Biology Journal 8/24/2015
How is this picture like the Endosymbiotic Theory?
What would happen next, in this analogy?
Remember the 4 major pieces of evidence that support the
Endosymbiotic Theory?
Endosymbiosis
Like all evolution, eukaryotes evolved through a series of small steps.
Today!
Get ready for your lab on osmosis. This lab will be
counted as evidence. It will eventually all be put in
your composition notebook.
• Read the entire lab
• Decide where you want to put it, and write your
pre-lab questions, procedure, and materials.
Do the homework questions for section 1.3
Is there any other practice you’ve skipped? You
can do the Endosymbiotic Theory worksheet, the
Cells, Cells, They’re made of Organelles
worksheet, the Measuring Magnification
worksheet…
Today!
Do your journal. Compare your answers with
another classmate, and add to your journal
anything they have that you didn’t think of.
Get ready for your lab on osmosis. This lab will be
counted as evidence. It will eventually all be put in
your composition notebook.
• Read the entire lab
• Decide where you want to put it, and write your
pre-lab questions, procedure, and materials.
Do the homework questions for section 1.3
Is there any other practice you’ve skipped? You
can do the Endosymbiotic Theory worksheet, the
Cells, Cells, They’re made of Organelles
worksheet, the Measuring Magnification
Biology Journal 9/14/12
What molecule is the
macromolecule DNA made
out of?
How did that molecule get its
name?
Biology Journal 9/20/10
What do ribosomes do?
What other organelle are
ribosomes often attached to?
What does that organelle do?
Biology Journal 11/21/13
How many
cells do you
think are in
the average
human’s
body?
Biology Journal 11/22/13
What are histones?
What are chromosomes?
What’s the difference between the DNA of a
eukaryote and the DNA of a prokaryote?
Biology Journal 11/27/13
The DNA of a prokaryote is called “naked.” Why is
that? What’s different about the DNA of a eukaryote
and a prokaryote?
Topic 1: Cell Biology (15 hours)
1.2 Ultrastructure of cells: Eukaryotes have a much more complex cell structure than prokaryotes.
Nature of science: Developments in scientific research follow improvements in apparatus—the invention of
electron microscopes led to greater understanding of cell structure.
Understandings:
• Prokaryotes have a simple cell
structure without
compartmentalization.
• Prokaryotes divide by binary fission.
• Electron microscopes have a much
higher resolution than light
microscopes.
• Developments in science, such as
electron microscopy, can have
economic benefits as they give
commercial companies
opportunities to make profits, but
this can affect cooperation between
scientists.
Applications and skills:
• Structure and function of organelles within exocrine gland cells of
the pancreas and within palisade mesophyll cells of the leaf.
• Drawing of the ultrastructure of prokaryotic cells based on
electron micrographs: cell wall, pili and flagella, and plasma
membrane enclosing cytoplasm that contains 70S ribosomes and a
nucleoid with naked DNA.
• Drawing of the ultrastructure of eukaryotic cells based on electron
micrographs: plasma membrane enclosing cytoplasm that contains
80S ribosomes and a nucleus, mitochondria and other membranebound organelles are present in the cytoplasm. Some eukaryotic
cells have a cell wall.
• Interpretation of electron micrographs to identify organelles and
deduce the function of specialized cells.
International-mindedness: Microscopes were invented simultaneously in different parts of the world at a time
when information travelled slowly. Modern-day communications have allowed for improvements in the ability to
collaborate, enriching scientific endeavour.
Theory of knowledge: The world that we inhabit is limited by the world that we see. Is there any distinction to
be drawn between knowledge claims dependent upon observations made by sense perception and knowledge
claims dependent upon observations assisted by technology?
Biology Journal 11/7/2014
A cell is 32 µm across. A student draws it as 250mm
wide. What is the magnification? Show your work.
A cell is 32 µm across. A student draws it as 250mm
wide. What is the magnification?
You don’t have to
draw it, but you can
if that helps!
Measured length
Actual size =
Magnification
250 mm
32 µm =
32 µm =
x
250000 µm
Solve for x
x
7800
times
X= 7800
magnified
Convert to the same
1000 µm
units before you divide! 250 mm
x
1 mm
= 250000 µm
Biology Journal 11/6/2014
What do you think
could be the smallest
things we can see
with a light
microscope?
What do you think
could be the smallest
things we can see
with an electron
microscope?
The kind of
microscopes we
have used are
called light
microscopes.
A more
powerful
microscope
is an
electron
microscope.
What do you think these could be?
1.2 The Ultrastructure of Cells
The invention of electron microscopes led
to greater understanding of cell structure.
All organisms can be divided into two groups
according to their cell structure.
Organisms
Prokaryotes
Eukaryotes
Germs!
You are a Eukaryote.
Smaller, simpler
Bigger, more complex
Cell wall with
peptidoglycan
Cell wall with
cellulose (plants),
chitin (fungi), or no
cell wall (animals)
70s ribosomes
80s ribosomes
Reproduces
through binary
fission
Reproduces through
mitosis
Eukaryotes are about 100 times
bigger than prokaryotes
Example IB topic skill:
Drawing of the ultrastructure of prokaryotic cells based on electron
micrographs: cell wall, pili and flagella, and plasma membrane enclosing
cytoplasm that contains 70S ribosomes and a nucleoid with naked DNA.
Example IB topic skill:
Drawing of the ultrastructure of prokaryotic cells based on electron
micrographs: cell wall, pili and flagella, and plasma membrane enclosing
cytoplasm that contains 70S ribosomes and a nucleoid with naked DNA.
A Terrible Drawing…
Too light
Unlabeled
Messy
Parts are
indistinguishable
Tiny
A Good Drawing…
•
•
•
•
•
Good use of space
Clear strong lines
Label lines are straight
Labels clearly written
Scale bar if appropriate
•
•
Lines touch the labeled
structure
No unnecessary shading
or coloring
Nucleoid
Region where naked DNA can be
found; may have plasmids
(loops of “extra” DNA, which can
introduce new genes)
Cytoplasm
Jelly-like
substance
Flagella
Whip like; allows the cell
to move
Cell
Membrane
Made out of
phospholipids;
controls what
enters and
leaves cell
Cell Wall
Made out of
peptidoglycan
(mesh of amino
acids and
sugars)
Pili
Allows cells to connect
and exchange DNA
(sexual reproduction)
70S Ribosomes
make protein
Example IB topic skill:
Drawing of the ultrastructure of eukaryotic cells based on electron
micrographs: plasma membrane enclosing cytoplasm that contains 80S
ribosomes and a nucleus, mitochondria and other membrane-bound
organelles are present in the cytoplasm. Some eukaryotic cells have a cell wall.
10µm
Plasma membrane
Mitochondria
Free 80S ribosomes
Lysosomes
Cytoplasm
Nucleus
Golgi apparatus
Rough Endoplasmic
Reticulum
10µm
Nucleus
DNA in a membrane
Mitochondria
Makes energy by
doing cellular
respiration
Vacuole
Large compartment
for storage of water
or other molecules
80S Ribosomes
They make protein;
sometimes attached
to ER
Cytoplasm
Jelly-like substance
Endoplasmic
Reticulum
Transports molecules; can
have ribosomes attached
(rough) or none (smooth)
Golgi Complex
Makes vesicles for molecules to
enter or leave the cell
Chloroplast
Makes glucose by doing
photosynthesis
Cell Wall
• In plant cells, it is made out of cellulose (a
carbohydrate)
• In fungi, it is made out of chitin (a carbohydrate)
• Animal cells don’t have one
Identify the structures in these false-colored microscopic images
Cell membrane
Cell wall
Cytoplasm
(the darker spheres are ribosomes)
Pili
Flagella
Nucleoid region
(where DNA is located)
Identify the structures in this false-colored microscopic image of a human liver cell
Cytoplasm
Mitochondria
Ribosomes
(free)
Plasma
membrane
Nucleus
Endoplasmic Reticulum
(rough)
Lysosome
Identify the structures in this microscopic image of a plant cell (not false colored)
Chloroplast
Vacuole
Cytoplasm
(little dots are
ribosomes)
Cell
Wall
Mitochondrion
Nucleus
Plasma
membrane
This is a sweat gland
attached to a hair
follicle!
1. Which cell parts can we
identify?
2. Which cells do you think…
• Excrete water and lipids?
• Make up the upper level
of skin (epidermis)?
• Make up the fatty,
squishy layer of tissue
under the skin?
This is a cross-section of a leaf! How do some of
the cells appear specialized for their job?
1. Which cell parts can we identify?
2. Which cells do you think…
• Do photosynthesis?
• Form a water-tight barrier?
• Transport sugars and carbohydrates?
Biology Journal 11/25/2013
Compare and contrast eukaryotes and prokaryotes in a
Venn diagram.
Eukaryotes
Both
Prokaryotes
Biology Journal 11/25/2013
Compare and contrast eukaryotes and prokaryotes in a
Venn diagram.
Eukaryotes
Both
Prokaryotes
•Large and more complex
•Have a cell membrane
and cytoplasm
•Small and simple
•Has a nucleus and
organelles
•Reproduce through
asexual cell division
•Lacks a nucleus and lacks
organelles
•DNA is linear and in
many pieces
(chromosomes)
Have ribosomes (but they •DNA is circular and in
are different)
one piece (usually)
•Cells divide through
mitosis
•Cells divide through
binary fission
•Have 80s ribosomes
•Have 70s ribosomes
•Attaches and transfers DNA
through pili
Biology Journal 11/26/2013
Compare and contrast plant and animal cells in a
Venn diagram.
Plant
Both
Animal
Biology Journal 11/26/2013
Compare and contrast plant and animal cells in a
Venn diagram.
Plant
Both
Animal
•Often are high in
lysosomes
•Have chloroplasts
•Are eukaryotes
•Has a plant cell
wall
•Have other organelles in
•Can have great
common (mitochondria,
ability to move
ER, golgi bodies…)
•Has a large
vacuole
•Are similar in size
•No / very limited
ability to move
•Cells asexually
reproduce through
mitosis
Extracellular Components – parts outside of the cell
The cell wall of plants
•Gives the cell shape
•Holds the cell up against
gravity
•Prevents it from exploding
from too much water
Glycoproteins of animals
•Made out of carbohydrates
attached to proteins
•Gives the cells adhesion
•Anchors the cell to
surrounding cells
•Allow for movement
On your notecard, write…
1.
2.
3.
4.
5.
Your name on the card
One question that’s a definition
One question that’s a drawing
One question that’s an explanation
Write the answers to these on the backside
Sarah Smith hr.1
What does flagella do?
What’s this thing?
Why do eukaryotes have to do
mitosis, but prokaryotes don’t?