sequences that make up minisatilites, and can be detected via southern blott

• **DNA fingerprinting **is used in forenstic medicine where several VNTR sequences are performed simultaneously

Question 3

SNP’s

Answer 3

Simple nucliotide polymorphisims used in HapMapping to idnetify populaiton-associated differences in DNA sequences. Dectected via sequencing.

SNP’s are used to determine diseases suseptiblility in diseases with multifactorial inheritance.

Question 4

What factors determine if organs will be rejected?

Answer 4

Blood type (A,B,O)

Presence of Rh factor (Rh+ is domiant to Rh-) mothers with Rh- whose prodce Rh+ offspring need anti-Rh Ig before and after giving birth

HLA alleles encode MHC I&II recptors identify cells as belonging to an organism, matching MHC receptors is the most difficult factor to match in organ transplant

• MHC I presents endogeneous protiens, MHC II presents exogeneous proteins
  
  • siblings have a 25% chance of sharing both HLA alleles
    
    • HLA alleles are hapilotypes and do not crossover with great frequency

Question 5

Hardy-Weinberg

Answer 5

equation

P²+2PQ+Q²=1

P+Q=1

Assumptions

• large populaiton
• random mating
• no mutations
• no natural selection

Question 6

Define fitness

what is the equation for mutation rate?

what is the equation for the selection coefficent?

Answer 6

**fitness **is the extent to which an allele will increase/decrease survivability

s=1-f

µ=sq

• q is allele frequency
• µ is mutation rate
• s is the selection coefficent
• f is fitness
  
  • f<1 allele reduces fitness
  • f>1 allele increases fitness

Question 7

What is gene flow?

Answer 7

the movement of genes between populaitons

Question 8

What is genetic drift?

Answer 8

Occurs when a populaiton migrates and fuses with another populaiton increasing genetic diversity.

Question 9

What is the founder effect?

Answer 9

Occurs when a few individuals leave a large population and form their own populaiton. Results in decreased gene pool diversity.

(amish)