The cell is the smallest functional unit of life, which is why it is sometimes referred to as the building block of life.
        
             
        
        
        
Answer:
1.Plant absorbing water from the soil.
Explanation:
Osmomsis occurs by the movement of a water from a region of higher concentration of water molecules to a region of lower concentration of water molecules, through a semi permeable membrane,
 <em><u>OR</u></em>
It occurs as a result of movement of substance molecules from a region of lower concentration to a region of Higher concentration of the substance.
 <em><u>Note</u></em><em><u>:</u></em> The higher the concentration of the substance molecules,the lower the concentration of water molecules.
 
        
             
        
        
        
Answer:
Alveoli are tiny, balloon-shaped air sacs. Their job is to move oxygen and carbon dioxide (CO2) molecules into and out of your bloodstream.
Explanation:
 
        
             
        
        
        
Answer:
A. anaerobic respiration in muscle cells, forming lactic acid
Explanation:
Running marathon is a vigorous exercise, which often leads to excessive use of oxygen in the cells of the athlete. This causes the cells to switch from the aerobic (with oxygen) to the anaerobic (without oxygen) mode of respiration. This anaerobic respiration produces a product called LACTATE OR LACTIC ACID. 
The lactic acid becomes excessive and gets stored in the muscle cells of the athlete. This often leads to cramps, muscle pulls etc. during the marathon. Therefore, an individual running a marathon may experience periods of oxygen deprivation that can lead to anaerobic respiration in muscle cells, forming lactic acid.