Basic Genetics

Question 1

Humans have how many chromosomes?

Answer 1

46

Question 2

How many pairs of autosomal chromosomes do humans have?

Sex chromosomes?

Answer 2

22 pairs of autosomal chromosomes

1 pair of sex chromosomes

Question 3

Which RBC antigen is sex-linked?

Answer 3

Xga

Question 4

Define:
Dominant
Recessive
Co-Dominant

Answer 4

Dominant: expressed in heterozygous or homozygous form-only one allele needs to be inherited to be expressed

Recessive: expressed only is inherited in homozygous form

Co-Dominant: Each gene is expressed in heterozygous form.

Question 5

A and B are…

dominant, recessive, or co-dominant?

Answer 5

co-dominant

Question 6

O is…

dominant, recessive, or co-dominant?

Answer 6

recessive

Question 7

Can you determine if a person is AA or AO via routine testing?

Answer 7

no, only via familial/genetic studies

Question 8

Define:
Phenotype
Genotype

Answer 8

Phenotype: what’s expressed

Genotype: inherited gene

Question 9

What does the Law of Independent Assortment state?

Answer 9

Factors are inherited independently if they are on different chromosomes.

Question 10

Which mathematical principal is used to calculate population genetics?

Answer 10

Hardy-Weinburg Principle

Question 11

What is the equation for the Hardy-Weinburg Principle?

Answer 11

p^2 + 2pq + q^2 = 0

p+q=1

Question 12

36% of the population has straight hair, which is recessive. What percent of the population would be homozygous for curly hair?

let p = curly hair and q = straight hair

Answer 12

q^2 = .36

q = .6

p = 1 - .6 = .4

p^2 = .16 = 16 %

Question 13

List the 5 things that must occur in order or the Hardy-Weinburg Principle to work.

Answer 13

Large population
No mutations
Mating is random
No differential in mortality
No differential in fertility