_____ is a thin layer where temperature falls rapidly in a lake.

Which of the following groups has the most threatened species?

Earth’s largest carbon reservoir is ______.

Match each term with the appropriate concept.

_____ is the movement of organic compounds through phloem.

_____ is all regions on Earth that can support life.

_____ is the conversion of nitrates or nitrites to gaseous forms of nitrogen.

Seeds are mature _____; fruits are mature ______.

Which is not a part of aerobic respiration

Which of the following structures do not aid in locomotion