Advertisements
Advertisements
Question
Give reason, why a matured mammalian erythrocyte lacks nucleus and mitochondria?
Advertisements
Solution
A matured mammalian erythrocyte lacks a nucleus and mitochondria. The lack of a nucleus
increases the surface area-volume ratio of RBCs, thus increasing the area for oxygen absorption.
Also, the lack of a nucleus reduces the size of the cell, making it easy to flow through the blood
vessels and more cells can be accommodated in a small area.
The lack of mitochondria implies that the cell does not use any oxygen absorbed for respiration,
thus increasing the efficiency of the cell to transport oxygen as all the oxygen absorbed is
transported without any loss.
RELATED QUESTIONS
The blood from the heart is transported to all parts of the body by the ______.
Give technical terms for The protective covering of the heart
Angina pectoris is due to
Name the following:
The fluid found between the membranes of the heart.
Match the items in Column ‘A’ with those in column ‘B’ Rewrite the correct matching pairs.
| Column A | Column B | ||
| (a) | SA Node | (i) | Plasma |
| (b) | Defective haemoglobin in RBC | (ii) | Serum |
| (c) | Muscle fibres located in heart | (iii) | Pacemaker |
| (d) | The liquid squeezed out of blood during clotting | (iv) | Sickle cell anaemia |
| (e) | Never tires, keep on contracting and relaxing | (v) | Purkinje fibres |
| (f) | Cardiac cycle | (vi) | Cardiac muscle |
| (g) | Liquid part of the blood without corpuscles | (vii) | 0·85 sec |
The table below is designed to indicate the transport of certain substance in our body. Fill in the
blanks with suitable answers.
| Substance | From | To |
| Lungs | Whole body | |
| Carbon dioxide | ||
| Urea | ||
| Digested carbohydrates |
Intestines | |
| Target organs |
Give reason for the following:
Atrial wall is less muscular than the ventricular wall.
Multiple choice questions. Tick ( ✓ ) the correct choice:
The four blood groups in humans are
______ prevent blood clotting.
Mention the phase of heart beat in which both the atrio-ventricular valves are closed.
