Cell ICSE class 9

(Q.1)   Name the plastid that impart colour to flowers and fruit.

(Ans) Chromoplast is the plastid that impart colour to flowers and fruit.

(Q.2)   What are those organisms called, which are made up of millions and billions of cells?

(Ans) Multicellular organisms are the organisms which are made up of millions and billions of cells.

(Q.3)   Define cell.

(Ans) A cell is the structural and functional unit of all living organisms.

(Q.4)   What are those organisms called, which are made up of only one cell.

(Ans) The organisms, which are made up of only one cell are called unicellular organisms.

(Q.5)   Name the plant cells that control opening and closing of stomata?

(Ans) Guard cells control the opening and closing of stomata.

(Q.6)   Name the basic unit of life.

(Ans) Cell is the basic unit of life.

(Q.59)  Who discovered the nucleus in the cell?

(Ans) Robert Brown in 1831 discovered the nucleus in the cell.

(Q.60)  What substances form cell membrane and cell wall?

(Ans) Cell membrane is made up of proteins and lipids.�Cell wall is made up of cellulose.

(Q.61)  Name two-cell organelles, which have DNA apart from nucleus.

(Ans) (1) Plastids
(2) Mitochondria

(Q.62)  Name the cell organelles that are� found only in plant cell.

(Ans) Plastids and cell wall.

(Q.63)  Name the cell organelle that is found only in animal cell.

(Ans) Centriole

(Q.64)  Name the cell organelle in which cristae are present?

(Ans) Mitochondria

(Q.65)  On what factors do shape and of cell depend?

(Ans) The shape and of cell depend on the functions they perform.

(Q.66)  Who coined the term protoplasm?

(Ans) J.E. Purkinje

(Q.81)  Answer the following question: i. Give two characteristics of plasma membrane? ii. List two functions of plasma membrane.

(Ans) i. The two characteristics of plasma membrane are:
a) Plasma membrane surrounds the cell.
b) It is selectively permeable.

ii. The two functions of plasma membrane are:
a) It separates cellular contents from its surroundings.
b) It maintains cellular shape in animal cells.

(Q.82)  Answer the following question: i. Give two characteristic features of cell wall. ii. List two functions of cell wall.

(Ans) i. The two characteristic features of cell wall are:
a) Cell wall is found only in plant cells.
b) It is made up of cellulose.

ii. The two functions of cell wall are:
a) It provides shape and rigidity to cell.
b) It provides protection against variations in temperature, high wind speed, atmospheric moisture etc.

(Q.83)  Answer the following question: i. Name the scientist who first constructed the simple microscope. ii. Who proposed that all plants are made up of cells?

(Ans) i. Antony van Leuwenhock first constructed the simple microscope.
ii. Matthias Schleiden proposed that all plants are made up of cells.

(Q.84)   Define: i. Unicellular organisms ii. Multicellular organisms

(Q.85)  Fill in the missing words in the given table:��������������� Plastids Salient Feature Function Chloroplasts � � � Coloured Helps pollination �Leucoplasts Colourless �

(Ans)

Plastids	Features	Function
Chloroplasts	Green coloured	Site of photosynthesis
Chromoplasts	Coloured	Helps pollination
Leucoplasts	Colourless	Stores food

(Q.86)  Fill in the vacant columns: Cell organelles Functions Mitochondria � � Protein synthesis Golgi apparatus � � Suicidal bags of the cell

(Ans)

Cell organelles	Functions
Mitochondria	Power house of the cell
Ribosomes	Protein synthesis
Golgi apparatus	Secretory functions
Lysosomes	Suicidal bags of the cell

(Q.87)  Why is the plasma� membrane called a selectively permeable membrane?

(Ans) The plasma membrane allows or permits the entry and exit of some materials in and out of the cell. It also prevents movement of some other materials in the cell membrane. Therefore, it is called a selectively permeable membrane.

(Q.88)  Which cell organelle is known as the kitchen of the cell? Why?

(Ans) Chloroplast is known as kitchen of the cell as photosynthesis takes place resulting in synthesis of food.

(Q.89)   Mention any three differences between prokaryotic and eukaryotic cells?

(Ans)

Prokaryotic cells	Eukaryotic cells
Membrane bound organelles are absent.	Membrane bound organelles are present.
They contain single chromosome.	They contain more than one chromosomes.
Cell division takes place by binary fission or budding.	Cell division takes place either mitotically or meiotically .

(Q.90)   Enlist any three differences between plant and animal cell?

(Ans)

Plant cell	Animal cell
Cell wall is present.	Cell wall is absent.
Centrosome is absent.	Centrosome is present.
Plastid is present.	Plastid is absent.

(Q.91)  Complete the given table: Cell organelle Characteristic Help in protein synthesis Found only in plant cell Digest cell organelles during cell starvation

(Ans)

Cell organelle	Characteristic
Ribosomes	Help in protein synthesis
Only in plant cell	Plastid
Lysosomes	Digest cell organelles during cell starvation

(Q.92)  Answer the following question: i. Who gave cell theory? ii. Explain cell theory

(Ans) i. Matthias Schleiden and Theodar Schwann gave the cell theory.

ii. The cell theory states that:
a) Every living organism is made up one or many cells.
b) Cell is the structural and functional unit of all living organisms.
c) All cells arise from pre-existing cells.

(Q.96)  Why are Mitochondria known as power house of the cell?

(Ans) Mitochondria are called power house of cell because respiration takes place in them and energy is released in the form of adenosine tri-phosphate (ATP). The cell� uses this energy to perform various functions such as mechanical work and making of new chemical compound .

(Q.97)  What are the types of plastids? Write their names and fuctions.

(Ans) Plastids are of three types -
i) Leucoplasts- Leucoplasts store starch, protein and fat.
ii) Chromoplasts- Chromoplasts provide colour to fruits and flowers.
iii) Chloroplasts- Green coloured chloroplast is the site of photosynthesis as it contains chlorophyll.

(Q.98)  Differentiate between prokaryotic and eukaryotic cell.

(Ans)

������ Feature	���� Prokaryotic cell	����� Eukaryotic
1. Nucleus	Lacks true nucleus. Circular DNA lies naked in the cytoplasm. No�nucleolus or nuclear membrane.One chromosome present. Nuclecoplasm undifferentiated from cytoplasm.	True nucleus bound by nuclear membrane contains DNA, chromosomes, nucleolus and nuclear membrane present, Nucleoplasm differentiated from cytoplasm.
2. Organelles	Membrane – bound organelles like Golgi bodies, plastids, mitochondria and endoplasmic reticulum (ER) are absent.�	Membrane – bound organelles present.
3. Cell division	Divides by simple fission, spindle is not formed, no mitosis and meiosis.	Divides by mitosis or by meiosis.
4. Examples	Bacteria and cyanobacterica (blue – green algae).	All other organism.

(Q.99)  State true or false and rewrite the false statements correctly. i. Ribosomes are the power house of the cell. ii. Chromoplast is the pigmented plastid. iii. Animal cell have cell wall. iv. Centrosome is absent in animal cell. v. The reserve food material of animal cell is starch.

(Ans) i. False; mitochondria is the power house of the cell.
ii. True
iii. False; cell wall is present in plant cell.
iv. True
v. False; reserve food material of animal cell is glycogen.

(Q.100)  Give one word answer for each of the following. i. Longest cells of the body ii. Reserve food of plant cell iii. Suicidal Bags of the cell iv. Non-pigmented plastid v. Power house of the cell

(Ans) i. Nerve cells
ii. Starch
iii. Lysosomes
iv. Leucoplast
v. Mitochondria

(Q.101)  a) What is the name given to�the�thread shaped structures in the nucleus? Why is it important? b) Draw a diagram of the nucleus to show the given parts:���� i) nucleolus ii) nuclear pore iii) nuclear envelope

(Ans)

a)      The�thread shaped structures in the nucleus are known as chromosomes. These are important because they contain information for inheritance of features from parents to the next generation.

(Q.103)  Write one fuctions of each of the following cell organelles. a) Plasma membrane b) Mitochondria c)�Lysosomes d) Endoplasmic reticulum e) Vacuoles

b)