Answer:
Neurilemma
Explanation:
Schwann cells are the neuroglia that produces myelin sheaths. There is a formation of multiple layers of the glial plasma membrane around axons. The cytoplasm and nucleus of Schwann cells from the outermost layer while the inner part has multiple layers of the Schwann cell membrane. The outer nucleated cytoplasmic layer of the Schwann cell that encloses the myelin sheath is called neurolemma. It is found only around axons in the PNS. Its function is to serve in the regeneration of injured axons by the formation of a regeneration tube.
Answer and Explanation:
A gene is a section of DNA. The change in the sequence of the DNA is known as mutation. Mutation always changes the sequence of the DNA. Sunlight can cause mutation. Sunlight produces structures named thymine dimers. Thymine dimers produce twist in the shape of DNA. These twists make DNA hard to copy, which can lead to mutation. It is essential to use sunscreen to block UVA and UVB rays to prevent thymine dimers from emerging in our cells. The US Food and Drug Agency recommends an SPF (sun protection factor) to defend against skin aging and skin cancer. X-ray radiation is a form used in x-rays. The energy level of the X-ray radiation is very high that can produce free radicals. Free radicals can steal electrons from DNA that can cause mutation. By using medical images, we can decrease exposure to X-rays. Less exposure to X-rays prevents mutation and also prevents the production of gene protein in other body parts.
Biologists do not fully understand DNA because there are constant changes and new discoveries developing.
Early in mitosis, during prophase and prometaphase, the nucleus, nucleolus and nuclear envelope begin to dissolve in preparation for cell division. During telophase, which is the final stage in mitosis,, there is a reversal of effects of prophase and prometaphase; nucleus, nucleolus and nuclear envelope are again formed.
