THE FUNDAMENTAL UNIT OF LIFE

• First cell (Cork cell):- Robert Hooke (1665) • Nucleus:- Robert Brown (1831)
• Living cell (pond):- Anton Van Leeuwenhoek (1674) CELL • Protoplasm:- Purkinje (1839)
• Modified Cell theory :- Rudolf Virchow (1855) • Cell theory:- M.J. Schleiden and T.Schwann

Based on Shape and Number Eukaryotic Cell Prokaryotic Cell

• Cell shapes: Biconcave and round, amoeboid, Cell has well defined nucleus and well developed • Primitive, lacking a nucleus and most
narrow and long, oval and round. membrane bound organelles. organelles except ribosomes (E.g. bacteria).
• Have a nucleoid region where genetic
material is freely suspended.
Animal cell Plant cell
Mitochondria Cytoplasm
Centrosome Peroxisome
Nerve Blood Bone Ovum Lysosome Cell Membrane
Ribosomes Nucleoid (DNA)
Cell Cells Cell
Ribosomes Smooth Amyloplast Ribosomes
Endoplasmic
endoplasmic Reticulum
Rough reticulum Mitochondria
endoplasmic Nucleus
reticulum Plasma
Sperm Smooth Fat Cell Vacuole Nucleolus
Nucleus Vacuole membrane
Muscle Cell Chromatin Cytoplasm Cell wall
Nucleolus
• Based on cell numbers: Unicellular [Amoeba, Golgi Capsule Pilus
Chloroplast
Chlamydomonas, Paramoecium, and bacteria] Apparatus Peroxisome Golgi Apparatus
Cell wall
and Multicellular [Fungi (except Yeast) plants Golgi Flagellum
and animals). Vesicle

Plasma Membrane Cytoplasm Cell Wall Nucleus

• An electron microscopic structure (Cell • Fluid content inside the plasma membrane • Rigid outer covering outside plasma membrane. • Double membrane bound dense protoplasmic cell body
membrane) made up of phospholipid bilayer and nucleus in which cell organelles are • Present in plants, bacteria and fungi. that regulates metabolism, growth, and heredity.
and selectively permeable membrane. suspended. • Maintains cell shape, protects against injury and • Chromosomes appear rodshaped during cell division.
• Regulates the movement of substances in and • Two primary components: Cytosol and desiccation and prevents shrinkage during plasmolysis. • DNA in chromosomes contains instructions for cell
out of the cell in various ways. Organelles. • Provides mechanical support against gravity. functions, with genes as functional units.

Types of Transport
• Diffusion: Simple Diffusion (Passive transport, particles move from high to low concentration without energy. E.g. gas exchange through stomata) and Facilitated Diffusion (Movement of substances along a concentration
gradient with the help of carrier proteins).
• Osmosis: Passive movement of water from higher to lower water potential through a selectively permeable membrane.
ACTIVE TRANSPORT Extracellular Fluid Cell plasma
Hypotonic Isotonic Hypertonic membrane
Solution Solution Solution Low/High Concentration
Solution Type Description
Gradient
Animal cell

HO
H2O H2O H2O 2
Water concentration is equal inside and Cytoplasm ENDOCYTOSIS
Isotonic Solution Secretory Vesicle
outside the cell, causing no net water movement.
Lysed Shriveled
Normal Higher water concentration outside the cell,
H 2O H2O H2O H2O Hypotonic Solution
leading to water entry and cell swelling. Cell plasma
Plant cell

membrane Secretory
Lower water concentration outside the cell, ATP Product
Hypertonic Solution
causing water loss and cell shrinkage.
Turgid Flaccid Plasmolyzed
High/Low Concentration EXOCYTOSIS
• Active transport: Molecules move from low to high concentration using ATP energy. Cytoplasm
Gradient Secretory Vesicle
• Endocytosis: Process of engulfing particles or substances from the external environment into the cell.
• Exocytosis: Process of transporting materials from inside the cell to the external environment using energy.
 CELL ORGANELLES
Membrane-bound organelles: Endoplasmic reticulum (rough and smooth), Golgi apparatus, vacuole,lysosomes,plastids and mitochondria.
Non-membrane-bound organelles: Ribosomes lack a membrane.

Endoplasmic Reticulum Vacuoles Golgi Apparatus Lysosomes Mitochondria Plastids

A large network of membrane bound • The central vacuole in plant Storage, modification and packaging • Waste disposal system of • Mitochondria is the power house of • Found in almost all plant cells
tubes and sheets. cells can occupy 50-90% of of products in vesicles. cell. the cell. and in euglenoids.
Ribosome
Nucleolus Smooth the cell and is enclosed by Incoming • Suicidal bags. ATP
synthase
• It is a double membranous
Nucleus endoplasmic • Scavengers of the cell. Cristae
the tonoplast membrane. Cis Face transport (discoidal, ‘U’ shaped, spiral,
Nuclear pore reticulum junction
(SER) vesicles coiled, ribbon shaped, etc.)
Rough Granules • Have their own DNA and
endoplasmic Tonoplast Matrix
reticulum Ribosomes Hydrolytic ribosomes.
Central
(RER) Vacuole Lumen enzyme
Inner Chromoplast
Cell Sap Cisternae Outer membrane (Coloured Plastids)
membrane DNA
Newly Secretory Yellow and red carotenoids
forming vesicle (e.g., carotene, xanthophylls)
vesicle • Sausage shaped (double mem-
Trans Face in fruits and flowers.
• Store solids and liquids, branous) structure found in all
SER including amino acids, Membrane eukaryotic cells except human
sugars, organic acids, and • Found in all eukaryotic cells except RBCs. Chloroplast
• Synthesizes lipids essential for cell
function. proteins. RBCs and absent in prokaryotic • Outer membrane has specific Green plastids with chlorophyll
• Contribute to membrane biogenesis. • Helps in osmoregulation in cells. • Single membrane bound proteins and the inner membrane and helps in photosynthesis.
• Brings about detoxification in the plant cells. • Camillo Golgi (1898) observed it in vesicular structures formed
liver. folds into cristae.
• Animal cells have small the form of a network in nerve cells by the Golgi body.
• "Storage battery" of the cell as it Leucoplast
vacuoles while plant cells of the owl. • Found only in the cyto-
RER contain very large vacuoles. • Known as dictyosomes in plant plasm of animal cells. perform aerobic respiration, (Colourless Plastids)
• In Amoeba, the contractile • Aid intracellular digestion extracting energy from food and
• Appears rough due to attached cells. Store sugars (e.g., in potatoes),
ribosomes. vacuole aids excretion while • Site of formation of glycoprotein by breaking down foreign storing it as ATP.
materials, old cell, and • Have their own DNA and oils, fats and proteins.
• Plays a key role in protein synthesis. protists form food vacuoles and glycolipids.
by engulfing particles. worn-out organelles. ribosomes.

Cell Division Ribosomes

• Composed of ribonucleic acid
• It is the process of forming new cells.
• In all living organisms, it occurs in a sequential manner known as the cell cycle. MITOSIS MEIOSIS (RNA) and protein.
• Not surrounded by any membrane.
• Smallest cell organelle that help in
Parent Parent
Mitosis Meiosis Cell Cell the synthesis of protein(Protein
factory of the cell).
• This division occurs in somatic cells. • This division occurs in reproductive cells.
DNA DNA
• This division occurs in both haploid and diploid cells. • Meiosis is only found in diploid cells. replicates replicates

• It produces two daughter cells. • It produces four daughter cells.

2n
2n
• Chromosome number in daughter cells is same as • Chromosome numbers in daughter cells reduce
the mother cell. to half of the mother cells.

• Equational Division. • Reductional/Germinal Division.

• Mitosis enables organism development. • Involves two sequential cycles of nuclear 2n 2n
and cell division called as Meiosis I and Meiosis II.
• It supports tissue growth and repair • Maintains species-specific chromosome
numbers across generations.
2 Daughter Cells n n n n
• In plants, meristematic cell division ensures • Enhances genetic variability in a population.
lifelong growth.
4 Daughter Cells
 ANIMAL TISSUES

GROUP OF CELLS SIMILAR IN STRUCTURE AND FUNCTION

Epithelial tissue Muscular tissue Nervous tissue Connective

1. They perform various functions such as absorption, protection, 1. Soft tissue and one of the four basic types • Receive, conduct and transmit Tissue
sensation and secretion. of animal tissue. electrical impulses.
2. Epithelial tissue or epithelium forms the outer covering of the 2. Muscles contract and relax, causing • Found in CNS
skin and also lines the body cavity. movement. • Neuron is the structural and Next Page
3. Possess unique properties that allow functional unit of nervous
movement. system
4. Muscle cells are excitatory, which means
they respond to stimull. They are also
contractile, which means they can shorten
Stratified Simple Glandular and exert a pulling force. When muscles are

Made up of more than Made up of one

(Specialised tissue) attached to two movable objects, such as
bones, they contract and cause the bones
Nucleus Dendrite
one layer of cells layer of cells to move.
e.g, Salivary gland
Node
of ranvier
Axon

Voluntary skeletal Involuntary

Squamous Cuboidal Columnar Pillar muscles muscles Schwann cage
Thin and flat cells forming Cube-shaped cells, form the Myelin sheath
• Activities under the control Responsible for
delicate lining of blood lining of renal tubules and Axon
of our will movements in the
vessels, alveoli of lungs ducts of salivary glands where terminal
• Long, cylindrical, unbranched, body that are not in
its main role is absorption
multinucleated, striated control of one’s will Cellular body
and secretion
Nuclei

Striations

Ciliated columnar Non-Ciliated Cardiac Smooth

epithelium columnar epithelium Cylindrical, Uninucleated, Located in inner walls of hollow
branched, striated visceral organs like alimentary
canal, reproductive tract of
Tall epithelial cells with hair Present in the digestive tract blood Vessels, bronchi of lungs
like projections
• Spindle shaped, uninucleated,
Location→ inner uining of unbranched
respiratory tract, oviduct Striations
Function→Propulsion
of mucus or particles
Nucleus
Nuclei

Spindle shaped muscle cell

 CONNECTIVE TISSUE

Bone Ligament Areolar connective Tendon Blood Cartilage Adipose

• Strong, non-flexible tissue Connect bone tissues Connects muscles to bones Transport gases , • Widely spread cells,
connective tissue
• Composed of bone cells to bone digested food,
& hard matrix of calcium • Found between skin and muscle, composed of proteins
hormones, and and sugars • Cells of it are filled with fat globules, found
and phosphorus com- around blood vessesl, nerves, and in waste materials below skin, in heart.
pound bone narrow Muscle
• Smoothens bones
Bony to different parts surfaces and present • Stores fat, acts as an insulator
• Bone forms framework • Fills the space inside organs, supports of body
Attachment Tendon in nose, ear, trachea
that supports organs, internal organs and helps in repair of
anchors muscles tissues and larynx Fat vacuole
• Bone cells such as the Chondrocyte cytoplasmic
Macrophage Fibroblast
osteocytes and the rim of a fat cell
osteoblasts are involved Hyaline
in the formation and the matrix
Nucleus of
mineralization of the a fat cell
bones whereas osteo-
clasts are responsible for Arteriole
the reabsorption of the
bone tissues
Plama Formed
(fluid matrix) elements
Collagen fibres Mast cell

Articular
Cartilage
Epiphyseal
Line
Erythrocytes Leucocytes Platelets
Canaliculus
• Most abundant of all the cells in blood. • Platelets also called thrombocytes,
Canaliculus Lamellae
Proximal • A healthy adult man has, on an average, 5 are cell fragments produced from
Epiphysis Spongy Bone millions to 5.5 millions of RBCs mm-3 of blood. Granular Agranular megakaryocytes (special cells in
Haversian
• Formed in the red bone marrow in the adults. • Cytoplasm filled • No granules present the bone marrow).
Compact Bone Canal with granules in cytoplasm
• Devoid of nucleus in most of the mammals and • Normally contains 1,500,00-3,500,00
Medullary Cavity platelets mm-3.
are biconcave in shape.
• They have a red coloured, iron containing • Involved in the coagulation or clotting
Periosteum complex protein called haemoglobin, hence the Basophil Lymphocyte of blood.
• A reduction in their number can lead
colour and name of these cells. A healthy
Diaphysis Osteon Artery individual has 12-16 gms of haemoglobin in to clotting disorders which will lead to
Vein every 100 ml of blood. These molecules play a excessive loss of blood from the body
Periosteum
significant role in transport of respiratory
Nerve
gases.
Volkmann's • RBCs have an average life span of 120 days
Artery Canal after which they are destroyed in the spleen
(graveyard of RBCs) Neutrophil Monocyte
Distal
Epiphysis Haversian
Canal Polypeptide chain

Articular Spongy Compact Red

Cartilage Bone Bone blood cell
Iron

Eosinophil
Blood Heme Oxygen
vessel group molecule

Hemoglobin molecule
 PLANT TISSUES

PLANTS ARE IMMOBILE AND HENCE HAVE BEEN PROVIDED WITH TISSUES
MADE UP OF DEAD CELLS, WHICH PROVIDE STRUCTURAL STRENGTH.

Meristematic Permanent
Apical
• Have lost the ability to grow and divide
• The growth of plants occurs meristem
• Differentiated to perform particular function
only in certain specific Intercalary
regions. This is because the meristem
dividing tissue, also known
as meristematic tissue, is
located only at these points. Lateral Complex Simple
• Have capability to divide. meristem
Made up of more than Made up of one
one type of cells type of cells

On the basis On the basis

of location of origin Xylem Phloem Parenchyma Collenchyma Sclerenchyma
• Phloem parenchyma • Food storage • Flexibility
• Tracheids • Hard & stiff
• Sieve tubes • Mechanical support • Mechanical support
• Vesels Dead Living • Cells are long, narrow
• Companion cells • Large intercellular • Little intercellular spaces
• Fibres • Thick walls due to lignin
Promeristem Apical • Parenchyma → living • Phloem fibres→ dead
spaces
• Living
• Thickened at corners
• Living
• No intercellular space
• Dead
• The earliest and youngest Apical meristem Vacoule Protoplasm
Cell Simple
meristematic tissue. upsurges the length Fibre Inter-
Fibre Wall Pit Pair
• It originates from the embryo. of the plant Cell cellular
• The primary meristem arises Sieve plates Wall space
from the promeristem. Tracheids Narrow
Lumen
• It is found in the root and the Perforation
shoot tips Lateral plates companion Nucleus Lignified
Cytoplasm Thick Wall
Lateral meristem cell
upsurges the thick Sieve
areas Thickened Vacuole Transverse Transverse
ness of the plant
Primary meristem Corners Section Section

• It arises from the promeristem.

• Cells divide actively.
• It is present below the prome-
ristem and forms the perma-
Intercalary Aerenchyma Chlorenchyma
nent tissue Intercalary meristem Vessel
members Parenchyma which Parenchyma consisting of
is found at the consists of big air voids is chloroplasts are termed
internodes or at the called aerenchyma.
Sieve elements as chlorenchyma. The
base of the leaves.
Secondary meristem Intercalary meristem
Buoyancy is the main
purpose of the
chlorenchyma helps in
photosynthesis.
upsurges the size of aerenchyma.
• It originates from the primary the internode.
meristem.
• The permanent tissue forms
from the secondary meristem