UPSC Civil Services Model Paper 7

The nucleus is generally spherical and located in the centre of the cell. Hence statement 1 is not correct.
It is separated from the cytoplasm by a double-layered membrane called the nuclear membrane.
This membrane is porous and allows the movement of materials between the cytoplasm and the inside of the nucleus . This process is known as Diffusion .
Hence statement 2 is correct.
The nucleus contains thread-like structures called chromosomes.
These carry genes and help in the inheritance or transfer of characters from the parents to the offspring. Hence statement 3 is correct.
The chromosomes can be seen only when the cell divides.
Gene is a unit of inheritance in living organisms.
It controls the transfer of a hereditary characteristic from parents to offspring.
This means that your parents pass some of their characteristics on to you.
The entire content of a living cell is known as protoplasm, containing cytoplasm and nucleus.
It includes the cytoplasm and the nucleus.
Protoplasm is called the living substance of the cell.
Large and complex cells need a lot of chemical activities to support their complicated structure and function.
These cells use membrane-bound little structures ( organelles ) within themselves tosegregate different activities.