Answer: To know if a document is a primary source, check to see when the document is published, if it is an autobiography of a person, a diary, a letter, or the documents happen at the time of the event.
The competition between two organisms can be seen if there is only 1 source of food or habitat space and they're competing against each other for the food or habitat.
There is cooperation between two organisms if they are helping each other with resources or alarming each other if there is danger.
Predation between two organisms happen when one organism hunts the other organism for food.
DNA! the question is a typical descrption of it
The nucleolus is the central support structure
Answer:
B) increased exchange surface provided by their membranes
Explanation:
Alveoli are tiny air sacs that are responsible for exchanging oxygen (O2) and carbon dioxide (CO2) in the lungs. Alveoli have elastic fibers in order to expand and recoil depending on the volume of air breathed in. The alveolar epithelial cells (pneumocytes) may adopt a shape that serves to increase the surface area of gas exchange. On the other hand, intestinal epithelial cells have microvilli, which are microscopic projections in the plasma membrane. Microvilli serve to increase the cell's surface area, thereby facilitating the absorption of nutrients and water.
