The myelin sheath is the protective layer, which is present in the outer layer of the neural cells. This myelin sheath prevents the loss of electrical impulses, which are being conducted in the neurons. This also act as an insulator between neuron and its external environment.
This layer is mainly made up of the protein and fatty substance. The degeneration of the myelin sheath result in many neurological disorders.
Hence, the correct answer is myelin sheath.
Answer:
Option (3).
Explanation:
Teratogens may be defined as the chemicals that can cause birth defects in the fetus. Substances like alcohol, lead and nicotine acts as the main agents of tertaogens.
Shamona is drinking water that contains high level of lead. The element lead is harmful for the fetus. Even the small concentration of lead is enough to cause birth defects. The lead exposure can cause the abnormal development of brain and damages the brain of fetus. The fetus has low birth weight also.
Thus, the correct answer is option (3).
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Answer:</h2>
A subduction zone is the zone of earth crust where tectonic plates meet.
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Explanation:</h2>
- A subduction zone is the zone of the Earth’s crust where tectonic plates meet.
- Tectonic plates are massive pieces of the Earth’s crust that interact with each other.
- The places where these plates meet are called plate boundaries.
- Plate boundaries occur where plates separate, slide alongside each other or collide into each other. Subduction zones happen where plates collide.
Result: Subduction zone is the zone of earth crust where tectonic plates meet.
<span>Two checkpoints during the cell cycle that regulate cell division are right before S phase and M phase.
</span>Cell cycle checkpoints are control mechanisms <span>necessary for proper cell division. </span><span>In the cell cycle, there are two checkpoints: </span><span>the G1 checkpoint and the G2 checkpoint. <u>The G1 checkpoint is right before the S phase, and G2 checkpoint is right before the M phase.</u>
If something is wrong at the G1 checkpoint, the cell will not enter the cell cycle. It is important to be delayed before cell enters S phase where DNA replication commences.
The G2 checkpoint is a DNA damage checkpoint and if DNA is damaged, entering the cell cycle is delayed before mitosis (M phase).</span>
A because carbon cause global warming and air pollution it's not helping the ecosystem