<span>A stem is one of two main structural axes of a vascular plant, the other being the root. The stem is normally divided into nodes and internodes. The nodes hold buds which grow into one or more leaves, conifer cones, roots, other stems, or flowers (inflorescences); the internodes distance one node from another.</span>
Answer:
Overfishing is one of the major concern no a days in aquatic systems. overfishing is resulting in the extinction of aquatic organisms and it can lead to several damage to other living organism.
Prawns and small fishes are important organisms in food web or in aquatic system as they maintain the bacterial level or other microorganism level in control.
Prawn and small fishes utilize oxygen and nutrients present in water to survive, if they will get extinct the amount of nutrient and oxygen left will be used by the bacteria and mold living in the system which can have bad impact on human and other organism.
Heron and pelican populations depends on prawn and small fishes for survival as they feed on them and when there will be not sufficient population of prawn and small fishes, there are chances that heron and pelican populations can also get extinct.
Answer:
1. gravel of the sand: a part is dissolved and the remainder is grouped at the bottom of the beaker.
2. drop of sunflower oil: It is not absorbed and heaps on the surface of the water contained in the beaker.
Explanation:
Gravel of the sand is a polar substance. This means that this substance has the ability to dissolve and mix with water in a system in which both were placed together, such as a beaker, for example. However, the beaker limits the amount of water, which limits its ability to dissolve polar substances. Therefore, depending on the quantity, the gravel of the sand, when placed in a beaker with water, will dissolve, in parts, what is not dissolved will accumulate in the bottom of the beacker, because the gravel of the sand is denser than the water.
With the drop of sunflower oil the exact opposite happens. This is because drops of oil are nonpolar substances, which means that they do not have the ability to be dissolved in water. This means that when dropped into the beaker with water, the drop of sunflower oil will not dissolve, but will pile up on the water surface, because it is less dense than water.
