In DNA, which is absent ?

• Adenine

• Guanine

• Uracil

• Cytosine

Which of the following constitute about 10-20% of total circular RNA?

• m-RNA

• r -RNA

• t-RNA

• hn -RNA

Jumping genes in maize were discovered by:

• Hugo de Vries

• T.H. Morgan

• Barbara McClintock

• Mendel

Innitiation codon is :

• AUG

• UUU

• UAG

• AAG

Non-coding sequences of DNA are:

• exon

• intron

• rhizoids

• cistron

Mutations which alter nucleotide sequence within a gene are :

• frame shift mutations

• base pair substitutions

• both 'a' and 'b'

• none of these

407.

Which organism was used by Beadle and Tatum to proposed one gene-one enzyme hypothesis ?

• E. coli

• Nostoc

• Drosophila

• Neurospora

Lac is obtained from :

• Laccifer

• Bombyx

• Dactylopius

• Lytta

A point mutation comprising the substitution of a purine by pyrimidine is called

• transition

• translocation

• deletion

• transversion

Wobble hypothesis was given by

• R.W. Holley

• M. Nirenberg

• H.G. Khorana

• F.H.C. Crick