The statements above are true;
In a host-versus-graft rejection the recipient's immune system recognizes the donor's tissue as foreign and rejects the transplant. On the other hand, in a graft-versus-host rejection, the donor tissue recognizes the recipient's tissue as foreign and the transplant rejects the recipient, causing destruction of the recipient's tissue and possibly death. Its important also to note that there are two types of rejection, the acute rejection, where the rejection of transplanted tissue that occurs several weeks after transplant. it is delayed hypersensitivity reaction, and the chronic rejection is a rejection of transplanted tissue that can occur at a late time. Immune complexes form in the arteries supplying the graft, choking off the blood supply and the tissue is rejected.
Firstly, the enzyme, DNA Helicase breaks the Hydrogen bonds between a specific region of the DNA molecule and unwinds the duplex DNA molecule at the targeted gene sequence site.
Then, RNA Polymerase binds at the 3` site of the gene sequence of the sense/coding strand(only one strand) that acts as the template for mRNA synthesis. RNA Polymerase then matches free nucleotides by complementary base-pairing(A-U & C=G), working in the 5`to3` direction. Hydrogen bonds then form between the complementary bases, holding the nucleotides in place. Each free adjacent nucleotide is joined at 3` ends by Condensation reactions with the other to form Phosphodiester bonds.
Once the mRNA molecule is formed, it is separated from the synthesis complex and leaves the nucleus through pores in the nuclear envelope to moves towards ribosomes for Translation.
Lastly, the DNA double helix rewinds by forming Hydrogen Bonds.
Plants' stomata refers to the small pores that are found on plants' tissues and leaves. They possess the ability to open and close and thus they regulate water and gases exchange in plants. Green plants have the ability to produce their own food by using the energy from the sun;the process is called photosynthesis. During the day, when there is sunshine, the plants' stomata are always open in order to trap energy from the sun for photosynthesis. The stomata also allow carbon dioxide and oxygen gases to diffuse in and out of the leaves' cells. The stomata usually closes at night in order to prevent excessive water loss.
Answer: red flowers are rich in nectar
Explanation:
