Answer:
Cells vary greatly in shape These shapes are often related to the function they perform. like the disk shape of  erythrocytes  can absorb and transport oxygen due to increased surface area., the amoeboid shape of leukocytes allow them to squeeze through capillaries. etc. 
Explanation:
Cells can be disc-like , polygonal, rectangular, cubopid thread like branched or even irregular. these are related to the functions that each cell performs.
Some examples showing relation between cell shape and function are as follows.:
- Human blood cells are circular and biconcave to transport oxygen.
- White blood cell are amoeboid to squeeze through thin capillaries.
- Nerve cells are long so that they can carry nerve impulse to a long distance very quickly.
- Guard cells of stomata are bean or dumbell shaped to open and close the stomata.
 
        
             
        
        
        
Answer:
A small piece of circular DNA called a plasmid? is extracted from the bacteria or yeast cell. A small section is then cut out of the circular plasmid by restriction enzymes, 'molecular scissors'. The gene for human insulin is inserted into the gap in the plasmid. This plasmid is now genetically modified.
Explanation:
 
        
             
        
        
        
Answer:
For muscle contraction to take place oxygen is needed. ... Oxygen allows the body to convert glucose into ATP more efficiently without creating a waste product.
Cellular respiration is the process in which your muscles use oxygen to produce ATP energy. ... Whether you're exercising or not, the oxygen in your body is used to break down glucose and create the fuel for your muscles called ATP
ATP= Adenosine triphosphate 
HOPE IT HELPS : )
PLEASE MARK ME BRAINLIEST.
Explanation:
 
        
             
        
        
        
Answer: "Constrictive" pyramid
[ I hope my answer is correct]