Question

question 31
the four most common elements used in living systems
a ca, he, o, & na
b c, h, o, & n
c c, h, o, & na
d c, mg, o, & n
e c, h, o, & p

question 32
the energy storage polysaccharide in plants is.
a a starch molecule
b a triglyceride molecule
c a glycogen molecule
d a cellulose molecule

Explanation:

Question 31

In living systems, the four most common elements are Carbon (C), Hydrogen (H), Oxygen (O), and Nitrogen (N). These elements are fundamental in forming biomolecules like proteins, nucleic acids, carbohydrates, and lipids. Option A has non - common elements for living systems (He, Ca, Na are not among the four most common). Option C includes Na which is not one of the four most common. Option D has Mg which is not among them. Option E has P which is not one of the four most common. Only option B has C, H, O, and N.

Plants store energy in the form of starch. Starch is a polysaccharide made up of glucose units. Triglycerides are lipids, not polysaccharides. Glycogen is the energy - storage polysaccharide in animals, not plants. Cellulose is a structural polysaccharide in plants, used for cell wall formation, not for energy storage.

Answer:

B. C, H, O, & N

Question 32