Ok here we go:
Science starts with observing which leads to hypothesis, which is tested by experiments.
The other two i am not sure of. Hope i was a help to you. One thing you can do to figure out the other two is google: "what type of science includes medicine and envirnmental science", and do the same for the other one.
Answer:
This experiment proved that DNA replicated semiconservatively; half the original polynucleotide is conserved in each of the two copies
Explanation:
Semi-conservative mode of replication means that the two strands of DNA unwind from each other, and each of themacts as a template for synthesis of a new, complementary strand. As a result, two formed DNA moleculesc ontain one original strand and one new strand.
Meselson and Stahl experiment showed this model by labeling the DNA of bacteria across generations using isotopes of nitrogen ( patterns of DNA labeling showed the mode of replication).
The major function of the contractile vacuole of amoeba is osmoregulation. The solute concentration found in the cell of amoeba's cytoplasm is more than the solute concentration in the freshwater that surround the external part of the organism, thus, water enter the cell through osmosis. The contractile vacuole collect the excess water and expel it through an opening in the cell membrane. By doing this, the contractile vacuole maintains the water balance in amoeba. This how the contractile vacuole normally operate.
In a situation where amoeba is placed in seawater, then water from the cell cytoplasm will rush out of amoeba cell, because of the higher salt content of the surrounding medium. The contractile vacuole will respond to the situation by increasing its contraction and pumping water out the cell in an accelerated manner, this will lead to the shrinking of the cell.
Answer: <span>Almost every type of bacteria has become stronger and less responsive to antibiotic treatment when it is really needed.
Hope this helps! :)</span>
We know that frequency of recombination is proportional with the distance between the genes on the chromosome. Therefore when the recombination rate is higher that means the distance between the genes on the chromosome is bigger. If the recombination rate is lower that means the genes are closer to each other on the chromosome. In this case the cross over rate is half the normal rate in the wild-type. That means that on the genetic map the distance between the two genes on the wild type will be twice bigger than the genes of the mutated Drosophila.
