MC. Researchers find that on average identical twins (who share all of their genes) are much more similar in height than are fraternal twins of the same gender (who share half of their genes). This provides evidence that:

A. There is no genetic variation in height

  • B. There is strong genetic variation in height

C. There is no environmental variation in height

D. There is strong environmental variation in height

E. LeBron James does not have an identical twin

MC. Claytonia virginica is a woodland spring herb with flowers that vary from white to pale pink to bright pink. The slugs which damage the plants prefer to eat pink-flowering over white-flowering plants. The bees that pollinate this plant prefer also prefer pink to white flowers, meaning that Claytonia with pink flowers reproduce more effectively, if they survive the slugs. A researcher observes that the percentage of different flower colors remains stable in the study population from year to year. If the researcher removes all slugs from the study population, what do you expect to happen to the distribution of flower colors in the population over time?

  • A. The percentage of pink flowers should increase over time.

B. The percentage of white flowers should increase over time.

C. The distribution of flower colors should not change.

D. The distribution of flower colors should randomly fluctuate over time.

MC. Which of the following is an example of acclimation?

A. Some animals’ hemoglobin enzymes bind oxygen better than others’ do.

  • B. Some animals grow thicker coats when exposed to low temperatures.

C. Some bacteria can use the energy from sunlight to make sugars.

D. Some plant species can absorb nitrogen better than others can.

E. Some types of fungi are larger than others are.

MC. Parasitic species tend to have simple morphologies. Which of the following statements best explains this observation?

A. Parasites are lower organisms, and this is why they have simple morphologies.

B. Parasites do not live long enough to inherit acquired characteristics.

  • C. Simple morphologies have been naturally selected for in most parasites.

D. Parasites have not yet had time to progress, because they evolved recently.

MC. Which of the following is an example of a fitness trade-off?

A. In some hornbill species, the male helps seal the female in a tree with her nest until the young are ready to fledge.

B. Moths are the best pollinators for datura flowers, but bees are the best pollinators for orchids.

C. Some lemmings run into the sea when overgrazing threatens the species.

  • D. Algal genotypes that can grow fast in nitrogen-limited environments are easier for predators to digest.

MC. You observe that in a certain population of birds individuals with sharper beaks survive better and reproduce more than individuals with less sharp beaks. You therefore embark on a study to see if beak shape is evolving in this population. If you later find that beak shape does not change over many generations, which of the following would be a reasonable conclusion?

A. There is no variation in beak shape in this population.

  • B. Variation in beak shape in this population is not heritable.

C. There is no differential reproductive success in this population.

D. Selection is not operating in this population

E. Any of the above would be reasonable

MC. Gazelles being chased by predators sometimes display a behavior called “stotting” – they stop running and jump straight up into the air. This slows them down, and seems to increase their chance of being caught. Which of the following is the least likely explanation of this behavior, based on evolutionary theory?

A. The gazelles are male gazelles trying to show females that they have good genes, so that they will have more mating success

B. The gazelles want to show the predator how fast and athletic they are, so that the predator will give up the chase and the gazelle can get back to eating

  • C. The gazelles want to warn the rest of the herd of the presence of predators, for the good of the species

D. The gazelles want to see if there are any other predators hiding nearby