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.
As you move up to the food chain, the energy will decrease. This explains that the more the consumers, the lesser the energy that the last consumer will get from the sunlight. This is because each energy will decrease as it passes by the consumers because each consumers takes a portion of the full energy from the sun.
Answer:
An enzyme refers to a kind of protein found inside a cell. The enzymes result in the chemical reactions within the body. The function to accelerate the rate of chemical reaction in order to support life. The enzymes in the body assist in performing very essential functions. These comprise eradicating toxins, building muscle, and dissociating particles of food at the time of digestion.
Enzymes are needed for performing the proper function of the digestive system. Digestive enzymes are primarily produced in the stomach, pancreas, and small intestine. However, even salivary glands generate digestive enzymes in order to dissociate the molecules of food at the time of chewing.
There are three prime kinds of digestive enzymes, which are classified on the basis of the reactions they catalyze. These are protease, amylase, and lipase.
Gas molecules across the membrane
It can be water molecules as well
Monosaccharides are simple sugar unit molecules, whereas polysaccharides are enormous, linking thousands of sugar units. Monosaccharides provide cells with short-term energy. Polysaccharides provide long-term energy storage and rigid structure to cell walls and exoskeletons of animals.