In nerve cells the sodium-potassium pump is used to generate gradients of both sodium and potassium ions to propagate electrical signals that travel along nerves. this is a(n)

How do the sperm cells get from the stigma to the ovules? a. they slide down the petals to the bottom of the flower. b. they travel through pollen tubes. c. they travel along filaments. d. insects carry the sperm cells from the stigma to the ovules.

The sea slug that considered to be a photosyntheesizing animal

Who discovered tuberculosis bacteria?