Which gas in the atmosphere made the development of eukaryotic cells possible? A. methane B. nitrogen C. oxygen D. carbon dioxide

All organisms that can synthesize thier own food by means of photosynthesis are heterotopic

A population that is small, but more than "endangered" is considered to be A) extinct B) alarmed C) threatened D) scarred

The key enzyme which regulates glycolysis through allosteric binding of atp and its products is

Study the following food chain: grass → rabbits → snakes → hawks. From this chain, you can correctly assume that each population A. is a species of herbivore. B. is always larger than the one before it. C. supports the next trophic level. D.

Which property would best distinguish sediment deposited by a river from sediment deposited by a glacier? A) thickness of sediment layers B) age of fossils found in the sediment C) amount of sediment sorting D) mineral composition of the sediment

How many homologous chromosome alignments are possible for independent assortment during meiosis? one two three four

What kind of tests are used to analyze data for experimental treatments?

Luis is doing an experiment on plants. He wants to find out if they grow taller when they are given more water.

Which is the last step that occurred in the speciation of the galápagos finches? a. establishing genetic equilibrium b. founders arrived c. geographic isolation d. ecological competition?

Intact skin and mucous membranes: First line of defense. 2. : Second line of defense. 3. : Third line of defense. 4. : Innate defense system. 5. : Adaptive defense system.