Lesson: Cell$—$Structure and Functions

Exemplar:

# Question: 1

Choose the correct statement with respect to unicellular organisms:

(a)   In unicellular organisms, tissues work in co-ordination to perform different functions.

(b)   Unicellular organisms do not require food.

(c)   Unicellular organisms respire and reproduce.

(d)   All unicellular organisms move by cilia.

c

# Question: 2

Majority of cells cannot be seen directly with our naked eyes because:

(a) Organisms are generally unicellular

(b) Cells are microscopic

(c) Cells are present only inside the body

(d) Cells are grouped into tissues

b

# Question: 3

Read the different combinations of terms given below:

(a) Cell wall, cell membrane, nucleus, plastid

(b) Cell wall, nucleus, ribosome, chromosome

(c) Cell membrane, mitochondria, ribosome, chromosome

(d) Cell membrane, ribosome, mitochondria, chloroplast.

The correct combination of terms with reference to an animal cell is _____.

c

# Question: 4

Which one of the following terms is not a part of the nucleus?

(a) Ribosome

(b) Nucleolus

(c) Chromosome

(d) Gene

a

# Question: 5

A suitable term for the various components of cells is:

(a) Tissue

(b) Cell organelles

(c) Chromosomes

(d) Genes

b

# Question: 6

The jelly-like fluid substance present in cells is called:

(a) Protoplasm

(b) Chromosome

(c) Chloroplast

(d) Cytoplasm

d

# Question: 7

Read the following pairs of examples of organisms:

(a) Moss and sponge

(b) Yeast and Amoeba

(c) Bacteria and blue-green alga

(d) Penicillium and Spirogyra

The pair that belongs to the group prokaryotes is_____

c

# Question: 8

Read the following terms and select the pair that is related to inheritance of characters.

(a) Cell wall and cell membrane

(b) Chromosome and mitochondria

(c) Chloroplast and cell membrane

(d) Chromosome and genes

d

# Question: 9

Choose the correct statement:

(a) Genes are located in the chromosomes.

(b) Cell is located in the nucleus.

(c) Chromosomes are located in the nucleolus.

(d) Cell membrane surrounds the nucleus.

a

# Question: 10

Green colour of leaves is due to presence of the pigment_____

(a) Chlorophyll

(b) Ribosomes

(c) Mitochondria

(d) Chloroplast

a

# Question: 11

The unit of measurement used for expressing dimension (size) of cells is:

(a) Centimetre

(b) Millimetre

(c) Micrometre

(d) Metre

c

# Question: 12

The most important function of cell membrane is that it:

(a) Controls the entry and exit of materials from cells.

(b) Controls only the entry of materials into cells.

(c) Controls only the exit of materials from cells.

(d) Allows entry and exit of materials without any control.

a

# Question: 13

Paheli accidentally placed her hand over a flame and immediately pulled it back. She felt the sensation of heat and reacted due to the action of

(a) Blood cells

(b) Skin surface

(c) Nerve cells

(d) Nucleus of cells

c

# Question: 14

Of the following parts of a cell listed below, name the part that is common to plant cell, animal cell and a bacterial cell.

(a) Chloroplast

(b) Cell wall

(c) Cell membrane

(d) Nucleus

c

# Question: 15

The thread-like structures present in the nucleus are:

(a) Nucleolus

(b) Chromosomes

(c) Genes

(d) Ribosomes

b

# Question: 16

Identify the statement which is true for cells.

(a) Cells can be easily seen with naked eyes.

(b) Insect’s egg is not a cell.

(c) A single cell can perform all the functions in a unicellular organism.

(d) The size and shape of cells is uniform in multicellular organisms.

c

# Question: 17

Which of the following is not a cell?

(a) Red Blood Corpuscle (RBC)

(b) Bacterium

(c) Spermatozoa

(d) Virus

d

# Question: 18

Which of the following feature will help you in distinguishing a plant cell from an animal cell?

(a) Cell wall

(b) Cell membrane

(c) Mitochondria

(d) Nucleus

a

# Question: 19

Under a microscope Paheli observes a cell that has a cell wall but no distinct nucleus.

The cell that she observes is:

(a) A plant cell

(b) An animal cell

(c) A nerve cell

(d) A bacterial cell

d

# Question: 20

Cheek cells do not have _______:

(a) Cell membrane

(b) Nucleus

(c) Golgi apparatus

(d) Plastids

d

# Question: 21

Identify the correct statement:

(a) Tissue is a group of dissimilar cells.

(b) An organ consists of similar cells.

(d) Prokaryotes do not have nucleus.

d

# Question: 22

Which of the following statements are true for eukaryotic cells?

(i) They do not have a nuclear membrane.

(ii) They have a well organised nucleus.

(iii) They have a nuclear membrane.

(iv) Blue green algae are eukaryotic cells.

(a) ii and iv

(b) ii and iii

(c) i and ii

(d) i and iv

b

# Question: 23

Identify the correct statement about cells.

(a) All the cells have nucleus.

(b) Cells of an organ have similar structure.

(c) Cells of a tissue have similar structure.

(d) Shape of all types of cells is round.

c

# Question: 24

The table given below has certain terms and four blank spaces named A, B, C and D.

 Cell Feature/part Function Amoeba Plant Cell C Nerve cell A Plastid Spindle shaped D Movement B Contraction Stimuli and response

From the options given below choose the correct combination of terms.

(a) A-Pseudopodia; B-Respirations; C-Muscle cell; D-Branched

(b) A-Pseudopodia; B-Photosynthesis; C-Muscle cell; D-Branched

(c) A-Contractile vacuole; B-Photosynthesis; C-Blood cell; D-Spindle shaped

(d) A-Pseudopodia; B-Photosynthesis; C-Cheek cell; D-Spindle shaped

b

# Question: 25

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

## Solution:

In leaves, the cell organelle and pigment that is responsible for green colour is chloroplast and chlorophyll respectively.

# Question: 26

The instrument used to observe cells is ________.

## Solution:

The instrument used to observe cells is microscope.

# Question: 27

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

Why?

## Solution:

Nails and hair are made up of dead cells and do not have nerve cells. Nerve cells are used to transmit signals from body parts to the brain. Hence, we do not sense any pain when they are cut.

# Question: 28

In a cell, where are the genes located?

## Solution:

In a cell, the genes are located in the chromosomes which are the thread like structures found in the nucleus.

# Question: 29

Amoeba and Paramecium belong to which category of organisms?

## Solution:

Amoeba and paramecium are unicellular organisms.

# Question: 30

What are the functions of cell wall in plant cells?

## Solution:

Functions of cell wall:

1.      It protects the cell contents.

2.      It provides rigidity and shape to the cell.

# Question: 31

Is the following statement correct? If it is wrong, correct the statement.

Statement: “Unicellular organisms do not respire, only multicellular organisms

respire”.

## Solution:

No, the statement is incorrect.

Both unicellular and multicellular organisms respire.

# Question: 32

Match the terms given in column I with their functions given in column II and fill the blanks given below the table:

 Column I Column II A. Chloroplast (i) Carries hereditary characters B. Cell membrane (ii) Controls the activities of cells C. Nucleus (iii) Site of photosynthesis D. Chromosome (iv) Controls the movement of materials into and out of cells.

A-_____; B-______; C-______; D-______

A-iii

B-iv

C-ii

D-i

# Question: 33

Observe the following diagram. Answer the following questions.

A. Does it represent a plant cell or an animal cell?

B. Does it represent a prokaryotic cell or a eukaryotic cell?

## Solution:

A. The diagram represents an animal cell.

B. It represents a eukaryotic cell.

# Question: 34

Label the parts A to E in the given diagram.

# Question: 35

Classify the following terms into cells, tissues and organs and write in the tabular column given below.

RBC, WBC, Nerve cell, blood, muscle, blood vessels, brain, heart, hand

 Cell Tissue Organ ________________ ________________ ________________ ________________ ________________ ________________ ________________ ________________ ________________

## Solution:

 Cell Tissue Organ RBC WBC Nerve cell Blood Muscle Blood vessels Heart Hand Brain

# Question: 36

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 offspring. Who am I?................

## Solution:

A. Nucleus                  B. Cell membrane                  C. Genes/Chromosomes

# Question: 37

Fill in the blanks with the terms given in the box below:

Nucleus, chromosomes, cell wall, cell membrane, protoplasm,

cytoplasm, ribosome, cell organelles

The outermost layer of plant cells is the_____(a)_____ beneath which is the ____(b) _____. The term ___(c) ______refers to the jelly-like substance containing all the____(d) ____. The _____(e) ______contains thread-like structures called_____(f) _______.

## Solution:

a)      cell wall

b)  cell membrane;

c)  cytoplasm;

d)  cell organelles;

e)  nucleus;

f)  chromosomes.

# Question: 38

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

Explain.

## Solution:

Cell organelles are the internal structures within a cell and they can perform their functions only when they are within a living cell. They cannot function as an independent unit outside the cell. Hence, they cannot be termed as structural and functional unit of living organisms.

# Question: 39

Why do plant cells have an additional layer surrounding the cell membrane?

What is this layer known as?

## Solution:

Plants do not move from one place to another. So, they require rigidity to protect themselves against variations in temperature, high wind speed, atmospheric moisture, etc. Therefore, plant cells have an additional layer surrounding the cells membrane for protection. This layer is called the cell wall.

# Question: 40

The size of the cells of an organism has no relation with the size of its body.