In a population of plants with a diploid number of 12, a new individual appeared with a chromosome number of 24. if this organism could self-fertilize, forming offspring with the same number of chromosomes (24), scientists would consider this an example ) sympatric speciation.

b) behavioral isolation.

c) formation of a hybrid zone.

d) reduced hybrid fertility.

A) sympatric speciation

Explanation:

Sympatric speciation leads to formation of new species from the existing one without the change in their location i.e. they share the same habitat but still become reproductively isolated from each other. It usually occurs in plants when they exhibit polyploidy.

Here, the plant species had originally 12 chromosomes and amongst them a plant appeared with tetraploid 24 chromosomes. Since plants can usually self fertilise, this plant can produce more offspring with 24 chromosomes without requiring a partner. The new plants with 24 chromosomes will form a different species from the original plant with 12 chromosomes.

b c a d mark me

answer: - b cells

explanation: -

so, the b cells mediate their action by identifying the antigens present on the surface of the pathogens and then producing antibodies in return to mediate its effect.