The seasons are caused by the tilt of the Earth's rotational axis. The answer is A
Answer:
Allopatric speciation
Explanation:
Speciation is the gradual process by which two different species are formed from a single species due to evolution.
Allopatric speciation will occur when the speciation is due to geographical isolation of a species to the extend it prevents or interferes with the gene flow. Therefore, the populations can not mate with each other and they evolve separately.
This is what happened to the fox species when they were separated by a mountain range.
Cell replication is meant to be a very regulated process. Messages are sent to the cell, telling it when to duplicate and when not to. When cells divide according to their natural plan, then there are no problems. However, when cells either do not receive those messages or misinterpret them, they can divide too fast and without pause. These renegade cells are what we call cancer cells.
Transport of a substance from the lumen (cavity) of an organ into one side of a cell and out the other side of the cell into the extracellular fluid is called <u>transcellular transport</u>.
The two routes of transport of substances across the epithelium of the gut are by transcellular method and paracellular method.
Transcellular transport refers to the transport of solutes across a epithelial cell layer through the cells. The best example is the movement of glucose from the intestinal lumen to the extracellular fluid by the epithelial cells. The epithelial cells use the active transport to generate the transcellular transport. Active transport refers to the transport of substances from a region of its lower concentration to a region of its higher concentration against the concentration gradient using cellular energy.
Mitosis is when a DNA error, aka mutation, occurs in a body cell. When cells divide, it needs a copy of the DNA. During DNA replication, that error can cause the instructions for building proteins to differ. The change can not affect offspring. Meiosis is the same situation, but in sex cells. This can be transferred to offspring.
