The mechanisms of reproductive isolation prevent the reproduction of two individuals from different species. The prezygotic mechanisms disrupt the stages of reproduction before the forming of the zygote or prevent the mating at the start, and the postzygotic mechanisms affect the stages of reproduction after the forming of the zygote.
So, the first and the third example (the urchins and the grasshoppers) show the prezygotic mechanism, as the two individuals are not able to mate or form a zygote.
The second and the fourth example ( zonkey and the death of a zygote) show the working of the postzygotic mechanisms, as the zygote is formed, but it seems to be inviable, and the zonkeys are sterile, preventing the individual to reproduce.
Answer:
<em>Goose Flesh</em><em> also known as </em><em>Goose Bumps</em><em> also known as</em><em> Cutis Anserina (scientific term).</em><em> It is a temporary change of skin. The skin becomes rougher due to fear, cold, excitement, etc. Small bumps appear on the surface of the skin because the arrector pili muscles contract. </em>
Hope this helped
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Answer:
i
Explanation:
long chains of repeating subunits, called nucleotides
A nucleotide is the basic building block of nucleic acids
