Substance transmission refers to the movement of substances from one place to another. This can occur through various mechanisms in living organisms and in the environment.
There are different ways in which substances can be transmitted:
Diffusion: The spontaneous movement of a substance from an area of high concentration to an area of low concentration. This occurs down the concentration gradient and does not require energy.
Active Transport: The movement of substances across a cell membrane against the concentration gradient, requiring energy in the form of ATP (adenosine triphosphate).
Osmosis: The diffusion of watermolecules across a selectively permeable membrane, from an area of lower solute concentration to an area of higher solute concentration.
By mastering the concepts and mechanisms of substance transmission, you will develop a deeper understanding of how living organisms and the environment function.
Use evidence and scientific reasoning to explain how characteristic animal behaviors (e.g., building nests to protect young from cold, herding to protect young from predators, attracting mates for breeding by producing special sounds and displaying colorful plumage, transferring pollen or seeds to create conditions for seed germination and growth) and specialized plant structures (e.g., flower brightness, nectar, and odor attracting birds that transfer pollen; hard outer shells on seeds providing protection prior to germination) affect the probability of successful reproduction of both animals and plants.