UPSC Prelims 2019 Question:

which one of the following statements is not correct?

Explanation: 

• DNA, or deoxyribonucleic acid, is the hereditary material in humans and almost all other organisms. Nearly every cell in a person’s body has the same DNA. Most DNA is located in the cell nucleus (where it is called nuclear DNA), but a small amount of DNA can also be found in the mitochondria (where it is called mitochondrial DNA or mtDNA).
  
  
• In the nucleus of each cell, the DNA molecule is packaged into thread-like structures called chromosomes. Each chromosome is made up of DNA tightly coiled many times around proteins called histones that support its structure.
  
  
• It is not possible to construct a functional chromosome by joining segments of DNA taken from different species. Chromosomes are very long and codes for so many genes. Within a specie, translocation can take place and different parts of two chromosomes may join to produce functional chromosome. But this often gives rise to abnormalities like Philadelphia Chromosome.
  
  

Therefore, option (1) is the answer.

Subject: Science & Technology | Biology