Free Molecular Basis Of Inheritance (Daily Quiz: 9) NEET Biology Questions & Answers with Detailed Explanation & Full Review

Answer: (d)

Haploid describes a nucleus cell or organism with a single set of unpaired chromosomes. The haploid number is designated as X. Reproductive cells, formed as a result of meiosis are diploid. Fusion of two such cells restores the normal diploid number. Therefore, haploids are more suitable for mutation studies than diploids. This is because all mutations, whether dominant or recessive expressed in haploids.

Answer: (b)

Splicing is a process in which introns and intervening sequences of non-essential nature are removed by nuclease. Okazaki fragments are newly synthesized DNA fragments that is associated with the lagging or discontinuous strand. Jacob and Monad were the first to elucidate a transcriptionally regulated system. They proposed lac (lactose) operon. The lac operon is an operon which is required for the transport and metabolism of lactose in Escherichia coli bacteria and some other enteric bacteria. It has three adjacent structural genes, lacZ, lacY, and lacA. Inducer is a molecule that regulates gene expression. It attaches to repressor and changes the shape of operator binding site so that repressor no more remains attached to the operator. In the lac operon, allolactose is the actual inducer while lactose is the apparent inducer.

Answer: (a)

RNA polymerase initiates and extends the RNA (chain elongation) and functions always in 5′ to 3′ direction. The structural component of DNA has 3′ to 5′ polarity. It is also called template DNA strand or antisense (–) strand.

Answer: (a)

Genetic code is non-ambiguous. Non-ambiguous code means that there is no ambiguity about a particular code. One codon specifies only one amino acid and not any other. There are 64 codons. Out of 64, 3 are stop codons or non-sense codons, i.e., these do not code for any amino acid and rest 61 code for one of the 20 amino acids. Neither of them code for more than one amino acids except GUG which normally code for valine but in certain conditions it also codes for N-formyl methionine as initiation codon.