The Fundamental Unit of Life Blog 6

CLASS 9 CHAPTER 5 

THE FUNDAMENTAL UNIT OF LIFE

Day 6

" Whenever you feel sad, just remember that there are trillions of cells in your body & all they care about is you!!"

Dear Students, 

Welcome Back!😊

I hope you have completed your yesterday's assignment. After this class, you will be able to:

• Explain the structure and function of Plastids and its types.
• Explain the structure and function of Vacuoles.
• Distinguish between Meiosis and Mitosis.

Note: Content written in blue should be recorded as notes in the Biology Notebook.

Happy Learning!😊

Plastids

(Not to be drawn in bio copy)

Structure:

• They are present in plant cells only.
• They consist of numerous membrane layers embedded in a material called Stroma.
• they are similar to mitochondria in external structure and also have their own DNA and ribosomes.

Functions:

Plastids are of three types:

• Chloroplast: The green color of the leaves is due to the presence of chloroplast. chloroplast contains the green pigment called chlorophyll which is responsible for the process of photosynthesis in plants. in addition to chlorophyll, chloroplast also contains various yellow or orange pigments.

• Chromoplast: They are the colored plastids and are responsible for imparting color to fruits and flowers.

• Leucoplast: They are white or colorless plastids in which material like starch, oils, and protein are stored.

https://youtu.be/yyvfBFtyF8c (Check this video on plastids)

Vacuoles

(Not to be drawn in bio copy)

Structure:

• are storage spaces for solid or liquid contents.
• they are small in size in the animal cells but large in plant cells. in some plant cells, they may occupy 50-90% of the cell volume.

Functions:

• Plant cell vacuoles are full of sap and provide turgidity and rigidity to the cell.
• it acts as a storage unit of amino acids, sugars, organic acids, and proteins.
• In amoeba, food vacuoles contain the food items that it has consumed.
• In some unicellular organisms, specialized vacuoles play important role in expelling excess water and some wastes from the cell.

https://youtu.be/wzFg6Iaj8js (Check this video on plastids)

Cell Division

• The process by which new cells are made is called Cell division.
• It is of following two types:

Mitosis: The process by which most of the cells divide for growth and repair in the organisms. Each cell (mother cell) divides to form two identical daughter cells which have the same number of chromosomes as the mother cells.

Meiosis: It involves two consecutive divisions. When a cell divides, it produces four new cells, which have only half the number of chromosomes than that of mother cells.

(To be recorded in bio copy, refer Pg. 66 for the diagram)

https://youtu.be/zrKdz93WlVk?t=50 (Check this video on Cell division)

Assignment

• Read Pg. 65 & 66 of the textbook.
• On the basis of your understanding, tabulate differences between plant and animal cells.
• Draw a well-labeled diagram of plant and animal cells.
• Answer Q. No. 7, 9 of exercise in bio copy.

I hope it helped!

See you for the Next Class!

Take care.😊😊😊