Transcript Level Of Organisation

Biology unit 1/2 -CHAPTER 2
Topic: Level Of Organisation (p42-46)
28/3/2012
BY
Muhammad Bilal Javed
Learning Objectives
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Upon completion student will understand ...
Uni / multi cellular organisation & characteristic
Level of organisation
Type of tissues ??
SA: V Ratio: how it works? its important to cell...!!
Delivery method
Organ & their system.
Comparison of plant and human organ system..!!
Summary of organisation
Cells
• Cells The basic structure of living things
• Human body contains about 100 trillion cells
UNICELLULAR ORGANISMS CELL
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Must carry out all the metabolic processes necessary for life
NB: “ uni-” = one (i.e. one cell)
Prokaryotes are unicellular organisms .
Some algae, some protists , and some eukaryotes (yeasts), are
unicellular
• Are complex cells capable of/or can still do
everything they need to stay alive
• Benefits over multicellular organisms:
- Need fewer resources
- Can live in harsher conditions
Multicellular Organisms
• Are dependent on each other for survival.
• NB: “ multi-”= more than one (millions of cells)
• Plants, animals , some protists, and most fungi
are multicellular.
• Start as a single cell -> many cells -> cells
differentiate (change) into different types of
cells -> cells group together (i.e. level of
organisation)
Levels of Organization
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Depend upon each type of
cell and its specific job
aka specialized cells.
??CAN YOU IN YOUR OWN WORDS
EXPLANIN WHAT ‘SPECIALIZED’
MEAN WHEN TALKING ABOUT
CELL ORGANIZATIONS??
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1st Level: cells
2nd Level: Tissues
3 rd Level: Organs
4th Level: Organ Systems
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?? Is sperm a cell ??
Therefore : Cells -> Tissues -> Organs -> Organ Systems
Multicellular Characteristics
• Larger size = benefit: have less predators and
have more options of things to eat
• Another benefit: Longer life – organism will
continue to live even if a single cell dies
• Biggest benefit: ‘Specialization’ – each type of
cell has a specific job, making the organism
more efficient
Tissue
• Are ‘group of same cells’ that work together to perform a specific
job.
• NB: Material around and between the cells is also part of the tissue.
• Different kind of tissue serves different function
• 4 MAIN TYPES:
- CONNECTIVE
- MUSCLE
- NERVOUS
- EPITHELIAL
Examples
• CONNECTIVE TISSUE: Connects other tissues
together. ie: Fat, cartilage, bones, blood, ligaments
and tendons.
• EPITHELIAL TISSUE: Covers the surface of your body
and lines the inside of organs. For out side only
epidermal = ‘outside’) NB: plants don't have
epithelial.
• MUSCLE TISSUE: Movement of the body’s functions.
ie: voluntary & involuntary.
• NERVOUS TISSUE: Controls & coordinates all body
functions. ie: brain, nerves
SA:V-to- Ratio
• Surface area : Volume ratio The surface area of
a sphere is calculated using the formula 3πr2
• The volume of a sphere can be calculated using
the formula 4/3πr2
• SA:V ratio can be calculated by simply dividing
the SA by the V.
• For a sphere of radius 1μm, what would the
SA:V ratio be?
Surface area:Volume ratio
• What is the apparent relationship between SA
and V in a sphere?
• The larger the sphere, the lesser the surface
area in comparison the volume.
Example :
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when cell size increase (i.e. radius) the SA:V decrease
Radius (r)
1 unit
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3
6
10
SA:V
3.0
1.5
1.0
0.5
0.3
How SA:V relates to cells
• Cells are roughly spherical in shape
• The plasma membrane is vital for the
importation of required substances and the
disposal of waste
• Cells need as large as possible a surface are
(in relation to their volume) in order to
interact effectively with their environment.
• This is the limiting factor on the size of cells.
Organization of cells in multicellular
organisms
Explanation: the number of cells occupying a particular space influences the rate of
movement of material into & out of the mass occupying the space. The greater the
overall SA:V Ratio the greater the efficiency of movement of material.
Important of SA:V Ratio
• Important in determining the cell efficiency to
move the materials across its membrane, and
that the higher SA:V Ratio of cells, the more
efficient it is in carrying out those functions.
• Exchange of martial between tissue and their
environment has the potential to be far more
efficient if the tissue is made up of many small
cells rather than fewer larger cells.
Delivery system...
• For the inner cells of a tissue to operate as
efficient as the outer cells, they must have a
delivery system that transport foods and gases
to them and takes away waste.
• In many animals, the delivery system is the
blood circulatory system.
Delivery system
This contact with the external environment is achieved by means of a delivery
system – ( i.e. blood flow)
Organs
• Only in multicellular organism
• Different tissue types working together with /
or for a specific job to be done at its best.
• Thus organs can be defined as a collection of
tissues.
• For example: your stomach consisting of
groups of tissues i.e. epithelium, smooth
muscle cells & blood
• ??What other organs can you think of ??
How about organ of Plants or Trees !!
• Leaf is a an organ for plants & trees
• Tissues of leaf include: epithelium, vascular
tissue, and parenchyma tissue.
• ??What other organs of plant/ or tress can
you think ??
Organ systems
• Our digestive system is
comprises various
organs that work
together to ensure that
the food we eat is
digested and voluble
nutrients from the
foods can be absorbed
and delivered to our
body.
Eg. Commences with mouth -> teeth -> oesophagus ->stomach ->intestine -> liver. Than,
blood carrying O2 picks up nutrients absorbed by intestine -> circulates to the body
Plant organ Vs Human organ
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Plants ...
Energy need is less
not/ or hardly mobile
Hence lacks complex
organs or don't need it as:
produce their own food
through photosynthesis
plus this process also
delivers or allows
exchange of O2 and CO2
• Human ...
• Energy need greater
• Depends on/ greater
mobility
• Thus require complex
system, such as:
- respiratory for
(energy /ATP)
- digestive system
(for food /nutrients)
Summary of levels of organisation in multicelullar organism
Home work to be completed in
holidays
• Do bio-challenge question (p-47)
• Do quick-check questions on (p-31, 35,42,46)
• Chapter review questions: Q 2) & Q6) applying
your understanding, as well as Q7d) analysing
informational and drawing your conclusions.
Hint; for Q7d) good idea have a look at videos
on YouTube or any appropriate site that suites
you to give you ideas.
• After the above please attempt reading on
chapter 3 for lessons
Reading’s for upcoming topics
• After finishing of home work from last slide
please attempt ‘reading on chapter 3’ and
attempt QUICK -CHECK questions on (p60 &
p71)
AND
Do reading on Chapter 4. As well as QUICK CHECK
questions (p84 & P88)
Thank you
&
enjoy your holidays :D