Tag: the cell structure

Questions Related to the cell structure

End of prophase is marked by?

  1. Initiation of condensation of chromosomal material

  2. Complete disintegration of nuclear membrane

  3. Reappearance of ER, Golgi body, nucleolus and nuclear envelop

  4. Alignment of chromosomes at the equator


Correct Option: A

Cells capable of division are

  1. Stem cells.

  2. Meristematic cells.

  3. Undifferentiated cells.

  4. All of the above.


Correct Option: D
Explanation:

Stem cells are totipotent cells that can able to differentiate and divide into any type of cells of the body. meristematic cells are undifferentiated cells of the plants that can able to divide and form tissues, organs of the plant. so cells capable of division are all the cells including stem cells, meristematic cells and undifferentiated cells. Hence option D is correct.

A nucleated differentiated cell that has lost the power to dedifferentiate is ____________.

  1. Nerve cells.

  2. Kidney cells.

  3. Liver cells.

  4. All of the above.


Correct Option: A
Explanation:
A nucleated differentiated cell that has lost the power to division are nerve cells. These are the cells of nervous system and carry electrical messages and signals throughout the body. They have lost their power to division because the existing ones can grow new connections by loosing the old ones and also these cells needs oxygen and nutrients and if it divides rapidly and get packed, it will become difficult to supply and hence will starve.
So, the correct answer is option A.

RBCs are

  1. Differentiated cells.

  2. Undifferentiated cells.

  3. Dedifferentiated cells.

  4. Dead cells.


Correct Option: A
Explanation:

Mammalian erythrocytes also called as red blood cells are formed in bone marrow from multipotential hemocytoblast and further converted to erythroblast (normoblast). The nucleus and mitochondria of erythroblast disappear and it is converted to mature erythrocyte with haemoglobin. So RBC's are differentiated cells which lack a nucleus.

Which one of the following is anucleate?

  1. Sieve tube

  2. Companion cell

  3. Medullary ray

  4. All of the above


Correct Option: A

Formation of meristems cork cambium from fully differentiated parenchyma cells is an example of :

  1. Differentiation

  2. Redifferentiation

  3. Dedifferentiation

  4. Regenration


Correct Option: C
Explanation:
Cambium is the layer which forms Cork and acts as a secondary meristem from a layer of collenchyma or parenchyma immediately beneath the epidermis. The cells which produce from cork cambium will differentiate and will get mature to perform a specialized function. The living cells which lost the capacity to divide can regain the capacity of the division under certain conditions is called as 'Dedifferentiation.'
So the correct option is 'Dedifferentiation.'

Any specialized plant cell that is dispersed among cells of a different kind is called a

  1. Marcophyll

  2. Xenophyte

  3. Normoblast

  4. ldioblast


Correct Option: D
Explanation:
An idioblast is an isolated plant cell that differs from neighboring tissues. They have various functions such as storage of reserves, excretory materials, pigments, and minerals. They could contain oil, latex, gum, resin, tannin or pigments etc. So, the correct answer is "Idioblast."

Dedifferentiated cells are formed in the region of

  1. Injury.

  2. Regeneration.

  3. Secondary growth.

  4. All of the above.


Correct Option: D
Explanation:

An undividable differentiated cell sometimes gains the power to divide. This process is called dedifferentiation. Wound healing after injury and secondary growth in plants are some of the best examples of dedifferentiation. Dedifferentiation is one of the mechanisms of natural regeneration. So answer D is correct.

Different cells have different sizes. Arrange the following cells in an ascending order of their size and select the correct option.
(i) Mycoplasma (ii) Ostrich egg (iii) Human RBCs (iv) Bacteria.
  1. $(i)\rightarrow (iv)\rightarrow (iii) \rightarrow (ii)$

  2. $(ii)\rightarrow (iii)\rightarrow (i) \rightarrow (ii)$

  3. $(ii)\rightarrow (i)\rightarrow (iii) \rightarrow (iv)$

  4. $(iii)\rightarrow (ii)\rightarrow (i) \rightarrow (iv)$


Correct Option: A

Different cells have different sizes. Arrange the following cells in ascending order of their size and select the correct option:


(i) Mycoplasma                  (ii) Ostrich egg
(iii) Human RBCs              (iv) Bacteria

  1. (i) $\rightarrow$ (iv) $\rightarrow$ (iii) $\rightarrow$ (ii)

  2. (i) $\rightarrow$ (iii) $\rightarrow$ (iv) $\rightarrow$ (ii)

  3. (ii) $\rightarrow$ (i) $\rightarrow$ (iii) $\rightarrow$ (iv)

  4. (ii) $\rightarrow$ (ii) $\rightarrow$ (i) $\rightarrow$ (iv)


Correct Option: A
Explanation:
  • The smallest cell is Mycoplasma (0.1-0.5$\mu m$). 
  • Bacterial cell measures 3-5$\mu m$ in length. 
  • Erythrocytes are 6-8$\mu m$ in diameter. 
  • The larges cell is the egg of Ostrich.