CELL — STRUCTURE AND FUNCTIONS

The size of the cells of an organism has no relation with the size
of its body. Do you agree? Give reason for your answer.

Why do plant cells have an additional layer surrounding the cell
membrane? What is this layer known as?

Why do plant cells have an additional layer surrounding the cell
membrane? What is this layer known as?

Cells consist of many organelles, yet we do not call any of these
organelles as structural and functional unit of living organisms.
Explain.

Read the following statements and write the appropriate term
against each statement.
A. I control the functions of a cell. Who am I? . .................
B. I am like a policeman. I do not allow anything and everything
to get in and out of the cell. Who am I? . .................
C. I transfer characters from parents to offsprings. Who am I?
..................

Is the following statement correct? If it is wrong, correct the
statement
Statement : “Unicellular organisms do not respire, only
multicellular organisms respire”

What are the functions of cell wall in plant cells?

Amoeba and Paramecium belong to which category of organisms?

In a cell, where are the genes located?

We do not sense any pain when we clip our nails or cut our hair.
Why?

The instrument used to observe cells is ________

The instrument used to observe cells is ________

In leaves, name the cell organelle and pigment that is responsible
for green colour.

Make sketches of animal and plant cells. State three differences between them.

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.

Explain why chloroplasts are found only in plant cells?

'Cells are the basic structural units of living organisms'. Explain.

Where are chromosomes found in a cell? State their function.

State the difference between eukaryotes and prokaryotes.

Which part of the cell contains organelles?

Write short notes on the following.

(a) Cytoplasm

(b) Nucleus of a cell

Make a sketch of the human nerve cell. What function do nerve cells perform?

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)