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Q1. Which of the following cell organelles store hydrolytic enzymes?

• Centrioles
• Lysosomes
• Chromoplasts
• Chloroplasts

Solution

Hydrolytic enzymes are present in lysosomes. These enzymes can hydrolyse proteins, nucleic acids, carbohydrates and lipids.

Q2. Cell theory is not applicable to  

• Bacteria  
• Fungus  
• Algae  
• Virus  

Solution

A virus is not considered as a living organism as it cannot grow.     A virus cannot replicate unless it infects a cell.     It then uses the host’s machinery for producing multiple copies of viruses.     Thus, even cell theory does not apply to viruses.  

Q3. Which of the following statements is not true for the plasma membrane?

• It is present in both plant and animal cell.
• Lipid is present as a bilayer in it.
• Proteins are present integrated as well as loosely associated with the lipid bilayer.
• Carbohydrate is never found in it.

Solution

The plasma membrane contains carbohydrates in the form of glycoproteins and glycolipids.

Q4. Different cells have different sizes. Arrange the following cells in an ascending order of their size. Choose the correct option among the following:     (i) Mycoplasma  (ii) Ostrich eggs     (iii) Human RBC  (iv) Bacteria  

• (i), (iv), (iii) and (ii)  
• (i), (ii), (iii) and (iv)  
• (ii), (i), (iii) and (iv)  
• (iii), (ii), (i) and (iv)  

Solution

Mycoplasma is 0.3 m in length.     Bacteria measure between 3 m and 5m.     Human RBCs have a diameter of 7m.     An ostrich egg measures about 13-15 cm.  

Q5. Eukaryotic cells are different from prokaryotic     cells in having  

• True nucleus  
• 70S ribosomes  
• Mitochondria in mesosome form  
• Only smooth endoplasmic reticulum  

Solution

In prokaryotes, genetic material is present in the form of a nucleoid, i.e. DNA is not bound by a nuclear membrane. In eukaryotes, DNA is enclosed within a nuclear membrane. This is called true nucleus.  

Q6. The cell organelle participating in photo-respiration is

• Nucleolus
• Dictyosome
• Peroxisome
• Glyoxysome

Solution

Three organelles are involved in photorespiration - mitochondria, peroxisomes and chloroplasts. Peroxisomes contain the enzyme glycolic acid oxidase. It oxidises glycolic acid to glyoxylic acid, a key step in photorespiration.

Q7. Which of the following organelles is called a suicidal bag of a cell?

• Lysosome
• Mitochondria
• Peroxisome
• Glycocalyx

Solution

Lysosomes contain hydrolytic enzymes. These enzymes can break down all types of biological polymers. Thus, lysosomes act as a waste disposal system of the cell. They help to get rid of unwanted material by digesting them. Because of this function, they are popularly referred to as ‘suicide bags’.

Q8. A single unit membrane surrounds the organelle:

• Lysosome
• Nucleus
• Microsome
• Chloroplast

Solution

Lysosomes have a single membrane made of a phospholipid bilayer.

Q9. The powerhouse of the cell is

• Golgi bodies
• Mitochondria
• Ribosomes
• Endoplasmic reticulum

Solution

Mitochondria convert the chemical energy found in glucose and other nutrients in the presence of oxygen, resulting in formation of ATP molecules. Thus, mitochondria are called powerhouses of a cell.

Q10. The detailed structure of the membrane was studied after the advent of the electron microscope during  

• 1930's  
• 1950's  
• 1970's  
• 1990's  

Solution

In the late 1950's, the use of electron microscopy helped to discover that the membrane was composed of proteins and lipids and has a bilayer structure.  

Q11. Chemiosmotic theory of ATP synthesis in the chloroplasts and mitochondria is based on  

• Membrane potential  
• Accumulation of Nat⁺ ions  
• Accumulation of Kt⁺ ions  
• Proton gradient  

Solution

Protons move from an area of high concentration to an area of low concentration across a membrane.     The kinetic energy created by this movement is used by ATP synthase to create ATP molecules.  

Q12. A chromosome having a centromere at its middle is  

• Telocentric  
• Acrocentric  
• Metacentric  
• Dicentric  

Solution

Depending on the position of the centromere, chromosomes are of the following types:           Metacentric chromosome: The centromere is present right in the middle of the chromosome.           Sub-metacentric chromosome: The centromere is present a little away from the middle of the chromosome.           Acrocentric chromosome: The centromere is present close to one of the ends of the chromosome.     Telocentric chromosome: A terminal centromere.  

Q13. Which of the following is not a feature of prokaryotes?

• Absence of nuclear membrane
• DNA associated with histones
• Absence of mitochondrion
• Both 2 and 3 above

Solution

Prokaryotic DNA is contained in a long loop called a nucleoid and features DNA-binding proteins but no histones, because it does not have to coil as tightly as eukaryotic DNA to fit into a fixed nuclear envelope. 

Q14. Cellular totipotency was first demonstrated by

• F. C. Steward
• Robert Hooke
• T. Schwann
• A. V. Leeuwenhoek

Solution

F. C. Steward and his co-workers conducted experiments on carrot root tissues and were the first to demonstrate totipotency.

Q15. The main organelle involved in modification and routing of newly synthesised proteins to their destinations is

• Mitochondria
• Endoplasmic reticulum
• Lysosome
• Chloroplast

Solution

Protein molecules are first folded in sacs called cisternae. These proteins are then transported in vesicles to the Golgi apparatus. Both these processes are carried out by the endoplasmic reticulum.

Q16. Aleuroplasts in a cell store

• Starch
• Oil
• Protein
• Nutrients

Solution

Aleuroplasts are colourless plastids which store proteins. They are found in plant cells particularly seeds.

Q17. The membrane around the vacuole is called

• Tonoplast
• Cytoplast
• Leucoplast
• Amyloplast

Solution

In plant cells, the membrane around a vacuole is single layered. This single-layered membrane is called tonoplast. It facilitates the transport of ions and other materials in the vacuole from the cell cytoplasm.

Q18. Which of the following is a part of the endomembrane system of a eukaryotic cell?  

• Peroxisomes  
• Chloroplasts  
• Mitochondria  
• Golgi complex  

Solution

Many of the cell organelles have their functions coordinated, and hence, they are considered together as the endomembrane system.     The endomembrane system includes endoplasmic reticulum, Golgi complex, lysosomes and vacuoles.  

Q19. A cell, when kept in a sugar solution, gets dehydrated. Then the solution is

• Hypotonic
• Hypertonic
• Isotonic
• None of the above

Solution

If a cell is placed in a hypertonic solution, then it loses water due to exosmosis and gets dehydrated.

Q20. The electron microscope was discovered by

• Robert Hooke
• Knoll and Ruska
• Jansen
• Robert Brown

Solution

In 1931, Ernst Ruska and Max Knoll constructed the first prototype electron microscope. This prototype had magnification power of 400.

Q21. Which method of transport in the plasma membrane does not require a carrier molecule?  

• Active transport  
• Facilitated diffusion  
• Simple diffusion  
• Na⁺-K⁺ pump  

Solution

Neutral solutes can move across the plasma membrane along the concentration gradient by the process of simple diffusion. As the solutes move along the concentration gradient, a carrier is not required.  

Q22. Thylakoids occur inside

• Mitochondria
• Chloroplast
• Golgi apparatus
• Endoplasmic reticulum

Solution

The stroma of chloroplasts contains several organised flattened membranous sacs called the thylakoids. Chlorophyll pigments are present in the thylakoids.

Q23. The vacuole in a plant cell  

• Lacks membrane and contains air  
• Lacks membrane and contains water and excretory wastes  
• Is membrane-bound and contains storage proteins and lipids  
• Is membrane-bound and contains water and excretory wastes  

Solution

A vacuole in a plant cell is a single membrane bound structure. The membrane is called tonoplast.     The vacuole contains water and cell sap. It also contains excretory products and other materials which are not useful for the plant cell.  

Q24. Carbohydrates, the most abundant biomolecules on Earth, are produced by

• Some bacteria, algae and green plant cells
• Fungi, algae and green plant cells
• All bacteria, fungi and algae
• Viruses, fungi and bacteria

Solution

Some bacteria called cyanobacteria, algae and green plant cells contain chlorophyll either free in the cell or in organelles called chloroplasts. Chlorophyll helps to bring about photosynthesis, a process by which carbohydrates are prepared in the presence of sunlight.

Q25. Which of the following is a prokaryote?

• Amoeba
• Spirogyra
• Bacteria
• Chlamydomonas

Solution

Amoeba is a protozoan, Spirogyra and Chlamydomonas are algae; all three are eukaryotes. Bacteria do not have a well-defined nucleus and membrane-bound organelles are absent; thus, bacteria are prokaryotes.

Q26. Which one of the following cellular parts is correctly described?  

• Thylakoids - flattened membranous sacs forming the grana of chloroplasts  
• Centrioles - sites for active RNA synthesis  
• Ribosomes - those in chloroplasts are larger (80S), while those in the cytoplasm are smaller (70S)  
• Lysosomes - optically active at a pH of about 8.5  

Solution

Thylakoids are flattened membranous sacs forming the grana of chloroplasts.     Centrioles help in the formation of spindle fibres during cell division.     The nucleolus possesses sites for rRNA synthesis.     The ribosomes are of 70S type in the chloroplast and of 80S type in the cytoplasm.     Lysosomes are active in acidic pH of about 5.  

Q27. Which one of the following has its own DNA?

• Peroxisome
• Mitochondria
• Dictyosome
• Lysosome

Solution

Mitochondria are semi-autonomous. They have their own DNA, RNA and proteins. Mitochondria can multiply when the energy needs of a cell increase.

Q28. Mesosome in a bacterial cell is  

• Plasmid  
• Connection between two cells  
• Plasma membrane infolds for respiration  
• None of the above  

Solution

Prokaryotic cells have a special membranous structure, mesosome, which is formed by the extensions of the plasma membrane into the cell. They help in cell wall formation, DNA replication and distribution to daughter cells. They also help in respiration, secretion processes and to increase the surface area of the plasma membrane and enzymatic content.   

Q29. The endoplasmic reticulum is in continuation with

• Golgi body
• Nuclear membrane
• Mitochondria
• Cell wall

Solution

The membranes of the ER are continuous with the outer membrane of the nuclear membrane.  

Q30. Flagella of prokaryotic and eukaryotic cells differ in

• type of movement and placement in cell
• location in cell and mode of functioning
• microtubular organization and type of movement
• microtubular organization and function

Solution

Flagella of prokaryotic and eukaryotic species differ in microtubular organization and type of movement. In eukaryotes, the arrangement is 9+2 and specialized whereas in prokaryotes arrangement is 9+0 and is simple.

Q31. Acid hydrolase is found in

• Golgi body
• ER
• Lysosome
• Vacuole

Solution

Lysosomes contain the enzyme acid hydrolase which can digest proteins, DNA, RNA, polysaccharides and lipids.

Q32. Most of the hydrolytic enzymes of lysosomes function at

• Acidic pH
• Basic pH
• Neutral pH
• Any pH

Solution

Lysosomal enzymes are active at acidic pH (about 5), which is maintained within lysosomes. They are inactive at the neutral pH (about 7.2) characteristic of the rest of the cytoplasm. Lysosomal enzymes function at acidic pH only, thus preventing uncontrolled digestion of cytoplasmic material. 

Q33. The stain used to visualise mitochondria is  

• Fast green  
• Safranin  
• Acetocarmine  
• Janus green  

Solution

Janus Green is a basic dye.     It is used for staining mitochondria.     Janus Green changes colour depending on the amount of oxygen present.     When oxygen is present, the indicator oxidises to a blue colour.  

Q34. Peptide synthesis inside a cell takes place in  

• Chloroplast  
• Mitochondria  
• Chromoplast  
• Ribosomes  

Solution

Ribosomes contain enzymes and co-factors required for the synthesis of peptides.     The groove present between the two subunits of ribosomes is where the synthesis of polypeptides takes place.  

Q35. What is true about ribosomes?  

• The prokaryotic ribosomes are 80S, where ‘S’ stands for sedimentation coefficient.  
• These are composed of ribonucleic acid and proteins.  
• These are found only in eukaryotic cells.  
• These are self-splicing introns of some RNAs.  

Solution

Ribosomes are found in both prokaryotic and eukaryotic cells. Prokaryotes have 70S ribosomes and eukaryotes have 80S ribosomes.     Ribosomes are composed of 32-67% RNA and the rest are proteins.  

Q36. Robert Brown discovered

• Nucleus
• Nucleolus
• Cell wall
• Mitochondria

Solution

In 1831, Robert Brown discovered the nucleus. He discovered the nucleus while working on orchid cells and stated it as a regular cell organelle.

Q37. Living organisms can be unexceptionally distinguished from non-living things on the basis of their ability for  

• Interaction with the environment and progressive evolution  
• Reproduction  
• Growth and movement  
• Responsiveness to touch  

Solution

Living beings reproduce to maintain their species, while non-living things cannot.  

Q38. The cell organelle associated with intercellular digestion of macromolecules is

• Lysosome
• Peroxisome
• Polysome
• Dictyosome
• Glycosome

Solution

Lysosomes contain hydrolytic enzymes. These enzymes can digest biological polymers. Thus, they help in the intracellular digestion of macromolecules.

Q39. Mitochondria will be more in  

• Germinating seeds  
• Dormant seeds  
• Dry seeds  
• None of the above  

Solution

The number of mitochondria per cell varies depending on the physiological activities of the cell. Germinating cells require more energy for growth; thus, they require more ATP and more number of mitochondria.  

Q40. The correct pair constituent which is made of aggregation of

• Cellulose - cell wall
• Ribosomes - ER
• Thylakoids - grana
• Acrosome - ER

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