Download File

Biology 11H
Name:
Mendelian Genetics and Chromosome Inheritance Review
In doing this review you should get a good idea of what will be tested. However, this is not a
comprehensive review. You will still be expected to know everything that we covered in class
1. A red, tall flower that is homozygous for colour and height is crossed with a homozygous white, short
flower. The resulting F1 generation was ALL red and short. Show the genotype of each parent and the F1
generation
Parent Red, tall =
Parent White, short =
F1=
The F1 generation was self-fertilized
Create a Punnett square to show the genotype and phenotype ratios of the F2 generation
Genotype Ratios:
Phenotype Ratios:
Biology 11H
Name:
2. A couple has 6 children, all daughters. What is the probability of having a 7th child that is a boy?
3. After all the inheritance patterns and contributors to genetic diversity have been calculated it was
found that the probability of a couple having a child with a specific disorder to be 1/5. Calculate the
probability of the following:
a) Having 2 consecutive children with the disorder
b) Having the first child healthy but both the next 2 children having the disorder
4. Given the following recombination frequencies, what is the correct order of the genes on the
chromosome? Draw the chromosome
A—B= 8 map units
A—C= 28 map units
A—D= 25 map units
B—C= 20 map units
B—D= 33 map units
5. Explain the difference between pleiotropy, epistasis and polygenic inheritance. Give examples
6. Explain how epigenetics can increase or decrease the amount of gene expression. What impact could
this have on the organism?
Biology 11H
Name:
7. Give the “most reasonable” pattern of inheritance and assign each person a genotype
8. Give the “most reasonable” pattern of inheritance and assign each person a genotype
9. If females have twice the number of x chromosomes in their cells, why don’t they express twice the
amount of protein? How does this impact egg cells where there is only 1 x chromosome?
Biology 11H
Name:
10. Here is a cross between 2 flowers
a) What would you expect the genotype of the F1 generation to be?
b) If the F1 generation was test crossed with bbll, what would be the expected ratio of their offspring?
c) Below is what the actual numbers of observed of each phenotype. Based on what you know, give an
explanation for the ratio
Biology 11H
Name:
11. Purple stem (A) is dominant to green stem (a), and short petals (B) is dominant to long petals (b).
AABB plants were crossed with aabb to generate a F1 dihybrids (AaBb) which were then test crossed
(AaBb x aabb). A total of 900 offspring were scored for stem colour and petal length. These genes are
not linked.
Offspring from
test cross of AaBb
x aabb
Expected Ratio
Expected number
of offspring (of
900)
Observed number
of offspring (of
900)
Purple, short
Green, short
220
Purple, long
Green, long
231
239
210
Null Hypothesis= _______________________________________________________________________
Testcross
Offspring
Purple, short
Green, short
Purple, long
Green, long
Expected (e)
Observed (o)
Deviation (o-e)
(o-e)2
(o-e)2/e
220
210
231
239
X2=sum
Using the critical values with probability of p = 0.05
Will you reject or accept your hypothesis. Explain