I believe the answer is linear :)
Answer: 1. Sea urchins and sea otters
2. They are prey for carnivores.
3. Sea otters, star fish
Explanation:
Sea urchins and sea otters are carnivores as they eat on the flesh of starfish and sea urchins respectively.
Starfish feed on the kelp forests which are the producers in the food chain and the starfish is the primary consumer and prey for sea urchins. So, starfish and kelp forests are the prey in the marine ecosystem.
Keystone species is the one which controls the population of other inferior species in an ecosystem. Here, sea otters consume sea urchins so the population of sea urchins remained in control Starfish controls the population of kelp forest.
Carbon is released into the atmosphere only during the burning of fossil fuels
Explanation:
During the process of fuel burning, carbon is released in the atmosphere. The human invented power plants, factories, cars and other vehicles releases carbon in the form of carbon di-oxide in atmosphere.
However, the cellular respiration is similar to that of fuel burning as it is too a combustion process. But the carbon produced in this process fuels the inner cellular activities rather than releasing it in the atmosphere.
Answer:
presence of cells
Explanation:
All living things are composed of cells. A cell can be defined as a complex biological arrangement that has all the structures and materials required for life. Cells carry out specialized functions such as, for example, metabolic functions to convert nutrients from food into energy (ATP), and reproduce by mitosis and/or meiosis. Thus, the cell is known to be the basic unit of life.