Ogy Review for DNA and RNA
ne Kara Revecy
1. Who proposed the structure for dna

James Watson and Francis Crick proposed the model of DNA.

The DNA is defined as the genetic information storing molecule of the cell. This molecule was proposed to have different shapes and sizes according to other scientists. But this model is still date accepted because of its enormous proofs and experimental successes.

The model consists of 2 sugar phosphate backbone composed of alternate units of phosphate and deoxyribose sugar. They have the nitrogen base attached to the inner side of the backbone and these nitrogen bases are attached with the complementary nitrogenous base by means of 2 or 3 hydrogen bonds.

the correct option is option d

unicellular organisms, like bacteria, are able to perform all life functions within one single cell. multicellular organisms need many different types of cells to carry out the same life processes. each of these special types of cells has a different structure that it perform a specific function.