Looking at your diagram, the purple particles represent gas particles. They are most dense near sea level and the least dense near the top of the atmosphere.
In the diagram given in the attachement depicts the model of density of gas in the atmosphere.
The purple balls represent the gas molecules and we can see that the number of purple balls is more near the bottom i.e. Sea level and gradually decreased moving towards the top i.e increasing height or top of the atmosphere.
This shows that the density and pressure of the air decreases with increase in height.
So, the Correct Option is:
They are less dense near the top of the atmosphere.
Chloroplast which is are only found in plant cells and algal. The chloroplast has a very high concentration of chlorophyll. The chloroplast is the cell organelle that produces energy by using photosynthesis.
No because if the body never met the pathogen before so the immune system would not have had any reason to make an antibody against it because body makes antibodies against specific pathogen :)) i hope this be helpful