Answer: restriction enzymes serve the purpose of defense against invading viruses.
Explanation:
It occurs because of contraction of the muscle layers. There are two types of muscle found in the alimentary canal; longitudinal and circular muscle, the alternating contraction of these muscles forces the bolus of food through the digestive system.
Macrophages are specialised cells involved in the detection, phagocytosis and destruction of bacteria and other harmful organisms. In addition, they can also present antigens to T cells and initiate inflammation by releasing molecules (known as cytokines) that activate other cells.
Answer:
Species accumulate their unique features rapidly, then change little for the duration of the species.
Explanation: