Question

what does the nucleus do in the cell and is it in a animal, plant, or both?

Answer 1

Both

Answer 2

Nucleus stores the genetic entropy necessary for reproduction, growth and metabolism of not only the cell it controls, but also of the organism on the whole.
It controls the transfer and replication of hereditary molecules (DNA and RNA) between the parent cell and the child cell.
Nucleus ensures equal distribution and exact copying of the genetic content during the process of cell replication. This is the main nucleus function in animal cells.
The nucleus sustains and controls the cell growth by orchestrating the synthesis of structural proteins in the cell.
Nucleus is the place for DNA transcription in which messenger RNA (mRNA) are produced which synthesize protein. The nucleus contains various types of proteins which can either directly control transcription or are indirectly involved in regulating the process.
The process of energy and nutrient metabolism in the cell is regulated by the nucleus, by directing the synthesis and functioning of enzymes, which is a type of protein.
The selective diffusion of cell's regulatory and energy molecules through the pores in the nuclear membrane is presided by the nucleus.
In plants, nucleus also controls the process of photosynthesis which is the main nucleus function in plant cells.