The answer is, "B", "Ribosomal RNA".
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: A) Mitochondria and chloroplasts are found in prokaryotes.
Explanation:
Both mitochondria and chloroplasts contain their own DNA and ribosomes. The first endosymbiotic event occurred: The ancestral eukaryote consumed aerobic bacteria that evolved into mitochondria. In a second endosymbiotic event, the early eukaryote consumed photosynthetic bacteria that evolved into chloroplasts.
Answer:
This eventual process of speciation by natural selection is illustrated by a sketch ... The integration of genetics with models of natural selection shed tremendous ... processes which cause adaptation within species also tend to create new species. ... Darwin, C. On The Origin of Species by Means of Natural Selection,
Explanation:
