what name is given to the circular arrangement of arterial blood supply at the base of the brain encircling the pituitary gland

Which of the following describes the difference in stimuli required to detect a difference between the stimuli? a. just noticeableb. signal detectionc. subliminald. top down

1. in what ways have non-native species been beneficial? 2. what are some of the hypotheses for the collapse of honeybee colonies? 3. distinguish between regional and functional extinction. 4. why is it difficult to measure background extinction rates? 5. what three factors are most important in causing extinction rates to climb?

Scientists studied reproduction in the new zealand mud snail to answer the question, “are there benefits to reproducing sexually or asexually? ” which of these hypotheses would least likely aid the scientists as they worked to answer the question? sexual reproduction is advantageous over asexual reproduction because it reduces the rate of mutation accumulation. asexual reproduction is advantageous over sexual reproduction because it allows the snails to produce more offspring. sexual reproduction is advantageous over asexual reproduction because it allows for snails to have increased genetic variation. asexual reproduction is advantageous over sexual reproduction because it decreases the snails’ need for social