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Chapter 5: The Fundamental Unit of Life



Chapter 5: The Fundamental Unit of Life

Class: IX

Exemplar sheet 5

Multiple Choice Questions

Question 1

 Which of the following can be made into crystal?

(a) A Bacterium

(b) An Amoeba

(c) A Virus

(d) A Sperm

Answer 1



Question 2

A cell will swell up if

(a) The concentration of water molecules in the cell is higher than the concentration of water molecules in surrounding medium

(b) The concentration of water molecules in surrounding medium is higher than water molecules concentration in the cell

(c) The concentration of water molecules is same in the cell and in thesurrounding medium

(d) Concentration of water molecules does not matter

Answer 2


Question 3

Chromosomes are made up of

(a) DNA

(b) protein

(c) DNA and protein

(d) RNA

Answer 3



Question 4

Which of these options are not a function of Ribosomes?

(i) It helps in manufacture of protein molecules

(ii) It helps in manufacture of enzymes

(iii) It helps in manufacture of hormones

(iv) It helps in manufacture of starch molecules

(a) (i) and (ii)

(b) (ii) and (iii)

(c) (iii) and (iv)

(d) (iv) and (i)

Answer 4



Question 5

Which of these is not related to endoplasmic reticulum?

(a) It behaves as transport channel for proteins between nucleus and cytoplasm

(b) It transports materials between various regions in cytoplasm

(c) It can be the site of energy generation

(d) It can be the site for some biochemical activities of the cell

Answer 5


Question 6

Following are a few definitions of osmosis

Read carefully and select the correct definition

(a) Movement of water molecules from a region of higher concentration to a region of lower concentration through a semipermeable membrane

(b) Movement of solvent molecules from its higher concentration to lower concentration

(c) Movement of solvent molecules from higher concentration to lower concentration of solution through a permeable membrane

(d) Movement of solute molecules from lower concentration to higher concentration of solution through a semipermeable membrane

Answer 6


Question 7

Plasmolysis in a plant cell is defined as

(a) break down (lysis ) of plasma membrane in hypotonic medium

(b) shrinkage of cytoplasm in hypertonic medium

(c) shrinkage of nucleoplasm

(d) none of them

Answer 7


Question 8

Which of the following are covered by a single membrane?

(a) Mitochondria

(b) Vacuole

(c) Lysosome

(d) Plastid

Answer 8


Question 9

Find out the false sentences

(a) Golgi apparatus is involved with the formation of lysosomes

(b) Nucleus, mitochondria and plastid have DNA; hence they are able to make their own structural proteins

(c) Mitochondria is said to be the power house of the cell as ATP is generated in them.

(d) Cytoplasm is called as protoplasm

Answer 9


Question 10

Find out the correct sentence

(a) Enzymes packed in Lysosomes are made through RER (rough endoplasmic reticulum)

(b) Rough endoplasmic reticulum and smooth endoplasmic reticulum produce lipid and protein respectively

(c) Endoplasmic reticulum is related with the destruction of plasma membrane

(d) Nucleoid is present inside the nucleoplasm of eukaryotic nucleus

Answer 10


Question 11

Which cell organelle plays a crucial role in detoxifying many poisons and drugs in a cell?

(a) Golgi apparatus

(b) Lysosomes

(c) Smooth endoplasmic reticulum

(d) Vacuoles   

Answer 11



Question 12

The proteins and lipids, essential for building the cell membrane, are manufactured by

(a) rough endoplasmic reticulum

(b) golgi apparatus

(c) plasma membrane

(d) mitochondria

Answer 12




Question 13

The undefined nuclear region of prokaryotes are also known as

(a) nucleus

(b) nucleolus

(c) nucleic acid

(d) nucleoid

Answer 13



Question 14

The cell organelle involved in forming complex sugars from simple sugars are

(a) endoplasmic reticulum

(b) ribosomes

(c) plastids

(d) golgi apparatus

Answer 14



Question 15

Which out of the following is not a function of vacuole?

(a) Storage

(b) Providing turgidity and rigidity to the cell

(c) Waste excretion

(d) Locomotion

Answer 15


Question 16

Amoeba acquires its food through a process, termed

(a) exocytosis

(b) endocytosis

(c) plasmolysis

(d) exocytosis and endocytosis both

Answer 16


Question 17

Cell wall of which one of these is not made up of cellulose?

(a) Bacteria

(b) Hydrilla

(c) Mango tree

(d) Cactus

Answer 17



Question 18

Silver nitrate solution is used to study

(a) endoplasmic reticulum

(b) golgi apparatus

(c) nucleus

(d) mitochondria

Answer 18


Question 19

Organelle other than nucleus, containing DNA is

(a) endoplasmic reticulum

(b) golgi apparatus

(c) mitochondria

(d) lysosome

Answer 19



Question 20

Kitchen of the cell is

(a) mitochondria

(b) endoplasmic reticulum

(c) chloroplast

(d) golgi apparatus

Answer 20



Question 21

Lipid molecules in the cell are sythesized by

(a) smooth endoplasmic reticulum

(b) rough endoplasmic reticulum

(c) golgi apparatus

(d) plastids

Answer 21



Question 22

Cell arises from pre-existing cell was stated by

(a) Haeckel

(b) Virchow

(c) Hooke

(d) Schleiden

Answer 22



Question 23

Cell theory was given by

(a) Schleiden and Schwann

(b) Virchow

(c) Hooke

(d) Haeckel

Answer 23


Question 24

The only cell organelle seen in prokaryotic cell is

(a) mitochondria

(b) ribosomes

(c) plastids

(d) lysosomes

Answer 24


Question 25

Organelle without a cell membrane is

(a) ribosome

(b) golgi apparatus

(c) chloroplast

(d) nucleus

Answer 25



Question 26

1 μm is

(a) 10–6 m

(b) 10–9 m

(c) 10–10 m

(d) 10–3 m

Answer 26


Question 27

Lysosome arises from

(a) endoplasmic reticulum

(b) golgi apparatus

(c) nucleus

(d) mitochondria

Answer 27


Question 28

Living cells were discovered by

(a) Robert Hooke

(b) Purkinje

(c) Leeuwenhoek

(d) Robert Brown

Answer 28


Question 29

Select the odd one out

(a) The movement of water across a semi permeable membrane is affected by the amount of substances dissolved in it.

(b) Membranes are made of organic molecules like proteins and lipids

(c) Molecules soluble in organic solvents can easily pass through the membrane.

(d) Plasma membranes contain chitin sugar in plants

Answer 29




Short Answer Questions

Question 30

Why are lysosomes known as ‘suicide-bags’ of a cell?

Answer 30

Lysosomes  are known as suicide bags because sometimes they release the powerful digestive enzymes  them within the cell cause self- destruction of  its cells.


Question 31

Do you agree that "A cell is a building unit of an organism". If yes, explain why?

Answer 31

Hint— Cell→ tissue → organ → organ system → organism

Question 32

Why does the skin of your finger shrink when you wash clothes for a long time?

Answer 32

This is because soap solution is very concentrated - Hypertonic solution, so water moves out of the cells of finger by osmosis.

Question 33

Why is endocytosis found in animals only?

Answer 33

Hint— Cell wall is absent in animals


Question 34

A person takes concentrated solution of salt, after sometime, he starts vomiting. What is the phenomenon responsible for such situation? Explain.

Answer 34

Exosmosis in intestine causes dehydration

Question 35

Name any cell organelle which is non membranous.

Answer 35


Question 36

We eat food composed of all the nutrients like carbohydrates, proteins, fats, vitamins, minerals and water. After digestion, these are absorbed in the form of glucose, aminoacids, fatty acids, glycerol etc.

What mechanisms are involved in absorption of digested food and water?

Answer 36

Diffusion and osmosis respectively

Question 37

If you are provided with some vegetables to cook. You generally add salt into the vegetables during cooking process. After adding salt, vegetables release water. What mechanism is responsible for this?

Answer 37


Question 38

If cells of onion peel and RBC are separately kept in hypotonic solution, what among the following will take place? Explain the reason for your answer.

(a) Both the cells will swell.

(b) RBC will burst easily while cells of onion peel will resist the bursting to some extent.

(c) a and b both are correct.

(d) RBC and onion peel cells will behave similarly.

Answer 38

Hint— (b) Onion peel has cell wall and RBC does not have cell wall

Question 39

Bacteria do not have chloroplast but some bacteria are photoautorophic in nature and perform photosynthesis. Which part of bacterial cell performs this?

Answer 39

Hint— Small vesicles associated with plasma membrane

Question 40

Match the following A and B

(A)   (B)

(a) Smooth endoplasmic reticulum   (i) Amoeba

(b) Lysosome   (ii) Nucleus

(c) Nucleoid   (iii) Bacteria

(d) Food vacuoles   (iv) Detoxification

(e) Chromatin material   (v) Suicidal bag

  and nucleolus

Answer 40

a—iv;  b—v;  c—iii;   d—i;  e—ii


Question 41

Write the name of different plant parts in which chromoplast, chloroplast and leucoplast are present.

Answer 41

Flower and Fruit— Chromoplast

Leaves of the plant— Chloroplast

Root of the plant— Leucoplast

Question 42

Name the organelles which show the analogy written as under

(a) Transporting channels of the cell——

(b) Power house of the cell——

(c) Packaging and dispatching unit of the cell——

(d) Digestive bag of the cell——

(e) Storage sacs of the cell——

(f) Kitchen of the cell——

(g) Control room of the cell——

Answer 42

(a) Endoplasmic reticulum   (b) Mitochondria

(c) Golgi body   (d) Lysosome

(e) Vacuole   (f) Chloroplast

(g) Nucleus

Question 43

How is a bacterial cell different from an onion peel cell?

Answer 43

Hint— Bacterial cell is a prokaryote

Onion peel cell is a plant cell— an eukaryote

Question 44

How do substances like carbon dioxide (CO2 ) and water (H2O) move in and out of the cell?

Answer 44

Hint—Diffusion and osmosis


Question 45

How does amoeba obtain its food?

Answer 45


Question 46

Name the two organelles in a plant cell that contain their own genetic material and ribosomes.

Answer 46

Hint—Mitochondria and plastids

Question 47

Why are lysosomes also known as "scavengers of the cells"?

Answer 47

Hint—Remove debris of the cell

Question 48

Which cell organelle controls most of the activities of the cell?

Answer 48



Question 49

Which kind of plastid is more common in

(a) roots of the plant

(b) leaves of the plant

(c) flowers and fruits

Answer 49

Hint—(a) Leucoplast   (b) Chloroplast   (c) Chromoplast

Question 50

Why do plant cells possess large sized vacuole?

Answer 50

Hint—Vacuoles not only store many important substances, they also contain cell sap that give turgidity to cell.

Question 51

How are chromatin, chromatid and chromosomes related to each other?

Answer 51

Hint—Chromosomes are made up of chromatids and chromatids are individual chromosome and are made up of chromatin

Question 52

What are the consequences of the following conditions?

(a) A cell containing higher water concentration than the surrounding medium

(b) A cell having low water concentration than the surrounding medium.

(c) A cell having equal water concentration to its surrounding medium.

Answer 52

(a) Exosmosis   (b) Endosmosis   (c) No effect

Long Answer Questions

Question 53

Draw a plant cell and label the parts which

(a) determines the function and development of the cell

(b) packages materials coming from the endoplasmic reticulum

(c) provides resistance to microbes to withstand hypotonic external media without bursting

(d) is site for many biochemical reactions necessary to sustain life.

(e) is a fluid contained inside the nucleus

Answer 53

Hint— (a) Nucleus

(b) Golgi apparatus

(c) Cell wall

(d) Cytoplasm

(e) Nucleoplasm.

Diagram of the plant cell can be drawn and label it with parts mentioned above

Question 54

Illustrate only a plant cell as seen under electron microscope. How is it different from animal cell?

Answer 54

  ncert science class 9 chapter 5

Plant Cell   Animal Cell

  1. Cell wall present 1. Cell wall absent
  2. Plastids are present 2. Plastids are absent
  3. It has a large vacuole 3. It has a small vacuole
  4. Centriole absent 4. Centriole present


Question 55

Draw a neat labelled diagram of an animal cell.

Answer 55

  ncert science class 9 chapter 5


Question 56

Draw a well labelled diagram of an eukaryotic nucleus. How is it different from nucleoid?

Answer 56

Any electron microscopic diagram of Nucleus can be drawn. It is a membrane bound organelle.

Question 57

Differentiate between rough and smooth endoplasmic reticulum. How is endoplasmic reticulum important for membrane biogenesis?

Answer 57

The ribosomes, which are present in all active cells, are the sites of protein synthesis. Endoplasmic reticulum helps in transporting these proteins to various places. The smooth endoplasmic reticulum help in manufacture of fat and lipids which along with proteins help in building the cell membrane.


Question 58

In brief state what happens when

(a) dry apricots are left for sometime in pure water and later transferred to sugar solution?

(b) a Red Blood Cell is kept in concentrated saline solution?

(c) the Plasma-membrane of a cell breaks down?

(d) rheo leaves are boiled in water first and then a drop of sugar syrup is put on it?

(e) golgi apparatus is removed from the cell?

Answer 58

Hints—(a) First dry apricots swells due to endosmosis and then it shrink due to lose of water (exosmosis).

 (b) It will lose water due to exosmosis and shrink.

 (c) The cell will die.

(d) The cell gets killed on boiling so no plasmolysis

(d) All sorts of vesicle formation stops.

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