Download Chapter 12 Review & Wrap-up

Chapter 12 Review & Wrap-up
1. What is a pedigree?
 1. Graphical representation of a families
genetic inheritance.
2. What is a pedigree used for?
 2. Help determine the likelihood of given
trait to show up in the offspring.
3. What does a square stand for? Circle?
3.
 Male
 Female
4. What is indicated by a shaded shape?
 4. The individual is affected.
5. What is a carrier?
 5. An individual who is heterozygous for a
given trait but does not show the trait.
6. A recessive trait which causes an
accumulation of thick mucus in the
lungs and digestive tract.
 6. Cystic Fibrosis
7. The absence of an enzyme that breaks
down a lipid produced in the central
nervous system(brain).
 7. Tay-sachs disease
8. A lethal genetic disorder caused by a
dominant allele.
 8. Huntington’s disease
9. If Huntington’s disease is lethal, how
is it passed on?
 9. It does not affect an individual with the
disorder until they are between the ages of
30-50.
10. In this type of inheritance, the phenotype
of the heterozygote is intermediate to those
of the two homozygotes.
 10. Incomplete dominance
11. This type of trait is controlled by
more than two alleles. Give an example.
 11. Multiple alleles
 ABO blood group
12. This trait is controlled by two or more
genes. Give an example.
 12. Polygenic inheritance
 skin color, eye color, height
13. What is the difference between the sex
and autosomal chromosomes.
 13. Sex chromosomes determine the sex of
an individual. The rest of an individuals
chromosomes are autosomal.
14. In this type of inheritance, the
phenotype of both homozygotes is
produced in a heterozygote individual.
 14. Codominance
15. List some examples of environmental
factors that can affect gene expression.
 15. Temperature, nutrition, light, chemicals,
infectious agents, hormone levels, age.
16. What happens as a result of
hemophilia?
 16. Blood is not able to clot due to the shape
of the cells, affected individuals can bleed to
death due to simple wounds.
17. What is a sex linked trait? Give an
example.
 17. Sex linked traits are carried on a sex
chromosome
 red-green color blindness and hemophilia.
18. Why is it that a male is more likely to
receive a recessive sex-linked trait (found on
X chromosome) that a female?
 18. Males only receive one X
chromosome…if it carries the disorder they
will show that trait.
19. What do we use a karyotype for?
 19. To detect genetic disorders in an
individual.