Question

1) What is a gene responsible for the expression of a trait called?
2) What are the nucleotides named according to?
3)The twisted ladder-like structure of the double-stranded DNA is also called?
4) What is polarity with reference to the double-stranded DNA?

Answer 1

1) A phenotype is defined as the observable characters of an organism such as height, colour, morphology. That's why phenotype gene is responsible for expression of traits. Traits are always observed in homozygous recessive, homozygous dominant, heterozygous dominant conditions.

2) Nucleotides are named according to the number of the phosphate group (mono, di, tri) and type of glucose if ribose sugar is present then the name of the nucleotide start with Ribo.

3) Twisted ladder-like structure of the double-stranded DNA is also called the DNA double helical structure.

4) Double-stranded DNA has no polarity. As both the strand of DNA containing 3' OH and 5'PO₄ end. Both strands are in antiparallel directions, that's why DNA has no polarity.