Genetics Unit Test Review - Mrs. Cox’s 8th Grade Science Class
Test on Thursday, April 15th, 2010
Answer all questions on a separate sheet of paper. Write in complete sentences.
TEKS:
8.11B: Distinguish between inherited traits and other characteristics that result from interactions with the
environment.
8.11C: Make predictions about possible outcomes of various genetic combinations of inherited characteristics.
1. Who was Gregor Mendel and what is he famous for?
2. What is the difference between sexual reproduction and asexual reproduction?
3. Give three examples of organisms that reproduce sexually. Give three examples of organisms that
reproduce asexually.
4. What are genes and where are they found?
5. What is the difference between a gene and an allele?
6. What is a genotype? Give three examples.
7. What is a phenotype? Give three examples.
8. Give 3 examples of inherited traits and 3 examples of characteristics that result from interactions with
environment.
9. What is the difference between dominant traits and recessive traits?
10. What is the difference between homozygous and heterozygous genotypes?
11. What is the difference between a purebred and a hybrid?
12. HH, Bb, dd, RR, ww, Ee, Ss, UU, pp, Qq, VV, xx, Zz, MM, nn, Ff, Gg, tt
a. Which of the genotypes above could be classified as homozygous dominant?
b. Which of the genotypes above could be classified as homozygous recessive?
c. Which of the genotypes above could be classified as heterozygous?
d. Which of the genotypes above could be classified as purebred?
e. Which of the genotypes above could be classified as hybrid?
13. What is a Punnett square and what are they used for?
14. Know how to read genetics word problems and drawing Punnett squares using the given information.
15. Using the table below, answer the following questions:
Characteristic
Eye Color
Face Color
Eye Shape
Dominant
Gene
Red Eyes
(R)
Yellow (Y)
Star (E)
Recessive
Gene
Blue Eyes
(r)
Green (y)
Blast (e)
a. Give the possible genotypes for each trait based on the
table above:
Purebred red eyes _________ Green face ___________
Hybrid star eyes __________ Purebred blue eyes
__________ Heterozygous yellow face ______ Homozygous
blast eyes _______
b. Give the phenotype for each genotype based on the table above:
RR ______ Yy ______ ee _______ Rr _______ yy ________ Ee _______ YY ________ rr _______
c. Sally is heterozygous for her eye shape. She married a man with blast eyes. Create a Punnett square to
find the probability of having starry-eyed children.
d. Bobby has a green face, but his wife is believed to be homozygous for her yellow face color. What
percentage of their children should have a green face? What percentage of their children should have a
yellow face? Draw a Punnett square to help you find your answer.
e. Homer is homozygous for his blue eyes and his wife is a hybrid for her red eyes. What is the probability
that their children will be homozygous dominant? Use a Punnett square to find your answer.
16. What is the probability that any offspring will be male? What is the probability that any offspring will be
female? Draw a Punnett square to illustrate this.
Vocabulary to know:
Gregor Mendel, dominant trait, recessive trait, gene, allele, Punnett square, purebred, hybrid, genotype,
phenotype, heterozygous, homozygous, pedigree, sexual reproduction, asexual reproduction
This website has a great genetics review, complete with an answer key:
http://sciencespot.net/Media/gen_spbobreview.pdf