Radioactive isotopes are often introduced into the body through the bloodstream. their spread through the body can then be monitored by detecting the appearance of radiation in different organs. one such tracer is 131i, a β− emitter with a half-life of 8.0

d. suppose a scientist introduces a sample with an activity of 345 bq and watches it spread to the organs.

Some species of wasps are social. the queen starts a colony from scratch each spring. she builds a small nest, and lays and raises a group of female workers. the workers enlarge the nest while the queen continues to lay eggs. unfertilized eggs become males that mate with newly hatched females. all of the wasps except the newly fertilized females die by the summer. which best describes this behavior? a)it is beneficial only to the males that do not fertilize eggs. b)it is beneficial only to the female workers that are not fertilized. c)it is beneficial to each one of the individual colony members. d)it is beneficial to the whole species, but not to all of the individual members.