Question

What are the four basic components of blood?

Answer 1

Plasma`(55%)`, red blood cells`(45%)`, white blood cells`(1%)` and platelets`("present per microliter of blood")`.

Explanation:

Plasma:
Blood plasma contain following components;

• Water `to` `90%`.
• In organic or mineral ions `to` `0.9%`
• Plasma proteins i.e antibodies, prothrombin,albumin and fibrinogin `to` `7-9%`
• Organic nutrients i.e glucose, fats, amnio acids, phospholipids etc
• Nitrogenous wastes i.e urea and uric acid `to` Small amount
• Gases i.e `CO_2` and `O_2`.

https://www.oneblood.org/about-donating/blood-donor-basics/what-is-blood/

Red Blood Cells:
The cytoplasm of a red blood cell contain:

• Haemoglobin `to` `95%`(for dry weight) and about `35%`(if water is counted).

• Enzymes, salts and other proteins `to` `5%`

https://www.medicinenet.com/script/main/art.asp?articlekey=5260

White Blood Cells:
WBCs don't contain any pigment.These are much larger in size than red blood cells. They are grouped into
`color(blue)("granulocytes i.e neutrophils, eosinophils and basophils")` and `color(green)(" agranulocytes i.e monocytes and lymhphocytes".`

• Monocytes and neutrophils `to` kill the invader microbes by damaging or digesting them by phagocytosis.

• Basophils `to` produce heparin and histamine. Heparin inhibits clotting of blood. Histamine participates in allergic reactions.

• Lymphocytes `to` provide immunity against disease.

• Eosinophils `to` Inactivate inflammation producing subsances and attack parasites.

Platelets:
Platelets also don't contain any pigment.

• Platelets don't have nucleus thus can't fit in the definition of cells.

• These are fragments of large cells called megakaryocytes.

• Platelets prevent bleeding by making blood clot at the site of injury.
  These convert the soluble fibrinogen into insoluble fibrin . The fibrin protein enmesh the red blood cells and other platelets in the area of damaged tissue and ultimately forms clot which act as a temporary seal to prevent bleeding.
  
  https://www.medicinenet.com/image-collection/blood_clot_picture/picture.htm