Page 25 - Innovator's Science-8

Points to Reflect

• Microorganisms are tiny living organisms that cannot be seen with the unaided eye. They are found in all
types of environments-even inside the bodies of plants and animals.
• Microorganisms can be either unicellular (made up of one cell) or multicellular (made up of many cells).
• The cell is the basic unit of life. All living things are made up of cells.
• A typical cell is surrounded by a cell membrane, filled with cytoplasm, and contains a nucleus. In addition,
plant, fungal, and bacterial cells have an extra layer called the cell wall.
• Unlike other cells, bacteria do not have a clearly defined nucleus.
• Cells vary in shape and size, and their shape is often related to the function they perform

NCERT Textbook Questions (Solved)

Let Us Enhance Our Learning

1. Various parts of a cell are given below. Write them
in the appropriate places in the following diagram. Only in Animal Cell
a. Nucleus Common to all three Cells
b. Cytoplasm
c. Chloroplast
d. Cell wall
e. Cell membrane
Only in Bacterial Cell Only in Plant Cell
f. Nucleoid
Ans. a. Nucleus: Present in plant and animal cells (not in bacterial
Only in Animal Cell
cells), controls the cell's ac vi es.
b. Cytoplasm: Jelly-like substance that fills the cell and Common to
contains all organelles. all three Cells
c. Chloroplast: Found only in plant cells, responsible for 1
photosynthesis. 2 & 5
3
d. Cell wall: Found in plant and bacterial cells, forms the 6 4
outermost layer.
e. Cell membrane: Found in all cells, located inside the cell Only in Bacterial Cell Only in Plant Cell
wall in plant/bacterial cells or as the outer layer in animal
cells.
f. Nucleoid: Found only in bacterial cells; the region where DNA is located since bacteria don't have a
true nucleus.

2. Aanandi took two test tubes and marked them A and B. She put two
spoonfuls of sugar solu on in each of the test tubes. In test tube B, she
added a spoonful of yeast. Then she a ached two incompletely inflated
balloons to the mouth of each test tube. She kept the setup in a warm place,
away from sunlight.
i. What do you predict will happen a er 3-4 days? She observed that the Experimental
balloon a ached to test tube B was inflated. What can be a possible set-up
explana on for this?

25
Science-8