Answer:
Option (d).
Explanation:
DNA is the genetic material of all the organism except some viruses. DNA is composed of nitrogenous base, deoxyribose pentose sugar and the phosphate group.
DNA replicatese by semi-conservative mode of replication in which one the daughter DNA consists of one newly synthesized strand and one parental strand. This mode of replication was explained by Messelson and Sthal experiment. The cells from 15N medium are transferred to 14N medium the band of intermediate density was observed. The daughter DNA consists of one 15N DNA strand and one 14N DNA strnd. This strand undergo replication in the 14N medium. This time one low density DNA band ( contains 14N - 14N DNA strand) and one intermediate density band ( 14N-15N DNA).
Thus, the correct answer is option (d).
Are sponges jointed not jointed or nothing
Sponge are are nothing
Answer: Option C.
The number of protons and neurons it's contain.
Explanation:
Mass number of an atom is also called atomic mass of an atom which is some what expressed in Dalton i.e 1/2. The mass number is the total number of protons and neutrons altogether called nucleons in an atomic nucleus.
