NEET MCQ On Cell Structure and Function

A cell is a fundamental unit of life. Therefore, if we were to break an organism apart to the cellular level, the smallest independent component which would be found would be  the cell.

A cell is the basic and smallest life’s unit which is responsible for all life's processes. Cells are the functional, structural, and biological units of all living beings. A cell can also be independently replicated. Thus, the cells are called the building blocks of life.

Each cell contains a fluid known as cytoplasm, enclosed by a membrane. Also,  the cytoplasm contains several biomolecules such as nucleic acids, proteins, and lipids. Furthermore, the cellular structures known as cell organelles are suspended in the cytoplasm.

Cell Structure

A cell structure is composed of individual components with specific functions important to carry out the processes of life. These components include cell membrane, cell wall, cytoplasm, nucleus, and also cell organelles.

Plasma/Cell Membrane

The plasma/cell membrane is the outermost layer of a cell. It controls the entry and exit of the cell. The gases move in and out through diffusion and liquid travels through the process of osmosis. 

Cell Wall

The cell wall is present outside the plasma membrane. This cell wall is present in the plant cells to provide structural support and thus is rigid in nature.  The cell wall is composed of cellulose.

Nucleus

The nucleus acts as a cell's command centre. It plays a very crucial role in the reproduction of a new cell. Nucleus contains Y shaped structures called chromosomes, which contain DNA or genes for the new cell's production.   

The nucleus is covered with a thin layer called the nuclear membrane and is filled with nucleoplasm. It contains nuclear pores that regulate the passage of molecules between the nucleus and cytoplasm, permitting some to pass through the membrane, but not others.   

Cytoplasm

The cytoplasm is a liquid component present in the cell. It is composed of water, salt and protein. All the important organelles of a cell including the nucleus are present in the cytoplasm. 

Lysosomes 

Lysosomes are responsible for the digestion process in a cell. All the food and worn out parts in the cells are broken down through the digestive enzymes. It keeps the cell clean and free from any kind of bacteria. In abnormal cases, the lysosomes burst and end up digesting their own cell, which is why they are also called suicide bags.

Mitochondria 

Mitochondria is the powerhouse of a cell. It provides energy to the cell for various types of chemical reactions that happen inside it. The energy is provided in the form of  ATP (Adenosine Triphosphate) molecules.  These are the energy currency of the cell. 

Importance of MCQs

In general, the Multiple Choice Questions (MCQs) are recognized as the most useful and widely applicable type of objective test elements. They could be used to measure the most important educational outcomes, such as understanding, knowledge, judgment, and problem-solving.

By preparing these MCQs once after completing every topic, we can able to attempt competitive exams like NEET easily and effectively.

Let us look at the MCQ on cell structure and function, including the cell structure and function MCQ with answers.

1. In the given list, which is the simplest amino acid?

a. Alanine

b. Glycine

c. Tyrosine

d. Asparagine

Answer: (b)

Explanation

Glycine is the simplest amino acid. It contains a single hydrogen atom as its side chain. It is also a proteinogenic amino acid.

2. Animal cells are interconnected by _______

a. Desmosomes

b. Cell wall

c. Plasmodesmata

d. Plasma membrane

Answer: (a)

Explanation

Desmosomes are the structure by which adjacent cells are attached and formed from the protein plagues in cell membranes linked by the filaments.

3. Polythene chromosomes are found because of _____?

a. Endomixes

b. Mitosis

c. Meiosis

d. Endomitosis

Answer: (d)

Explanation

Endomitosis is the replication or duplication of the chromosome in the absence of nuclear division or cell, resulting in numerous copies within each cell, which occurs in the Drosophila salivary glands. 

Polytene chromosomes are popularly called salivary chromosomes. They contain 1000- 16000 times DNA, as compared to ordinary somatic chromosomes and can reach a length of 2000 μm. During the interphase stage of the cell division in the nuclei of the salivary gland cells of the larvae of Drosophila melanogaster, polytene chromosomes are formed due to endoreduplication, duplication without separation and replication of DNA without cell division. These chromosomes undergo somatic pairing to form identical chromosomes which are joined along their length to one another.

4. The rRNA is synthesized by _________

a. Golgi body

b. Nucleus

c.  Nucleolus

d. Cytoplasm

Answer: (c)

Explanation

A nucleolus is the small dense spherical structure in the cell nucleus. It acts as a site for active rRNA synthesis. Rough ER (absence of ribosomes)- helps in the synthesis of proteins. 

5. Which of the following is known as mitoplast?

a. Mitochondria without outer membrane

b. Another name for mitochondria

c. Mitochondria without membranes

d. Mitochondria without inner membrane

Answer: (a)

Explanation

Mitoplast is mitochondria where the outer membrane stripped in it has been removed, by keeping the inner membrane unchanged or intact.

6. The Lipid drugs’ detoxification including the other harmful compounds of various types in the ER is carried out by ______?

a. Cytochrome F

b. Cytochrome bf

c. Cytochrome P450

d. Cytochrome D

Answer: (c)

Explanation

Cytochrome P450 enzymes function to metabolize the potentially toxic compounds. There exist 57 human genes coding for different cytochrome P450.

7. Sodium and potassium pumps are examples of __________

a. Plasmolysis

b. Active transport

c. Passive transport

d. Osmosis

Answer: (b)

Explanation

Active transport is the movement of either ions or molecules across a cell membrane into a higher concentration region assisted by the enzymes and requiring energy. Sodium and potassium pumps are good examples of active transport.

8. The histone octamer contains __________?

a. 5 types of histones

b. 6 types of histones

c.  8 types of histones

d. 8 histones of four different types

Answer: (d)

Explanation

Histone octamer is an 8 protein complex that is found at the centre of the core particles of the nucleosome. It contains 2 copies of 4 core histone proteins.

9. Centriole takes part in the formation of ________?

a. Nucleus

b. Spindle

c. Cell plate

d. To start cell division

Answer: (b)

Explanation

Centrioles are cylindrical structures that are composed of tubulin. These take part in the formation of a Spindle.

11. Which of the below option is/are examples of an organ that contain a smooth muscle?

a. Uterus only

b. Iris of eye

c. Bronchi only

d. All of the above

Answer: (d)

Explanation

Smooth muscles are also called involuntary muscles, and these muscles contract slowly and automatically. Uterus, iris and bronchi are examples of smooth muscles. 

12. The Major difference between the human cheek cells and onion peel cells is ______?

a. Presence of mitochondria in onion peel

b. Absence of plasma membrane in cheek cells 

c. Cell wall presence in onion peel cells

d. Absence of endoplasmic reticulum in cheek cells

Answer: (c)

Explanation 

The major difference between an animal cell and a plant is that, unlike plant cells, animal cells are devoid of cell walls and chloroplast. Therefore,  C is the answer above.  

13. An organelle that mainly serves as a packaging area for molecules that are distributed across the cell and are called ____?

a. Golgi apparatus

b. Mitochondria

c. Plastids

d. Vacuole

Answer: (a)

Explanation 

Golgi apparatus, also known as the Golgi body, is a cell membrane that is a part of the endomembrane system in the cytoplasm. It is a 'membrane-bound organelle' of the eukaryotic cell which is made up of a series of 'flattened, stacked pouches’ called 'cisternae'. This organelle serves as a 'primary packaging area' for molecules that will be distributed throughout the cell. It packs the protein into membrane-bound vesicles inside the cell before sending it to its destination. 

14. The cell theory is not applicable to-

a. Fungi

b. Microbes

c. Algae

d. Virus

Answer: (d)

Explanation 

Viruses are considered neither living nor non-living. The cell structure is not present in the viruses, and do not use cells in their reproduction.  Thus, cell theory is not applicable to viruses. 

15. In the below-given list, which one includes the blood tissue?

a. Muscle tissue

b. Connective tissue

c. Epithelial tissue

d. Nervous tissue

Answer: (b)

Explanation

Blood is a type of connective tissue. Connective tissue has three main components: cells, fibres, and ground substance. Together the ground substance and fibres make up the extracellular matrix. Blood in the body has a network in our body through which it transports gases like oxygen and carbon dioxide, hormones, and required nutrients in the body.

16. Which is the longest cell in the human body

(a) Muscle cells

(b) Nerve cells

(c) Bone cells

(d) Gland cells

Answer: (b)

Explanation:

Nerve cells, also known as neurons, are the longest cells in the human body. These cells can extend over long distances, such as from the spinal cord to the tips of the fingers or toes. Nerve cells have a unique structure with a long, slender projection called an axon, which conducts electrical impulses over long distances. This axon can vary in length, with some reaching several feet in certain parts of the body. Therefore, nerve cells are considered the longest cells in the human body due to their remarkable length and ability to transmit signals over extensive distances.

17. Which among the following is an example of the organ containing a smooth muscle?

(a) Iris of eye

(b) Bronchi only

(c) Uterus only

(d) All of the above

Answer: (d)

Explanation: Smooth muscle is a type of muscle tissue found in the walls of various organs and structures in the body. It is called "smooth" because its cells lack the striations (stripes) characteristic of skeletal and cardiac muscle cells.

(a) Iris of the eye: The iris is the colored part of the eye responsible for controlling the size of the pupil. It contains smooth muscle fibers called the iris sphincter and iris dilator muscles, which regulate the diameter of the pupil.

(b) Bronchi: The bronchi are the main air passages that lead from the trachea (windpipe) into the lungs. The walls of the bronchi contain smooth muscle tissue, which helps regulate the diameter of the airways and control airflow into the lungs.

(c) Uterus: The uterus, also known as the womb, is an organ of the female reproductive system. It contains smooth muscle tissue, which contracts during labor to facilitate childbirth and during menstruation to expel menstrual blood.

Therefore, all of the options listed (iris of the eye, bronchi, and uterus) contain organs or structures that contain smooth muscle tissue, making option (d) "All of the above" the correct answer.

18. What is the major difference between a human cheek cell and an onion peel cell?

(a) Presence of cell wall in onion peel cells

(b) Presence of mitochondria in onion peel cells

(c) Absence of endoplasmic reticulum in cheek cells

(d) Absence of the plasma membrane in cheek cells

Answer: (a)

Explanation: The major difference between a human cheek cell and an onion peel cell lies in the presence of a cell wall in onion peel cells. Onion peel cells, akin to most plant cells, possess a rigid cell wall composed mainly of cellulose, providing structural support and protection. In contrast, human cheek cells lack a cell wall and are instead enclosed by a flexible plasma membrane, regulating cellular shape and substance passage. Both types of cells contain mitochondria for energy production and endoplasmic reticulum for various cellular functions, while the presence of a cell wall distinguishes onion peel cells from human cheek cells.

19.  Which organelle serves as a primary packaging area for molecules that will be distributed throughout the cell? 

(a) Vacuole

(b) Plastids

(c) Mitochondria

(d) Golgi apparatus

Answer: (d)

Explanation: The organelle that serves as the primary packaging area for molecules destined to be distributed throughout the cell is the Golgi apparatus, indicated by option (d). The Golgi apparatus, composed of flattened membranous sacs, receives proteins and lipids from the endoplasmic reticulum and modifies, sorts, and packages them into vesicles for transport to various cellular destinations. While vacuoles primarily store water, nutrients, and waste products, plastids are involved in processes such as photosynthesis and pigment synthesis. Mitochondria function in cellular respiration, producing energy in the form of ATP. Therefore, the Golgi apparatus stands out as the key organelle responsible for sorting and packaging molecules for cellular distribution.

20. The Cell theory does not apply to which of the following? 

(a) Fungi

(b) Algae

(c) Virus

(d) Microbes

Answer: (c)

Explanation: The Cell theory, a fundamental principle in biology, asserts that all living organisms are composed of cells, cells are the basic structural and functional units of life, and all cells arise from pre-existing cells through cellular division. However, this theory does not apply to viruses, as they are not considered living organisms according to traditional biological classification. Viruses lack cellular structure and cannot carry out metabolic processes on their own; instead, they require a host cell to replicate and proliferate. Therefore, option (c), viruses, is the correct answer.

Conclusion

MCQs on Cell Structure and Function provide a vital tool for NEET Biology preparation. These questions offer a targeted approach to revising and assessing understanding of fundamental cellular biology concepts. By engaging with a variety of multiple-choice questions, students can reinforce their knowledge, identify areas of weakness, and gain confidence in tackling related topics in the NEET exam. With focused practice and thorough review of these MCQs, aspirants can enhance their readiness and maximize their performance in the NEET Biology section.