They increase the permeability of the lymph capillaries. Interstitial fluid enters the lymphatic vessels through the mini valves (which are overlaps of endothelial cells
from multiple lymph capillaries). The valves also prevent the backflow of the lymph from the vessels back to the tissues.
Answer: Of all the branches of complex animals, sponges are the only group lacking TRUE TISSUE.
Explanation:
<span>An advantage for the angiosperm approach to the formation of nutritive tissue is in energy conservation.</span> <span>The nutritive tissue is formed via double fertilization in Angiosperms. The advantage of double fertilization is that the plant does not invest energy in seed nutritive tissue until after an egg has been fertilized. This means that endosperm (nutritive tissue) starts to develop and store nutrients after it has been fertilized by a sperm cell.</span> Another advantage is that the endosperm nucleus is very active and <span>divides rapidly, so it forms the nutritive tissue very quickly.</span>