CBSE Questions for Class 11 Medical Biology Body Fluids And Circulation Quiz 2 - MCQExams.com

Red blood cells are also called RBCs or Red blood corpuscles. RBC transport oxygen to tissues and remove carbon dioxide from the body. Nearly half of the blood's volume i.e 40 to 45% is red blood cells. In humans, mature red blood cells are flexible and oval biconcave disks with an average diameter of 7.2μm

So, the correct answer is ‘7.2 μm’

• Red blood cells develop and mature in the bone marrow.
• Red blood cell takes the shape of a biconcave disc, approximately 7 - 8 micrometers in diameter.
•  Mature RBC has no nucleus and no organelles, so option A is correct.

• Solution:
• Correct answer is option B
• Explanation for correct option: Red Blood Cells are produced in the bone marrow and they have a nucleus when they are initially produced.
• Later, they lose nucleus in order to accommodate more haemoglobin so that they can transport more amount of oxygen.
• Since they don’t have nucleus at maturity, they lack DNA as well.
•  Explanation for incorrect option: Rest all options i.e., nucleated ovum , mature spermatozoa, hair cells have nucleus and thus posses DNA too. 

• The oxygenated blood leaves the lungs through pulmonary veins, which return it to the left heart, completing the pulmonary cycle. 
• This blood then enters the left atrium, which pumps it through the mitral valve into the left ventricle. 
• So, the correct option is 'Left atrium'.

$$\textbf{Correct Option C}$$

$$\textbf{Solution}$$

$$\bullet$$  $$\textbf{Option A}$$ All systemic arteries are branches, either directly or indirectly, from the aorta. It carries oxygenated blood from the left ventricle, through the arteries, to the capillaries in the tissues of the body.

$$\bullet$$ $$\textbf{Option B}$$  The liver has two blood supplies, the hepatic artery and the portal vein. The hepatic artery provides oxygen and nutrition. So, hepatic artery is the one which supplies oxygenated blood to the liver, pylorus of the stomach, duodenum, pancreas, and gallbladder.

 $$\bullet$$ $$\textbf{Option C}$$ The pulmonary artery carries from your heart to your lungs. It carries deoxygenated blood from the right side of the heart to the lungs. This is the only artery which carries deoxygenated blood,

$$\bullet$$ $$\textbf{Option D}$$  Cardiac artery also called, coronary arteries run along the coronary sulcus of the myocardium of the heart. Their main function is to supply blood to the heart.

So, the correct option is C.

• White blood cells or WBCs are the cells of the immune system, that are involved in defending the body against infections. There are different types of WBCs such as eosinophils, neutrophils, lymphocytes, monocytes etc.