Autosomal Linkage/ Epistasis

Question 1

Define autosomal linkage

Answer 1

Any 2 genes on the same chromosome are linked

Question 2

Define autosome

Answer 2

Chromosomes excluding sex chromosomes

Question 3

Aa and Bb are not linked.

State the gametes formed

Answer 3

Ab AB aB ab

Question 4

AB and ab are linked

State the gametes formed

Answer 4

AB ab

Question 5

What rule does autosomal linkage not follow?

Answer 5

Does not follow Mendel’s rule of independent segregation

Question 6

For a 4 marker on autosomal linkage what should you mention?

Answer 6

Name which alleles are linked
State that mainly parental gametes are produced
If crossing over occurs the other gametes are produced which is less rare hence they are in a smaller quantity

Question 7

What is clear evidence of sex linakge?

Answer 7

Only males have the disease

Question 8

Define Epistasis

Answer 8

When one gene affects or masks the expression of another in the phenotype

Question 9

Name the statistical test that tests the null hypothesis

Answer 9

Chi-Squared test

Question 10

What does the Chi-Squared test ?

Answer 10

tests the null hypothesis

compares experimental with theoretical results

Question 11

What conditions must be satisfied for the Chi Sqaured test ?

Answer 11

Sample size larger than 20
Data must fall into discreate categories
Only raw counts can be used

Question 12

How is significance determined in the Chi-squared test?

Answer 12

The degrees of freedom

Question 13

Meiosis results in cells that have the haploid number of chromosomes and show genetic variation. Explain how.

Answer 13

1. Homologous chromosomes pair up / bivalents form; 2. Crossing over / chiasmata form;
2. Produces new combination of alleles;
3. Chromosomes separate;
4. At random;
5. Produces varying combinations of chromosomes / genes / alleles (not twice) ;
6. Chromatids separated at meiosis II / later;