Answer:
Drugs interfere with the way neurons send, receive, and process signals via neurotransmitters. Some drugs, such as marijuana and heroin, can activate neurons because their chemical structure mimics that of a natural neurotransmitter in the body.
Explanation:
All carbons in propane are sp3 hybridized.
Answer:
D) An ecosystem
Explanation:
An ecosystem is a community of living organisms in conjunction with the nonliving components of their environment, interacting as a system. These biotic and abiotic components are linked together through nutrient cycles and energy flows.
Bird sounds are made in the syrinx, but of course, the air sacs, passageways and the bird's lungs, also contribute to the production of sounds.
When birds start to sing,the 2 passageways between the lung and the syrinx, closes. Then, the sir is squeezed into the air sacs by the chest muscles. Squeezing the air sacs that surrounds the syrinx forces each of the two thin membranes in the syrinx into the 2 passageways between the lung and the syrinx.This process does not allow air to travel through.Afterwhich, muscles around the syrinx contract and tighten one membrane and pulls it out into the passageway (1 of the passageway). Air in that passageway can now move,which passes quickly over the membrane. That fast moving air causes a vibration, thus, sound is produced.
Echinoderms are marine invertebrates. They include sea stars, sand dollars, and feather stars. They have a spiny endoskeleton.
Chordates include vertebrates and invertebrates that have a notochord.
