Italian IMAT Q29

Which of the following are characteristics attributable to mitochondria

  1. replication site of DNA molecules
  2. site of synthesis of water molecules
  3. seat of transport by simple diffusion
  4. present in autotrophic cells

A. All
B. Only 1,3 and 4
C. Only 1,2 and 3
D Only 2,3,4
E Only 1,2

This might seem like a silly question but the answer says all are attributed to mitochrondria. (answer is A) Could someone explain it to me? Thanks!

1 is correct cuz we know that mitochondria has it’s own genetic material which is circular Ds DNA also called as mitochondrial DNA Hence, replication do takes places inside the mitochondrial matrix.

2 As we know that mitochondria is the site of cellular respiration inside cells and when we write the general equation of respiration it is:- C6H12O6 + 6O2-----> 6CO2 + 6H2O.
All these 6 water molecules are produced at complex IV of the E.T.C.
which makes answer option 2 correct.

3 Although this option seems a bit weird but it’s true due to the fact that we have O2 as well as water molecules inside mitochondria which could simply diffuse out of the plasma membrane when present in small amounts. so, answer option 3 do makes sense.

4 Autotrophic cells let’s say plants or photosynthetic protists do have mitochondria.
Hope it helps:)


I forgot about how 3 and 4 were right, thank you so much Ujjwal, slipped my mind!

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