BIO 1: Exam 4 Essay Questions
Four of these questions will be on the exam and you will choose to write on three out of the four. Each of the three
questions will be worth 10 points on the exam.
1. A) Describe the two principles of evolution that Charles Darwin proposed: 1) Common Descent with Modification and 2)
Natural Selection.
B) Describe what microevolution and macroevolution are.
2. Explain how 1) fossil evidence, 2) evidence from comparing anatomy, 3) evidence from comparing embryos 4) evidence
from molecular biology, and 5) experimental evidence support the occurrence of evolution.
3. The five agents of microevolution are 1) mutation, 2) gene flow, 3) genetic drift, 4) sexual selection, and 5) natural
selection. Describe how each brings about change in allele frequencies in a population.
4. Two outcomes of genetic drift are the 1) bottleneck effect and 2) founder effect. Describe what each effect is.
5. Read p. 294-295 “Essay: An Evolving Ability to Drink Milk” and answer the following questions:
A) What event in human history occurred around the same time as the ability for adult humans to digest milk?
B) What is the name of milk sugar and what type of biological molecule is it (carbohydrate, protein, lipid, or nucleic
acid)? What is the name of the molecule that humans use to break down milk sugar and what type of biological
molecule is it?
C) What was the default position for the human lactase gene and why was this the default position?
D) What mechanisms brought about the ability for adults to digest milk in three different regions?
E) Describe how recent and how relatively long it took for lactase persistence to arise in adults.
6. Define the following reproductive isolating mechanisms that can stop a population from interbreeding and possibly lead
to the formation of a new species: 1) geographic, 2) ecological, 3) temporal, 4) behavioral, 5) mechanical, 6) gametic,
and 7) hybrid inviability/infertility.
7. Read p. 362-375 “Arriving Late, Traveling Far: The Evolution of Human Beings” and answer the following:
A) On what continent have all of the oldest hominin fossils and oldest remains of modern humans been found?
B) Describe how brain size has generally changed over time in the Hominin family.
C) Explain why a small amount of DNA of today’s Europeans and Asians is of Neanderthal origin.
D) Describe what has happened to genetic variation in human populations from sub-Saharan Africa and in
populations from increasing distances from Africa.
E) Explain why this trend in human genetic variation has occurred.
8. State the two main life history patterns of populations and list 4 characteristics that species using each pattern tend to
have. (4 characteristics for each pattern)
9. A) Describe the three reasons, that we discussed, that explain why predator/prey interactions are important to have in a
community.
B) Give an example of a predator that we discussed. And describe the cascading effects that occur when the predator is
present versus no longer present in the community.
10. A) Name and describe the two outcomes of competition.
B) Name and describe the three types of symbiosis that interacting organisms display.
11. Using what you know about how energy is transferred through an ecosystem:
A) Describe why there is a stepwise decline of energy as it is transferred up the food chain.
B) Describe why there are more herbivores (lower level consumers) than carnivores (higher level consumers).
C) State which type of consumer is more “expensive” for an ecosystem to support and describe why that is.
D) Describe why certain animals at lower trophic levels can be much larger in size than carnivores.
MORE QUESTIONS ON BACK
12. A) The three types of extinction that we discussed were 1) background extinction, 2) mass extinction, and 3)
ecologically extinct. Describe what each type is.
B) State three causes of species loss and briefly describe how they can negatively affect species.
13. Read the online article “Counting the Last Fish” and answer the following questions:
A) Describe two specific reasons, that the article discusses as to, why overfishing has occurred in our oceans.
B) Describe what the term “fishing down the food web” means.
C) Describe two specific approaches, that the article discusses, that can help resolve our overfishing problem.