Download Genetics Review

Genetics Review Questions
Answer questions on a separate sheet of paper
1. Make a punnett square showing a heterozygous cross for tall pea plants: Tt x Tt. Give the ratio for the genotype
(Homozygous Dominant : Heterozygous : Homozygous Recessive) and the ratio for the phenotype (Tall : Short).
2. Define the following terms:
a. Allele
b. Homozygous
c. Heterozygous
d. Genotype
e. Phenotype
f. Sex-linked trait
g. Autosome
3. If a pea plant that is homozygous for tall is crossed with a pea plant that is homozygous for short, which phenotype will be
expressed in all their offspring?
4. What does it mean when Mendel stated that alleles segregate?
5. What is independent assortment?
6. What is a gamete?
7. If an individual had the following allele combinations, according to independent assortment, what different gametes could it
make?
a. BBDd
c. AAff
b. TtGg
d. hhEe
8. What is codominance. Give an example.
9. What is incomplete Dominance? Give an example
10. What are the different human blood types? Give the genotypes and phenotypes.
11. Create a punnett square in which one parent has Type B blood and the other has Type A blood are able to produce children
with all the blood types. What is the genotype of each parent? What is the ratio of phenotypes produced?
12. What is a chromosome?
13. Define diploid and haploid. What symbols do they have?
14. If a parent cell has 26 chromosomes, what would be the chromosome number after
a. Mitosis
b. Meiosis
15. What does it mean when two chromosomes are homologous?
16. Draw the three steps of chromosomes crossing over (Textbook pg. 277)
17. What is happening when two chromosomes crossover?
18. What is the genotype for a male human? A female human?
19. How many sets of chromosomes are in a gamete?
20. List three differences between mitosis and meiosis?
21. How many sperm are produced at the end of spermatogenesis?
22. How many eggs are produced at the end of oogenesis?
23. What is a zygote and how is it formed?
24. If a sperm with a Y chromosome fertilizes an egg with an X chromosome, what is the gender of the zygote? Draw a
diagram that shows this.
25. What is the difference between autosomes and sex chromosomes?
26. Which chromosomes are sex-linked genes usually carried on?
27. Why do males display sex-linked traits more often than females?
28. What is nondisjunction?
29. What is a karyotype used for?
30. What is the difference between a monosomy and a trisomy? Give an example of each.
31. When two heterozygous black rabbits are crossed, the probability of a black rabbit
32. When two heterozygous, red-eyed Drosophila are crossed, the probability that a
homozygous red-eyed Drosophila
will be produced is
33. If a female fruit fly heterozygous for red eyes (XRXr) crossed with a white-eyed male (XrY), what percent of their
offspring would have white eyes?
34. Both John and Cathy have normal colorvision. After 10 years of marriage, Cathy gives birth to a colorblind son.
Colorvision is a sex linked trait. What is the genotype of each parent and the child?
35. If the same parents have a daughter, what are the chances she would be colorblind?
36. Use the pedigree provided to determine how the trait is passed. Write the genotypes of the lettered individuals
A
B
C
D
E
F
G
H
A
F
B
G
C
H
D
I
E
I