1
Which cell organelle is often referred to as the 'powerhouse of the cell'?
🔬 Biology — Cell & Life Processes
Biology — Cell & Life Processes
By Priya Sharma · Static GK Expert
47 Questions Science & Technology
A comprehensive collection of 20 high-quality objective questions focusing on cellular structure, functions, and fundamental biological life processes.
2
Which of the following is known as the 'suicide bag' of the cell?
3
The 'fluid mosaic model' describes the structure of:
4
Which organelle is responsible for the synthesis of proteins?
5
Which of the following organelles is absent in animal cells?
6
The process of movement of water molecules across a semi-permeable membrane is called:
7
Which cell organelle acts as the 'packaging and dispatching unit' of the cell?
8
DNA is primarily found in which part of the eukaryotic cell?
9
Which organelle is responsible for photosynthesis in plants?
10
The primary function of the Rough Endoplasmic Reticulum (RER) is:
11
Which of the following is known as the 'control center' of the cell?
12
What is the main component of the plant cell wall?
13
Which organelle is involved in the detoxification of drugs and poisons in liver cells?
14
The process by which a cell engulfs large particles is known as:
15
Which of the following is a semi-autonomous organelle?
16
What are the thread-like structures composed of DNA and protein found in the nucleus called?
17
Which of the following describes 'Active Transport'?
18
The fluid portion of the cytoplasm is known as:
19
Which type of cell division is responsible for growth and tissue repair?
20
Which organelle helps in the formation of the spindle apparatus during cell division?
21
Which specific region within the nucleus is primarily responsible for the synthesis of ribosomal RNA (rRNA)?
22
Lysosomes are derived from which of the following cell organelles?
23
Which of the following cellular structures is known as the '9+2' arrangement characteristic?
24
Peroxisomes are primarily involved in which metabolic activity?
25
The 'Cell Theory' that states 'all cells arise from pre-existing cells' (Omnis cellula e cellula) was proposed by:
26
In which phase of the cell cycle is the DNA content doubled?
27
What is the primary role of the Cytoskeleton in eukaryotic cells?
28
Which bond is responsible for holding the two strands of the DNA double helix together?
29
What are the small pores in the nuclear envelope that allow transport of molecules between nucleus and cytoplasm called?
30
Which of the following is considered the 'unit of inheritance'?
31
In plant cells, the large central vacuole is enclosed by a membrane called:
32
Which structure in a plant cell facilitates the transport of materials between adjacent cells?
33
Chromosomes condense and become visible during which stage of Mitosis?
34
Which polysaccharide is a major constituent of the fungal cell wall?
35
Ribosomes are composed of which two primary components?
36
Which pigment is responsible for the green color of plants and is found within the thylakoid membranes?
37
Which organelle is synonymous with the site of lipid and steroid hormone synthesis?
38
What is the phenomenon called when a plant cell loses water and the cell membrane pulls away from the cell wall?
39
Which of the following cellular components is described as 'non-membrane bound' organelles?
40
Which phase of mitosis is characterized by the alignment of chromosomes at the equatorial plate?
41
The folding of the inner mitochondrial membrane into finger-like projections is known as:
42
The specific enzyme responsible for cell wall degradation in the process of protoplast fusion is:
43
Which of the following cell junctions acts as a 'seal' to prevent leakage of fluids between epithelial cells?
44
What is the primary function of the 'Nucleosome' in eukaryotic cells?
45
Which organelle contains its own DNA and 70S ribosomes, supporting the 'Endosymbiotic Theory'?
46
The process of 'Programmed Cell Death' is scientifically known as:
47
Which of the following is responsible for the movement of cilia and flagella?
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Important Notes — Biology — Cell & Life Processes
The Fundamental Unit of Life: The Cell
The cell is the basic structural, functional, and biological unit of all living organisms. Known as the "Building Block of Life," the study of cells is termed Cytology.
Historical Milestones
- 1665: Robert Hooke discovered the cell while examining a thin slice of cork under a primitive microscope. He published his findings in the book *Micrographia*.
- 1839: Matthias Schleiden (botanist) and Theodor Schwann (zoologist) proposed the Cell Theory, stating that all living organisms are composed of cells.
- 1855: Rudolf Virchow added the principle *Omnis cellula-e cellula* (all cells arise from pre-existing cells).
Key Cell Components (Organelles)
- Nucleus: Known as the "Brain of the Cell," it contains genetic material (DNA and RNA) and regulates cell activities. It was discovered by Robert Brown in 1831.
- Mitochondria: Referred to as the "Powerhouse of the Cell," it produces energy in the form of ATP (Adenosine Triphosphate) via cellular respiration. It possesses its own DNA.
- Ribosomes: The "Protein Factories" of the cell; sites of protein synthesis.
- Lysosomes: Called "Suicidal Bags" because they contain digestive enzymes capable of destroying the cell itself.
- Golgi Apparatus: Responsible for packaging, modifying, and transporting proteins and lipids.
- Endoplasmic Reticulum (ER):
- Rough ER: Studded with ribosomes; involved in protein synthesis.
- Smooth ER: Involved in lipid synthesis and detoxification.
Vital Life Processes in Organisms
Life processes are the basic functions performed by living organisms to maintain survival, including nutrition, respiration, transportation, and excretion.
Core Processes
- Nutrition: The intake of nutrients.
- Autotrophic: Organisms (e.g., green plants) prepare their own food via Photosynthesis.
- Heterotrophic: Organisms depend on others for food (e.g., animals, fungi).
- Respiration: The process of releasing energy from food.
- Aerobic: Occurs in the presence of Oxygen; yields higher energy.
- Anaerobic: Occurs in the absence of oxygen; common in yeast (fermentation) and during heavy exercise in human muscles (producing Lactic Acid).
- Transportation: In humans, the Circulatory System (Heart, Blood, Blood Vessels) transports oxygen, nutrients, and waste. In plants, Xylem transports water and Phloem transports food.
- Excretion: The removal of metabolic waste. In humans, the Kidneys (using units called Nephrons) are the primary organs for filtering blood and removing urea.
Frequently Asked Exam Points (SSC/UPSC)
- Prokaryotic vs. Eukaryotic: Prokaryotes (e.g., Bacteria) lack a well-defined nucleus; Eukaryotes (e.g., Plants, Animals) have a membrane-bound nucleus and organelles.
- Cell Wall: Present in plants (made of Cellulose) but absent in animal cells.
- Chloroplasts: Found only in plant cells; contain Chlorophyll (magnesium-based pigment) responsible for photosynthesis.
- Blood: The human body typically contains 5 to 6 liters of blood. Plasma makes up about 55% of blood volume.
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About the Author
PS
Priya Sharma Static GK Expert
Indian History · Geography · Polity & Economy Specialist
With 8+ years of teaching static GK for competitive exams, Priya has helped thousands of students master the foundational subjects that appear year after year in UPSC, SSC, and Railway exams. She focuses on making history, geography, and polity approachable through well-structured MCQs and memorable explanations.
