<span>Eutrophication or more precisely hypertrophication, is the enrichment of a water body with nutrients, usually with an excess amount of nutrients. This process induces growth of plants and algae and due to the biomass .... Although eutrophication is commonly caused by human activities, it can also be a natural process, ...</span><span>
</span>
Food enters the stomach during the third stage of digestion, hope this helps.
<span>Large changes in allele frequencies can occur in a short time - any changes in frequency, occurring as a result of random chance, would have a proportionally larger effect in a small population. </span>
<h3><u>Connective tissue:</u></h3>
It is the layer under the epithelial tissue in the body. It is stronger than epithelial tissue and is found in many organs. It provides protection.
<h3><u>Epithelial tissue:</u></h3>
It covers the outside of the body like a veil. located in the outermost part of the body. Protects the body against microbes and infections.
<h3><u>Muscle tissue:</u></h3>
It is located in the joint areas and forms the support and movement system. It allows us to make bodily movements.
<h3><u>Nervous tissue:</u></h3>
It is the fastest communication tissue. It allows us to feel pain and the sense of touch. It is impossible to repair this tissue after it is damaged. It causes paralysis. It is very important as it plays a role in the activity of neural transmission.
The valves are responsible for preventing blood from flowing in the wrong direction, they are present in the veins, and the arteries don't need them because the aorta (biggest artery) pumps or in other words pushes it with such a force that no other force can change its direction, in the veins there is no structure present for pumping them as a result we have got valves so that they go in one direction...... the meaning of the word valve is to allow in one direction
