Question

Nucleic acid sequences that undergo few changes over the course of evolutionary time are said to be conserved. A researcher wants to determine the genetic relatedness of several breeds of dog (Canis familiaris). The researcher should compare homologous sequences of __________ that are known to be __________.

a. proteins or nucleic acids; highly conserved

b. carbohydrates; poorly conserved

c. amino acids; highly conserved

d. lipids; poorly conserved

e. proteins or nucleic acids; poorly conserved

Answer 1

The researcher should compare homologous sequences of Proteins or nucleic acids that are known to be highly conserved.

If we want to determine the genetic relatedness then the sequences should be highly conserved so the options (b) , (d) , (e) are incorrect.

?As coding sequences, amino acids and nucleic acids are often conserved to retain the structure and function of a protein. Conserved proteins undergo few amino acid replacement or are more likely to substitute amino acids which have similar biochemical properties. So amino acids are important only for the coding sequences of protein.

Alongwith coding sequences of protein, nucleic acids are important for structure and function of a non-coding RNA. This non-coding RNA (ncRNA) can also be conserved.

So the correct answer will be :-

(a) Protein or nuceic acids ; highly conserved.