Question

a. Respiratory system
b. Internal structure of heart.
. Explain with reasons.
a. Human blood is red coloured.
b. Upward and downward movement of
diaphragm occurs consecutively.
c. Blood donation is considered to be
superior of all donations.
d. Person with 'O' blood group is considered
as 'universal donor'.
e. Food must have limited amount of salts.​

Answer 1

Explanation:

Human blood is red because of the protein hemoglobin, which contains a red-colored compound called heme that's crucial for carrying oxygen through your bloodstream. Heme contains an iron atom which binds to oxygen; it's this molecule that transports oxygen from your lungs to other parts of the bod