Question

How many following statements are correct?
(A) Nucleus as a cell organelle was first described by Robert Brown as early as $1651$.
(B) The interphase nucleus has highly condensed nucleoprotein fibres called chromatin.
(C) During different stages of cell division, cells show structured chromatin in place of the nucleus.
(D) Every chromosome essentially has a primary constriction which is also known as NOR.
(E) Many membrane bound minute vesicles called microbodies that contain various enzymes are present in both plant and animal cells.

• A. One
• B. Two
• C. Three
• D. Four

Answer 1

Answer: (B)

Two

Nucleus as a cell organelle was first described by Robert Brown as early as 1831.

During interphase, chromatin is in its least condensed state and appears loosely distributed throughout the nucleus.

Chromatin is a complex of DNA and proteins that forms chromosomes within the nucleus of eukaryotic cells. During cell division, the structure of the chromatin and chromosomes (structured chromatin) are visible under a light microscope, and they change in shape as the DNA is duplicated and separated into two cells.

Nucleolus organizer regions (NORs) are chromosomal regions crucial for the formation of the nucleolus. Every chromosome essentially has a primary constriction which is also known as centromere.

Microbodies are membrane-bound vesicles, that contain various enzymes, are present in both plant and animal cells.

So the correct answer is option B.