D. The heat is there via convection from the sun
The cell membrane that helps to control what enters and leaves a cell is the outer boundary of the cytoplasm
Carbon dioxide is returned to the atmosphere primarily by the Respiration of animals and plants (the consumers).
Explanation;
Respiration by both plants and animals is an important natural source of carbon dioxide. Carbon dioxide is a by product of the process of respiration, a chemical reaction that plants and animals use to produce energy they need to carry out day to day activities.
Plants and animals use this process to produce energy which is used to fuel normal activities such as growth and movement. The process uses oxygen to break down nutrients and release energy, but also creates water and carbon dioxide as byproducts.
