Question

Chromosomes are made up of-
A.DNA only
B.Protein only
C.DNA and protein
D.RNA only

Answer 1

Chromosomes are thread-like structures which are located inside the nucleus of the plant and animal cells. Chromosomes are the units that pass on the genetic information from parents to their offspring. They are named so because these structures get strongly stained by dyes. A chromosome is an organized package of DNA.

Complete answer: Chromosomes have a specific structure that keeps DNA tightly wrapped around a group of proteins called histones. This packaging of DNA is necessary because without this packaging it would be very hard for DNA to be fitted inside the nucleus of the cells. Chromosome is very important for the process of cell division as it ensures proper DNA replication and its distribution.
Chromosomes are made up of DNA molecules and proteins, which are positively charged basic histone proteins.
Chromosomes show the 3D structure and play a very significant role in the regulation of transcription. Chromosomes are visible under the microscope during the metaphase stage of the cell cycle, when all the chromosomes are aligned at the metaphase plate in the condensed form. The duplication of chromosomes takes place at the S-phase of the interphase in the cell cycle.
Hence here the correct answer will be an option (C), DNA and protein.

Note: Both the copies of the chromosome are joined by a centromere. One chromosome is composed of 2 sister chromatids which are basically the DNA molecules, 1 centromere that joins the two sister chromatids, and 2 kinetochores. Chromatin contains DNA and some basic proteins histones as well as some non-histone proteins and also RNA.