The answer is a (4) I hope this helps out a bit
Brain energy requirement, metabolism and neurotransmitter turnover consume 20 % of the available oxygen and glucose in the body.
<span>Even though, the brain is only about 2% of the body weight, it consumes about 20% of the body's energy. It is the main consumer of glucose-derived energy. When the mental strain increases, the brain's demand for energy in the form of oxygen and glucose is higher.</span>
Answer;
-Pellicle
Explanation;
-Protist cells may contain a single nucleus or many nuclei; they range in size from microscopic to thousands of meters in area. Protists may have animal-like cell membranes, plant-like cell walls, or may be covered by a pellicle.
-On a paramecium's exterior is found the pellicle. The pellicle is stiff to maintain the paramecium's shape and provide stability but it is also flexible to allow movement. It also acts as an attachment site for external organelles such as cilia.
