One of the major elements of natural selection is that all species have genetic variation. Natural selection is a process when organisms adapt better to their environment. It is an essential key in evolution. There is a change in phenotype of a population over time.
The Griffith's experiment, the Avery-MacLeod-McCarty experiment, and the Hershey–Chase experiments were the set of experiments that established DNA as the key hereditary molecule. The Avery-MacLeod-McCarty experiment was an extension to the Griffith's experiment. The heat killed virulent S strain cells of the Griffith's experiment were lysed to form a supernatant containing a mix of RNA, DNA, proteins and lipids from the cell. The supernatent was equally divided into 3 parts after the removal of the lipids. The 3 parts were respectively treated with an RNAase to degrade the RNA, DNAase to degrade the DNA and proteinase to degrade the proteins. The treated supernatant was then added into the culture containing the non-virulent R cells. In case of the supernatant treated with the DNAse, no transformation of R cells into S cells occurred. The transformation of R cells to S cells occurred in the proteinase and the RNAse cases. This indicated that DNA was the hereditary molecule and not protein or RNA.

Answer:
Nitrogen is removed from the atmosphere mainly by nitrogen-fixing bacteria in the soil and oceans (blue-green algae).
Explanation:
Nitrogen is removed from the atmosphere mainly by nitrogen-fixing bacteria in the soil and oceans (blue-green algae).
Answer:
Rice plants possesses several traits which allow sthem to grow in large amount of water because standing water helps them to produce air channel known as aerenchyma that connects roots with shoots and transport oxygen to submerged tissues. Standing water also help many weed to grow and rice plants also takes nutrients from them as well.
Genes are responsible for the traits that allow rice plants to grow in large amount of water but if the gene of rice plant is genetically modified with new gene which is resistant to drought, that can allow the rice to grow in less water.
The genetically modified rice plant then do not require large amount of water and can grow easily.