to support life, why must a planet have a roughly circular orbit around a sd tar? A. so fresh water is available. B. to keep the proper air molecules in the atmosphere. C. to support chemical reactions. D. for temperature regulation

Which of the following is an example of an organ? A) Stomach B) Brain cell C) Muscle Tissue D) Heart

What are the three main parts that comprise a virus

What is the purpose of the tympanic membrane

At what ph do fish in lake ecosystems fail to reproduce

Which statement best describes the amount of catalyst that remains at the end of a reaction?

Which statement describes the reaction for cellular respiration? The equation is carbon dioxide + water → glucose + oxygen + water and energy is required in the form of light O The equation is glucose + oxygen carbon dioxide + water and energy is

When is energy needed to move substances across the cell membrane

Which term describes the highest pressure against the walls of the blood vessels?

How might more than one agent of physical weathering operate in the same place

What is the primary source of energy for food chains in an ecosystem? decomposers producers consumers the sun