Houses usually have a light source in every room, but it would be a waste of energy to leave every light on all the time, so there are switches to turn off the lights in rooms that are not in use. sometimes one switch controls several lights in the same room. likewise, prokaryotic cells can turn genes on and off based on environmental factors. sometimes related genes are grouped together with one switch. this group of genes, along with the sections of dna that regulate them, is called a

How many years would it take the atlantic ocean to grow 500 centimeters? show your work.

8) animals respond in various ways to stimuli detected through their senses. some of these responses are stimulated by the presence of danger. which of these animal responses is the best example of a response to an immediate threat? a) a rooster crows every morning at the first sign of light. b) as something approaches an octopus, it shoots a cloud of ink. c) from late fall until spring, bears hibernate to preserve energy. d) a dog is getting hot in the sunlight, so he moves to a shaded area.

In which order does sexual reproduction take place in plants? a. pollination, germination, fertilization b. germination, fertilization, pollination c. pollination, fertilization, germination d. fertilization , pollination, germination