VII SCIENCE CELL BIOLOGY EVALUATION QUESTION ANSWERS

 

CELL BIOLOGY


EVALUATION

I. Choose the correct answer


1. Basis unit of life.

A) Cell

B) Protoplasm

C) Cellulose

D) Nucleus

Ans: A) Cell


2. I am the outermost layer of an animal cell. Who am I?

A) Cell wall 

B) Nucleus

C) Cell membrane 

D) Nuclear membrane

Ans: C) Cell membrane 


3. Which part of the cell is called the brain of the cell?

A) Lysosome 

B) Ribosome

C) Mitochondria 

D) Nucleus

Ans: D) Nucleus


4. _______ helps in cell division

A) Endoplasmic reticulum

B) Golgi complex

C) Centriole

D) Nucleus

Ans: C) Centriole


5. Suitable term for the various components of cell is__

A) Tissue 

B) Nucleus

C) Cell 

D) Cell organelle

Ans: D) Cell organelle


II Fill in the Blanks

1. The jelly like substance present in the cell is called _____

Ans: cytoplasm


2. I convert the Sun’s energy into food for the plant. Who am I? ____

Ans: chloroplast


3. Mature Red blood cell do not contain a ____.

Ans: nucleus


4. Unicellular organisms can only be seen under a _____.

Ans: microscope


5. Cytoplasm plus nucleoplasm is equal to___.

Ans: protoplasm


III. True or False – If false give the correct answer


1. Animal cells have a cell wall.

Ans: Flase

Plant cells have a cell wall.


2. Salmonella is a unicellular bacteria.

Ans: True


3. Cell membrane is fully permeable

Ans: False

Cell membrane is partially permeable


4. Only plant cells have chloroplasts.

Ans: True


5. Human stomach is an organ.

Ans: True


6. Ribosomes are small organelles with a Membrane.

Ans: Flase

Ribosomes are small organelles without a Membrane.



IV. Match the following


Transporting channel

Nucleus

Suicidal bag

Endoplasmic reticulum

Control room

Lysosome

Power house

Chloroplast

Food producer

Mitochondria


Ans:


Transporting channel

Endoplasmic reticulum

Suicidal bag

Lysosome

Control room

Nucleus

Power house

Mitochondria

Food producer

Chloroplast



V. Analogy

1. Bacteria : microorganism :: mango tree : _______

Ans: Macroorganism


2. Adipose : tissue :: eye : ______

Ans: Organ


3. Cell wall : plant cell :: centriole : ____

Ans: Animal cell


4. Chloroplast : photosynthesis :: mitochondria : ____

Ans: Respiration


VI. Choose the correct alternative from the following


1. Assertion (A) : Tissue is a group of dissimilar cells.

Reason (R) : Muscle is made up of Muscle cell.

a). Both A and R are true

b). Both A and R are false

c). A is true but R is false.

d). A is false but R is true.

Ans: d). A is false but R is true.


2. Assertion (A) : Majority of cells cannot be seen directly with naked eye

because.

Reason (R) : Cells are microscopic.

a). Both A and R are true

b). Both A and R are false

c). A is true but R is false.

d). A is false but R is true.

Ans: a). Both A and R are true


VII. Very short answer


1. What are the functions of cell wall in plant cell?


Cell wall provides a framework to plant cells for shape, support and stability.


2. Which organelle uses energy from sunlight to make starch?


Chloroplast uses energy from sunlight to make starch.


3. What are the main things in a nucleus?


Nuclear membrane,nucleolus, chromatin body,karyoplasm. 


4. What does cell membrane do?


Cell membrane acts as the boundary of an animal cell, which is also called a plasma membrane.


5. Why lysosomes are known as scavengers of the cell?


Lysosomes are known as scavengers of the cells, because they remove the dead and non-functioning cell organelle by digesting them.


6. Teacher said “A virus is not an organism” Do you agree with this statement or not? Explain Why?


Yes, I agree with the statement. 

A virus acts as a living organism in the body of a host and behaves like a non-living thing outside the body.


Organisms should have a cell wall, cell membrane, cytoplasm and organelles. As virus do not have any of these, it is not an organism.



VIII. Give short Answer


1. Why the cell is very important for us?


No organism exists without a cell.

✱The cell is a basic structural and functional unit of life. 

✱Cell is the building unit of living organisms. 

✱Cells work together to perform its functions. 

✱Cell is known as the basic unit of life

So, the cell is very important to us.


2. Distinguish between the following pairs 


✱Smooth ER and Rough ER

✱Cell wall and cell membrane

✱Chloroplast and mitochondria



Smooth ER

Rough ER

It is a network of tubular sacs without ribosomes on the membrane

It is rough due to the ribosomes attached to the membrane.

It helps in the synthesis of lipids, steroids and also transport them within the cell

It  helps in the synthesis of protein




Cell wall

Cell membrane

It present only in plant cells

It presents in both the plant and animal cell

It is made of cellulose

It is made of protein and lipids

Cell wall around the cell membrane that is rigid and provides support and protection to the cell content.

Cell membranes are selectively permeable



Chloroplast

Mitochondria

It’s an organelle seen only in green plant cells

It’s an organelle present both in plant and animal cells.

Chloroplasts with chlorophyll pigments produce food by photosynthesis.

Mitochondria are responsible for cellular respiration, which releases the energy from the food.



3. Write correct sequence from cell to organism?


Cell → Tissue → Organ → Organ system → Organism


4. Write a short note on nucleus.


✱Nucleus is seen in the cytoplasm of plant and animal cells.

✱It is surrounded by a nuclear envelope. 

✱One or two nucleolus and the chromatin body are present inside the nucleus. ✱Storage of genetic material and transfers heredity characters from generation to generation.


Functions of Nucleus 

✱In controls all the processes and chemical reactions that take place inside the cell. 

✱Inheritance of character from one generation to another. 


5. Classify the following terms into cells, tissues, organs and write in the tabular column given below Neuron, Lungs. Xylem, brain, adipose, Leaf, RBC, WBC, hand, muscle, heart, ovum, squamous, phloem, cartilage. 




Cell

Tissue

Organ

Neuron

Xylem

Lungs

RBC

Adipose

Brain

WBC

Muscle

Leaf

Ovum

Squamous

Hand


Phloem

Heart


Cartilage




6. On the lines given below, write about what you have learned from the activities done in this lesson.


Let me tell you about some of the important things I’ve learned about cells. First, I’ll start with…____________________________________________________.


✱Cells are the basic structural and functional units of all living organisms.

✱Cells are microscopic and can be seen only under a microscope. 

✱Cell walls present only in plant cells.

✱Cell membranes present in both plant and animal cells.

✱Mitochondria are responsible for cellular respiration, which releases the energy from the food.

✱Plants have chloroplasts to produce food by photosynthesis. 

✱Nucleus controls all the process inside the cell.

✱A group of different tissues makes up an organ. 

✱Organs working together in groups form systems or organ systems. 

✱Organ systems make up an organism, such as a human.


IX. Give long answer


1. Write about any three organelles in detail.


Golgi Complex

✱Membrane bounded sacs are stacked on top of the other with associated secretory vesicles collectively known as golgi complex. 

✱Functions of golgi complex are the production of secretory substances, packaging and secretion. This is the secret behind the change in the colour and taste of fruits.

Lysosome:

✱Lysosomes are very small to view using a light microscope. 

✱They are the main digestive compartments of the cell. 

✱They lyse a cell, hence they are called “suicidal bag”


Centrioles:

✱They are generally found close to the nucleus and are made up of tube-like structures. 

✱Centrioles or centrosomes are present only in animal cells and absent in plant cells. 

✱It helps in the separation of chromosomes during cell division

2. In a situation, how to explain, while your friend asks what is this, never seen before?

✱This is a animal cell

✱Cell membrane is also called as plasma membrane

✱It is the boundary of an animal cell.

✱The cell has organelles like mitochondria, golgi apparatus, ribosomes, etc.

✱Ribosome is a minute particle consisting of RNA.It synthesizes proteins.

✱Cytoplasm includes all living parts of the cell within the cell membrane but excluding the nucleus.

✱Nucleus is the controlling centre of the cell.

✱Mitochondria is the powerhouse of the cell. 


3. Compare the plant cell and the animal cell and complete the illustration given below



X. Higher order thinking question 


Virus is called Acellular. Why?


✱Viruses are acellular, because they do not have a cellular structure. 

✱Viruses are acellular entities that can usually only be seen with an electron microscope. 

✱They lack most of the components of cells, such as organelles, ribosomes, and cytoplasm.


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