A mutation that involves the addition, subtraction, or substitution of a single base is known as: a. genetic drift. b. a basic mutation. c. polyploidy. d. a chromosomal aberration. e. a point mutation.

Option E) a point mutation

Explanation:

Point mutation is the exchange of a single nucleotide for another. It could be classified as: transition (change of a purine for another purine or a pyrimidine base for another pyrimidine); transversion (change of a purine base for a pyrimidine or a pyrimidine for a purine).

Also, Point mutation that occur within the protein coding region of a gene can be classified into different kinds, they are:

- Silent mutation

- Missense mutation

- Non-sense mutation

- Frameshift mutation - this is a kind of point mutation where a single nucleotide can be added or subtracted from the DNA sequence.

Thus, point mutation is the answer

E) A point mutation

Explanation:

A point mutation is a genetic mutation where a single nucleotide base is replaced, inserted or deleted from a sequence of DNA or RNA.

correct answer is option a.

tropopause, stratopause and mesopause have all in common aspect that is point of maximum temperature in its layer of the atmosphere. all layers of atmosphere observe abrupt change in temperature. tropopause is the boundary between troposphere and stratosphere. stratopause is the boundary between stratosphere and mesosphere. mesopause is the boundary between mesosphere and thermosphere. these all boundaries are ranges between altitude of 0 to 80 km.

im not intirely sure but i think the anwser is d relative humidity