1. Which organelle in the cell, other than the nucleus, contains DNA?
(a) Centriole
(b) Golgi apparatus
(c) Lysosome
(d) Mitochondrion
[I.A.S. (Pre) 2001]
Ans. (d) Mitochondrion
- DNA can be found not only in the nucleus of cells but also in the mitochondria and chloroplast.
- This genetic material carries traits from parents to their offspring, just like a horoscope.
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2. Which one of the following statements is correct?
(a) Prions are the smallest free-living cells.
(b) The cell wall of Mycoplasmas is made up of amino sugars.
(c) Viroids consist of single-stranded RNA molecules
(d) Rickettsias lack cell wall
[I.A.S. (Pre) 2002]
Ans. (c) Viroids consist of single-stranded RNA molecules
- Prions are the tiniest infectious particles made of proteins.
- The smallest free-living cells are Mycoplasmas.
- Mycoplasma bacteria don’t have a wall around their cell membrane unlike other bacteria.
- Viroids are small, circular, single-stranded RNA molecules that infect plants. They do not have a protein coat like viruses do.
- Rickettsia are bacteria that don’t move and have a cell wall. Some of them are very damaging to crops.
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3. Which of the following statements are correct regarding the general difference between plant and animal cells?
1. Plant cells have cellulose cell walls whilst animal cells do not.
2. Plant cells do not have plasma membranes, unlike animal cells which do.
3. Mature plant cell has one large vacuole whilst animal cell has many small vacuoles.
Select the correct answer using the code given below:
(a) 1 and 2 only
(b) 2 and 3 only
(c) 1 and 3 only
(d) 1, 2 and 3
[I.A.S. (Pre) 2020]
Ans. (c) 1 and 3 only
| Feature |
Plant Cell |
Animal Cell |
| Cell Wall |
Present (cellulose) |
Absent |
| Plasma Membrane |
Present (inside cell wall) |
Present (only outer boundary) |
| Vacuoles |
One large central vacuole |
Many small vacuoles (if any) |
4. How does the plant cell differ from the animal cell?
(a) Mitochondria
(b) Cell wall
(c) Presence of protoplasm
(d) Cell nucleus
[U.P.P.C.S. (Pre) 1991]
Ans. (b) Cell wall
- Plant cells and animal cells are different mainly because plant cells have a cell wall.
- This cell wall is made of cellulose and is not found in animal cells.
- Plant cells also have green plastids, which are something that animal cells don’t have.
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6. Which part of the animal cell is called a powerhouse?
(a) Cell wall
(b) Nucleus
(c) Mitochondria
(d) Entire cell
[M.P.P.C.S. (Pre) 2010]
Ans. (c) Mitochondria
- Mitochondria are small organelles found in most cells and are sometimes called the “powerhouse of the cell” because they produce energy.
- The energy production process starts in the cytoplasm and then continues in the mitochondria.
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9. Plasma membrane is built up of
(a) Protein
(b) Lipid
(c) Carbohydrate
(d) Both (a) and (b)
[U.P.P.C.S. (Mains) 2008]
Ans. (d) Both (a) and (b)
- The cell membrane, also called the plasma membrane, is a barrier between the inside of a cell and the outside environment.
- It is made of two layers of phospholipids with proteins inside them.
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10. Which of the following cell organelles play the most significant role in protein synthesis?
(a) Lysosome and Centrosome
(b) Endoplasmic reticulum and Ribosome
(c) Golgi apparatus and Mitochondria
(d) Lysosome and Mitochondria
[I.A.S. (Pre) 2001]
Ans. (b) Endoplasmic reticulum and Ribosome
- The ribosome (for translation) and the endoplasmic reticulum (for synthesis and processing) are the most significant organelles in protein synthesis.
- Lysosomes are involved in digestion and waste breakdown.
- Centrosomes are important for cell division.
- The Golgi apparatus modifies, sorts, and packages proteins.
- Mitochondria produce energy (ATP).
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11. The cellular and molecular control of programmed cell death is known as :
(a) Apoptosis
(b) Ageing
(c) Degeneration
(d) Necrosis
[I.A.S. (Pre) 2001]
Ans. (a) Apoptosis
- Apoptosis is the process of cells dying in a planned way.
- It is important for keeping the body healthy by getting rid of cells that are not needed or are not good for the body.
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12. One term that generates the maximum number of ATP atoms in our system?
(a) Decomposition of glucose
(b) Kreb’s cycle
(c) Last respiratory series
(d) Water decomposition
[R.A.S./R.T.S. (Pre) 1999]
Ans. (b) Kreb’s cycle
- Kreb’s cycle is a set of chemical reactions that take place in living cells to break down carbohydrates, proteins, and fatty acids using oxygen, producing carbon dioxide and forming ATP.
- This cycle produces the most ATP (energy) in the cell and was discovered by Hans Kreb in 1937, occurring in the matrix of the mitochondrion.
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