Molecular Basis of Inheritance Test - 5

DNA content is halved during meiosis cell division and not during mitosis cell division. Chromosome is made of DNA protein and same amount of DNA is present in all cells of an individual.

Sir Archibald Garrod, a British medical doctor, was the first to suggest that genes were connected to enzymes.

George W. Beadle (1903-1989) and Edward L. Tatum (1909-1975) show genes direct the synthesis of enzymes that control metabolic processes using genetic and biochemical studies of the bread mold Neurospora.

A probe is a fragment of DNA or RNA of variable length (usually 100–1000 bases long) which can be radioactively labeled. It can then be used in DNA or RNA samples to detect the presence of nucleotide sequences (the DNA target) that are complementary to the sequence in the probe.

In 1966, Francis Crick proposed the Wobble Hypothesis. He postulated that the 5' base on the anticodon, which binds to the 3' base on the mRNA, was not as spatially confined as the other two bases, and could, thus, have non-standard base pairing.

Crick creatively named it for the small amount of play that occurs at this third codon position. Movement ("wobble") of the base in the 5' anticodon position is necessary for small conformational adjustments that affect the overall pairing geometry of anticodons of tRNA.

Chargaff's rules states that DNA from any cell of all organisms should have a 1:1 ratio (base Pair Rule) of pyrimidine and purine bases and, more specifically, that the amount of guanine is equal to cytosine and the amount of adenine is equal to thymine.

In DNA, sugar and nitrogenous base are attached with each other through glycosidic bond. Phosphate and next sugar with Phosphodiester linkage and purine and pyrimidine with hydrogen bonds.

In the DNA molecule, there are two strands which run antiparallel one in the 5′→3′direction and other in the 3′→5′.

Two strands are combined by Hydrogen bonds between nitrogenous bases of complementary strands.

In semiconservative replication, when the double stranded DNA helix is replicated, each of the two new double-stranded DNA helices consisted of one strand from the original helix and one newly synthesized. It has been called "the most beautiful experiment in biology.

Semi-conservative replication of DNA was proved by the Meselson and Stahl in 1958.

Retrovirus is a type of virus that uses RNA as its genetic material. After infecting a cell, a retrovirus uses an enzyme called reverse transcriptase to convert its RNA into DNA.

The retrovirus then integrates its viral DNA into the DNA of the host cell, which allows the retrovirus to replicate. HIV, the virus that causes AIDS, is a retrovirus.