Blood vessels expand during hot weather and retract/ tighten in cold weather
Answer is B. Porifera
Members of the phylum porifera includes animals which lack tissues. These animals are also called sponges. These are the simplest multicellular animals. Even though they are multicellular, they do not have any tissues or organs. They have cellular level of body organization. Sponges are aquatic animals and water plays a major role in the feeding, exchange of gases and as well as excretion.
Answer: Let me help you, its affects the Ecosystem because it basically heats the planet up. It causes the balance of air to shift and become extremly warm.
Explanation:
Cytoplasm is a jello like substance that hold all the cells organelles in place|
Imaging a fruit cup with jello in it,the fruits in the cup represent organelles and the jello in the cup represents cytoplasm.