Answer:
Explanation:An example of such a substance is table salt. The chemical formula for table salt is NaCl. ... That there are no numbers present in the chemical formula means that there is one atom of each element present in the molecule. The Periodic Table reveals that Na is the symbol for sodium, and Cl is the symbol for chlorine.
The right answer is vein (it contains blood and has valves).
The infra-cardiac veins of small and medium caliber possess this system of fight against gravity. The valves consist of a dense connective tissue, surmounted by endothelial cells, corresponding to a fold of the intima. They allow blood circulation in the sense organ / heart but prevent venous reflux.
A compound light microscope is a microscope with more than one lens and its own light source. In this type of microscope, there are ocular lenses in the binocular eyepieces and objective lenses in a rotating nosepiece closer to the specimen.
<u>The four types of interactions in communities are:</u>
- Mutualism
- Parasitism
- Commensalism
- Competition
<u>Definition of each interaction:</u>
<em>Mutualism: </em>
The type of interaction in which both the species involved are benefited, it is called mutualism.
<em>Parasitism:</em>
The type of interaction in which one species is benefited, whereas the other is harmed, it is called parasitism.
<em>Commensalism:</em>
The type of interaction in which one species gets benefited without harming or providing benefits to others is called commensalism.
<em>Competition:</em>
The type of interaction in which both species lose is called competition. It is opposite of mutualism.
<u>Symbiotic relationship:</u>
It refers to the type of interaction in which lastly one species gets benefited. The type of interactions such as <em>mutualism, commensalism, and Parasitism </em>are considered as symbiotic relationship.