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प्रश्न
Why are leucocytes classified as granulocytes and agranulocytes? Name each cell and mention its functions.
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उत्तर
White blood corpuscles are colourless. They are nucleated cells. They are found in the bone marrow, spleen, thymus, and lymph nodes. They are grouped into two categories:
1. Granulocytes: They contain granules in their cytoplasm. Their nucleus is irregular or lobed. The granulocytes are of three types:
- Neutrophils: They are large in size and have a 2 – 7 lobed nucleus. Their numbers are increased during infection and inflammation.
- Eosinophils: It has a bilobed nucleus. Their numbers increases during conditions of allergy and parasitic infections. It brings about the detoxification of toxins.
- Basophils: Basophils have a lobed nucleus. They release chemicals during the process of inflammation.
2. Agranulocytes: Granules are not found in the cytoplasm of these cells. Thy is of two types:
- Lymphocytes: Lymphocytes produce antibodies during bacterial and viral infections.
- Monocytes: They are the largest of the leucocytes and are amoeboid in shape. They are phagocytic and can engulf bacteria.
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संबंधित प्रश्न
| The liquid connective tissue A circulates in our body continuously without stopping. This tissue contains a pigment B which imparts it a colour C. The tissue A consists of four components D, E, F and G. The component D fights infection and protects us from diseases. The component E helps in the clotting of tissue A if a person gets a cut. The component F is a liquid which consists mainly of water with many substances dissolved in it and component G carries oxygen from the lungs to all the parts of the body. |
- What is (i) tissue A (ii) pigment B, and (iii) colour C?
- Name (i) D (ii) E (iii) F, and (iv) G.
- Name one substance (other than oxygen) which is transported by tissue A in the human body.
- Which two components of tissue A are the cells without nucleus?
- Name any two organisms ( animals) which do not have liquid like A in their body.
Name the following:
Components of blood
State the Function: Vitamin K
Match the following.
| 1. Leukaemia | (a) Thrombocytes |
| 2. Platelets | (b) Phagocyte |
| 3. Monocytes | (c) Decrease in leucocytes |
| 4. Leucopenia | (d) Blood Cancer |
| 5. AB blood group | (e) Allergic condition |
| 6. O blood group | (f) Inflammation |
| 7. Eosinophil | (g) Absence of antigen |
| 8. Neutrophils | (h) Absence of antibody |
Why is the colour of the blood-red?
Direction: In each of the following questions a statement of assertion (A) is given and a corresponding statement of Reason (R) is given just below it. Mark the correct statement as.
Assertion: Persons with AB blood group are called a universal recipient because they can receive blood from all groups.
Reason: Antibodies are absent in persons with AB blood group.
What prevents the backflow of blood inside the heart during contraction?
Single circulation i.e. blood flows through the heart only once during one cycle of passage through the body, is exhibited by
What is the special feature present in a human heart which does not allow mixing of blood when oxygen-rich and carbon dioxide-rich blood reach the heart?
Least abundant leucocyte is ______.
