Nucleic acid $(DNA)$ is $NOT$ found in:

What are $P, Q,$ and $R$ in the given plant cell?

Which of the following statements are incorrect?
$(i)$ Plant cells have centrioles which are absent in almost all animal cells.
$(ii)$ Ribosomes are the site of protein synthesis.
$(iii)$ The middle lamella is a layer mainly of calcium carbonate which holds the different neighbouring cells together.
$(iv)$ In animal cells, steroidal hormones are synthesized by smooth endoplasmic reticulum.
Of the above statements:

Identify the labels $A, B, C, D$ and $E$ in the given diagram. The following components are listed:
$(i)$ $SER$
$(ii)$ Ribosome
$(iii)$ Nucleus
$(iv)$ Nuclear pore
$(v)$ $RER$

Is extragenomic $DNA$ present in prokaryotes and eukaryotes? If yes,indicate their location in both the types of organisms.

Which of the following cell organelles were discovered after the introduction of electron microscope?