Which of the following types of reproductive barriers separates two flowering plant species that could interbreed except that one has a deep flower tube and is pollinated by bumblebees, whereas the other has a short, narrow flower tube and is pollinated by honeybees?

These are from two different populations of a species of stickleback fish. The one on top lives in the Pacific Ocean, and the one on the bottom lives in nearby lakes that were formed by the sea level falling and the lakes becoming isolated from the ocean. The lake population has fewer spines made of calcium. This is an example of the beginning of:

The Rb protein prevents mitosis by inhibiting cells from entering S phase. Human papillomavirus (HPV) is thought to inhibit the action of the Rb protein in cervical epithelial cells. What would be the effect of cervical cells being infected with HPV? (NOTE: “inhibit” means to stop, or slow down.)

Certain whale species were hunted to near extinction. With a ban put in place on hunting them, their population sizes have expanded. Which of the following is true?

The image below shows a cavefish (TOP) that lives in a cave with no light and a related fish (BOTTOM) that lives nearby in water exposed to normal light. The cavefish has no eyes. This is an example of:

The first tetrapods (four-legged animals) were amphibians, which evolved from a specialized group of lobed-fin fish. An unusual fossilized animal (named Tiktaalik) was recently found; this animal possessed a mixture of fish and amphibian characteristics. What is the term used to describe such an intermediate organism?

The earliest life forms date back to __________ years ago.

DEFINITIONS. Define the following terms. (2 points each) Convergent evolution Homologous structures Adaptive radiation Microevolution Macroevolution Natural selection Bottleneck effect Sexual selection Sexual dimorphism Artificial selection

The origin of oxygen in the atmosphere of earth dates to __________ years ago.

You set your time machine for earth 3 billion years ago and push the start buttom. When the dust clears, you look out the window. Which of the following best describes what would be there?