Over the past 200 years the level of carbon dioxide in the atmosphere has

A. Decreased slightly

B. increased until recently, then decreased

C. Increased steadily

D. Stayed aboutbthe same

Why was modern classification invented? Traditional classification could not classify all living things. Scientists realized related organisms do not share similar characteristics. Scientists understood that species share a common ancestor.

What type of blood vessel returns blood to the heart? A. Artery B. Vein C. Capillary D. None of the above

What best descride what heredity is?

True or false: wes j. Moore was very close to his father

How many germs are on animals

Forming the cell walls of stems, leaves, and roots, what compound is the primary structural constituent of plant tissues?

All microorganisms cause illness and disease? true or false

10. Which of the following is an emerging dis- ease that was unknown 50 years ago? a. malaria b. dengue fever C. Lyme disease d. schistosomiasis

What would be the effect of a mutation in the coding region of the lactase gene?

Which of the following can be said about the use of agriculture? a. It bears no effect on the environment. b. It stunted the growth of civilization and development. c. It prohibited the use of machinery. d.