What distinguishes one human body system from another?

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.

Which of the following requires the use of energy and the of transport proteins to move a molecule across a cell membrane?

Which action is a reflex action. a. asking for coffe in a cold climate b. blinking when light is flashed in the eyes c. drinking water when thirsty. d. swallowing food e. taking an exam