The answer is single opening. The gastrovascular cavity varies from the alimentary canal in that only the gastrovascular cavity has only a single opening. In addition, an alimentary canal has two openings and food moves over it unidirectional. The gastrovascular cavity is a construction establish in primitive animal phyla. It is accountable in cooperation with the digestion of food and the transportation of nutrients all over the body.
An organism must has a large surface area to volume ratio in order to exchange material easier
in animals erythrocytes have a flat concave shape that allows them to carry more haemoglobin and also increases its surface area to volume ration so that the length and availability of a surface is less for the materials to travel
multi cellular organisms tend to have flat and elongated respiratory surfaces to allow for a higher surface area to volume ratio in order to increase the rate of gas exchange
the ilium in most mammals is flat and elongated and is covered with microvilli to increase surface area and to reduce the cells volume therefore reducing its surface area to volume ratio
hope that helps
B creates a disturbance called an electromagnetic wave
Answer:
(B) DNA instructs the building of various carbohydrates that provide energy for the cell (C) The DNA of an organism will dramatically change
Explanation: