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.
<span>is to regenerate the co enzyme NAD+, so that the glycolysis process can continue to breakdown glucose, produce ATP, and also produce pyruvate for the continuation of the process at the same time in anaerobic conditions when no oxygen is available.</span>
Unwanted pregnancy or std ( sexually transmitted disease <span />
Embryologically, the space for the development of right lobe is made earlier by the closure of <span>pleuroperitoneal and pleuropericardial membranes, thereby creating more space for the development of right lobe. Molecular stimulation factors are also involved in the process. </span>
The triceps extends -----------
