Answer:
The correct answers would be maintain chromosome number through generations  and cause genetic variations by recombination.
In Meiosis a cell divides into four daughter cells all of which have half the number of chromosomes present in a parent cell.
It helps in the formation of gametes in sexually reproducing organisms.
These gametes (one from father and one from mother) fuse together to form a zygote. It re-established the chromosomal number as that of the parent.
In absence of meiosis, the chromosomal number would have doubled after each generation.
In addition, the meiosis also increases the genetic variation among the population with the help of crossing over which occurs during the pachytene stage of prophase I.
During this event, genetic information is exchanged between the non-sister chromatids of the homologous chromosomes. It produces a new combinations of genes that are different from either parent.
 
        
                    
             
        
        
        
Answer: Active transport
Explanation: requires the cell to spend energy, usually in the form of ATP. Examples include the transport of large molecules (non-lipid soluble) and the sodium-potassium pump. Types of active transport.
 
        
             
        
        
        
Carbon ,hydrogen ,and oxygen
        
                    
             
        
        
        
<span>The calculated to surface area for red blood cells by Gorter and Grendel found to be 36u2.
 The surface area that would be covered once they spread across the surface of the water is 72u2. 
If they spread across the surface area will double. This is because the lipid bilayer with phospholipid the head faces the water on each surface of the membrane.
 It clearly shows that there must be more to membranes than lipid bilayer because membranes grew and the surface tension of membranes is much lower than those of pure lipid structures.</span>