Download 10-12 Study Guide

Biology
Chapter 10-12 Study Guide
Name_____________________________________
Per_______________
1. What is the difference between a gamete and a zygote?
2. What is the relationship between genotype and phenotype?
3. What is the relationship between homozygous and heterozygous?
4. What are the three rules that all simple heredity traits follow?
5. Match the inheritance pattern on the left with their sample gametes and their definition on the
right.
Ans. #1
_______
Ans. #2 Inheritance Patterns
_______ 1. Simple Heredity
Possible Answers
a. RR, RR’, R’R’
b. When a single gene has more than two possible
______
______
______
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2. Incomplete Dominance
traits it can code for
c. TT, Tt, tt, with gender considered
d. Traits that are on the X or Y chromosomes
3. Co dominance
e. AYARBRBRCYCYDRDY
f.
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______
______
______
______
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4. Multiple Alleles
All alleles are equally dominant
g. BB, BW, WW
h. Traits that are expressed based on an organism’s
gender
5. Sex-Linked Trait
6. Sex-Determined Trait
i.
XR, Xr, Y
j.
Only one gene, with two alleles, and one is
dominant
k. WW, Ww, ww
l.
______
7. Polygenic Inheritance
Traits that are controlled by more than one gene
m. Y, Yb, Yc, Yd, Ye
n. The heterozygote is a mix of the two
homozygote phenotypes
For questions 6-12, perform all of the following steps:
A. Identify the labels for each allele (use appropriate styles for the inheritance pattern)
B. Write mom and dad’s genotypes
C. Draw a Punnett square, and fill in appropriately
D. Find the genotype ratios
E. Find the phenotype ratios
6. Simple Heredity. The peas of pea plants come in two colors, yellow and green. Yellow is
dominant to green. Find the results of a cross between a homozygous recessive father and a
heterozygous mother.
7. Dihybrid. Nearsightedness is dominant to normal eyesight. Broad lips are dominant to thin lips.
Find the results of a cross between a mother who is homozygous recessive for both traits and a
father who is heterozygous for both traits.
8. Incomplete dominance. Burmese cats have three shades of coats (silver, white, and an
intermediate gray). Find the results of a cross between a silver-haired father and a white-haired
mother.
9. Codominance. Dog species have gums that can be entirely black, entirely pink, or black and pink
spotted. Find the results of a cross between a spotted father and a spotted mother.
10. Multiple Allele. In humans, blood types are represented by multiple alleles. The alleles are A, B,
and O. Find the results of a cross between a mother with AB blood type and a father with BO
blood type. (A and B are codominant, and both are dominant to O).
11. Sex-Linked Trait. Calico coloring in cats is a recessive X-linked trait. Find the results of a cross
between a mother who is calico and a father who is not.
12. Sex-Determined Trait. Facial hair can be defined as thin/fuzzy (dominant) or thick/bushy
(recessive). This only applies to males, however, as females will always have thin/fuzzy hair no
matter their genes.
a. Assuming a couple has four boys, find the phenotype ratio of the children if mom is
heterozygous and dad is homozygous recessive.
b. If the couple had 8 children (6 girls, and 2 boys) what is the likely phenotype ratios of
the children?
13. Polygenic Trait. Wheat stalks have two alleles for height: dwarf and tall. Five separate genes
control the height for stalks. Assume the following set of parents. Is it possible for an offspring
of this cross to have seven dwarf alleles? Why or why not?
Mom: ATATBDBTCTCTDTDTETED
Dad: ADATBDBTCTCTDDDDETED
14. Use the dihybrid cross below to answer the following questions
a. What are Mom and Dad’s genotypes and phenotypes?
b. What is the probability of an offspring having an FFdd genotype?
c. What is the probability of an offspring having a Freckles/Dimples phenotype?
d. What is the probability of an offspring having a No Freckles/No Dimples phenotype?