Oxygen was introduced into the atmosphere as a byproduct of a. respiration. c. dehydration. b. photosynthesis. d. osmosis.

Select the correct answer. Mary is campaigning for improved air quality in her city. She is very concerned about carbon and methane outputs, but not phosphorous. Why is that? A. She thinks phosphorous makes a positive contribution to air quality. B.

Which statement BEST describes a relationship between the organisms in the food web shown above?

The major mechanism driving cellular differentiation is the difference in gene ... A) Expression B) Sequences C) Order D) Replicaiton

Where does a peptide bond form?

For his science fair experiment, Cole decided to determine how different types, of surface material, affect how fast a matchbox car will go. He chose to use a tile floor, concrete patio and carpet. He used the same car for each of the 20 trails.

Write a paragraph to explain the steps of metamorphasis using the words adult, egg, larva, body parts, grow, rearange, and life cycle

The process of creating a current in a circuit by changeing a magnetic field

Explain why the fact that invasive species did not co-evolve with the native species unbalances an ecosystem.

23 - You work for a furniture moving company. Your boss sends you to the hardware store to buy tie down rope. He tells you to buy the best deal. What is the best deal on rope? 10 feet for $7.00 20 feet for $13.00 50 feet for $28.00 100 feet for $57.

How does an atom become a positive ion?