The formula for the Karyoplasmic Index $(K.I.)$ is:

Two sister chromatids are held together at the chromosome by which of the following structures?

Which organelle controls the activities of the cell?

Which of the following statements is/are correct?
$(a)$ The nuclear matrix or nucleoplasm contains the nucleolus and chromatin.
$(b)$ The outer nuclear membrane $(Ectokaryotheca)$ is usually continuous with the endoplasmic reticulum and also bears ribosomes on it.
$(c)$ Cells that are actively synthesizing protein have small and fewer nucleoli.

The tips of a chromosome are called:

Robert Brown is well known for the discovery of . . . . . . .