A star is a fusion reactor. Under enormous pressure, resulting from gravity, light nuclei of gases such as hydrogen merge to form helium, and since this process releases energy, the start begins to radiate the excess energy. Later on, helium fusion produces heavier elements, and so on.
The amniotic egg is a characteristic of both B and C. Both reptiles and birds have the characteristic of the amniotic egg.
The answer is D. A cold tundra
Answer:Conservation biologists, philosophers, environmental ethicists, and others offer several key reasons to conserve biodiversity. One argument is that organisms have direct economic value for humans. We use plants and animals for medicines, food, clothes, building materials, recreation, and other luxuries and necessities. But what if an organism that is of no use to us for food or hides is screened for useful medicinal compounds and found to have none? Do we sanction its extermination? Why must a plant or animal be of direct economic benefit to humans to have worth? Economic value alone is not the only reason to preserve biodiversity.
Another reason often given…to conserve biodiversity is that organisms, as components of ecosystems, provide services, and their interactions with other organisms contribute to the overall healthy functioning of ecosystems… On a practical level, biologists want to know just how much the loss of a few species will reduce the quality of services within a specific ecosystem. Two schools of thought prevail.
Two brain structures the size of matchsticks that rest above the nasal cavities are the olfactory bulbs.
It is a part of your brain which is responsible for providing your with olfactory activities, meaning, the ability to smell. It is located at the foremost front of your brain, somewhere around your eyes, and is connected with the nose to give the smelling sensation.