Answer: 80
Explanation: The atomic number is the number of protons in an atom's nucleus. Since mercury has an atomic number of 80 it has 80 protons.
Answer:
Farmers have been using selective breeding for improving their crop qualities and producing animals with better characteristics.
improved so that mankind can benefit from it.
Selective breeding is not okay on a bigger level where it might eradicate the natural varieties of plants and animals completely. When done on a larger level, the wild-type traits of plants and animals will change and be removed completely. This will lead to lesser genetic diversity.
Correct answer: D). Deletion
Tay-Sachs disease is an autosomal hereditary disease that is known to affect the central nervous system. It results from the mutation caused in the gene that encodes for the beta-hexosaminidase enzyme. It is a lysosomal enzyme that is composed of the beta and alpha polypeptides.
It is caused when both the parents are a carrier, it occurs when a baby is born in absence of hexosaminidase. It affects the nervous system and can change the physical appearance after a few months of the birth.