When does the nuclear membrane and nucleolus disappear? When do they reappear?

Prophase

Explanation:

The nucleus during mitosis. Micrographs illustrating the progressive stages of mitosis in a plant cell. During prophase, the chromosomes condense, the nucleolus disappears, and the nuclear envelope breaks down.

The nuclear membrane dissolves in the first part of mitosis, so that the cell can grow and divide.  It is prophase.

Explanation:

the correct answer is option b

behavioral response need communication and thus co-ordination at several levels such as interaction among cells, organ system and the entire organism.

behavioral response produces both internal and environmental stimulus.

the generally accepted parts of modern cell theory include: all known living things are made up of one or more cells. all living cells arise from pre-existing cells by division. the cell is the fundamental unit of structure and function in all living organisms.