As Earth rotates, different parts of Earth receive sunlight or darkness, giving us day and night. Since different parts of Earth enter and exit daylight at different times, we need different time zones. In the late 1800s, a group of scientists figured out a way to divide the world into different time zones.
Answer: CHANNEL PROTEINS provide openings in the plasma membrane for substances to flow through without changing structure, and CARRIER PROTEINS allow passage of substances through the plasma membrane after undergoing a subtle change in shape.
Explanation: They are described thus:
A channel protein is a protein that allows the transport of specific substances across a cell membrane.
Carrier proteins are proteins that carry substances from one side of a biological membrane to the other. Many carrier proteins are found in a cell’s membrane, though they may also be found in the membranes of internal organelles such as the mitochondria, chloroplasts, nucleolus, and others.
Answer:
What is the most in danger from the effects of overfishing?
Animals that are normally eaten by fish.
Explanation:
There will be distruption of the food chain as the feeding pattern of those that feeds on fish changes as a result of scarcity of fish in the ocean due to overfishing which poses a danger
The guard cell is responsible for controlling the size of the stomata in leaves. These do so as a result of an interaction between potassium ions and water in and around the cells. When potassium ions accumulate inside the guard cells the water potential inside these cells is lower than that of the outside and as a result, water has to be taken in. This makes the guard cells turgid which in turn stretches them and results in the opening of the stomata. Meanwhile, when potassium ions accumulate outside the cell, the opposite scenario results. Water from inside the cell moves out, making the guard cells flaccid, thus causing these to cover (and effectively close) the stomata.
