The correct answer is: A. A change in a cell's genetic material.
Mutations occur in DNA as a result of mistakes during the DNA replication (when repair mechanisms don’t fix it) or as the result of environmental factors (e.g. UV light). Mutations can have positive impact, by increasing the genetic variation or can have negative effect, causing the diseases or cancer.
Answer:
increasing birth rate with a greater number of young organisms
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.
D. Scientists use all of the above skills.
Activity like having brightness all the way on or depending on how much data is used, having Bluetooth on also decreases the battery, having a charger on even when over 100 percent can make charging electronic slower. It's better to have the brightness low.