Question

question 77
if breathing is halted, animals die because they lack sufficient ______ to perform cellular processes.
a oxygen
b proteins
c ph
d carbon dioxide
e glucose

question 78
the most common molecule used in cellular respiration of all organisms as a source of energy is:
a protein
b cellulose
c glucose
d sucrose

Explanation:

Question 77

Breathing is the process of taking in oxygen. Cellular processes like aerobic respiration require oxygen. Without oxygen, cells can't produce enough ATP (energy) through aerobic respiration, leading to death. Proteins are for structure/function, pH is a measure of acidity/alkalinity, carbon dioxide is a waste product (in animals' cellular respiration context here), and glucose is the fuel but needs oxygen (in aerobic respiration) to be fully utilized.

Glucose is the most common molecule used in cellular respiration (especially glycolysis, the first step of aerobic and anaerobic respiration in many organisms). Proteins are used less commonly (after being broken down and converted), cellulose is a structural carbohydrate (not easily used for energy in most cellular respiration of all organisms), sucrose is a disaccharide (not as commonly the first - choice as glucose in cellular respiration pathways across all organisms).

Answer:

A. oxygen

Question 78