Which system is responsible for defending the body against harmful substances? A circulatory system B muscular system C endocrine system D immune system

Which scientists was the first to suggest that growth of cancerous cells was a result of abnormal chromosomes? a. Carl Correns b. Walter Sutton c. Theodor Boveri d. Hugo de Vries

Blood has traveled from the heart to the toes. Which describes the next step of the circulation process? A. The blood goes back to the heart to get oxygen. B. The blood releases oxygen on the way back to the heart. C.

Dna and rna always contain a 5 carbon sugar known as what

What structures do protists such as amoebas use for movement

A light ray is striking the surface of the Earth. Which factors would make the light ray more likely to be absorbed than reflected? Check all that apply.

By what process do all living organisms grow and repair themselves?

What is the name of the heart's contraction?

Which describes the habitat of a frog?

The size of a population refers to the

An electric current will always follow a. the path of least resistance. b. a path toward the north pole. c. a path toward the south pole. d. the path that leads through insulators.