Download Biology Unit Tissues, Organs, and Systems of Living Things

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Link Between Our Knowledge and
Technology

As in all fields of science, or any other field of
study our knowledge increases as technology
improves
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Result of the fact that new technologies provide
new perspective and allow observations that
were not possible before
A clear example of this in Biology is the
development of the Microscope
 http://www.youtube.com/watch?v=BTicXXxzQA
4&feature=related
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Microscope Development
First developed in the
mid-1600s
 With the development
allowed a once invisible
world to now be visible
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Called the structures cells
because they reminded him
of the cells inhabited by
monks living in a monastery
 The World of Cells
This world of cells was
first described by
Robert Hooke
 Hooke used his
primitive microscope to
view cork and the
structures he saw, he
called “cells”
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Cell History Continued

Next came Anton van
Leeuwenhook
 Made his own more
advanced microscopes
 Used his microscopes
to be the first to
observe drop of pond
water and various
bacteria samples

His findings were
confirmed and Anton
became a worldwide
celebrity soon after
People were skeptical
of his findings so
Robert Hooke sent to
confirm his findings
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Cell History Continued
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The real importance of
cells not recognized until
the 1830s
1838-1839 Matthias
Schleiden and Theodor
Schwann work with cells
made the first two tenets
of the cell theory
The final tenet of the cell
theory came in 1855
from the work of Rudolf
Virchow
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Cell Theory

Made of the following three tenets:
1. All organisms are composed of 1 or more
cells
2. The cell is the structural unit of life
3. Cells can arise only by division from a
preexisting cell
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Basic Properties of Cells
Cells are highly complex
and organized
 Cells possess a genetic
program and a means to
use it
 Cells are capable of
producing more of
themselves
 Cells acquire and utilize
energy

Cells carry out a variety of
chemical reactions
Sum total of the reactions in a cell
represent the cell’s metabolism
Cells engage in numerous
mechanical activities
Cells are able to respond to
stimuli
Cells are capable of self
regulation
Cells evolve
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The Cell Classes
Prokaryotic Cells
Considered to be structurally
simpler
Findings suggest started to
exist approximately 2.7 billion
years ago
Eukaryotic Cells
Considered to be structurally
more complex
Findings suggest started
approximately 2 billion years
ago
Cell Parts and Functions

Cell is composed of
many structures and
parts with various
functions
The functions a cell must
carry out include:
Intake of nutrients
Movement
 These functional parts of Growth
cells are called organelles Response to stimuli
Exchange of gases
 These functions allow
Waste removal
cells to survive in
Reproduction
unicellular (single-
celled) and multicellular
organisms
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Plant Cell
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Animal Cell
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Organelles Common to Both
Plant and Animal Cells
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Cell Membrane
Cytoplasm
Nucleus
Vacuoles and Vesicles
Mitochondria
Lysosomes
Golgi Apparatus
Cytoskeleton
Ribosomes
Endoplasmic Reticulum (ER)
 Smooth Endoplasmic
Reticulum
 Rough Endoplasmic
Reticulum
Common Organelles
Cell Membrane
Forms a protective barrier
around the cell
Made of a double layer of
lipids
Lipid is a fat-like molecule that
does not dissolve in water
Cell Membrane

Diffusion relies on the amount of
Designed to allow
movement of certain dissolved particles present, the
concentration, to occur
substances
Particles will diffuse, or move,
 One form of movement across the membrane from area of
is called diffusion
high concentration of that
substance to areas of low
concentration of that substance.
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Common Organelles
Cytoplasm
Jelly-like substance that fills
the cell and surrounds the
organelles
Contains the nutrients to
allow the cell to carry out its
life processes
Allows things to move within
the cell
Common Organelles
Nucleus
Control centre organelle of the
cell
Controls everything (e.g. growth and
reproduction)
Surrounded by a nuclear
envelope
Movement across this occurs
through nuclear pores
Most have a small dense area
called the nucleolus
Contains all the cell’s DNA
DNA= Deoxyribonucleic Acid
Common Organelles
Vacuoles
Membrane bound organelle
Help with storage of nutrients,
wastes and other substances used
by cells
Important in plants as often
have central vacuole
Mainly stores water, causing cells
to swell, making the plant become
firm
Vesicles
Membrane bound organelle
Also helps with storage
Bigger role in the transport of
the stored substances
throughout the cell
Common Organelles
Mitochondria
Provides the supply of energy for
the cell
Does this by converting chemical
energy in sugars into usable for
the cell, ATP
ATP=Adenosine Triphosphate
Powerhouses of the cell
Common Organelles
Lysosomes
Organelles where digestion
takes place
Are small organelles packed
with enzymes
Enzymes are proteins that speed up
chemical reactions in a cell
Also help break down invading
bacteria and damaged
organelles
Work as the clean up system
In the image the purple structures are
lysosomes
Common Organelles
Golgi Apparatus
Receives proteins from
endoplasmic reticulum
Function is to modify, sort,
and package these proteins
for delivery throughout the
cell or outside the cell
Looks like a stack of
flattened membranes
Resembles stack of pancakes
Common Organelles
Cytoskeleton
Internal network of fibres
Made of protein filaments
Helps maintain cell’s shape
Ribosomes
Small, dense-looking
organelles
Either free floating in
cytoplasm or attached to the
rough endoplasmic reticulum
Site of protein assembly
Common Organelles
Endoplasmic Reticulum
Organelle made of series of
interconnected small tubes that
carry materials through the cell
Found in 2 forms:
1. Smooth Endoplasmic
Reticulum
Associated with the production
of fats and oils
2. Rough Endoplasmic
Reticulum
Associated with making
proteins
Considered rough due to
presence of ribosomes
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Plant vs Animal Cells
Organelles that are only
found in Plant cells
Cell Wall
Chloroplasts
Organelles that are only
found in Animal cells
Centrioles
Plant Cells
Chloroplasts
Contains chlorophyll
Chlorophyll uses energy from the Sun to
convert carbon dioxide and water into
sugar and oxygen through
photosynthesis
Made of little sacs called
thylakoids
Stack in fashion that resembles a coin
stack
A stack of thylakoids is called a granum
Chloroplasts have many grana
Stack of thylakoids surrounded by
thick fluid called stroma
Thylakoids are “solar collectors”
Plant Cells
Cell Wall
Rigid frame around the cell
that provides:
Strength
Protection
Support
Animal Cells
Centrioles
Paired structure
Involved in cell division
Other Differences Between
Plant and Animal Cells
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Compounds / Chemical
 Plants cells have specialized chemical compound
called chlorophyll, a pigment that allows
photosynthesis
 Animal cell have some specialized compounds like
hemoglobin in red blood cells
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Vacuoles
 Plant cells have large central vacuole
 Animal cells vacuoles tend to be small
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Energy storage
 Plants cells store energy in the form of starch or oils
 Animal cells store energy in the form of glycogen (a
carbohydrate) or as lipids in the form of fats
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