LIFE AND LIVING
Do the 2 worksheets on the
rules for drawing scientific
diagrams.
INSTRUCTIONS:
• Everything in blue, must be underlined in
pencil in your textbook.
• Everything in green must be added to
your notes in your textbook in pencil or
copied into your script in pen.
• Brown indicates an activity
CHAPTER 1 (p1): Cells as the basic unit of
life
• Smallest living part of your body =
single cell
• There are lots of different types
• e.g. muscle cells, nerve cells, bone cells
• Different types of cells – have
different functions
• All living things are made of cells
Leaf cells of a plant
Cheek cells of a human
• Humans are multicellular – made up of
many cells
• Some organisms are made up of a single
cell – unicellular
• Uni = one
• Cells are very small
• Can only be seen by using a microscope
Do Act 1 on P1
nr 1-4
CELL STRUCTURE (p2)
• Cell = basic structural and functional
unit of all living organisms
• structural – what it is made up of
• functional – doing the “job”
• Cells can only be seen under a
microscope = microscopic
• All cells have the same basic structure
• See figure 2 on page 2
A typical cell
Cell membrane
•
•
•
•
Outer boundary of the cell
Surrounds the contents
FUNCTION:
Selectively permeable – controls
which materials pass into or out
of the cell
Cytoplasm
• Cells are filled with a jelly-like
substance – cytoplasm
• Mainly water with structures (like
organelles) and materials dissolved or
suspended in it (hanging in it)
• FUNCTION:
• Provides a liquid medium for all the
chemical reactions inside the cell
Nucleus(p3)
Draw this sketch of a nucleus
(You can leave out the ribosome label)
NOT! Draw on board.
• DNA is found in the nucleus
• Specifically in the chromatin material
• Nucleus is surrounded by a double
nuclear membrane
• Nucleoplasm – jelly part inside nuclear
membrane
• Nuclear pores – tiny gaps in nuclear
membrane which allow particles to move
between nucleoplasm and cytoplasm
• Nucleolus – round body in nucleoplasm
• FUNCTIONS of the nucleus:
• Controls all the functions of the cell
• Stores the genetic/hereditary info
• DNA contains information of organism’s
inherited characteristics
• E.g. eye colour, hair colour
• Each person’s DNA is unique
• Children inherit a mixture of their mom
and dad’s DNA
• Accounts for variation within a single
species
Do the note on the
message in cells
Organelles(p3)
• Perform different functions for the cell
• Found in the cytoplasm of cells
Mitochondrion(P3)
• Draw
this
sketch
NOT!
Off board
• Also see
the
micrograph
picture
on p3
Micrograph picture = photo
taken of something seen under
a microscope
More mitochondria
• Mitochondria are found in both plantand animal cells
• FUNCTION:
• Cellular respiration – energy is released
from glucose
• This energy (ATP) is used for all
activities of cells
• Equation for cellular respiration:
• Glucose + Oxygen → ATP + water +
Carbon dioxide
Vacuoles
• Fluid-filled sacs that are surrounded by
a membrane
• This membrane is called: tonoplast
• FUNCTION:
• Store water and substances (sugar,
salts) – that can be used by the cell
• Animal cells – several small vacuoles or
none
• Plant cells – one or two large vacuoles
Chloroplast
• Also
see the
micrograph
picture
on p6
(Stick in chloroplast sketch)
• Chloroplasts are only found in plant cells
of green plants
• FUNCTION:
• Photosynthesis
• Equation for photosynthesis:
• Radiant energy(from sun) + water +
Carbon dioxide → Glucose + Oxygen
• Radiant energy is converted into
chemical potential energy in glucose
More chloroplast sketches:
Use these sketches to label your
diagram of a chloroplast:
• Chloroplasts fall in a group of
organelles called plastids
• There are 3 types of plastids
• Plastids are only found in plant
cells
Plastids (Copy this table)
Colour
Where found
Function
GREEN
MAINLY IN
LEAVES
PHOTOSYNTHESIS
CHROMOPLAST
RED
ORANGE
YELLOW
RIPE FRUIT
ATTRACT
ORGANISMS >
THEY EAT
FRUIT >
DISPERSE SEED
LEUCOPLAST
When exposed to
sunlight > change
to chloroplasts
E.g. potato goes
green in light
COLOURLESS
IN PLANT
ORGANS WHICH
STORE STARCH
E.G. POTATO
STORE STARCH
(the form in
which glucose is
stored in a plant)
CHLOROPLAST
Can become a
chromoplast when
a green fruit
ripens
Complete the labels of the 2
sketches on your note on
plant- and animal cells
Draw your own
labelled plant- and
animal cells
(from overhead)
You must start on your
Cell model project now
(You will get 2 weeks to
complete this project)
Differences between plant- and
animal cells (p5)
• Study the 2 sketches on p5
• Plant cells differ from animal cells in the
following ways:
• Plant cells have a cell wall outside the cell
membrane – made of a rigid material called
cellulose
• FUNCTION: Supports and protects cell.
• Animals don’t need a cell wall, because
animals have a skeleton for body support
• Plant cells have chloroplasts that contain
chlorophyll.
• Chlorophyll absorbs light energy from
the sun – converts it into energy-rich
glucose – process of photosynthesis
• Glucose is stored as starch in plants
• Animals cannot photosynthesise – do not
have chloroplasts
• Animals get their energy from eating
plants or animals that ate the plants
• Plant cells have one or two large
vacuoles
• Animal cells usually do not have vacuoles
or if they are present, they are very
small
• Plant cells have angular shape and animal
cells are more rounded
• Plant cells have intercellular air spaces
between adjacent cell → animal cells
don’t
Draw and complete the table:
Differences between plant- and
animal cells
CHARACTERISTIC
SHAPE
CELL WALL
VACUOLES
INTERCELLULAR AIR
SPACE
CHLOROPLASTS
MITOCHONDRIA
PLANT CELL
ANIMAL CELL
Do Activity 4 on p6
nr 1 and 2
How are cells made? (Stick in note)
• Cell uses some food to make new protoplasm
• Cell gets bigger
• Reaches a certain size – divides into 2 smaller
cells
• Repeat this process until cells body needs
have been reproduced - growth
• Process is called Mitosis
• Each new cell receives exactly the same
genetic information
• Body makes more cells at it grows
• Fully grown – body goes on making new cells to
replace cells worn out and damaged - repair
Copy this process of
mitosis onto your note:
Parent cell is also called a
Mother cell
Start of mitosis
The nucleus now makes a
copy of itself – not seen in
sketch
The mother cell divides
into 2 daughter cells
The 2 daughter cells are
identical to one another as
well as the original mother
cell
More MITOSIS sketches:
What is a Microscope?(p7)
• An instrument that contains one or
more magnifying lenses
• Allows us to look at things that are too
small to see with the naked eye
• Light microscope - uses light to view the
specimen
• Electron microscope – uses beams of
electrons to make an image of the
specimen. (Can magnify much more)
Parts of the microscope
Use the sketch on p7 only
as an extra note. Stick in
your note on the
microscope and study its
labels.
The light microscope
Test your knowledge:
Do the worksheet on the
Microscope
*YOU MUST USE THE LABEL:
OCULAR – NOT eyepiece *
Carry a Microscope Correctly
How to use a light microscope(p8)
1. Place microscope on a level surface.
Lowest power objective lens (4x) in
place.
2. Turn coarse focussing knob/coarse
adjustment screw that objective lens
moves away from the stage.
3. Place slide on the stage. Ensure
specimen is directly over the hole in
the stage. Do not let the slide touch
the lens.
Continued…
4. Look through the ocular. Turn the
coarse focusing knob slowly – stage
moves to objective lens. Specimen
comes into focus.
5. Use the fine focusing knob to get a
clear image of the specimen (final
focus)
6. Move the slide to find the best cells to
view
7. Carefully use clamps to hold slide in
position
Continued…
8. Increase the magnification – swing the
medium power objective lens (10x) into
place by turning the nose piece.
9. Look through ocular and use fine focus
knob to fine focus again.
10. Change to high power objective lens
(40x) and then repeat step 9.
Continued…
Determine total magnification:
Multiply the magnification of the
ocular with the magnification of
the objective lens.
The discovery of microscopes
(p 9)
For interest only – NOT TO STUDY
What is a wet mount slide?(p10)
Wet mount =
Specimen is placed in a drop of liquid on a
glass slide.
The liquid is usually water.
A dye may be added to stain the cells or
part of the cells to make them more
visible when it’s too light in colour.
Cover this with a coverslip.
How to make a wet mount slide of
onion epidermis(p10)
• Place a clean glass slide
on a flat surface
Pull off the
epidermis
of an onion
• Place a small
piece of the
onion
epidermis on
the middle of
the glass slide.
• Place 2 to 3
drops of water
or iodine
solution (stain)
if needed on
the onion
tissue.
• Place the
coverslip at an
angle on the
glass slide.
• See sketch on
p10
• Coverslip must
touch liquid and
will flow across
the edge of the
coverslip.
Rest the
coverslip on
a dissecting
needle or
pencil at 45º.
Lower the
coverslip as
slowly as
possible.
Use tissue to
dry any
excess
water.
DO NOT
WIPE →
suck water
into tissue
In short:
What you need to make a slide:
• Use the previous info to draw
the following sketch:
• The parts of a slide
• Add these labels: Glass slide,
coverslip and specimen.
In permanent slides the
coverslips are stuck onto the
glass slide with special glue and
can be used over and over again.
You are now ready to do
your 3 CELL PRACS
The info on p11 is for
reading only, NOT TO
STUDY
Cells in tissues, organs, systems
and organism (p12)
CELLS
• In many different shapes and sizes
• Organisms are made up of different
numbers of cells
CELLS cont…
• Microscopic organisms (can only be seen
with a microscope):
1. Bacteria - not even a true cell, because
it does not have a nucleus
CELLS cont…
2. Amoeba – made up of a single cell
All the life processes (feeding,
respiration, excretion and reproduction
are carried out within one cell. Called a
unicellular organism. Uni =one
CELLS cont…
• Macroscopic organisms – humans – made
up of thousands of cells = multicellular
• In complex organisms groups of cells
will specialise(look a certain way) to
perform a specific function
• They will have the same shape and
structure - muscle cells
• Able to contract and relax to enable
your body to move
Muscle cells
Tissues, organs, systems and
organism (p13)
• A group of CELLS that look the same
and perform a specific function =
TISSUE
• A group of tissues working together =
ORGAN
• Organs working together = SYSTEM
• Systems make up = ORGANISM
CELLS: Heart cells
TISSUE: Heart tissue
ORGAN: Heart
SYSTEM: Circulatory
ORGANISM: Human
Do the worksheet on cells,
tissues, organs, systems
NOT
Do Activity 8 on p14
nr 1 (a + c)
nr 2 (a + b)
Draw 3 of the cells seen in
micrograph (a) only
Stem cell research (p15)
• Stem cells = cells that have not yet
developed and can specialise into almost
any type of cell in the human body
Stem cell cont.
• Stem cell research = harvesting stem
cells and trying to use it to cure disease
• Human stem cells can be harvested in a
number of ways:
1. Adult stem cells
2. Umbilical stem cells
3. Embryonic stem cells
Stem cell cont.
Adult stem cells harvested from the
blood, fat tissue and bone marrow:
Stem cell
cont.
Umbilical stem
cells are
harvested from
the blood in the
umbilical cord
when a baby is
born.
Embryonic stem
cells are
harvested from
human embryos.
Stem cell cont.
• Many people are opposed to stem cell
research, because the best source is
from human embryos
• Embryo is destroyed
• Considered ethically and morally wrong
by many people
• They feel a human life is being
destroyed when stem cells are
harvested from embryos
Do Revision activity on p16
(Do everything on p16, except
no 3 of the “Test yourself”)