Answer:
D. The two students who have two fragments have one restriction site in this region.
Explanation:
The DNA samples from the cheek cells were subjected to digestion with a restriction enzyme. This enzyme is an endonuclease and cuts the DNA at a specific sequence only. This sequence is called a restriction site. If the restriction site is not present in the sample DNA, the restriction enzyme cannot cut it. The presence of one restriction site in the sample DNA would cut it into two DNA fragments.
Similarly, the presence of two restriction sites in each DNA molecule would obtain a total of three DNA fragments per DNA molecule.
Circulatory system.....circulates blood (a vital delivery system of oxygen) throughout the whole body when tissues need it the most and with a constant supply.
Strong, naive, perfect balance of strong and naive.
I don’t see the “following” that ur talking abt but it is diffusion
Answer: Mosses retain soil humidity and prevents its degradation, besides are habitat for little invertebrates.
Explanation: Mosses are non-vascular plants (they don't have conductive vessels as xylem and phloem) that live places as tree trunks, rocks, walls and soils. This habitats must be humids because mosses need water for nutrient transport, because they don't have cuticle (prevents water lost) and for fertilization. Mosses are important for the ecosistems where they live because retain water in the soils thus prevent erosion and harbor invertebrates as Tardigrades (water bears).