PPT On The fundamental unit of life - Karareports

The Fundamental Unit of Life Class 9 | CBSE Class 9 Science This article is all about CBSE Class 9 Science Chapter 5 - The Fundamental Unit Of Life PPT
  on the most impotant topic i.e. the Cell.

Chapter PPT on CBSE Class 9 Science, chapter 5: The fundamental unit of life, are available here.

The Fundamental Unit of Life PPT

Hypotonic Solution: If the medium surrounding the the cell has a higher water concentration than the cell, meaning that the outside solution is very dilute the cell will gain water by osmosis such a solution is known as a hypotonic solution.

Isotonic Solution: If the medium has exactly the same water concentration as the cell, there will be no net movement of water across the cell membrane. Such a solution is known as an isotonic solution. 

Hypertonic Solution: If the medium has a lower concentration of water than the cell, meaning is a very concentrated solution the cell will lose water by osmosis. Such a solution is known as a hypertonic solution.

Plasmolysis: When a living plant cell loses water through osmosis there is shrinkage of contraction of the contents of the cell away from the cell wall. This phenomenon is known as plasmolysis.

The Fundamental Unit of Life class 9 notes Questions Answers

NCERT The Fundamental Unit of Life Pg-59

Q.1 who discovered the cells and how?
Answer: Cells were discovered by in English botanist call Robert Hooke in 1665. He Observed the cell in a cork slice with the help of a simple microscope.

Q.2 why is the cell called the structural and fundamental unit of life?
 Answer:  A cell is the smallest unit of life and is capable of performing of all the life functions. Cells are also the building blocks of a living organism. That is why cells are called the structural and fundamental unit of life.

The Fundamental Unit of Life Page-61

Q.1 How do substances like CO² and water  move in and out of the cell discuss? Answer: The cell membrane is selectively permeable and regulation the movement of substances in and out of the cells full stop carbon dioxide is produced during cellular respiration full stop therefore, CO² is present in high concentration inside the cell then out the cell. As a result see you to come out by the process called diffusion similarly oxygen also move the same process.

  Water pass through the cell membrane by the process of diffusion from a region of higher concentration to a region of lower concentration. This process movement is known as osmosis.

  Q.2 Why is the plasma membrane called a selectively permeable membrane?
 Answer: The plasma membrane is called selectively permeable membrane because it regulates the movement of substances in and out of the cell. It does not allow all kinds of materials to pass through it.

  The Fundamental Unit of Life Page-65

  Q.1 Can you name the two organelles we have study that contain their own genetic material.
Answer: The two cells organelles that contain their own genetic material are mitochondria and plastids.

  Q.2 If the organisation of a cell is destroyed due to some physical or chemical influence, what will happen?
 Answer: If the organisation of a cell is destroyed due to some reason then the lysosome will secret a powerful enzyme which will digest the cell. Thereby the particular area of the body will be cleaned up.

 Q.3 Why lysosomes known as suicide bags? Answer: During any disturbance in cellular activities the cell may get damaged. In that situation the lysosomes may burst and the enzyme present in it would digest the cell. Therefore lysosomes are known as suicide bags of a cell.

 Q.4 Where are proteins synthesized inside the cell?
 Answer: The rough endoplasmic reticulum which contain ribosomes are sites of protein synthesis.

The Fundamental Unit of Life Exercise

Q.1 Make a comparison and write down ways in which plant cell are different from animal cell.
Answer:

Plant Cell Picture| The Fundamental Unit of Life 
Animal Cell Picture| The Fundamental Unit of Life

 i.Plant cells are bounded by cell membrane and and cell wall but in animals cell wall is absent.
ii. Plastics are present in plant cells but absent in animal cells.
iii. In plant cells because a larger in size but in animal cells vehicles are smaller in size.


 Q.3 What should happen if the plasma membrane ruptures or breakdown?
  Answer: If the plasma membrane is ruptured the cell will die. The plasma membrane regulate the movement of materials in and out by the process of diffusion. So if the membrane reach down all the materials will come out and as a result the cell will destroy.
 
   Q.4 What would happen to the life of a cell if there was no Golgi apparatus?
    Answer: If there was no Golgi apparatus the following situations may occur-
     i. The process of storage, modification and packaging of various materials inside the cell do not take place.
ii. To the formation of complex sugars from single sugar would not be possible.
iii. The Golgi apparatus is involved in the formation of lysosomes so if there is no Golgi apparatus the formation of lysosomes would be impossible.

Q.5 Which organelle is known as the powerhouse of the cell? Why?
 Answer: The mitochondria is known as the powerhouse of a cell. This is because respiration occurs in it. As a result of respiration energy is produced in stored in the form of ATP molecules. Whenever energy is required ATP molecules are utilised. For this reason ATP molecules are known as energy currency. Where do the lipids and proteins constituting the cell membrane get synthesised answer lipids is synthesized in smooth endoplasmic reticulum and proteins are synthesized in the ribosomes of rough endoplasmic reticulum.

 Q.7 How does an amoeba obtain its food?
  Answer: Amoeba obtain its food by a process called endocytosis. The flexibility of the cell membrane enables the cell to engulf solid food particles and other materials from the environment.

Q.8 What is osmosis?
Answer: the movement of water molecules from a region of higher concentration to a region of lower concentration is called osmosis. It is a special case of diffusion.

The Fundamental Unit of Life Class 9 Extra Question and Answers

Q.1 Who discovered cell?
 Answer: Robert Hooke in 1605 
Q.2 What is cell?
 Answer: The fundamental and structural unit of life is called cell.
 Q.3 What are the different parts of cell?
  Answer: 
  i.Cell Membrane/plasma membrane 
  ii. Cell walls (plant cell only)
  iii. Nucleus 
  iv. Cytoplasm
   v. Cell Organelles 

Q.4 What are the different types of cell organelles?
 Answer: The different types of cell organelles are -
 i. Endoplasmic Reticulum (ER)
 ii.Golgi Apparatus
 iii. Lysosomes Mitochondria
iv. Plastids (animal cell)
v. Vacuoles
Osmosis Picture |The Fundamental Unit of Life

Q.4 What is hypotonic solution?
Answer:  If the medium surrounding the the cell has a higher water concentration than the cell, meaning that the outside solution is very dilute the cell will gain water by osmosis such a solution is known as a hypotonic solution.

Q.5 What is Isotonic Solution?
Answer: If the medium has exactly the same water concentration as the cell, there will be no net movement of water across the cell membrane. Such a solution is known as an isotonic solution. 

Q.6 What is hypertonic solution?
Answer: If the medium has a lower concentration of water than the cell, meaning is a very concentrated solution the cell will lose water by osmosis. Such a solution is known as a hypertonic solution.

Q.7 What is Plasmolysis?
Answer: When a living plant cell loses water through osmosis there is shrinkage of contraction of the contents of the cell away from the cell wall. This phenomenon is known as plasmolysis.

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