RBSE Solutions for Class 6 Science Chapter 7 Cell

Rajasthan Board RBSE Class 6 Science Chapter 7 Cell

RBSE Solutions for Class 6 Science

RBSE Solutions for Class 6 Science Chapter 7 Cell

RBSE Class 6 Science Cell Intext Questions and Answers

Page No 54.

Question 1.
Can you guess the total number of cells in our body?
Answer:
Our body is generally made up of billions of cells. Organisms made up of more than one cell are called multicellular organisms.

Page No 55.

Question 2.
What is the shape of our body cells?
Answer:
The shape of cells of our body depends upon the type of work they, perform. The cells of our body are of various shapes like round and flat cells (blood cells), long and spindle cells (muscle cells), quite long and branched cells (nerve cells) etc.

Page No 57.

Question 3.
Do bigger animals have larger cells?
Answer:
No, ft is not necessary that smaller organisms will have small cells and bigger organisms will have large cells. The size of the cell is related to its function e.g. inspire of difference in the size of human and rats, the nerve cells in both are long and branched.

RBSE Class 6 Science Cell Text Book Questions and Answers

Choose the Correct Option:

Question 1.
Who discovered cell?
(a) Robert Brown
(b) Robert Hooke
(c) Schleiden
(d) Schwann
Answer:
(b) Robert Hooke

Question 2.
Which of these is absent in the animal cell?
(a) mitochondria
(b) nucleus
(c) cytoplasm
(d) plastid
Answer:
(d) plastid

Question 3.
A group of similar cells performing a specific function is called –
(a) organ
(b) cell
(c) system
(d) tissue
Answer:
(d) tissue

Fill in the blanks:

  1. Thread like structures found in the nucleus are called ……………………..
  2. Amoeba is a ……………………… organism.
  3. An organism made up of more than one cells is called …………………… organism.
  4. Nerve cells are …………………… and ……………………..

Answer:

  1. chromosomes
  2. unicellular
  3. multi cellular
  4. quite long, branched

Short Answer Type Questions:

Question 1.
What is the difference between prokaryotic and eukaryotic cell?
Answer:
Differences between prokaryotic and eukaryotic cell are –

1. Prokaryotic cell

  • Nuclear membrane around the nucleus is absent.
  • Cell organelles are absent.
    Example – bacteria and mycoplasma.

2. Eukaryotic cell

  • Nuclear membrane around the nucleus is present.
  • Cell organelles are present.
    Example – All animals and plant cells.

Question 2.
Define a tissue.
Answer:
A group of similar cells performing a specific function is called tissue.

Question 3.
Why mitochondria is called the power house of the cell?
Answer:
Biological energy ATP is produced inside the mitochondria because of which it is called the power house of the cell.

Question 4.
Why lysosomes is known as suicidal bag?
Answer:
It contains very strong digestive enzymes. When the cell gets injured or is dead, then the lysosomes rupture and the digestive enzymes digest their own cell. That is why they are also called suicidal bags.

Long Answer Type Questions:

Question 1.
Explain the following parts of the cell along with diagrams –

  1. nucleus
  2. cell membrane
  3. cytoplasm.

Answer:
1. Nucleus –
It is generally spherical. In animal cell, it is located in the centre hut in plant cell, it is not located in the centre and shifts towards one side due to large vacuoles. It is enveloped by a double layered membrane. This membrane is porous and allows the movement of materials. Nucleus contains a small dense structure called the nucleolus. Nucleus contains thread – like structures called chromosomes. Chromosomes carry genes which carry hereditary information from the parents to the offspring. Nucleus controls all the activities of the cell.

2. Cell membrane –
It is the outer covering of the cell. Ii is also called plasma membrane. It is porous and is made up of fats and proteins. Cell membrane allows selective substances to enter the cell and helps in removal of waste substances. This membrane is similar in animals and plants. In plants, a thick covering of cellulose is present outside the cell membrane which is called cell wall. The cell wall gives definite shape to the plant cells.

3. Cytoplasm –
The fluid present between the cell membrane and the nucleus is called cytoplasm. It is a jelly – like substance. Structures like – mitochondria, vacuoles, golgi body, endoplasmic reticulum, chloroplast etc. are present in the cytoplasm. These structures present in the cytoplasm are called cell organelles.
RBSE Solutions for Class 6 Science Chapter 7 Cell-2

Question 2.
What are the differences between animal cell and plant cell?
Answer:
Differences between animal cell and plant cell are as tinder –

1. Animal Cell

  • In animal cell, cell wall is absent.
  • Chlorophyll is absent in animal cell.
  • Vacuoles are of small size in animal cell.
  • Nucleus is present in the center in animal cell.

2. Plant Cell

  • In plant cell, cell wall is present.
  • Chlorophyll is present in the plant cell.
  • Vacuoles are large size in plant cell.
  • Nucleus is present in side i.e. this peripheral in plant cell.

Question 3.
Draw a labelled diagram of the animal cell?
Answer:
RBSE Solutions for Class 6 Science Chapter 7 Cell-4

RBSE Class 6 Science Cell Important Questions and Answers

Choose the Correct Options:

Question 1.
The organism whose body is made up of more than one cell is called –
(a) parasite
(b) amoeba
(c) multicellular organism
(d) symbiotic
Answer:
(c) multicellular organism

Question 2.
An example of unicellular organism is –
(a) mosquito
(b) amoeba
(c) human
(d) fish
Answer:
(b) amoeba

Question 3.
The structural unit of each organism is –
(a) tissue
(b) organ
(c) cell
(d) None of these
Answer:
(c) cell

Question 4.
Endoplasmic reticulum is of types.
(a) one
(b) two
(c) three
(d) four
Answer:
(b) two

Question 5.
The role of nucleotide in protein synthesis is firstly represented by which scientist?
(a) Satish C. Maheshwari
(b) Dr. Hargobind Khurana
(c) Kannad
(d) Bose
Answer:
(b) Dr. Hargobind Khurana

Fill in the blanks:

  1. ……………………… type of cells are found in our body. (Different/Same)
  2. Energy cell has a ……………. (gene/nucleus)
  3. Organ forms system and system forms ……………….. (tissue/body)
  4. The structures found in the cytoplasma are called ……………………. (cell organelles/liquid)
  5. For the process of photosynthesis ………………….. pigment is very necessary. (chlorophyll/chlorophyte)

Answer:

  1. Different
  2. nucleus
  3. body
  4. cell organelles
  5. chlorophyll

Match the Column (1) with Column (2) –

Question 1.
RBSE Solutions for Class 6 Science Chapter 7 Cell-5
Answer:

  1. (d)
  2. (a)
  3. (e)
  4. (b)
  5. (c)

Very Short Answer Type Questions:

Question 1.
Who invented cell and when?
Answer:
Robert Hooke invented cell in the year 1665.

Question 2.
On the basis of number of cells how many types of organisms are there?
Answer:
On the basis of number of cells, organisms are of two types –

  1. Unicellular organism (example – amoeba, paramecium)
  2. Multicellular organism (example – human, tree etc.)

Question 3.
State the type of cells on the basis of shape?
Answer:

  • Irregular shape
  • Round and flat
  • Long and spindle shape
  • Quite long and branched cell.

Question 4.
Give two examples of unicellular organisms.
Answer:

  • Amocha
  • Paramecium.

Question 5.
Write the stages of formation of organism from the cell.
Answer:
Cell → Tissue → Organ → System → Organism

Question 6.
What are organs?
Answer:
Group of similar functioning tissues is called organ.

Question 7.
Name the biggest cell.
Answer:
The largest cell in living beings is the egg of ostrich, whose size is 170 mm x 130 mm.

Question 8.
Where arc chromosomes found?
Answer:
Chromosomes are found in the nucleus of the cell.

Question 9.
What are genes and where are they found?
Answer:
Genes are found in the thread like structures of nucleus called the Chromo somes, that carry hereditary characters from one generation to another.

Question 10.
What is nucleolus?
Answer:
The nucleus of each cell contains a small dense structure called the nucleolus.

Question 11.
Name the main parts of a cell.
Answer:
Every living cell contains mainly three parts –

  • Cell membrane
  • Cytoplasm
  • Nucleus.

Question 12.
Who controls all the functions of a cell?
Answer:
The functions of cell of every living is controlled by is nucleus.

Question 13.
Where is protein synthesized in a cell?
Answer:
Ribosomes are attached to the rough endoplasmic recticulum of each cell and perform the function of protein synthesis.

Question 14.
Name the main components of cell membrane and cell wail.
Answer:
The main component of cell membrane is cellulose and cell wall is liquid and protein.

Short Answer Type Questions:

Question 1.
What is cell wall?
Answer:
In plant cell outside the cell membrane is present a thick covering made up of cellulose. It is called cell wall. Due to the presence of cell wall only the shape of plant cell is fixed or definite.

Question 2.
Give one example of round and flat cell along with its diagram.
Answer:
Example of round and flat cell is blood cell.
RBSE Solutions for Class 6 Science Chapter 7 Cell-6

Question 3.
Draw a diagram of spindle shaped muscle cell.
Answer:
RBSE Solutions for Class 6 Science Chapter 7 Cell-7

Question 4.
What is the shape of nerve cells or neutron? Also draw its figure.
Answer:
The nerve cells or neurons are quite long and branched in shape.
RBSE Solutions for Class 6 Science Chapter 7 Cell-8

Question 5.
What are plastids?
Answer:
They are present in the cytoplasm of plant cells. Most plastids contain a green pigment called chlorophyll and the green coloured plastids are called chloroplast. These give green colour to the leaves. Plants perform photosynthesis and make their food with the help of chlorophyll. Chlorophyll is very essential for photosynthesis.

Question 6.
Draw a labelled diagram of a plant cell
Answer:
RBSE Solutions for Class 6 Science Chapter 7 Cell-9

Question 7.
Give general information regarding the size of a cell.
Answer:
The size of cells may he as small as a millionth of a meter (micrometer) or as large as few centimetre. Most of the cells are microscopic in size. They are not visible to the unaided eye. Cell can he seen with the help of a microscope. The smallest cell is 0.1 to 0.5 micrometer, which is a bacterial cell. The largest cell is the egg of an ostrich. measuring 170 x 130 mm.

Question 8.
Explain about the shape of cells.
Answer:

  • Irregular shape cells like amoeba, mycoplasma.
  • Round and flat cells like blood cells.
  • Long and spindle shaped cells like muscle cells.
  • Quite long and branched cells like nerve cells. The shape of the cell is related to its function.

Question 9.
Explain the activity of cell in a thin layer of onion cell with diagram.
Answer:
Take a piece of onion. Separate a thin layer of onion with the help of forceps. Place it on a glass slide. Add a drop of methylene blue solution to the layer and place a coverslip on it. While placing the coverslip ensure that there are no air bubbles under the coverslip. Carefully observe the slide under the microscope. Various small cells are seen in it.
RBSE Solutions for Class 6 Science Chapter 7 Cell-10

Question 10.
Draw the diagram of amoeba cell.
Answer:
RBSE Solutions for Class 6 Science Chapter 7 Cell-11

Question 11.
Explain the process of formation of organism starting from the cell.
Answer:

  • Cell is the structural unit.of every living organism
  • A group of cells performing similar function is called a tissue.
  • A group of tissues performing similar function is called an organ.
  • Different organs form an organ system.
  • Different organ systems form the body.

RBSE Solutions for Class 6 Science Chapter 7 Cell-12

Essay Type Questions:

Question 1.
Explain the cell organelles found in the cytoplasm.
Answer:
The main cell organelles found in the cytoplasm are as under –

1. Lysosomes –
At contains very, strong digestive enzymes. When the cell gets injured or is dead. then the lysosomes suptured and digestive enzymes digest their own cell. That is why they are also called the suicidal bags of cell.

2. Golgi body –
They are flattened membranous structures arranged one above the other. It was first of all described by a scientist named, Camillio Golgi. The substances produced in the endoplasmic reticulum are trapped in golgi apparatus and are sent to various locations inside and outside the cell.

3. Mitochondria –
It is a structure covered by a double layer membrane. Its inner membrane is extensively folded. These folds are called cristae. Biological energy ATP is produced in the mitochondria. That is why it is also called the power house of the cell.

4. Endoplasmic reticulum –
This structure appears as a network of thin tubules present in cytoplasm. It is of two types:

1. Rough endoplasmic reticulum
2. Smooth endoplasmic reticulum Ribosomes are attached to the rough endoplasmic reticulum and perform the function of protein synthesis.

5. Plastids –
They are the green coloured pigment found in the plant cell which are called chlorophyll. ‘They are essential for photosynthesis.

6. Vacuoles –
Large vacuoles are found in plant cell while animal cells contain small vacuoles.

Question 2.
Tabulate the cell organelles like cell wall, nucleus, vacuoles, plastids position, their presence, size, etc. of a plant cell and a animal cell.
Answer:

1. Part of cell

  • Cell membrane
  • Position of nucleus
  • Size of vacuole
  • Plastid

2. Animal cell

  • Absent
  • In center
  • Small
  • Absent

3. Plant cell

  • Present
  • On one side
  • Big
  • Present

Question 3.
Give a brief introduction and workings of Indian scientist Dr. Har Govind. Khurana.
Answer:
He was born in a town named Raipur of Multan district. Punjab in the unpartitioned india. He passed B.Sc. (honours) in 1943 and M.Sc. (honours) in 1945 from Punjab University and went lo England after receiving scholarship from The Government of India. He achieved a doctorate degree from liverpool University by researching under the guidance of A. Robertson. Dr. Khurana was the first to show the role of nucleotides in protein synthesis. In 1968, he was awarded the Nobel prize for outstanding work in the field of genetics. Government of India awarded him the Padma Vibhushan award.

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