4. Cell is the
fundament
al unit of
life
Cell is the
structural and
functional unit
of life
Structural
because all
living forms are
made up of cells
and consist of
cells
Functional
because all cells
perform basic life
processes for an
organism’s
6. By – Jyotsna
Cell theory –given
by Schleiden,
Schwann, Virchow
ALL LIVING
ORGANISMS
ARE
COMPOSED
OF ONE OR
MORE
CELLS.
THE CELL IS
THE BASIC
UNIT OF
STRUCTURE
AND
ORGANIZATI
ON IN
ORGANISMS.
CELLS ARISE
FROM PRE-
EXISTING
CELLS.
7. By – Jyotsna
Variation
in
cells
Cell
Number
Organisms can be either
unicellular(amoeba) or
multicellular (humans) in
nature.
Cell Shape
Cell shape defines the
functions
of the cell
Nerve cell is long so that it
can
send and receive it
messages
Amoeba and WBC are
shapeless
so that they can move
anywhere
Cell Size
Cell size ranges
from micrometers
to meters
0.1µm – mycoplasma
cells
Length of a nerve cell –
1.0m
8. By – Jyotsna
CellVolume
The volume to surface
area ratio of a cell is
very high.
It means a lot of
space is available in a
cell when compared
to the size of the cell
9. By – Jyotsna
Unicellular and multicellularorganisms
• Unicellular organisms are
made
up of only a single cell.
•The single cell does all the
function for the survival of
the organism.
•Multicellular organisms are
made up of more than one
cell.
•Division of labour - All cells
work together to sustain life.
10. By – Jyotsna
Cell
types
Based on presence
of a nucleus and
membrane bound
organelles.
Organelles are tiny
structures found within a
cell that perform a specific
function
Procaryotes / prokaryotes
Cells that lack nucleus
and membrane bound
organelles
All bacterial cells are
prokaryotic
Instead of a nucleus their
genetic material is present
in a region called nucleoid
Eukaryotes
Cells that have nucleus
and
membrane bound
organelles
Human cells, sunflower
plant
cells
12. By – Jyotsna
Bacterial cell;
The chlorophyll
in photosynthetic prokaryotic
bacteria is associated with
membranous vesicles (bag like
structures) but not with plastids as in
eukaryotic cells
14. By – Jyotsna
Protoplasm refers to the living
material of the cell andconsists
of the nucleus and cytoplasm
enclosed within a plasma
membrane.
A dead cell is nota protoplast.
17. By – Jyotsna
(v) Maintains homeostasis within the cell –
homeostasis refers to state of steady internal,
physical, and chemical conditions maintained
by living systems.
18. By – Jyotsna
Transport
of
substances
across
the
cell
membrane
Passive transport – refers to
movement of substances across the
cell membrane without the use of
energy
Occurs based on the
concentration gradient of
the substance
Three types of passive
transport
Simple diffusion – oxygen
and CO
2
Facilitated diffusion -
Glucose
Osmosis – water
molecules
Active transport – refers to the
movement of substances across the
cell membrane with the help of
energy that is using energy
molecules called ATP
Occurs against the concentration
gradient
19. By – Jyotsna
Transport type Simple Diffusion Facilitated diffusion Osmosis
Definition A process that transports
molecules from a region of
high concentration to a
region of low concentration
without a carrier protein aid
A process that transports
molecules from a region of
high concentration to a
region of low concentration
with the help of a protein
carrier
The process of movement
of water molecules from
the region of high
concentration to the
region of low
concentration across a
semi permeable
membrane
Moving molecules Carbon di oxide, oxygen Glucose Water only
Occurrence Through the lipid bilayer Through the carrier protein Aquaporin channels
21. By – Jyotsna
Effects
of
osmosis
on
cells
when
placed
in
different
solution
types
Isotonic solution – when the medium
around the cell has equal water
concentration , there willbe no net
movement of water across the plasma
membrane, the cells maintain their shape
Animal cell –
lysed
Hypotonic solution – when the medium
surrounding the cell is dilute ( which means
there
is more water in the solution outside the cell),
water moves into the cell and the cell bulges
Plant cell – turgid ( cell wall
protects)
Hypertonic solution – when the medium
surrounding the cell is concentrated (
which means that there is less water in
the solution outside the cell and more
water inside the cell) water moves out of
the cell and the cellshrivels
Animal cell –
shrinks
Plant cells – plasmolysed and
then die
47. By – Jyotsna
Semi-autonomous
organelle –
contains its own DNA.
Disc like structures called the
thylakoid – stacked on top of each
other forming a granum
60. The pocket
pinches
off, resultingin
the
particle
bein
g
contained in a
newly
created
intracellul
ar
vesicleformed
from
the
plasm
a
membrane.
The
plasm
a
membrane of the
cell
invaginates,
formin
g
a pocket around
the
target particle.
Endocytosis is a
type
of active
transport
that moves
particles,
such as
large
molecules,parts
of
cells, and even
whole
cells, into a cell.