Module 8: Genetics
Study Guide	
Complete this study guide to prepare for the test.

Principles of Genetics
1. Distinguish between heredity and genetics.

2. What is selective breeding or artificial selection?  Give an example.

3. What two models existed to describe inheritance of traits?  Which was the more accurate model?

4. Distinguish between genotype and phenotype and give an example using flower color.

5. Match each of the following:
a.	homozygous dominant		___ tall plant
b.	allele					___ TT
c.	heterozygous				___ T
d.	phenotype				___ tt
e.	homozygous recessive		___ Tt

6. What does purebred mean?  Write a genotype for something that is purebred for a trait.  

7.  An offspring receives ___ allele from each parent.  It’s genotype for a trait is made up of ___ alleles.

14.  In any mating between humans, what are the chances that a boy will be born? ____%  What about the chances for a girl? ____%

15. Which parent determines the sex of a baby?  Explain.

16.  Two parents have a boy.  The woman is pregnant.  What is the likelihood she will have a boy for her second child?  ______%

Punnett Squares
17. What is purpose of Punnett Squares?

18.  Which of the following Punnett Squares is completed incorrectly?  Circle it and then correct it!
Types of Inheritance

23. What is the difference between incomplete and complete dominance?

24. What is the difference between alleles that are codominant and those that are incompletely dominant?

25.  When a characteristic is X-linked, is it more or less likely to appear more often in males?  (circle one)

26. Match each description with the type of inheritance that is described:
a. Codominant 	b. incomplete dominant    c. Sex linked trait	d. Complete domiance

____ Red flowers and white flowers are crossed.  All the offspring have pink flowers.
____ The alleles for a gene are L and M.  Both alleles are expressed in a heterozygote with the genotype LM.
____ Straight hair (S) is dominant over curly hair (s.)  Sally has the genotype Ss and has straight hair.
____ In Reebops, the gene for ears is carried on the X chromosome. 
  
Pedigrees
27. Which of the people in this pedigree is a “carrier?” (circle all)  Which of the people in this pedigree are affected by the condition? (cross out all)  What type of inheritance is likely represented by this pedigree?  ___________________

28. What patterns are characteristic for a pedigree of a sex-linked trait?

29. What patterns are characteristic for a pedigree of a autosomal dominant trait?

30.  What is hemophilia and how is it inherited?  Who is more likely to get hemophilia in families where the gene is present?