Final practice questions
1. You discover a wild, red-striped snake, and want to reveal its genotype. It has the same genetic
system that we dealt with before: Gene R determines stripe color with R (red) dominant over r
(orange). Gene D determines color production, and therefore stripe presence or absence, with D
(color) dominant over d (no color). List the genotype of the snake you would use to perform a
testcross, to uncover the genotype of the wild snake.
1.1. If the offspring from that cross occur in the following ratios, 1 red: 1 orange: 2 stripeless, then
what must be the genotype of the wild snake? Show the parent gametes and offspring
genotypes.
2. In your antibiotic resistance lab you learned that bacteria in hospitals have tremendous resistance
levels to multiple antibiotics. Explain which evolutionary forces are operating to promote those
resistant phenotypes.
2.1. When patients who acquire those resistant bacteria leave the hospital, why do those bacteria
usually not spread and replace all non-resistant bacteria in the community?
2.2. If, in that community, antibiotic use increases, along with consumption of meat that was raised
using antibiotics, would you expect the resistant strains of hospital-acquired bacteria to persist
for a longer time in the community than they did before? Explain.
3. Draw the phylogenetic tree of Animals, and indicate where on the tree the major synapomorphies
appear. Label nodes as well as tips.
4. Draw the lifecycle of a fern, labeling structures as haploid or diploid, sporangia and gametangia,
spores and gametes, etc.
5. Discuss two steady patterns of change that occurred in the evolution of green plants from their algal
ancestors.
6. What did the development of a waxy cuticle and a vascular system allow land plants to do?
7. What major group are animals most closely related to?
8. Name two groups of fungi that are useful to humans as food sources and name those foods.
9. What is the point of a mushroom? In other words, what function does it perform for the
Basidiomycete fungi?
10. The A and B genes are closely linked on a chromosome (an autosome). Gene D resides on a separate
autosome. Draw these chromosomes in a 2n cell (with unreplicated chromosomes) whose genotype
is: AB d
aB D
If two (or four) crossover events occur between genes A and B, will you see the results of those
events in the gametes? What if one (or three, or five) occur: will you see the results then? Try it!