What part of the brain controls breathing and heart rate?

A. Thalamus

B. Brain stem

C. Hypothalamus

O D. Midbrain

Phytoplankton are the main primary producers on land.

Gram-positive bacteria have a thick cell wall that stain what color?

Which factor does not contribute to the high suicide rate among the elderly?

Which of the following are limiting nutrients

Microtubules, intermediate fibers, and microfilaments are all parts of the

What is the main function of the large intestine? A. digestion of proteins B. absorption of nutrients C. breaking down complex carbohydrates D. removing water from undigested waste

Which type of environmental scientist is most likely to study how whales are affected by pollution? a. Hydrologist b. Toxicologist c. Ecologist d. Oceanographer

How did Francesco Redi disprove the idea of spontaneous generation? He showed that flies were not produced by meat. He showed that microorganisms are present in air. He showed that microorganisms cause disease. He showed that flies spread disease.

Of the millions of sperm who start the long journey to the egg, how many sperm are actually allowed to enter the egg?

A mineral leaves a gray trail when scraped against an unglazed porcelain plate. Which property of a mineral is being measured? A. luster B. streak C. color D. hardness