BIOLOGY FOR KVPY - MBBS PDF Download

 Page 1


Bio lo g y
Bio lo g y
0744-2757575  |  www.allen.ac.in
Stream : SA
KVPY
Page 2


Bio lo g y
Bio lo g y
0744-2757575  |  www.allen.ac.in
Stream : SA
KVPY
h
 a pter
Contents
KVPY BIOLOGY
Botany
01. Cell Cycle & Cell Division 1
02. Plant Physiology 18
03. Plant tissue 28
04. Genetics 31
05. Ecology 39
Zoology
01. Animal Tissue 41
02. Animal Physiology 53
03. Human Health & Diseases 86
04. Immunology 92
05. Origin of Species 95
Page 3


Bio lo g y
Bio lo g y
0744-2757575  |  www.allen.ac.in
Stream : SA
KVPY
h
 a pter
Contents
KVPY BIOLOGY
Botany
01. Cell Cycle & Cell Division 1
02. Plant Physiology 18
03. Plant tissue 28
04. Genetics 31
05. Ecology 39
Zoology
01. Animal Tissue 41
02. Animal Physiology 53
03. Human Health & Diseases 86
04. Immunology 92
05. Origin of Species 95
node05\B0B0-BA\KVPY\KVPY BIOLOGY Module\01_Botany [Th]
Biology ????? 1
E
DISCOVERY OF THE CELL
• Robert Hook discovered dead cell in the 1665.
• Anton Von Leeuwenhoek discovered first living cell in 1674.
• Robert Brown discovered nucleus in 1831.
• Purkinjee gave the term protoplasm.
• T.H.Huxley described protoplasm as "physical basis of life" in 1868.
• Rudolf Virchow stated "omnis  cellula e cellula"
• The German botanist Malthias Jacob Schleiden (1838) and the British zoologist Theodore Schwann in 1839
gave the cell theory.
• Further formalized by the German researcher Rudolf Virchow in 1855. In its modern form, this theorem has
four basic parts :
1. The cell is the basic structural and functional unit of life; all organisms are composed of cells.
2. All cells are produced by the division of pre-existing cells.
3. All basic chemical and physiological functions - for example, repair, growth, movement, immunity,
communication and digestion are carried out inside the cells.
4. The activities of cells depends on the activities of sub-cellular structures within the cell (these subcellular
structures include organelles, the plasma membrane and if present the nucleus)
Electron microscope was invented by Knoll and Ruska. Scanning electron microscopes are used to examine
the external parts of various organisms. The transmission electron microscope is used to view the internal
structure of a cell and its organelles.
NUMBER OF CELLS
• Organisms consist of more than one cell are called multicellular organisms. An organism with billions of cells
begins life as a single cell which is the fertilized egg(zygote).
• The single-celled organisms are called unicellular organisms. A single celled organism performs all the necessary
functions that multicellular organisms perform.
SHAPE OF CELL
• Types of shapes of cells in bacteria
In bacteria shapes of cells are of 4 main types
(i) Rod shaped i.e. Bacilllus( pl. Bacilli) e.g. Bacillus subtilis
(ii) Spherical shaped i.e. Coccus( pl. Cocci) e.g. Streptococcus sp.
(iii) Spiral shaped i.e. Spirillum e.g. Azospirilum
(iv) Comma shaped i.e. Vibrio e.g. Vibrio cholerae
Pleomorphism is the ability of few cells to change its shape during their life cycle. This property is seen in
many bacteria, fungi and in some plant cells.
The White Blood Corpuscle (WBC) is the only animal cell that can change its shape
Types of shapes of cells in eukaryotes:
(i) Squamous, cuboidal, columnar shaped cells are found in epithelium.
(ii) Muscle cells or muscle fibres are elongated in shape.
(iii) Neuron is thread like in shape with extentions.
(iv) Red blood cells are flexible biconcave in shape.
(v) Green alga like Spirogyra, Zygnema have cylindrical cells.
(vi) Cells in fungi are mainly long, branched and filamentous in nature.
CELL
Page 4


Bio lo g y
Bio lo g y
0744-2757575  |  www.allen.ac.in
Stream : SA
KVPY
h
 a pter
Contents
KVPY BIOLOGY
Botany
01. Cell Cycle & Cell Division 1
02. Plant Physiology 18
03. Plant tissue 28
04. Genetics 31
05. Ecology 39
Zoology
01. Animal Tissue 41
02. Animal Physiology 53
03. Human Health & Diseases 86
04. Immunology 92
05. Origin of Species 95
node05\B0B0-BA\KVPY\KVPY BIOLOGY Module\01_Botany [Th]
Biology ????? 1
E
DISCOVERY OF THE CELL
• Robert Hook discovered dead cell in the 1665.
• Anton Von Leeuwenhoek discovered first living cell in 1674.
• Robert Brown discovered nucleus in 1831.
• Purkinjee gave the term protoplasm.
• T.H.Huxley described protoplasm as "physical basis of life" in 1868.
• Rudolf Virchow stated "omnis  cellula e cellula"
• The German botanist Malthias Jacob Schleiden (1838) and the British zoologist Theodore Schwann in 1839
gave the cell theory.
• Further formalized by the German researcher Rudolf Virchow in 1855. In its modern form, this theorem has
four basic parts :
1. The cell is the basic structural and functional unit of life; all organisms are composed of cells.
2. All cells are produced by the division of pre-existing cells.
3. All basic chemical and physiological functions - for example, repair, growth, movement, immunity,
communication and digestion are carried out inside the cells.
4. The activities of cells depends on the activities of sub-cellular structures within the cell (these subcellular
structures include organelles, the plasma membrane and if present the nucleus)
Electron microscope was invented by Knoll and Ruska. Scanning electron microscopes are used to examine
the external parts of various organisms. The transmission electron microscope is used to view the internal
structure of a cell and its organelles.
NUMBER OF CELLS
• Organisms consist of more than one cell are called multicellular organisms. An organism with billions of cells
begins life as a single cell which is the fertilized egg(zygote).
• The single-celled organisms are called unicellular organisms. A single celled organism performs all the necessary
functions that multicellular organisms perform.
SHAPE OF CELL
• Types of shapes of cells in bacteria
In bacteria shapes of cells are of 4 main types
(i) Rod shaped i.e. Bacilllus( pl. Bacilli) e.g. Bacillus subtilis
(ii) Spherical shaped i.e. Coccus( pl. Cocci) e.g. Streptococcus sp.
(iii) Spiral shaped i.e. Spirillum e.g. Azospirilum
(iv) Comma shaped i.e. Vibrio e.g. Vibrio cholerae
Pleomorphism is the ability of few cells to change its shape during their life cycle. This property is seen in
many bacteria, fungi and in some plant cells.
The White Blood Corpuscle (WBC) is the only animal cell that can change its shape
Types of shapes of cells in eukaryotes:
(i) Squamous, cuboidal, columnar shaped cells are found in epithelium.
(ii) Muscle cells or muscle fibres are elongated in shape.
(iii) Neuron is thread like in shape with extentions.
(iv) Red blood cells are flexible biconcave in shape.
(v) Green alga like Spirogyra, Zygnema have cylindrical cells.
(vi) Cells in fungi are mainly long, branched and filamentous in nature.
CELL
node05\B0B0-BA\KVPY\KVPY BIOLOGY Module\01_Botany [Th]
2
KVPY ?????
E
SIZE OF CELL
Cell size has no relation with the body size of an organism. Therefore, the large size of an elephant is due to
larger number of cells present in the body.
• The smallest objects that the unaided human eye can see are about 0.1 mm long.(Amoeba,Paramecium)
• Cells are measured in Microns (abbrevation as µm). One micron is one-thousandth of a millimeter.
• Prokaryotic cell ranges between 1-10 µm.
• Smallest cell-Mycoplasma (0.1 µm)
• Eukaryotic cell ranges between 10-100 µm.
• Largest cell-Ostrich egg(18 cm)
• Largest plant cell-Ovule of Cycas
• Longest cell-neuron(upto 1m)
CELL VOLUME
• Cells that are metabolically more active should have larger surface area per unit volume.
STRUCTURE  AND FUNCTION OF CELL
The basic components of a cell are cell membrane, cytoplasm and nucleus.
1. CELL MEMBRANE
• The cell membrane functions as a selectively permeable barrier, allowing a very few molecules (uncharged polar
molecules)  across it while fencing the majority of organically produced chemicals inside the cell.
• The cytoplasm and nucleus are enclosed within the cell membrane, also called the plasma membrane.
• The membrane separates cells from one another and also the cell from the surrounding medium.
• The plasma membrane is porous and allows the movement of substances or materials both inward and outward.
• The cell membrane gives shape to the cell.
• Cell membrane is mainly composed of lipids and proteins (Phospholipid membrane).
• Proteins and cholesterol molecules are scattered throughout the flexible phospholipid membrane. Membrane
carbohydrates are on the surface of the plasma membrane and recognize other cells (glycoproteins & glycolipids).
• Peripheral proteins attach loosely to the inner or outer surface of the plasma membrane. Integral proteins
lie across the membrane, extending from inside to outside.
• A variety of proteins are scattered throughout the flexible matrix of phospholipid molecules, somewhat like
icebergs floating in the ocean, and this is termed the fluid mosaic model of the cell membrane.
• "Fluid mosaic model" given by Singer and Nicolson in 1972.
There are a variety of membrane proteins that serve various functions:
• Channel proteins :Proteins that provide passage through the membranes for certain hydrophilic or water- soluble substances such as polar and charged molecules. No energy is used during transport, hence this type of
movement is called facilitated diffusion.
• Transport proteins : Proteins that spend energy (ATP) to transfer materials across the membrane. When
energy is used to provide passage for materials, the process is called active transport.
• Recognition proteins :Proteins that distinguish the identity of neighbouring cells. These proteins have
oligosaccharide or short polysaccharide chains extending out from their cell surface.
• Adhesion proteins : Proteins that attach cells to neighboring cells or provide anchors for the internal filaments
and tubules that give stability to the cell.
• Receptor proteins : Proteins that initiate specific cell responses once hormones or other trigger molecules
bind to them.
• Electron transfer proteins : Proteins that are involved in moving electrons from one molecule to another
during chemical reactions.
How Do Substances Move Across Membranes?
• Molecules in Fluids Move in Response to Gradients
• Movement Across Membranes Occurs by Both Passive and Active Transport
Page 5


Bio lo g y
Bio lo g y
0744-2757575  |  www.allen.ac.in
Stream : SA
KVPY
h
 a pter
Contents
KVPY BIOLOGY
Botany
01. Cell Cycle & Cell Division 1
02. Plant Physiology 18
03. Plant tissue 28
04. Genetics 31
05. Ecology 39
Zoology
01. Animal Tissue 41
02. Animal Physiology 53
03. Human Health & Diseases 86
04. Immunology 92
05. Origin of Species 95
node05\B0B0-BA\KVPY\KVPY BIOLOGY Module\01_Botany [Th]
Biology ????? 1
E
DISCOVERY OF THE CELL
• Robert Hook discovered dead cell in the 1665.
• Anton Von Leeuwenhoek discovered first living cell in 1674.
• Robert Brown discovered nucleus in 1831.
• Purkinjee gave the term protoplasm.
• T.H.Huxley described protoplasm as "physical basis of life" in 1868.
• Rudolf Virchow stated "omnis  cellula e cellula"
• The German botanist Malthias Jacob Schleiden (1838) and the British zoologist Theodore Schwann in 1839
gave the cell theory.
• Further formalized by the German researcher Rudolf Virchow in 1855. In its modern form, this theorem has
four basic parts :
1. The cell is the basic structural and functional unit of life; all organisms are composed of cells.
2. All cells are produced by the division of pre-existing cells.
3. All basic chemical and physiological functions - for example, repair, growth, movement, immunity,
communication and digestion are carried out inside the cells.
4. The activities of cells depends on the activities of sub-cellular structures within the cell (these subcellular
structures include organelles, the plasma membrane and if present the nucleus)
Electron microscope was invented by Knoll and Ruska. Scanning electron microscopes are used to examine
the external parts of various organisms. The transmission electron microscope is used to view the internal
structure of a cell and its organelles.
NUMBER OF CELLS
• Organisms consist of more than one cell are called multicellular organisms. An organism with billions of cells
begins life as a single cell which is the fertilized egg(zygote).
• The single-celled organisms are called unicellular organisms. A single celled organism performs all the necessary
functions that multicellular organisms perform.
SHAPE OF CELL
• Types of shapes of cells in bacteria
In bacteria shapes of cells are of 4 main types
(i) Rod shaped i.e. Bacilllus( pl. Bacilli) e.g. Bacillus subtilis
(ii) Spherical shaped i.e. Coccus( pl. Cocci) e.g. Streptococcus sp.
(iii) Spiral shaped i.e. Spirillum e.g. Azospirilum
(iv) Comma shaped i.e. Vibrio e.g. Vibrio cholerae
Pleomorphism is the ability of few cells to change its shape during their life cycle. This property is seen in
many bacteria, fungi and in some plant cells.
The White Blood Corpuscle (WBC) is the only animal cell that can change its shape
Types of shapes of cells in eukaryotes:
(i) Squamous, cuboidal, columnar shaped cells are found in epithelium.
(ii) Muscle cells or muscle fibres are elongated in shape.
(iii) Neuron is thread like in shape with extentions.
(iv) Red blood cells are flexible biconcave in shape.
(v) Green alga like Spirogyra, Zygnema have cylindrical cells.
(vi) Cells in fungi are mainly long, branched and filamentous in nature.
CELL
node05\B0B0-BA\KVPY\KVPY BIOLOGY Module\01_Botany [Th]
2
KVPY ?????
E
SIZE OF CELL
Cell size has no relation with the body size of an organism. Therefore, the large size of an elephant is due to
larger number of cells present in the body.
• The smallest objects that the unaided human eye can see are about 0.1 mm long.(Amoeba,Paramecium)
• Cells are measured in Microns (abbrevation as µm). One micron is one-thousandth of a millimeter.
• Prokaryotic cell ranges between 1-10 µm.
• Smallest cell-Mycoplasma (0.1 µm)
• Eukaryotic cell ranges between 10-100 µm.
• Largest cell-Ostrich egg(18 cm)
• Largest plant cell-Ovule of Cycas
• Longest cell-neuron(upto 1m)
CELL VOLUME
• Cells that are metabolically more active should have larger surface area per unit volume.
STRUCTURE  AND FUNCTION OF CELL
The basic components of a cell are cell membrane, cytoplasm and nucleus.
1. CELL MEMBRANE
• The cell membrane functions as a selectively permeable barrier, allowing a very few molecules (uncharged polar
molecules)  across it while fencing the majority of organically produced chemicals inside the cell.
• The cytoplasm and nucleus are enclosed within the cell membrane, also called the plasma membrane.
• The membrane separates cells from one another and also the cell from the surrounding medium.
• The plasma membrane is porous and allows the movement of substances or materials both inward and outward.
• The cell membrane gives shape to the cell.
• Cell membrane is mainly composed of lipids and proteins (Phospholipid membrane).
• Proteins and cholesterol molecules are scattered throughout the flexible phospholipid membrane. Membrane
carbohydrates are on the surface of the plasma membrane and recognize other cells (glycoproteins & glycolipids).
• Peripheral proteins attach loosely to the inner or outer surface of the plasma membrane. Integral proteins
lie across the membrane, extending from inside to outside.
• A variety of proteins are scattered throughout the flexible matrix of phospholipid molecules, somewhat like
icebergs floating in the ocean, and this is termed the fluid mosaic model of the cell membrane.
• "Fluid mosaic model" given by Singer and Nicolson in 1972.
There are a variety of membrane proteins that serve various functions:
• Channel proteins :Proteins that provide passage through the membranes for certain hydrophilic or water- soluble substances such as polar and charged molecules. No energy is used during transport, hence this type of
movement is called facilitated diffusion.
• Transport proteins : Proteins that spend energy (ATP) to transfer materials across the membrane. When
energy is used to provide passage for materials, the process is called active transport.
• Recognition proteins :Proteins that distinguish the identity of neighbouring cells. These proteins have
oligosaccharide or short polysaccharide chains extending out from their cell surface.
• Adhesion proteins : Proteins that attach cells to neighboring cells or provide anchors for the internal filaments
and tubules that give stability to the cell.
• Receptor proteins : Proteins that initiate specific cell responses once hormones or other trigger molecules
bind to them.
• Electron transfer proteins : Proteins that are involved in moving electrons from one molecule to another
during chemical reactions.
How Do Substances Move Across Membranes?
• Molecules in Fluids Move in Response to Gradients
• Movement Across Membranes Occurs by Both Passive and Active Transport
node05\B0B0-BA\KVPY\KVPY BIOLOGY Module\01_Botany [Th]
Biology ????? 3
E
Passive Transport Across the Cell Membrane
Passive transport describes the movement of substances down a concentration gradient and does not require
energy use.
• Bulk flow is the collective movement of substances in the same direction in response to a force, such as
pressure. Blood moving through a vessel is an example of bulk flow.
• Simple diffusion or diffusion is the net movement of substances from an area of higher concentration to an area
of lower concentration. This movement occurs as a result of the random and constant motion characteristic of
all molecules, (atoms or ions) and is independent from the motion of other molecules.
• Facilitated diffusion is the diffusion of solutes through channel proteins in the plasma membrane. Water can
pass freely through the plasma membrane without the aid of specialized proteins (Aquaporins).
• Osmosis is the diffusion of water molecules across a selectively permeable membrane. When water moves into
a body by osmosis, hydrostatic pressure or osmotic pressure may build up inside the body.
• Dialysis is the diffusion of solutes across a selectively permeable membrane.
Active Transport Across the Cell Membrane
Active transport is the movement of solutes against a concentration  gradient and requires the expenditure of
energy, usually in the form of ATP. Active transport is achieved through one of these two mechanisms:
I. Protein Pumps
• Transport proteins in the plasma membrane transfer solutes such as small ions (Na
+
, K
+
, Cl
–
, H
+
), amino acids,
and monosaccharides.
• The proteins involved with active transport are also known as ion pumps.
• The protein binds to a molecule of the substance to be transported on one side of the membrane, then it uses
the released energy (ATP) to change its shape, and releases it on the other side.
• The protein pumps are specific, there is a different pump for each molecule to be transported.
• Protein pumps are catalysts in the splitting of ATP to form ADP and phosphate, so they are called ATPase enzymes.
Cystic fibrosis is a genetic disorder that results in a misshappen chloride ion pump. By not regulating chloride
levels properly resulting the cells produce thick mucus.
II. Vesicular Transport
• Vesicles or other bodies in the cytoplasm move macromolecules or large particles across the plasma membrane.
Types of vesicular transport include:
• Exocytosis, which describes the process of vesicles fusing with the plasma membrane and releasing their
contents to the outside of the cell. This process is common when a cell produces substances for export.
• Endocytosis, which describes the capture of a substance outside the cell when the plasma membrane merges to
engulf it. The substance subsequently enters the cytoplasm enclosed in a vesicle.
There are three kinds of endocytosis
• Phagocytosis or cellular eating, occurs when the dissolved materials enter the cell. The plasma membrane
engulfs the solid material, forming a phagocytic vesicle.
• Pinocytosis or cellular drinking occurs when the plasma membrane folds inward to form a channel allowing
dissolved substances to enter the cell. When the channel is closed, the liquid is encircled within a pinocytic
vesicle.
• Receptor-mediated endocytosis occurs when specific molecules in the fluid surrounding the cell bind to specialized
receptors in the plasma membrane. As in pinocytosis, the plasma membrane folds inward and the formation of
a vesicle follows.
How Are Cell Surfaces Specialized?
Various specialized junctions allow cells to connect and communicate
• Desmosomes attach cells together
• Tight junctions make the cell leakproof
• Gap junctions and plasmodesmata allow communication between cells