Q: What according to scientists is the major cause of depression? A:
OPTIONS:
- low thyroid levels
- high fat diets
- high serotonin levels
- low serotonin levels
low serotonin levels

Q: Hair and nails are made of what? A:
OPTIONS:
- chromatin
- proteins
- cellulose
- keratin

Answer: keratin

Question: Q: What are broken down during digestion to provide the amino acids needed for protein synthesis? A:
OPTIONS:
- sugars
- carbohydrates
- metabolytes
- dietary proteins
Answer: dietary proteins

input with options: Q: After the blood in the pulmonary capillaries becomes saturated with oxygen, it leaves the lungs and travels where? A:
OPTIONS:
- to the lungs
- to the kidneys
- to the brain
- to the heart
output: to the heart

Q: Q: An amide bond joining two amino acid units is called a what? A:

OPTIONS:
- carboxyl bond
- ammonia bond
- precipitate bond
- peptide bond

A: peptide bond

Q: What instruments used in guidance systems to indicate directions in space must have an angular momentum that does not change in direction? A:
OPTIONS:
- actuators
- elevators
- magnets
- gyroscopes
gyroscopes