Some cells are specialised to perform specific functions. Class 9

Some cells are specialised to perform specific functions. Class 9

Threads of Curiosity (Page 14)

Some cells are specialised to perform specific functions. For example, mature Red Blood Cells (RBCs) in humans do not have a nucleus (enucleate). The absence of a nucleus provides more space for haemoglobin, allowing it to transport a larger amount of oxygen to all cells of the body. Since they lack a nucleus, they cannot repair or divide themselves. As a result, their lifespan is short and they survive approximately for 120 days.

Question 1.

Do you know any other cells without nucleus? Class 9

Answer:

Platelets (thrombocytes) are another example of cells in the human body that lack a nucleus. In plants, sieve tube cells (found in the phloem) also lose their nucleus when they mature.

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Question 2.

Are there any other plastids in plant cells that contain any pigments other than the green pigments? Class 9

Answer:

Yes, chromoplasts contain pigments that give colour to fruits and flowers.