Cell Biology MCQs | BIO201 MCQs | Set 1

MCQs (Multiple Choice Questions)

1)    _________ energy is the energy of motion.

    a)        Kinetic

    b)       Potential

    c)        Chemical

    d)       Atomic

Correct Answer: 

The correct answer is  'a'.

Explanation:

Kinetic energy is the energy of motion because it is the energy an object possesses due to its movement. When an object is in motion, it has kinetic energy, which is determined by its mass and velocity. This energy is associated with the object's ability to do work or cause changes in its surroundings as a result of its motion.

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2)    Ribosomes can be free or attached with

    a)        golgi apparatus

    b)        lysosomes 

    c)        endoplasmic reticulum

    d)        necleus

Correct Answer: 

The correct answer is  'c'.

Explanation:

Ribosomes can be free or attached to the endoplasmic reticulum. When ribosomes are attached to the endoplasmic reticulum, they are involved in the synthesis of proteins that are either secreted from the cell or incorporated into the cell's membranes. This attachment helps in the proper folding and processing of these proteins. Ribosomes that are not attached, often referred to as free ribosomes, primarily synthesize proteins that function within the cell itself. The endoplasmic reticulum provides a platform for these ribosomes to synthesize specific proteins for different cellular functions.

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3)    Which organ/molecule can convert light energy ?

    a)       NAD

    b)       Retina

    c)       Biotin

    d)       Coenzyme A

Correct Answer: 

The correct answer is  'b'.

Explanation:

The retina is the part of the eye that can convert light energy into neural signals. Specialized cells in the retina, called photoreceptors (rods and cones), are sensitive to light and can capture the energy from incoming light, initiating a cascade of biochemical reactions that ultimately send visual information to the brain. This process allows us to perceive and interpret visual stimuli, making the retina an essential organ for converting light energy into a form that the brain can process.

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4)    Beta pleated sheet is found in

    a)        Primary protein structure

    b)        Secondary protein structure 

    c)        Tertiary protein structure 

    d)       Quaternary protein structure

Correct Answer:

The correct answer is  'b'.

Explanation:

Beta pleated sheets are a characteristic feature of the secondary protein structure. In the secondary structure of a protein, the polypeptide chain folds into regular, repeating structures. Beta pleated sheets are formed when adjacent segments of the polypeptide chain are stabilized by hydrogen bonds between the amino acid residues, resulting in a sheet-like structure. This is distinct from the primary structure, which refers to the linear sequence of amino acids in a protein. The tertiary structure involves the three-dimensional folding of the entire polypeptide chain, while the quaternary structure pertains to the arrangement of multiple polypeptide chains in a protein complex. Beta pleated sheets are a key component of the secondary structure and contribute to the overall folding and stability of proteins.

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5)    Inhibitor that binds to a site other than the active site of the enzyme

    a)        Competitive inhibitor 

    b)        Irreversible inhibitor 

    c)         Reversible inhibitor

    d)        Non competitive inhibitor

Correct Answer:

The correct answer is  'd'.

Explanation:

A non-competitive inhibitor binds to a site on the enzyme that is different from the active site. This binding site is known as the allosteric site. When a non-competitive inhibitor binds to this site, it causes a conformational change in the enzyme's structure, which reduces the enzyme's activity. This type of inhibition is not affected by the concentration of the substrate because it doesn't compete with the substrate for the active site.

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6)     lipid act as a following in which many components of cell membrane floats.

    a)       Pond

    b)       Lake

    c)        River

    d)       Stream  

Correct Answer:

The correct answer is  'b'.

Explanation:

Lipids act as a "Lake" in which many components of the cell membrane float. The lipid bilayer of the cell membrane creates a fluid and dynamic environment where various components, such as proteins and other molecules, can move around, much like substances floating on the surface of a lake.

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7)    How many macromolecules a cell has___________.

    a)        2

    b)        4

    c)        6

    d)       8

Correct Answer: 

The correct answer is  'b'.

Explanation:

A cell has "4" macromolecules. These macromolecules are proteins, nucleic acids (DNA and RNA), carbohydrates, and lipids.

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8)    Beta pleated sheet is found in :

    a)        Secondary protein structure

    b)        Primary protein structure

    c)        Tertiary protein structure 

    d)       Quaternary protein structure 

Correct Answer: 

The correct answer is  'a'.

Explanation:

The beta pleated sheet is a common structural motif in the secondary protein structure. It consists of linear chains of amino acids that are connected by hydrogen bonds to form a sheet-like structure. In the secondary protein structure, you primarily have two main structural elements: alpha helices and beta sheets. Alpha helices and beta sheets are formed by the regular, repetitive folding of the polypeptide chain, and they are considered secondary structures because they are the result of hydrogen bonding and interactions between nearby amino acids in the protein sequence. The beta pleated sheet, with its characteristic arrangement of hydrogen-bonded strands, is a classic example of a secondary protein structure. 

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9)     Cell membrane expels particles by vesicle formation.

    a)        pinocytosis 

    b)        Phagocytosis

    c)         Endocytosis 

    d)        Exocytosis

Correct Answer: 

The correct answer is  'd'.

Explanation:

Exocytosis is the process by which cells release particles or substances from inside the cell to the external environment. During exocytosis, a vesicle, which is a membrane-bound structure, fuses with the cell membrane, and its contents are expelled from the cell. This is the opposite of endocytosis, where cells take in particles by engulfing them with vesicles.

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10)   Molecule of phospholipids has:  

    a)        hydrophobic & Hydrophilic domain 

    b)        hydrophobic only

    c)        hydrophilic only 

    d)       hydrogen linkage

Correct Answer: 

The correct answer is  'a'.

Explanation:

Phospholipids have both hydrophobic and hydrophilic domains due to their unique structure. A phospholipid molecule consists of a hydrophilic "head" and two hydrophobic "tails." The head is typically a charged or polar group, making it attracted to water (hydrophilic), while the tails consist of hydrocarbon chains, which repel water (hydrophobic). This amphipathic nature of phospholipids is crucial in the formation of lipid bilayers in cell membranes, where the hydrophobic tails are oriented inward, away from the surrounding aqueous environment, and the hydrophilic heads are oriented outward, interacting with the surrounding water. This arrangement is essential for the structure and function of cell membranes.

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