Afive-year review of threats to the southern resident orca population of the united states concluded that the top threats were prey availability, contaminants, and effects from recreational and whale watching vessels. further down the list are oil spills, disease, and effects from commercial vessels not targeting whales. how might this list be different if it were for transient whale populations, which have a larger average population size and live farther offshore in open waters?
a)the transient population is more likely to be affected by contaminants.
b)the transient population is less likely to be affected by whale watching vessels. c)the transient population is more likely to be affected by disease. d)the transient population is less likely to be affected by prey availability.

The correct answer is option b) "The transient population is less likely to be affected by whale watching vessels".

Explanation:

The five-year review of threats to the southern resident orca reports a list of the principal threats that these animals are exposed to. If the study was to be performed for transient whale populations it is likely that they would not be as much affected by whale watching vessels. Whale watching vessels' negative impact comes from people looking for whales close to the shore, the fact that transient whale populations live farther offshore in open waters will reduce their negative impact.

The transient population is less likely to be affected by whale watching vessels.

Explanation:

answer: the blood-brain barrier is a layer of specialized membranes and cell processes designed to keep undesirable substances from passing from the bloodstream into the precious tissues of the brain. while the blood-brain barrier does keep most bad things out of the central nervous system, it is not impermeable.

explanation:

desert perennials often survive by remaining dormant during dry periods of the year, then springing to life when water becomes available. most annual desert plants germinate only after heavy seasonal rain, then complete their reproductive cycle very quickly.