An earthworm has a complete digestive system.

how does the earthworm remove undigested food?

a.
it uses the same opening in which the food was taken in.

b.
the waste diffuses out through the skin.

c.
waste is removed through a designated opening.

d.
tentacles are used to remove the waste.

Ascience research group is testing a new type of plant food. one trial is conducted in a controlled experiment. the data from the trial show that the plant that received the new food grew faster than the control plant. the group announces that the new plant food makes plants grow faster. what is the main weakness in this scientific claim?

Which of the following best describes the purpose of the parathyroid hormone? a. it decreases the blood calcium level and decreases blood phosphorus level. b. it decreases the blood calcium level and increases the blood phosphorus level. c. it increases the blood calcium level and increases blood phosphorus level. d. it increases the blood calcium level and decreases blood phosphorus level.

Are gametes exactly the same? explain why or why not?