Which of the following scenarios may produce an active trend in evolutionary change? Briefly justify your answer
A. The mechanic stability of the exoskeleton of a group of terrestrial arthropods imposes an upper limit on the body size of these organisms.
B. The evolution of an endoparasitic lifestyle results in overall smaller body size as parasite species diversify to utilize small-bodied hosts that are more common than large bodied hosts.
What will be an ideal response?
ANS:
B. Each lineage of parasite is expected to "actively" evolve smaller body sizes as they start to exploit small organisms as hosts.
You might also like to view...
What are the two most important variables for cells to survive?
a. Temperature and pH b. Temperature and solute concentration c. Solute concentration and nutrient levels d. Solute concentration and pH e. Temperature and nutrient levels
What prevents plants and bacteria from experiencing cell lysis?
a. A plasma membrane around cell walls b. A cytoskeleton of protein fibers c. Organelles suspended in cytosol d. A protective nuclear envelope
All humans belong to the same species.
a. true b. false
Give the sex-chromosome constitution (X and Y chromosomes) and possible genotypes of offspring resulting from a cross between a white-eyed female (Xw XwY) and a wild-type male (normal chromosome complement) in Drosophila melanogaster
Include all zygotic combinations whether viable or unviable.