#Question id: 4994
#Unit 11. Evolution and Behavior
In certain motile prokaryotes, dozens of different proteins comprise the motor that powers the prokaryotic flagellum. The motor has a complicated structure, and its various proteins interact to carry out its function. Based on Darwinʹs explanation for the existence of human eyes, how would he probably have explained the existence of such motors?
#Question id: 9155
#Unit 9. Diversity of Life Forms
The success of plants extending their range northward following glacial retreat is primarily determined by ________.
#Question id: 26818
#Unit 8. Inheritance Biology
#Question id: 2440
#Unit 2. Cellular Organization
Microtubule assembly in vitro requires
a. ATP.
b. a threshold (critical) concentration of tubulin.
c. warming the solution to 37°C.
d. microtubule-associated proteins.
e. GTP.
#Question id: 4637
#Unit 11. Evolution and Behavior
A biologist studied a population of squirrels for 15 years. During that time, the population was never fewer than 30 squirrels and never more than 45. Her data showed that over half of the squirrels born did not survive to reproduce, because of competition for food and predation. In a single generation, 90% of the squirrels that were born lived to reproduce, and the population increased to 80. Which inference(s) about this population might be true?
A) The amount of available food may have increased.
B) The number of predators may have decreased.
C) The squirrels of subsequent generations should show greater levels of genetic variation than previous generations, because squirrels that would not have survived in the past will now survive.
Choose correct combination,