Question

A nucleotide base sequence with 300 codons serves as the template for ______.

		a polypeptide containing 100 amino acids
		a polypeptide containing 300 amino acids
		a polypeptide containing 900 amino acids
		a chromosome containing 300 genes
		a chromosome containing 100 alleles

Answer 1

Answer :

A polypeptide containing 300 amino acids.

Discussion and explanation :

According to Central Dogma, genetic information passes in the following direction :

DNA > mRNA > Polypeptide or protein.

Process of synthesis of mRNA from DNA is termed as transcription. Process of synthesis of protein or polypeptide from mRNA is termed as translation.

DNA transfers its genetic information to mRNA which can code for amino ACIDS. These codes are in triplet from, and each triplet is termed as 'codon'. When translation starts tRNA molecule carrying amino acid and its anticodon loop recognises its complementary codon on mRNA and adds one amino acid each time it reads and attaches to one codon. Amino acids are linked by peptide bond. Thus each codon on mRNA codes for one amino acid. Hence 300 codons will code for a polypeptide having 300 aminoacids.