Which structure made of $DNA$ is present in the nucleus?

Which of the following is a characteristic of a telocentric chromosome?

The nucleus is separated from the surrounding cytoplasm by a nuclear membrane,which is

$DNA$ genetic material occurs by itself in lower organisms and combined with proteins as nucleoproteins in higher organisms. The nucleoprotein is organized in higher forms to form

Chromosomes with unequal arm lengths are known as ...........

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.