Answer:
The correct answer is: Mutation.
Explanation:
- Mutation can be defined as a phenomenon due to which the nucleotide (DNA or deoxyribonucleotide) sequence present in the genome of an organism gets altered.
- Mutation can occur because of various factors like error-prone replication (DNA polymerase fails to proofread and incorporate the correct nucleotide in the daughter strand), improper DNA repair, exposure to mutagens (that causes mutations like Ultraviolet rays or UV rays that causes the formation of thymine dimer in the DNA), exposure to mobile genetic components like Transposons.
- The different types of mutations with respect to their effect on the DNA sequence are:
- Indel mutations: Also called Insertion Deletion Mutations where large sequences of DNA are either incorporated or removed from the genome. If such a mutation occurs in the protein coding region of a gene, then no functional protein can be obtained from such a gene.
- Base substitution: Here the required nucleotide in the DNA sequence is replaced with some other nucleotide during the process of replication. If this happens in the wobble nucleotide of a codon (the last nucleotide in the triplet codon. A Codon is responsible for encoding for an amino acid. Due to degeneracy of the genetic code, multiple codons can encode for a particular amino acid), that would not affect the protein sequence but if it happens in the other two nucleotide of the codon it can cause change in the amino acid sequence of the protein, resulting in a non-functional protein.
- Silent Mutation: Where the mutation has occurred either in the non-protein coding region of a gene or in the wobble nucleotide of a codon such the amino acid sequence does not get altered.
- Non-sense Mutation: Where the mutation is such that a stop codon is introduced in the middle of the protein coding region of a gene. Hence, a truncated non-functional protein can be produced from such a gene.
A single B-type spermatogonium produces 8 sperms via the meiosis process. As each spermatogonium has 2 spermatocytes and each spermatocyte undergoes meiosis to produce 4 sperm.
The process of producing male gametes from the spermatogonium is known as spermatogenesis (proliferative cells that give rise to sperm cells).
Meiotic cell division is a necessary step in the process of spermatogenesis (reductional cell division).
One spermatogonium can produce 512 spermatids after five meiotic divisions of each kind of spermatogonium, which results in the development of 32 type B spermatogonia, 64 primary spermatocytes, and 32 type B spermatogonia from one spermatogonium.
Consequently, one type B spermatogonium can undergo mitosis to produce two primary spermatocytes (equational division).
Additionally, each spermatocyte undergoes meiosis to produce 4 sperm.
As a result, one B-type spermatogonium can yield 8 sperm.
To learn more about spermatogenesis please click on the given link: brainly.com/question/15828440
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Answer:
DNA là phân tử mang thông tin di truyền, chỉ dẫn cách tạo ra các protein quan trọng cho sự tăng trưởng, phát triển của mọi sinh vật. Xét nghiệm DNA có thể tiết lộ những thay đổi (đột biến) trong gen có thể ảnh hưởng đến tình trạng sức khỏe.
Explanation:
Answer:
All of the choices are correct
Explanation:
The respiratory syncytial virus (RSV) is an enveloped, negative-strand RNA virus (Paramyxoviridae family) capable of infecting ciliated cells of the airways by using its surface glycoproteins G and F for attachment and fusion during viral entry in target cells. RSV can affect the lungs and parts of the respiratory system (e.g., nasopharynx). Although RSV generally causes mild, cold-like symptoms, this virus may also lead to severe infection in babies (12 months) and infants, being one of the most common types of respiratory infections in children, older adults, and immunocompromised patients. Some common symptoms in individuals with RSV pneumonia include fever, nonproductive cough, dyspnea, wheezes, rales, rhonchi, etc.