Answer:
Molecules which move against the concentration gradient across the cell membrane employ the mechanism of active transportation.
Explanation:
Normally, permitted molecules moves across the cell membrane of the cell by the process of diffusion and osmosis. This is used when molecules move from hypertonic region to hypotonic region (if ions) and hypotonic to hypertonic (if water). This is a passive transportation which do not require the expense of energy from the cell.
In contrast, when molecules move in or out of the cell against their concentration gradient, that is ions moving from hypotonic region to hypertonic region, they implore the expense of energy in form of adenosine triphosphate (ATP), and the involvement of the membrane carrier proteins. This is called active transport.
A force is a push or a pull that acts upon an object as a results of its interaction with another object. ... These two forces are called action and reaction forces and are the subject of Newton's third law of motion
Answer:
1. Skin Creams
Explanation:
An independent variable is the only variable that is changed while the rest is kept the same. In this setup, the doctor is using different creams on the same patient with the same skin condition so the independent variable is the skin cream and not the skin condition.
Answer: D. a genetic bottleneck
Explanation:
A genetic bottleneck also known as a population bottleneck is one that describes a sharp reduction in the size of a population caused by environmental events like in the above or caused by human activities.
