Question

what do you mean by nucleus ?

Answer 1

in cell: it is the cell organallae found in eukaryotes which is covered by membrane called nuclear membrane
it contains genetic material ( DNA)
in atom : it lies in the centre of the atom which contains proton and neutron
it gains + charge ( because presence of proton because neutron dosen't have charge
so the charge of nucleus is + )

Answer 2

$\huge{\underline{\sf{\green{Answer-}}}}$

It is discovered by a english botanist, robert brown in 1831,and is designated as the 'director of the cell’.

• It is the largest organelle within eukaryotic cells, ranges from 5 to 25 mm in size

• Some cells like those of sieve tubes of vascular plants and RBCs of mammals do not posses nuclei at maturity. As they can no longer divide, their life span is limited.
• it consist of nuclear envelope Or karyotheca

• The term ‘chromosome’ was coined by waldeyer is 1888.

• Their number is constant in the nucleus for a particular species.

• The lowest diploid number known among plants is 4,found in Haplopappus gracillis whereas ophioglossum reticulatum has a high as 1260 chromosomes.

_________________________________________