The interphase nucleus has a loose and indistinct network of nucleoprotein fibres called chromatin, but during different stages of cell division, cells show "structured chromosomes" in place of the:

Q. 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.

Q.

The structure formed when the chromatin network condenses during cell division is called ___

Q. The nucleoplasm contains a network of dark-coloured fibres called . These condense into during cell division.

Q. Match the terms to these definitions.
Centromere, centrosome, chromatin, chromosome, spindle, cell cycle, karyotype, meiosis, mitosis, sister chromatids, interphase, metaphase
.......... A type of cell division where chromosome number in daughter cells remains the same as in parent cell.

Q.

Match the following stages during Mitotic cell division with the key changes:

$$\begin{array}{cc}\text{Column I}& \text{Column II}\\ \text{i. Prophase}& \text{a. Formation of 2 daughter cells, preparation for next division.}\\ \text{ii. Metaphase}& \text{b. Organelles disappear, formation of chromosomes.}\\ \text{iii. Anaphase}& \text{c. Spindle fibres, chromosomes at equatorial plate.}\\ \text{iv. Telophase}& \text{d. Splitting of chromatids, chromosomes move towards poles.}\\ \text{v. Interphase}& \text{e. Spindle fibres disappear, Cytokinesis follows.}\end{array}$$