1. A new mutation may be _____________. (check all that apply)
c. none of these
2. Structural mutations of chromosomes that can occur during meiosis include _________. (check all that apply)
b. crossing-over (recombination)
3. Mutations result from ______________. (check all that apply)
a. certain types of environmental toxins
b. crossing-over (recombination) during meiosis
c. structural alterations in chromosomes during meiosis
d. mistakes in the replication of DNA
e. certain types of radiation
4. Which of the following statements is true about trisomy? (check all that apply)
a. Down Syndrome is an example of Trisomy
b. Trisomy results from nondisjunction during meiosis
c. Trisomy is characterized by three chromosomes instead of a homologous pair in a zygote.
d. Trisomy leads to nonviable zygotes.
5. In autosomal (nonsex) recessive inheritance, individuals carry a recessive allele that is not expressed in their own phenotype (observable traits).
6. In autosomal (nonsex) dominant inheritance, the phenotype of at least one parent expresses the dominant trait.
7. The ABO blood type system has _____ major alleles.
8. In the ABO blood type system _________.
a. the allele for O is dominant over those for A and B
b. alleles A and B are codominant
c. the allele for B is dominant over the allele for A
d. the allele for A is dominant over the allele for B
9. The genotype of living things sets limits and potentials, but also always interacts with the environment.
10. All of an organism’s genotype is expressed in its phenotype.
11. Polygenic traits are influenced by genes at two or more loci on chromosomes.
12. Features, such as stature, skin tone, and cognition are polygenic in humans.
13. Microevolution is _______________.
a. progress toward a more humanlike condition over time
b. an increase in complexity over time
c. a change in physical appearance over time
d. a change in allele frequencies over time
14. A Y-linked trait is passed down from father to ______________.
a. half of his sons but none of his daughters
b. all of his sons but none of his daughters
c. all of his sons and half of his daughters
d. none of his sons but all of his daughters
15. Hemophilia is due to the presence of an allele on ______________.
a. none of these
b. multiple autosomes
c. a Y chromosome
d. an X chromosome
e. one autosome
16. A population would not be evolving if the allele frequencies remained constant from one generation to the next, a hypthetical situation known as ________________.
a. natural selection
b. none of these
c. genetic drfit
d. gene pool
e. genetic equilibrium
17. Genetic equilibrium would be maintained in a gene pool under ideal conditions. In nature, this equilibrium is disturbed by _________________. (check all that apply)
b. gene flow
c. natural selection
d. non-random matin
e. genetic drift
18. A condition which must be assumed for the state of genetic equilibrium to occur is __________.
a. differential fertility
b. small population size
c. differential mortality
d. random mating
e. low mutation rate
19. The known sources of genetic variation include ______________. (check all that apply)
a. gene flow
b. crossing-over, or recombination, during meiosis
c. genetic drift
e. natural selection