L18.12, L14.1, L14.3 Bio EOC Bootcamp

L 18.12 - Water Properties

Multiple Choice

Water has a much higher specific heat than most other covalent compounds. What do you

predict might happen if water had a low specific heat instead?

• Flooding would occur and animals would be forced to migrate

• Harmful organisms living in water would reproduce at a rapid rate

• Organisms that are sensitive to changes in temperature would die

• Plants would not have enough water to effectively carry out photosynthesis

Multiple Choice

Small insects can walk across the surface of calm water. Their feet push the surface of the water

down slightly, somewhat like a person walking across a trampoline, but they do not break the surface.

What is the best explanation for why this happens?

• The insects are light enough so that they do not break the hydrogen bonds holding the

  water molecules together

• The insects actually use their wings to hover slightly above the water's surface and they

  only skim it with their feet

• The insects' feet are non-polar, so they are repelled by the polar water molecules and are

  pushed away from the water's surface

• The insects are small enough to see the individual water molecules, so they are able to

  step carefully from one molecule to the next

Multiple Choice

A florist places a bouquet of white carnations in water containing blue dye. After a time, the

flowers turn blue. What process helped the carnations to change color?

• Specific heat

• Surface tension

• Cohesion and adhesion of water molecules

• Formation of covalent bonds between hydrogen and oxygen molecules

Multiple Choice

Water makes up approximately 60% of the human body and plays a vital role in regulating body

temperature. Which property of water makes it good at regulating temperature?

• Water is a good solvent.

• Water exhibits strong cohesion.

• Water has an unusual crystalline structure.

• Water has a high capacity for heat.

Multiple Choice

Water is essential for life. Its special properties make water the single most important molecule

in plant life. Which of the following properties of water enable it to move from the roots to the leaves

of plants?

• Water expands as it freezes.

• Water is an excellent solvent.

• Water exhibits cohesive behavior.

• Water is able to moderate temperature.

Multiple Choice

Large bodies of water, such as lakes and oceans, do not quickly fluctuate in temperature. What is

the reason for this phenomenon?

• Water is an acid.

• Water is a versatile solvent.

• Water acts as a buffer.

• Water has a high heat capacity.

L14.1 - Cell theory

Let’s Recall: What are the 3 components of modern
Cell Theory?

1.

All living things are made of cells.

2.

Cells are the most basic unit of life.*

3.

Cells arise from the division of pre-existing cells.

*What does this mean? It means that cells are the lowest level of
biological organization that is considered alive. A cell can live on its own,
but a single organelle could not.

The Cell Theory was originally introduced in 1838. In 1858, it gained its third component,
finalizing it as the modern Cell Theory we know today. That means that over 160 years have
passed!

Why isn’t Cell Theory a law by now?

Review the characteristics of scientific theories, scientific laws, and hypotheses.

Now we’ll take a deeper look at the different scientists who contributed to Cell
Theory.
Number off in 3s. Only read the biographies for your number:

1s: Hooke and Von Leeuwenhoek

2s: Schleiden and Schwann

3s: Virchow and Pasteur

Biographies file:
https://docs.google.com/document/d/1e_pP_tqIzLRZmEB3d4AQgLngUjjVfmS2BsMbiEcPR3s/copy

Discovery of Cells

1665- English Scientist, Robert Hooke, discovered
cells while looking at a thin slice of cork.
He described the cells as tiny boxes or a honeycomb
He thought that cells only existed in plants and fungi

Hooke's Microscope - 1665

Anton van Leuwenhoek

1673- Used a handmade microscope to

observe pond scum & discovered
single-celled organisms

He called them “animalcules”

He also observed blood cells from fish,

birds, frogs, dogs, and humans

Therefore, it was known that cells are

found in animals as well as plants

Leuwenhoek’s handmade microscope 1

1 Photo credit: Jeroen Rouwkema http://www.flickr.com/photos/rouwkema/2262158965/

150-200 Year Gap

• Between the Hooke/Leuwenhoek discoveries and the

mid 19th century (1850’s), very little cell advancements
were made.

• This is probably due to the widely accepted, traditional

belief in Spontaneous Generation – making living
things from non-living things.

• Examples:

-Mice from dirty clothes/corn husks
-Maggots from rotting meat

+

=

?

19th Century Advancement

• However, there was much doubt around the idea of

Spontaneous Generation. To many it didn’t make sense.

• Conclusively disproved by Louis Pasteur

Ummm, I
don’t
think
so!!!

Louis Pasteur & Pasteurization

Development of the Cell Theory

• 1838- German Botanist, Matthias Schleiden, concluded that all

plant parts are made of cells

• 1839- German physiologist, Theodor Schwann stated that all

animal tissues are composed of cells.

Matthias Schleiden Theodor Schwann

Development of the Cell Theory

• 1858- Rudolf Virchow - after extensive study of

cellular pathology, concluded that cells must arise
from preexisting cells.

Illustration of Virchow's cell theory - 1847

The Initial Cell Theory

The 3 Basic Components of the Cell Theory were
then complete:
1.

All organisms are composed of one or more
cells.

2.

The cell is the basic unit of life in all living
things.

3.

All cells are produced by the division of
preexisting cells.

The cell theory would not have been developed
without the contribution of these scientists and

the invention of the

__________________________.

Multiple Choice

Which statement is NOT a part of the cell theory?

• Every organism contains at least one cell.

• All cells spontaneously generate.

• All existing cells must have a parent cell.

• A cell has all of the characteristics that define life.

Multiple Choice

The cell theory has existed for over two hundred years. Why is it not a law by now?

• There isn't enough experimental evidence to make it a law.

• It takes four hundred years for a theory to be considered a law.

• A theory does not become a law.

• Not all scientists agree with the cell theory.

Multiple Choice

Both Schwann and Virchow developed important theories about cells in the mid

1800s. Which best explains the reason these theories were made within a few years

of each other?

• Hooke’s Micrographia inspired both theories.

• New microscopes provided better viewing of cells.

• Scientists invented the microscope in the mid 1800s.

• The electron microscope was used for the first time.

Multiple Choice

Orlando wrote four facts he had learned about cells on separate index cards. The

four facts Orlando wrote are listed below.

1. Cells come only from existing cells.

2. All cells contain hereditary information.

3. All living things are made of one or more cells.

4. A cell is the basic unit of structure and function for all living things.

He shuffled the index cards, spread them out on his desk, and asked Martha to pick

out the cards that described the cell theory. Which cards did Martha correctly select?

• 1,2, 3

• 1,2,4

• 1,3,4

• 2,3,4

Multiple Choice

Francine drew the diagram below to illustrate one of the statements that make up the

cell theory.

Which statement of the cell theory was Francine illustrating?

• Cells come from existing cells.

• All living things are made of one or more cells.

• The cell is the basic unit of structure and function.

• Cells contain specialized parts known as organelles.

Multiple Choice

Observations can lead to a hypothesis. In turn, repeated experiments that support

several hypotheses can lead to a theory. This is how the cell theory developed. What

did scientists use to develop the cell theory?

• educated guesses

• chemical analysis

• careful observations

• evolutionary relationships

Multiple Choice

Like all theories, the cell theory is never accepted by scientists as an “absolute

truth.”

Which statement best explains why?

• Future evidence may cause a theory to be modified or even rejected.

• A scientific theory is not based on experimental evidence or observations.

• A theory is only a collection of hypotheses that have been verified by

  experimentation.

• A theory evolves from collecting information, forming hypotheses, and then

  verifying the predictions of the hypotheses.

Multiple Choice

Which statement is correct about all organisms that are eukaryotes?

• They consist of many cells.

• They have organelles such as a nucleus.

• They can be seen without a microscope.

• They consist of cells that are surrounded by a cell wall.

Multiple Choice

Organisms are classified as either prokaryotes or eukaryotes. Which of the following

would you find in all prokaryotic cells and eukaryotic cells?

• nucleus

• cell wall

• cytoplasm

• mitochondria

Multiple Choice

Many animals have a skeleton to provide support. What do plants cells depend on

for support so that the stems of the plant can remain upright?

• cell wall

• chloroplasts

• mitochondria

• cell membrane

Multiple Choice

Which cell structure is correctly paired with its primary function?

• ribosome - protein synthesis

• mitochondrion - movement

• vacuole - cell division

• nucleus - storage of nutrients

Multiple Choice

The diagram below represents a cell.

Which organelle is the site where amino acids are synthesized into proteins?

• 1

• 2

• 3

• 4

Multiple Choice

Which of these best completes this concept map?

• an animal cell

• a prokaryotic cell

• a virus

• a plant cell

Multiple Choice

Using a microscope in the science lab, Jill observed two unknown cells: Cell 1 and Cell 2. Cell 1

she identified as a plant cell and Cell 2 as an animal cell. Her teacher told her she identified the cells

correctly. What did Jill most likely observe to correctly identify the cells?

• Cell 2 had a cell membrane and Cell 1 did not.

• Cell 1 had a cell wall and Cell 2 did not.

• Cell 2 had a chloroplast and Cell 1 did not.

• Cell 1 had a nucleus and Cell 2 did not.

Multiple Choice

A lab technician needs to determine whether cells in a test tube are prokaryotic or eukaryotic.

The technician has several dyes she could use to stain the cells. Four of the dyes are described in

the table below:

Which dye could the technician use to determine whether the cells are prokaryotic or eukaryotic?

• acridine orange

• osmium tetraoxide

• eosin

• Nile blue

L14.3 - Organelles

There are a few characteristics that all cells share:

1.

Cell membrane (sometimes called plasma membrane) - encloses the cell and
acts as a thin, flexible barrier.

2.

DNA - the genetic information in the cell

3.

Ribosomes - small structures that produce proteins

4.

Cytoplasm - the fluid filled space in which cell structures are found

All cells can be categorized in two broad
groups: Prokaryotes and Eukaryotes

Prokaryotes

●Relatively small and simple

●No nucleus (‘pro’ = before; ‘kary’ = nucleus)

○DNA is located in a region of the cell called the
nucleoid

●No membrane-bound organelles

●First cells to exist on Earth! They eventually gave
rise to more complex cells through a process called
endosymbiosis

●Were the first photosynthetic organism (thank you
cyanobacteria!)

●Always unicellular

●EX - bacteria

●Relatively large, complex

●Nucleus encloses DNA (‘eu’ = true; ‘kary’ =
nucleus)

●Many membrane bound organelles that work
together in the cell

●Evolved from prokaryotic cells through a
process called endosymbiosis

●May be unicellular or multicellular

●EX - plants, animals, fungi, and protists

Eukaryotes

The basic shape and structure of the cell

●Cell wall - rigid, supports shape and protects cell

○Fun fact: made of carbs! Plants = cellulose, Fungi = chitin, Bacteria = depends on type

○Animal cells LACK this!

●Cell membrane - regulates what enters and
leaves the cell

○A double layer of phospholipids - their chemistry makes
this function happen (but more on that next week!)

○Inside the cell wall!

●Cytoplasm - the jelly that fills the cell

○Water-based

●Cytoskeleton - maintains cell shape, helps cell move,
provides “travel lanes” within the cell

○Two types of fibers: microtubules and microfilaments

○Fun fact: the “spindle fibers” in cell division are really microtubules!

Production

●Nucleus - encloses the cell’s DNA; DNA is instructions for building [mainly] proteins

○Prokaryotic DNA just floats in the cell’s middle (NOT enclosed within a membrane compartment)

○Prokaryotes usually have one main DNA circle, but they can also have little extra DNA circles called
plasmids

●Nucleolus - region of the DNA that codes for ribosomes (not proteins)

●Ribosomes - assemble proteins from amino acids

○Can be free-floating to make proteins that work within the cell, or can be attached to the rough ER to
make proteins that will be released by the cell (or embedded in membrane)

●Endoplasmic reticulum -

○Smooth ER - makes and packages lipids

○Rough ER - makes and packages proteins (rough because of the attached ribosomes)

●Golgi - receives “packages” from ER, modifies, sorts, repackages for destination

○“Packages” are membrane-bound compartments called vesicles; they travel along cytoskeleton fibers
(microtubules)

Energy

●Chloroplasts (only in plants) - produce carbohydrates

○Plants literally make food out of thin air! Chloroplasts have sets of proteins that convert carbon
dioxide in air into carbohydrates (food) using energy harnessed from light.

○Who remembers what this process is called?

●Mitochondria (found in all eukaryotes!) - breaks down food molecules for
energy (“ATP”)

○Everyone knows “the powerhouse of the cell,” but what does that mean??? Breaks down
carbs to release their energy, and converts that energy into the cell’s energy currency, ATP.
ATP then gets used to power cell reactions that need energy.

○Who remembers what this process is called?

Plants have both! They make their own food with chloroplasts and break it down
with mitochondria.

Storage and Maintenance

●Vacuoles - long-term and/or large storage compartments

○Plant cells usually have one large Central Vacuole (stores water)

○Vacuoles can hold food, water, and even invading germs (trapped until destruction)

●Vesicles - short-term, small storage compartments

○Membrane bubbles that enclose materials as they travel around the cell: ER to Golgi, Golgi to
membrane or other organelles

●Lysosomes - break down and recycle large molecules

○Membrane bubble filled with digestive enzymes

○Merges with a vacuole or vesicle to expose things to the digestive enzymes, such as food
molecules, old organelles to-be-recycled, or trapped germs

Motility

These structures can help a cell move through its environment, or can help
to move the environment around the cell!

●Cilia - small projections that row like oars

○Prokaryotes have something similar called pili

●Flagella - long, whiplike projections that rotate like a propellor

○Prokaryotes and eukaryotes can have these

○Cells that have these usually only have one or two.

Watch this animation of interacting cell parts: How do you see organelles
working together?

Example: Chloroplasts

Chloroplasts capture light energy and use it to
convert air (CO2) into food (carbs). They do this
with a series of proteins embedded in disks.

Chloroplasts have many stacks of flat disks so
they can have many sets of these proteins and
convert many air molecules into food.

Structure (many disks) → Function (more food)

Structure → Function

Multiple Choice

There are some similarities between prokaryotic and eukaryotic cells. Which of the following structures is found in both prokaryotic and eukaryotic cells? 

• lysosome

• mitochondrion

• nucleus

• The electron microscope was used for the first time.

Multiple Choice

The diagram below represents a cell of a green plant. 

Solar energy is used to produce energy-rich compounds in which structure?

• A

• B

• C

• D

Multiple Choice

A specific type of cell is being studied by a scientist. She notices the cell contains a nucleus, lysosomes, a cell membrane and cell wall. What is the correct classification of this cell? 

• A prokaryotic animal cell

• A eukaryotic animal cell

• A eukaryotic plant cell

• A prokaryotic plant cell

Multiple Choice

How are cellular respiration and photosynthesis related, in terms of energy? 

•  The energy captured in photosynthesis is used to power cellular respiration.

• The energy transformed in cellular respiration is used to power photosynthesis.

• Photosynthesis and respiration perform the same task in terms of energy transformation.

• Energy is not involved in either photosynthesis or cellular respiration.

Multiple Choice

The diagram below shows the relationship between photosynthesis and cellular respiration and the organelles in which they occur.

Which statement describes how photosynthesis and cellular respiration are interrelated?

• Oxygen is produced during cellular respiration and stored during photosynthesis.

• Carbon dioxide and water released by cellular respiration are used in photosynthesis.

• Photosynthesis releases the energy that is stored during the process of cellular respiration

• Glucose is used during cellular respiration to produce food that is broken down during photosynthesis.

Multiple Choice

Scientists have found an organism beneath the surface in a remote area in the rain forest. When studied in their lab using high powered microscopes, the scientists identified the following structures: mitochondria, nucleus, and ribosomes. No cell wall was found. What kind of organism did the scientists find?

• Virus

• Bacteria

• Plant

• Animal