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    8 Science NCERT Solutions Chapter 8

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    Raj Anand
    This document contains a class 8 worksheet on cell biology with 10 multiple choice and short answer questions. The questions cover topics like the basic structure and components of plant and animal cells, the differences between prokaryotic and eukaryotic cells, the functions of organelles like the nucleus, cytoplasm, and chloroplasts. The answers define key cell structures, explain their roles in cellular processes, and distinguish characteristics between plant and animal cells. Overall, the worksheet assesses a student's understanding of the basic units and functions of life at the cellular level.

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    8 Science NCERT Solutions Chapter 8

    Uploaded by

    Raj Anand
    98 views6 pages
    This document contains a class 8 worksheet on cell biology with 10 multiple choice and short answer questions. The questions cover topics like the basic structure and components of plant and animal cells, the differences between prokaryotic and eukaryotic cells, the functions of organelles like the nucleus, cytoplasm, and chloroplasts. The answers define key cell structures, explain their roles in cellular processes, and distinguish characteristics between plant and animal cells. Overall, the worksheet assesses a student's understanding of the basic units and functions of life at the cellular level.

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    This document contains a class 8 worksheet on cell biology with 10 multiple choice and short answer questions. The questions cover topics like the basic structure and components of plant and animal cells, the differences between prokaryotic and eukaryotic cells, the functions of organelles like the nucleus, cytoplasm, and chloroplasts. The answers define key cell structures, explain their roles in cellular processes, and distinguish characteristics between plant and animal cells. Overall, the worksheet assesses a student's understanding of the basic units and functions of life at the cellular level.

    Copyright:

    © All Rights Reserved
    Download as PDF, TXT or read online from Scribd
    Download as pdf or txt
    98 views6 pages

    8 Science NCERT Solutions Chapter 8

    Uploaded by

    Raj Anand
    This document contains a class 8 worksheet on cell biology with 10 multiple choice and short answer questions. The questions cover topics like the basic structure and components of plant and animal cells, the differences between prokaryotic and eukaryotic cells, the functions of organelles like the nucleus, cytoplasm, and chloroplasts. The answers define key cell structures, explain their roles in cellular processes, and distinguish characteristics between plant and animal cells. Overall, the worksheet assesses a student's understanding of the basic units and functions of life at the cellular level.

    Copyright:

    © All Rights Reserved
    Download as PDF, TXT or read online from Scribd
    Download as pdf or txt
    of 6

    (www.tiwariacademy.

    com)

    (Class – VIII)

    Exercises
    Question 1:
    Indicate whether the following statements are True (T) or False (F).
    (a) Unicellular organisms have one-celled body. (T/F)
    (b) Muscle cells are branched. (T/F)
    (c) The basic living unit of an organism is an organ. (T/F)
    (d) Amoeba has irregular shape. (T/F)
    Answer 1:
    (a) Unicellular organisms have one-celled body. (True)
    (b) Muscle cells are branched. (False)
    (c) The basic living unit of an organism is an organ. (False)
    (d) Amoeba has irregular shape. (True)

    Question 2:
    Make a sketch of the human nerve cell. What function do nerve cells perform?
    Answer 2:
    The nerve cell receives and transfers messages, thereby helping to control and coordinate
    the working of different parts of the body.

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    (Class – VIII)

    Question 3:
    Write short notes on the following:
    (a) Cytoplasm
    (b) Nucleus of a cell
    Answer 3:
    (a) Cytoplasm
    The jelly-like substance between the nucleus and the cell membrane is called cytoplasm.
    Various cell organelles like ribosomes, mitochondria etc. are suspended inside cytoplasm.
    It helps exchange and storage of substances among cell organelles. Most of the metabolic
    activities occur inside cytoplasm.

    (b) Nucleus of a cell


    The central dense round body in the centre is called the nucleus. It is an important
    component of the living cell. It is generally spherical and located in the centre of the cell.
    It can be stained and seen easily with the help of a microscope. Nucleus is separated from
    the cytoplasm by a membrane called the nuclear membrane. This membrane is also
    porous and allows the movement of materials between the cytoplasm and the inside of
    the nucleus. A smaller spherical body in the nucleus, is called the nucleolus. Nucleus also
    contains thread-like structures called chromosomes. These carry genes and help in
    inheritance or transfer of characters from the parents to the offspring.

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    (Class – VIII)

    Question 4:
    Which part of the cell contains organelles?
    Answer 4:
    Cytoplasm, gelatinous fluid inside a cell contains various organelles like mitochondria,
    Golgi bodies, ribosomes etc.

    Question 5:
    Make sketches of animal and plant cells. State three differences between them.
    Answer 5:
    Sl. No. Part Plant Cell Animal Cell
    1. Cell wall Present Absent
    2. Centrosomes Absent Present & helps in cell division
    3. Plastids Present Absent
    4. Vacuole Large Vacuole Small Vacuole or Absent

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    (Class – VIII)

    Question 6:
    State the difference between eukaryotes and prokaryotes.
    Answer 6:
     Prokaryotes: The cells having nuclear material without nuclear membrane are
    termed as prokaryotic cells. The organisms with these kinds of cells are called
    prokaryotes.
    Examples: Bacteria and blue green algae.
     Eukaryotes: The cells having a well-organized nucleus with a nuclear membrane
    are termed as eukaryotic cells. The organisms with these kinds of cells are called
    eukaryotes.
    Examples: Onion cells and cheek cells.

    Question 7:
    Where are chromosomes found in a cell? State their function.
    Answer 7:
    Chromosomes are found in the nucleus of the cell. These carry genes and help in
    inheritance or transfer of characters from the parents to the offspring.

    Question 8:
    ‘Cells are the basic structural units of living organisms’. Explain.
    Answer 8:
    Both, bricks in a building and cells in the living organisms, are basic structural units. All
    basic functions for the organism survival take place inside cells. As bricks assemble to
    make a building, cells assemble to make the body of every organism. A group of cells form
    a tissue which performs a specific function. A group of tissue forms an organ and in the
    same way a group of organs form an organism. That is why cells are considered as the
    basic structural units of living organisms.

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    (Class – VIII)

    Question 9:
    Explain why chloroplasts are found only in plant cells?
    Answer 9:
    Chloroplasts are found in plant cells only because chloroplasts contain chlorophyll which
    is essential for photosynthesis. Chlorophyll traps cell energy and use it to prepare food
    for plants.

    Question 10:
    Complete the crossword with the help of clues given below:
    Across
    1. This is necessary for photosynthesis.
    3. Term for component present in the
    cytoplasm.
    6. The living substance in the cell.
    8. Units of inheritance present on the
    chromosomes.
    Down
    1. Green plastids.
    2. Formed by collection of tissues.
    4. It separates the contents of the cell from the
    surrounding medium.
    5. Empty structure in the cytoplasm.
    7. A group of cells.
    Answer 10:
    Across
    1. Chlorophyll
    3. Organelle
    6. Protoplasm
    8. Genes
    Down
    1. Chloroplasts
    2. Organ
    4. Membrane
    5. Vacuole
    7. Tissue

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    (Class – VIII)

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