By the end of prophase, each of the following has occurred except
question 7 options:

tighter coiling of the chromosomes

breaking down of the nuclear envelope

disappearing of the nucleolus

lining up of chromosomes in the cell

By the end of prophase, each of the following has occurred except lining up of chromosomes in the cell.

Explanation:

The lining up of the chromosomes in the cell occurs during the third stage of cell division. This stage is termed as the metaphase.

Prophase is the first stage of cell division. Hence, the lining of the chromosomes does not occur by the end of prophase.

During the prophase, the chromatin material condenses and become more compact so that the chromosomes become visible. The nucleolus and the nuclear envelope disappear by the end of prophase. Hence, all other options A, B and C occur by the end of prophase except option D.

unicellular organisms, like bacteria, are able to perform all life functions within one single cell. multicellular organisms need many different types of cells to carry out the same life processes. each of these special types of cells has a different structure that it perform a specific function.