Why is carbon dioxide considered a greenhouse gas? (a) it is released when fossil fuels are burned. (b) it is part of the carbon cycle, which is also known as the greenhouse cycle. (c) it can absorb infrared radiation. (d) it is responsible for protecting organisms from uv radiation.

1. describe the structure and function of the specialized cells you observed in the video. 2. research the types of cells present in the kidney.

Drag each tile to the correct box. the body monitors the levels of oxygen in the blood to regulate breathing. isabel is running in a marathon and is near the finish line. she feels out of breath. how will her nervous system work to generate a reaction? arrange the tiles in chronological order. isabel's breathing rate increases. sensory receptors in the arteries detect low oxygen levels. the brain sends signals through motor neurons. sensory neurons generate an impulse. the central nervous system relays an impulse to certain brain regions.

The human body needs energy in order to carry out life processes such as breathing. where does the body get this energy? a. from eating food b. from learning about new things c. from lying in the sun d. from sleeping