NEET BIOLOGY

Detailed explanation-1: -All cells have a nucleus. True, with some qualifications. See notes. All plant and animal cells have a nucleus.

Detailed explanation-2: -Only the cells of advanced organisms, known as eukaryotes, have a nucleus. Generally there is only one nucleus per cell, but there are exceptions, such as the cells of slime molds and the Siphonales group of algae. Simpler one-celled organisms (prokaryotes), like the bacteria and cyanobacteria, don’t have a nucleus.

Detailed explanation-3: -Nucleoli are present in almost every eukaryotic cell type and represent the most prominent compartment of the cell nucleus.

Detailed explanation-4: -Prokaryotes are organisms whose cells lack a nucleus and other organelles. Prokaryotes are divided into two distinct groups: the bacteria and the archaea, which scientists believe have unique evolutionary lineages. Most prokaryotes are small, single-celled organisms that have a relatively simple structure.

Detailed explanation-5: -The nucleus is the largest and most significant living organelle of the cell. All the cellular activities of the cell are regulated by the nucleus. Hence it is called brain or control centre of the cell.