In Meselson and Stahls experiment cells were grown in media

In Meselson and Stahl\'s experiment, cells were grown in media containing^15 N in place of^14 N. and then the cells\' DNA was separated by equilibrium centrifugation. This experiment demonstrated that DNA is replicated by DNA polymerase replication is conservative. replication is semiconservative. forms double helices by means of hydrogen bonding between base pairs. replication occurs in opposite directions on complementary strands. Deduction of the structure of DNA was based on a series of key X-ray crystallographic studies done by Avery, MacLeod, and McCarty, Beadle and Tatum, Meselson and Stahl, Wilkins and Franklin, Watson and Crick.

Solution

2) The correct option is option C - Peas.
Gregor Mendel was an Austrian monk who established the classical tenets of genetics based on his experiments on the garden pea (Pisum sativum). He studied various characters such as height of plant, pea pod shape and colour, flower colour etc. Based on his observations, he came up with the 3 basic laws of genetics - The law of dominance, The law of segregation and The law of independent assortment.

3) The correct option is option C- replication is semi-conservative
This is another classical example in molecular genetics performed by Messelson and Stahl. The aim of the experiment was to establish the semi-conservative replication status of DNA strands. Basically, it means that during replication of DNA, the double helix unwinds and separates into two strands. Each strand then acts as a guiding strand ( template strand) over which the new strand is synthesized. At the end of the replication cycle, one DNA molecule would have replicated into two DNA molecules. Each molecule of DNA would have two strands- one original parent strand and the other being the newly synthesized daughter strand.

4) The correct option is option D- Wilkins and Franklin
Maurice Wilkins and Rosalind Franklin performed the key X-ray diffraction experiments on DNA. Their data was ultimately helpful for Watson and Crick to deduce the structure of DNA.