Nitrogen in the atmosphere must be "fixed" before it can be used by plants. Atmospheric nitrogen is "fixed" by A) plants. B) bacteria. C) bacteria and insects. D) bacteria and lightning.

Which evidence supports the hypothesis that four-limbed animals came from fish? select all that apply. select all that apply. fossil evidence shows there have always been four-limbed animals on earth.

The proliferation of cyanobacteria was a major contributing factor to the appearance of advanced organisms. identify the gas released by the cyanobacteria that supports this statement. A. ferrous oxide B. oxygen C. hydrogen

Choose an example that best describes sphere interdependency. a rabbit eating grass for energy a plant using carbon dioxide for photosynthesis a deer dying and decomposing a bear catching a fish to eat

An objects ... forming car center of the universe but its ... can change from planet to planet if you increase the mass of a planet what happens to gravity.

When people with severe obesity undergo bypass surgery that seals off part of the stomach, the remaining stomach then produces much less?

Match each description with the correct division of the peripheral nervous system. somatic nervous system regulates voluntary activities parasympathetic nervous system regulates involuntary activities sympathetic nervous system called the rest and

Which of the following diseases is caused by a spirochete? tularemia relapsing fever rheumatic fever Rocky Mountain spotted fever

The brain of the nervous system and the endocrine glands of the endocrine system are similar to one another in certain ways. Both act to send messages to distant body parts. What is a significant difference of the activity of endocrine glands? A.

After reviewing the process of meiosis describe how an error during meiosis could lead to polyploidy

The requency of the red eyes (p ellele) in fruit flies is 63% what is the frequncy of the white eyes allele q allele