Nucleus is to cell asis to organism

Nucleus of an animal cell

The nucleus is an organelle found in eukaryotic cells. Inside its fully enclosed nuclear membrane, it contains the majority of the cell's genetic material. This material is organized as DNA molecules, along with a variety of proteins, to form chromosomes

Explanation: big brain

d. carbohydrates.

Explanation:

Sugar-consisting molecules. As a source of energy and energy storage cells employ carbs. The carbohydrates in the cells of an organism are broken down to release the stored energy.

Simple carbohydrates

Composed of one or a few molecules of sugar. Examples of simple carbs are table sugar and fruit sugar.

Complex Carbohydrates

Extra sugar from an organism may be preserved as complex hydrates of carbon. They consist of hundreds of molecules of sugar.