Answer:
Positive feedback loops occur most frequently in the human body.
Answer:
1.It produces silk which is a high quality fibre
2.to destroy the gelatinious substance inside cocoon so as to obtain silk thread
3.To avoid it from hatching
4.they carry pollen grains while roaming plant to plant and help in cross pollination
Answer:
Mutations of enzymes involved in nucleotide excision repair.
Explanation:
- Xeroderma pigmentosum is a genetic disorder and the person suffering from this disorder is sensitive to ultraviolet light due to the disability of the enzymes involved in nucleotide excision repair which prevents DNA damage caused by ultraviolet light.
- Thus, the individuals are sensitive to the exposure of UV and suffer severe problems when exposed to sunlight.
- The major cause of the disorder is the inability to repair DNA damage caused by exposure to sunlight due to the mutation in an enzyme involved in nucleotide excision repair.
- Nucleotide excision repair is a DNA repair process that can excise out single-stranded DNA that is damaged by UV.
- UV exposure leads to the addition of bulky adducts in the DNA known as thymine dimers. The enzymes of NER are involved in the removal of these adducts by excising out a segment of DNA that contains such lesions.
- However, in the case of XP, the mutations make this repair system non-functional or partially functional and thus, the individual becomes highly sensitive to UV exposure.
<span>The average heart rate is the number of heart beats counted in 15 seconds divided by 15 seconds. The instantaneous heart rate is the time it takes for a single heart beat. Since the heart can beat at varying rates, these values are not necessarily the same.</span>
Answer:
6 ,Be electrons ,8,neutrons (mass number)
