Answer:
Photosynthesis and cellular respiration allow the carbon and oxygen that organisms consume and produce to be cycled through the ecosystem. They work together so that what is made from one process is used in the other. Without them the ecosystem would run out of carbon dioxide and oxygen, and everything would die.
The most applicable answer would be D. Energy
Level 1 - Cells.
Level 2 - Tissues.
Level 3 - Organs.
Level 4 - Organ Systems.
Level 5 - Organisms.
Which simple machine can be described as a rope that is threaded through a wheel or disk?
The correct answer is B - Pulley
A pulley is a simple machine that is used to lift loads. It consists of a wheel on which a rope is placed and the rope is pulled by the person towards himself to lift the load that is tied on the other side of the rope. There are three main types of pulleys: fixed, movable, and compound.