Afaq NSS - Science 6 - Unit 2 Cell to Organism

Afaq New Sun Series - Science 6 - Unit 2 Cell to Organism solved exercise and Question/Answer

Afaq NSS - Science 6 - Unit 2 Cell to Organism
Unit 2 Cell to Organism
Exercise (Solved)
 
Points to Remember!
  • A cell is the building block of all multicellular organisms.
  • As their names suggest, unicellular organisms have only one cell but multicellular organisms have many cells.
  • Cells have different organelles inside them that aid in cell maintenance.
  • Plant and animal cells differ because plant cells have a cell wall and chloroplast but they lack centrioles.
  • Organisms who a cellular hierarchy from cell to organism.
Important Definitions:
  • Cell: It is the basic structural and functional unit of life.
  • Tissue: A group of different cells performing the same function, e.g. muscle tissue, connective tissue, etc.
  • Organ System: It is the coordination of different organs to perform a specific function, e.g. nervous system, digestive system, etc.
  • Organism: A collection of different organ systems working together in a coordinated manner, e.g. lions, humans, plants, etc.

1. Answer the following questions briefly.

  1. Differentiate between a cell and tissue.
    Ans: Cell: It is the basic structural and functional unit of life.
    Tissue: A group of different cells performing the same function, e.g. muscle tissue, connective tissue, etc.

  2. List down the similarities between a plant cell and an animal cell.
    Ans: a. In the animal cell there is no cell wall and the outer covering is called cell membrane while in the plant cell wall is the outer covering.
    b. In animal cell Nucleus lies in the center of the cell while in plant cell Nucleus is pushed towards the boundary of the cell because of a large vacuole.

  3. Why are mitochondria called the powerhouse of a cell?
    Ans: Double membrane-bound structure, provide energy to the cell for all activities. Mitochondria is responsible for cellular respiration.

  4. What are the functions of the brain and lungs?
    Ans: Brain: The brain regulates all the activities taking place in the body. The brain controls our thoughts, memory and speech, movement of the arms and legs, and the function of many organs within our body.
    Lungs: The main role of the lungs is to transfer life-giving oxygen into the blood supply, but they also have other functions.

  5. Write down the cellular hierarchy of a lion.
    Ans: a. Cell: the basic unit of life.
    b. Tissue: Grouping of Cells.
    c. Organ: Grouping of tissues
    d. Organ System: Grouping of organs
    e. Multicellular Organism (Loin)

2. Answer the following questions in detail.

  1. Describe the plant organ system in detail.
  2. Explain the following organ systems.
    1. Shoot System
    2. Circulatory System
    3. Nervous System
    4. Skeletal System
3. Choose the correct option.
  1. The basic building block of a multicellular organism is a/an _ _ _ _ _ _ _.
    1. tissue        2. cell            3. organ              4. system

  2. Which one of the following is a unicellular organism?
    1. bee           2. butterfly            3. paramecium            4. sparrow

  3. _ _ _ _ _ _ _ _ is / are the brain of the cell.
    1. Mitochondria            2. The chloroplast            3. The nucleus            4. Centrioles
  4. Which one of the following is NOT present in a plant?
    1. mitochondria            2. chloroplast            c. Ribosomes            Epidermal Tissue
  5. Which of the following tissue is not present in plants?
    1. Mesophyll Tissue          2. Vascular Tissue           c. Vervous Tissue           d. Epidermal Tissue

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