THESE NOTES ARE PREPARED ACCORDING TO JKBOSE SYLLABI IN SIMPLIFIED AND CONCISE PATTERN
Q. What is cell? Who discovered the cell and How?
Ans: The cell is small structural and functional unit of life.
The cell was first discovered by Robert Hook in 1665 when he was observing cork slices under a primitive microscope.
Q. Why is cell called Structural and Functional unit of life?
Ans: The cell is structural and functional unit of life.
Ans: The cell is small structural and functional unit of life.
The cell was first discovered by Robert Hook in 1665 when he was observing cork slices under a primitive microscope.
Q. Why is cell called Structural and Functional unit of life?
Ans: The cell is structural and functional unit of life.
It performs all functions characteristic of living forms.
All organisms evolved from single cells.
Cell has organelles and form tissues, organs and organ systems.
Q. Write a note on Plasma membrane?
Or
Why is plasma membrane selective permeable?
Ans: Plasma membrane is the outermost covering of cell.
It is made of lipids and proteins.
It seperates cytoplasm from external environment.
It is selective permeable membrane as it allows only certain substances enter or leave the cell.
If plasma membrane breaks down, it will cause lysis of cell.
Q. What would happen if the plasma membrane ruptures or breaks down?
Ans: Plasma membrane is the selectively permeable covering of all cells. If it ruptures or breaks down, the cytoplasm and cell organelles will leak out of the cell and the cell will die.
Q. How do substances like CO2 and H2O move in and out of cell?
Ans: The CO2 and H20 move in and out of cell through plasma membrane.
Ans: The CO2 and H20 move in and out of cell through plasma membrane.
They move by diffusion.
Q. What is Cell Wall? In which organism is cell wall found?
Ans: Cell wall is external rigid covering found in plant cells.
The cell wall lies outside of plasma membrane.
It is made of cellulose.
It provides strength to plant cell.
Q. Fill in the gaps in the following table illustrating differences between prokaryotic and eukaryotic cells.
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Ans:
|
Prokaryotic
Cell |
Eukaryotic Cell |
|
Size:
Generally Small |
Size: Generally
Large |
|
Nuclear Region:
No proper membrane bound nucleus and the known as Nucleoid |
Nuclear
region: Well defined and surrounded by nuclear membrane |
|
Chromosome:
Single |
More than one
chromosome |
|
Membrane
bound organelles absent |
Membrane bound
organelles present |
Q. Distinguish between Prokaryotic and Eukaryotic cell? Or
How is a prokaryotic cell different from a eukaryotic cell?
Ans:
Ans:
Q. Differentiate between Plant cell and Animal Cell?
Or
Make a comparison and write down ways in which plant cells are different from animal cells.
Ans:
Ans:
Q. Write a note on endoplasmic reticulum?
Or
Where do the lipids and proteins constituting cell membrane get synthesized?
Or
Where are proteins synthesized inside the cell?
Ans: Endoplasmic reticulum (ER) is network of membrane bound tubes and sheets.
ER acts as framework for biochemical activities.
It is of two types:
Rough endoplasmic reticulum (RER) i.e ER with ribosomes.
Or
Where do the lipids and proteins constituting cell membrane get synthesized?
Or
Where are proteins synthesized inside the cell?
Ans: Endoplasmic reticulum (ER) is network of membrane bound tubes and sheets.
ER acts as framework for biochemical activities.
It is of two types:
Rough endoplasmic reticulum (RER) i.e ER with ribosomes.
Smooth Endoplasmic reticulum (SER) i.e ER without ribosomes
The protein synthesis takes place at RER and Lipid synthesis takes place at SER
Q. What would happen to the cell if there are no golgi apparatus?
Or
What are Golgi bodies?
Ans: Golgi apparatus was first discovered by Camillo golgi.
It is network of vesicles arranged in form of cysternae.
It serves as packing and distribution centre of cell.
Complex sugars are formed from simple sugars in golgi bodies.
If there are no golgi bodies, the materials produced in cell cannot be transfered outside cell.
Or
What are Golgi bodies?
Ans: Golgi apparatus was first discovered by Camillo golgi.
It is network of vesicles arranged in form of cysternae.
It serves as packing and distribution centre of cell.
Complex sugars are formed from simple sugars in golgi bodies.
If there are no golgi bodies, the materials produced in cell cannot be transfered outside cell.
Q. What are Lysosomes? Why are lysosomes called sucidal bags?
Ans: Lysosomes are tiny sac like structures in the cell.
Ans: Lysosomes are tiny sac like structures in the cell.
They have single membrane.
They contain enzymes which help to neutralize foreign agents in the cell.
They can also kill cell if the cell is damaged or not functioning properly. Hence, they are called sucidal bags.
Q. Write a short note on Plastids?
Ans: The Plastids are found in plant cells.
They have their own DNA.
Plastids can be coloured i.e chromaplasts or colourless i.e leucoplasts.
Plastids store food, fats, provide colour or help in photosynthesis.
Plastids that contain chlorophyll pegment called chloroplasts. They helps in photosynthesis.
Q. Write a note on Mitochondria?
Or
Why is mitochondria called powerhouse of cell?
Or
Which organelle is known as the powerhouse of the cell? Why?
Ans: Mitochondria are rod shaped bodies.
They have double membrane. Outer membrane is porous and inner membrane have folds called cristae.
Inner membrane also contain F1 particles.
Inside mitochondria there is gel like substance called matrix.
Mitochondria are site of cellular respiration, which releases energy to cell.
The energy is stored in form of ATP. Hence mitochondria are called powerhouse of cell.
Ans: Mitochondria are rod shaped bodies.
They have double membrane. Outer membrane is porous and inner membrane have folds called cristae.
Inner membrane also contain F1 particles.
Inside mitochondria there is gel like substance called matrix.
Mitochondria are site of cellular respiration, which releases energy to cell.
The energy is stored in form of ATP. Hence mitochondria are called powerhouse of cell.
Q. Can you name the two organelles we have studied that contain their own genetic material?
Ans: Two cell organelles that contain their own genetic material are Chloroplast and Mitochondria.
Q. If the organisation of a cell is destroyed due to some physical or chemical influence, what will happen?
Ans: If the organization of a cell is destroyed due to some physical or chemical influence, it will not be able to perform its functions such as respiration, nutrition, excretion and division.
This will lead to cell death.
Q. Where are proteins synthesized inside the cell?
Ans: The proteins are synthesized at the rough endoplasmic reticulum.
Q. Draw the labelled diagram of Animal cell?
Ans:
Ans:
Q. Draw the labelled diagram of Plant cell?
Ans:
Ans:
Q. How does an Amoeba obtain its food?
Ans: Amoeba possesses Pseudopodia which help it to obtain the food. The food enters the body of Amoeba by the process of Phagocytosis.
Q. What is osmosis?
Ans: Osmosis is the movement of Water molecules from the solution with higher concentration of solute to the solution with lower concentration of solute across the semi-permeable membrane.
Q. Carry out the following osmosis experiment:
Take four peeled potato halves and scoop each one out to make potato cups. One of these potato cups should be made from a boiled potato. Put each potato cup in a trough containing water. Now,
(a) Keep cup A empty
(b) Put one teaspoon sugar in cup B
(c) Put one teaspoon salt in cup C
(d) Put one teaspoon sugar in the boiled potato cup
Keep these for two hours. Then observe the four potato cups and answer the following:
(i) Explain why water gathers in the hollowed portion of B and C.
(ii) Why is potato A necessary for this experiment?
(iii) Explain why water does not gather in the hollowed-out portions of A and D.
Ans:
(I): Since a teaspoon of Sugar and Salt were present in the hollowed portions of B and C respectively, the water moved into the potato by the process of Osmosis.
(II): Potato A is necessary for the experiment because it acts as a control for our experiment.
(III): The water does not gather in the Potato A because A is empty and osmosis will not occur. The water will also not gather in the potato D as it has been boiled which ruptures the membranes and kills the cells of Potato.
Q. Which type of cell division is required for growth and repair of body and which type is involved in formation of gametes?
Ans: Mitosis is required for the growth and repair of the body and Meiosis is involved in the formation of gametes.
(a) Keep cup A empty
(b) Put one teaspoon sugar in cup B
(c) Put one teaspoon salt in cup C
(d) Put one teaspoon sugar in the boiled potato cup
Keep these for two hours. Then observe the four potato cups and answer the following:
(i) Explain why water gathers in the hollowed portion of B and C.
(ii) Why is potato A necessary for this experiment?
(iii) Explain why water does not gather in the hollowed-out portions of A and D.
Ans:
(I): Since a teaspoon of Sugar and Salt were present in the hollowed portions of B and C respectively, the water moved into the potato by the process of Osmosis.
(II): Potato A is necessary for the experiment because it acts as a control for our experiment.
(III): The water does not gather in the Potato A because A is empty and osmosis will not occur. The water will also not gather in the potato D as it has been boiled which ruptures the membranes and kills the cells of Potato.
Q. Which type of cell division is required for growth and repair of body and which type is involved in formation of gametes?
Ans: Mitosis is required for the growth and repair of the body and Meiosis is involved in the formation of gametes.
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