The Invisible Living World: Beyond Our Naked Eye MCQ for class 8 science chapter 2. In this MCQ, here we present 31 MCQ questions with their answers and 2 match the following question. We have curated both easy, moderately taught and challenging questions for overall practice of the students.
The Class 8 Science MCQ for Chapter 2, The Invisible Living World: Beyond Our Naked Eye is about cells, microorganisms, and the hidden living world. The chapter covers the microorganisms that cannot be seen without a microscope.
Important Definitions and Key Points from Chapter 2
- Cell: A cell is the basic unit of life.
- Microscope: A microscope is an instrument used to see very small objects that cannot be seen with the naked eye.
- Cell Membrane: The cell membrane is the thin outer covering that separates one cell from another and allows materials to move in and out.
- Cytoplasm: Cytoplasm is the jelly-like substance inside a cell where most life processes take place.
- Nucleus: The nucleus is the control centre of the cell and regulates its activities and growth.
- Cell Wall: The cell wall is a tough outer layer found in plant cells that gives shape, strength, and support.
- Chloroplast: Chloroplast is the green cell structure in plant cells that contains chlorophyll and helps in photosynthesis.
- Vacuole: A vacuole is a storage sac in the cell that stores substances and helps maintain cell shape.
- Plant Cell: A plant cell has a cell wall, chloroplasts, and a large vacuole along with the cell membrane, cytoplasm, and nucleus.
- Animal Cell: An animal cell has a cell membrane, cytoplasm, and nucleus but does not have a cell wall or chloroplasts.
- Unicellular Organism: A unicellular organism is made up of only one cell.
- Multicellular Organism: A multicellular organism is made up of more number of cells.
- Tissue: A tissue is a group of similar cells that perform a particular function.
- Yeast: Yeast is a unicellular fungus. It is used in making bread, cakes, and other fermented foods.
- Lactobacillus: Lactobacillus is a bacterium. It helps convert milk into curd.
- Rhizobium: Rhizobium is a bacterium. It is found in the root nodules of legumes that helps fix nitrogen in the soil.
Class 8 Science Chapter 2 MCQ The Invisible Living World: Beyond Our Naked Eye Online Test Questions and Answers
Question 1. The invention that opened up the hidden world of tiny living organisms was the:
a) Telescope
b) Periscope
c) Microscope
d) Kaleidoscope
Answer:
c) Microscope
Question 2. A lens is thicker in the middle and thinner at the edges. Such a lens helps by:
a) Making small objects appear larger
b) Producing sound
c) Absorbing water
d) Changing the colour of objects
Answer:
a) Making small objects appear larger
Question 3. Rhizobium bacteria are useful to leguminous plants because they:
a) Produce flowers directly
b) Make the roots longer by photosynthesis
c) Fix nitrogen and improve soil fertility
d) Turn milk into curd
Answer:
c) Fix nitrogen and improve soil fertility
Question 4. Robert Hooke observed a thin slice of cork and named the small empty spaces as:
a) Fibres
b) Tissues
c) Cells
d) Threads
Answer:
c) Cells
Question 5. Antonie van Leeuwenhoek is known as the Father of Microbiology because he:
a) Discovered electricity
b) Clearly observed tiny living organisms like bacteria
c) Invented the telephone
d) Found chlorophyll in leaves
Answer:
b) Clearly observed tiny living organisms like bacteria
Question 6. All living organisms are made up of:
a) Tissues only
b) Organs only
c) Cells
d) Blood
Answer:
c) Cells
Question 7. The stain used in preparing onion peel cells for observation is:
a) Iodine
b) Methylene blue
c) Safranin
d) Lime water
Answer:
c) Safranin
Question 8. Glycerin is added while preparing onion peel or cheek cell slides mainly to:
a) Increase temperature
b) Prevent drying and improve clarity
c) Remove the nucleus
d) Change the shape of cells
Answer:
b) Prevent drying and improve clarity
Question 9. The stain commonly used to observe human cheek cells is:
a) Safranin
b) Methylene blue
c) Vinegar
d) Alcohol
Answer:
b) Methylene blue
Question 10. The three basic parts of a typical cell are cell membrane, cytoplasm, and:
a) Chloroplast
b) Cell wall
c) Nucleus
d) Vacuole
Answer:
c) Nucleus
Question 11. The cell membrane is important because it:
a) Produces food in all cells
b) Separates one cell from another and allows movement of materials
c) Gives green colour to plants
d) Controls only plant growth
Answer:
b) Separates one cell from another and allows movement of materials
Question 12. Most life processes in a cell take place in the:
a) Cell wall
b) Cytoplasm
c) Nucleus
d) Chloroplast
Answer:
b) Cytoplasm
Question 13. The part of the cell that regulates activities and growth is the:
a) Cytoplasm
b) Nucleus
c) Cell wall
d) Vacuole
Answer:
b) Nucleus
Question 14. Plant cells are firm and closely packed mainly because of the presence of the:
a) Cytoplasm
b) Nucleus
c) Cell wall
d) Mitochondria
Answer:
c) Cell wall
Question 15. Chloroplasts are found in plant cells and help in:
a) Respiration only
b) Photosynthesis
c) Digestion
d) Movement
Answer:
b) Photosynthesis
Question 16. Compared to animal cells, plant cells usually have a large:
a) Nucleoid
b) Vacuole
c) Cilium
d) Flagellum
Answer:
b) Vacuole
Question 17. Muscle cells are generally spindle-shaped because this shape helps them in:
a) Photosynthesis
b) Contracting and relaxing
c) Storing chlorophyll
d) Fixing nitrogen
Answer:
b) Contracting and relaxing
Question 18. Nerve cells are long and branched mainly to:
a) Absorb water quickly
b) Reach different parts of the body and pass messages
c) Store food
d) Form a protective covering
Answer:
b) Reach different parts of the body and pass messages
Question 19. The correct order of levels of organisation in living organisms is:
a) Cell → Organ → Tissue → Organ system → Organism
b) Tissue → Cell → Organ → Organism → Organ system
c) Cell → Tissue → Organ → Organ system → Organism
d) Organ → Tissue → Cell → Organism → Organ system
Answer:
c) Cell → Tissue → Organ → Organ system → Organism
Question 20. Living beings made up of many cells are called:
a) Unicellular organisms
b) Multicellular organisms
c) Non-cellular organisms
d) Acellular organisms
Answer:
b) Multicellular organisms
Question 21. Microorganisms are organisms that:
a) Are always harmful
b) Can be seen clearly without any aid
c) Cannot be seen with the naked eye
d) Live only in dirty water
Answer:
c) Cannot be seen with the naked eye
Question 22. Which of the following is a unicellular microorganism mentioned in the chapter?
a) Amoeba
b) Mould
c) Mushroom
d) Cowpea
Answer:
a) Amoeba
Question 23. According to the chapter, mould is an example of a:
a) Unicellular fungus
b) Multicellular fungus
c) Protozoan
d) Virus
Answer:
b) Multicellular fungus
Question 24. Yeast is classified as a:
a) Unicellular fungus
b) Multicellular alga
c) Bacterium
d) Protozoan with chlorophyll
Answer:
a) Unicellular fungus
Question 25. Bacteria differ from plant and animal cells because they do not have a well-defined:
a) Cell wall
b) Cytoplasm
c) Cell membrane
d) Nucleus
Answer:
d) Nucleus
Question 26. In bacteria, the genetic material is present in a region called the:
a) Vacuole
b) Nucleoid
c) Chloroplast
d) Centriole
Answer:
b) Nucleoid
Question 27. Viruses are different from other microorganisms because they:
a) Are always multicellular
b) Reproduce only inside a living host cell
c) Can make their own food
d) Have chloroplasts
Answer:
b) Reproduce only inside a living host cell
Question 28. Fruit and vegetable peels turn into manure mainly due to the action of:
a) Sunlight and wind only
b) Bacteria and some fungi
c) Roots of plants only
d) Insects only
Answer:
b) Bacteria and some fungi
Question 29. Manure formation from plant waste occurs best under:
a) No moisture and very low temperature
b) Optimal temperature and appropriate moisture
c) Total darkness only
d) Frozen conditions
Answer:
b) Optimal temperature and appropriate moisture
Question 30. Biogas released during decomposition in oxygen-free conditions contains a high proportion of:
a) Oxygen
b) Nitrogen
c) Methane
d) Hydrogen
Answer:
c) Methane
Question 31. In dough, yeast makes it soft and fluffy mainly by releasing:
a) Oxygen
b) Carbon dioxide
c) Nitrogen
d) Hydrogen
Answer:
b) Carbon dioxide
Question 32 – Match the Following
| Column A | Column B |
|---|---|
| 1. Cell membrane | A. Regulates cell activities |
| 2. Cytoplasm | B. Site of most life processes |
| 3. Nucleus | C. Gives rigidity and strength to plant cells |
| 4. Cell wall | D. Controls entry and exit of materials |
| 5. Chloroplast | E. Helps in photosynthesis |
Answer:
| Column A | Correct Answer |
|---|---|
| 1. Cell membrane | D. Controls entry and exit of materials |
| 2. Cytoplasm | B. Site of most life processes |
| 3. Nucleus | A. Regulates cell activities |
| 4. Cell wall | C. Gives rigidity and strength to plant cells |
| 5. Chloroplast | E. Helps in photosynthesis |
Question 33 – Match the Following
| Column A | Column B |
|---|---|
| 1. Yeast | A. Makes curd sour |
| 2. Lactobacillus | B. Fixes nitrogen in root nodules |
| 3. Rhizobium | C. Helps dough rise |
| 4. Microalgae | D. Help produce much of Earth’s oxygen |
| 5. Virus | E. Reproduces only inside a host cell |
Answer:
| Column A | Correct Answer |
|---|---|
| 1. Yeast | C. Helps dough rise |
| 2. Lactobacillus | A. Makes curd sour |
| 3. Rhizobium | B. Fixes nitrogen in root nodules |
| 4. Microalgae | D. Help produce much of Earth’s oxygen |
| 5. Virus | E. Reproduces only inside a host cell |
True or False type Questions for Class 8 Science Chapter 2 “The Invisible Living World: Beyond Our Naked Eye”
7 true or false questions based on Chapter 2, “The Invisible Living World: Beyond Our Naked Eye,” of the NCERT Science book for Class 8:
1. A simple lens helped humans begin exploring tiny living things that could not be seen with the naked eye.
Answer:
True
2. Robert Hooke was the first scientist to clearly describe bacteria and is known as the Father of Microbiology.
Answer:
False
3. In plant cells, the cell wall gives rigidity and strength, helping the cells remain firm in structure.
Answer:
True
4. Nerve cells are spindle-shaped because they help in churning food inside the stomach.
Answer:
False
5. Microorganisms may be found in pond water, soil, air, and even inside the bodies of living organisms.
Answer:
True
6. Yeast makes dough rise because it releases oxygen bubbles during respiration.
Answer:
False
7. Rhizobium bacteria living in the root nodules of legumes help improve soil fertility by making nitrogen useful to plants.
Answer:
True
Fill in the Blanks Questions for Class 8 Science Chapter 2 “The Invisible Living World: Beyond Our Naked Eye”
7 fill-in-the-blank questions based on Chapter 2, “The Invisible Living World: Beyond Our Naked Eye,” of the NCERT Science book for Class 8 –
1. The basic unit of life is the ______.
Answer:
cell
2. The jelly-like substance between the cell membrane and nucleus is called the ______.
Answer:
cytoplasm
3. In bacteria, the nuclear material is present in a region called the ______.
Answer:
nucleoid
4. A single-celled organism is called a ______ organism.
Answer:
unicellular
5. The microorganism commonly used to make bread and cakes soft and fluffy is ______.
Answer:
yeast
6. The bacterium that helps convert milk into curd is ______.
Answer:
Lactobacillus
7. Tiny plant-like organisms in water that produce more than half of Earth’s oxygen are called ______.
Answer:
microalgae
