So here's the mind map of Cell : The unit of life. This is chapter 8 of class 12. This mind map is 100% from NCERT and nothing extra is put from outside.
The main topics to study in this lesson -
1. What is a Cell?
2. Cell Theory
3. An Overview of Cell
4. Prokaryotic Cells
5. Eukaryotic Cells
Cell was discovered by Robert Hooke and Anton von Leeuwenhoek was first person to saw a living cell. Nucleus was discovered by Robert brown.
There are two types of cell based on presence or absence of nuclear membrane. The cell which doesn't have nuclear membrane is known as prokaryotic cell and cell which have nuclear membrane is known as eukaryotic cell.
Cell theory was given by 2 scientists - Schleiden and Schwann. Rudolph Virchow observed that a cell arises from pre existing cell. He also contributes to cell theory.
Prokaryotic cell includes bacteria, blue green algae or cyanobacteria, mycoplasma. Mycoplasma is the smallest living organism that is found on earth. All prokaryotes have cell wall except mycoplasma.
No membrane bonds are found in prokaryotic cell. For locomotion prokaryotes can have flagella or cilia.
Diesel envelope of prokaryotic cell has three layers. These are cell wall, cell membrane and glycocalax.
Eukaryotic cells have a nuclear membrane. The fluid field in cell is known as cytoplasm and the fluid filled in nucleus is known as protoplasm.
Ribosome is only organel that is found in both prokaryotic cells and eukaryotic cells. Prokaryotic ribosome is 70s while eukaryotic ribosome is 80s. Ribosome is made up of two sub - units one is large and other is small. Ribosomes do not have any membrane.
This cell membrane has lipid, protein and carbohydrate. The best model for cell membrane is fluid mosaic model which was given by Singer and Nicolson in 1972.
The cell membrane or plasma membrane is selectively permeable membrane. Transport across this membrane can happen in both active and passive ways. Active transport requires energy. Passive transport includes facilitated diffusion and simple diffusion and it does not require any energy.
In eukaryotic cells, there is compartmentalisation of cytoplast. Many organels are found in eukaryotic cells, like -
Endoplasmic reticulum, Golgi body, lysosomes, vacuoles and ribosomes, chloroplast, mitochondria, plastids etc.
Cilia and flagella also find in these cells and they help in locomotion. The core of Cilia and flagella is known as axoneme and it has 9 + 2 arrangement.
The nucleus is double membrane bound. The space between two membranes is known as peri nuclear space. Nucleus have DNA as genetic material. The chromosomes can be of four type this are metacentric, submetacentric, acrocentric and telocentric.
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10 previous year questions are given below. You can analyse your performance by solving them -
1. Names of Schleiden and Schwann are associated with
(a) protoplasm as the physical basis of life
(b) cell theory
(c) theory of cell lineage
(d) nucleus functions as control centre of cell
2. The concept of “Omnis cellula-e-cellula” regarding cell division was first proposed by
(a) Aristotle (b) Rudolf Virchow
(c) Theodore Schwann (d) Schleiden.
3. The site of respiration in bacteria is
(a) ribosome (b) microsome
(c) episome (d) mesosome.
4. Which of the following statements is not correct?
(a) Lysosomes are formed by the process of packaging in the endoplasmic reticulum.
(b) Lysosomes have numerous hydrolytic enzymes.
(c) The hydrolytic enzymes of lysosomes are active under acidic pH.
(d) Lysosomes are membrane-bound structures.
5. Which of the following pairs of organelles does not contain DNA?
(a) Nuclear envelope and Mitochondria
(b) Mitochondria and Lysosome
(c) Chloroplast and Vacuoles
(d) Lysosomes and Vacuoles
6. Mitochondria and chloroplast are
(A) semi-autonomous organelles
(B) formed by division of pre-existing organelles and they contain DNA but lack protein synthesising machinery.
Which one of the following options is correct?
(a) (A) is true but (B) is false.
(b) Both (A) and (B) are false.
(c) Both (A) and (B) are correct.
(d) (B) is true but (A) is false.
7. Select the correct statement from the following regarding cell membrane.
(a) Na+ and K+ ions move across cell membrane by passive transport.
(b) Proteins make up 60 to 70% of the cell membrane.
(c) Lipids are arranged in a bilayer with polar heads towards the inner part.
(d) Fluid mosaic model of cell membrane was proposed by Singer and Nicolson.
8. Which of the following types of plastid does not contain stored food material?
(a) Chromoplasts (b) Elaioplasts
(c) Aleuroplasts. (d) Amyloplasts
9. Vacuole in a plant cell
(a) lacks membrane and contains air
(b) lacks membrane and contains water and excretory substances
(c) is membrane-bound and contains storage proteins and lipids
(d) is membrane-bound and contains water and excretory substances.
10. Which of the following ribosomes are engaged in protein synthesis in animal cell?
(a) Ribosomes which occur on nuclear membrane and ER
(b) Ribosomes of only cytosol
(c) Ribosomes of only nucleolus and cytosol
(d) Ribosomes of only mitochondria and cytosol
3 Comments
Sir please upload pdf of Class 12th Biology Chapter 5 (Principles of Inheritance and variation) and Chapter 6 (Molecular Basis Of Inheritance)....
ReplyDeleteyou have to buy the pdfs of those chapters...all genetics and evolution chapters including human reproduction
DeleteI bought it too. its very very cheap and affordable.
Delete