Even after seemingly complete endoscopic resection recurrence of neoplasia is frequent and independent of additional thermal therapy.
The answer to 2-7 would be -5, but 7-2 would be 5, depends how specific one is trying to be.
Human activities have altered various natural environments around the planet. Various lands are now fields where only one farm crop is cultivated, is an example of monoculture farming.
An agricultural method of growing or producing a single plant, crop, or a livestock species, breed, or a variety in a field of the farming system at a time is known as a monoculture. Hence, the correct answer is option D, that is, monoculture.
Answer:
B. A sperm cell
Explanation:
Meiosis creates gametes/sex cells, such as the sperm and egg.
So, sperm cells are formed by meiosis.
Meiosis doesn't create fertilized eggs, it instead creates normal egg cells.
Meiosis also doesn't create heart and bacterial cells because those are made in mitosis.
So, B is the correct answer.
A Nerve electrical impulse only travels in one direction. There are several reasons nerve impulses only travel in one direction. The most important is synaptic transport.
In order for a "nerve impulse" to pass from cell to cell, it must cross synaptic junctions. The nerve cells are lined up head to tail all the way down a nerve track, and are not connected, but have tiny gaps between them and the next cell. These tiny gaps are called synapses.
When you get a nerve firing, you have probably heard that it is an electrical impulse that carries the signal. This is true, but it is not electrical in the same way your wall outlet works. This is electrochemical energy. Neurotransmitters are molecules that fit like a lock and key into a specific receptor. The receptor is located on the next cell in the line. When the neurotransmitter hits the receptor on the next cell in line, it signals that cell to begin a firing as well.
This will continue all the way down the length of the nerve track. In a nutshell, a nerve firing results in a chain reaction down the nerve cell's axon, or stemlike section. Sodium (Na+) ions flow in, potassium (K+) ions flow out, and we get an electrochemical gradient flowing down the length of the cell. You can think of it as a line of gunpowder that someone lit, with the flame traveling down the length of it. Common electrical power is more like a hose full of water, and when you put pressure on one end, the water shoots out the other.
Therefore, nerve impulses cannot travel in the opposite direction, because nerve cells only have neurotransmitter storage vesicles going one way, and receptors in one place.
