1. The main function of red blood cells is to:

a) Transport oxygen from the lungs to body tissues.

b) Fight off infection and pathogens.

c) Produce and release hormones.

d) Filter waste products in the kidneys.

Answer: a. Red blood cells contain the protein hemoglobin,

which binds to oxygen and carries it from the lungs to body

tissues. This function ensures efficient delivery of oxygen

to cells throughout the body.

2. Which of the following hormones regulates blood sugar

levels?

a) Insulin

b) Adrenaline

c) Estrogen

d) Testosterone

Answer: a. Insulin is the hormone responsible for

regulating blood sugar levels. It lowers blood sugar by

facilitating the uptake of glucose into cells and promoting

its storage as glycogen.

3. Which of the following best describes the function of the

pancreas in human biology?

a) Secretion of digestive enzymes

b) Regulation of blood glucose levels

c) Filtration of blood and waste removal

d) Production of red and white blood cells