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Chapter 1 – Cells
Page 17
1. Living things are i) made up of cells ii) they reproduce, grow and repair iii)
they require energy iv) the respond to the environment v) they have a set life
span vi) they produce waste
2. No they are not because they do not show ALL of the characteristics listed in
#1.
3. a) responding to the environment b) growing
d) need food and energy e) reproduce
c) producing waste
Pg. 21
1.
Structure
Nucleus
Plant Cell
Y
Animal Cell
Y
Chromosomes
Y
Y
Cell Membrane
Y
Y
Cytoplasm
Y
Y
Vacuole
Y (large)
Y (small)
Cell Wall
Y
N
Function
Control center of
the cell Contains
DNA.
What make up the
DNA. They
contain all of the
info needed to
make an
organism.
Protects the cell
and controls what
goes in and out of
the cell.
“Selectively
permeable”
The gel like water
based material
inside of the cell.
All organelles are
found in here.
Used for storage
in a cell.
Protects plant
cells and gives
plants support
Chloroplasts
Y
N
Flagellum
N
Y
Cilia
N
Y
Centrioles
N
Y
Used to collect
sun’s energy in
plants. Contain
chlorophyll – a
green pigment in
plants.
Used by cells to
move around their
environment.
Used by cells to
move around their
environment.
Used by animal
cells in cell
division.
2. All genetic information for a cell is found in the nucleus.
3. If a cell looks like it has two nuclei, then it was probably just getting ready to
divide.
4. If a cell membrane was replaced by a plastic coat, the cell would slowly get
poisoned by its own waste. In addition, the cell would “starve” to death as there
would be no nutrients getting into the cell.
Pg. 27
1. organelles are tiny structures inside of a cell. They do everything from
digesting food, to creating energy, to determining when a cell divides.
3. If a cell’s mitochondria stop working then the cell would no longer be able to
create the energy needed for cellular processes.
4. Many Golgi apparatus are found in the stomach cells due to the fact that the
Golgi are protein “sorting centers”. They are responsible for taking basic forms of
protein found in the cells, processing the protein in the apparatus and then
releasing it as an enzyme.
Pg. 29
1. Diffusion is the passing of materials across a cell membrane without using any
energy. This is always done by movement from an area of high to low
concentration. Once the concentrations are in balance, diffusion DOES NOT
stop….it is just in balance or equilibrium.
2. Impermeable means that nothing can pass. Permeable means that
everything can pass and selectively permeable means that certain substances
can pass while others cannot.
3. All cells have selectively permeable membranes. The membranes are
designed to block some substances from crossing into or out of the cell.
Likewise, the are designed to let certain substances specifically into and out of
the cell.
4. The pores are different sizes due to the fact that the molecules or substances
being allowed into and out of the cell are also of different sizes. Each pore fits a
specific substance.
5. a) Imagine a mechanism that looks like a lock and a key.
b) The sugar in their blood would be too high as it is not being used by their cells
due to the pores not being opened.
c) Mitochondria are affected as they need sugar to create energy for the cell.
Pg. 33
1. Both osmosis and diffusion are the passage of materials across a selectively
permeable membrane without using any of the energy in the cell. Osmosis is the
special name given to the movement of water across the cell membrane.
2. The concentration of salts either inside or outside of a cell determines the
movement of water both in and out of a cell. The water will always move from an
area of high concentration to low until a balance is reached.
3. The cell wall is what prevents a plant cell from bursting as water flows into it
by osmosis.
4. Animal cells are more likely to burst due to the fact that they do not have a cell
wall to provide extra support.
5. Turgor pressure is the pressure that develops in plant cells due to water
moving in and out of it. If a plant cell is filled up with water then it has a high
turgor pressure. When a plant is in need of being watered, then it has a low
turgor pressure and a plant looks wilted.
6. Grocery stores spray their vegetables so that the plant cells can take up water
and increase the turgor pressure. Then the vegetables look fresh and not like
they have been sitting there for a week!
7. The red blood cells burst due to the fact that the concentration of salts inside if
the cell is larger than the dilute blood, due to all of the extra water that the person
had. To try to balance out the concentrations, water enters the blood cells
through osmosis and eventually bursts them. This is why man sport drinks have
electrolytes in them which are basically salts.
Pg. 37
1. Irrigation with salt water would be harmful to plants as it would draw all of the
water OUT of a plant cell, causing it to wilt and die.
2. These potatoes taste better due to the fact that minerals get drawn up with the
water into the plant and become part of the plant tissue. This makes for a better
tasting potato.
Pg. 41
1. Tissues make up organs and organs make up organ system. For instance a
group of heart cells make up tissue and together the make up your heart, which
is an organ. Then the heart along with another group of organs make up the
circulatory system.
2. molecule – cell – tissue – organ – organ system
5. Large multicellular organisms are more complex and cannot depend on just
basic cells to carry out all life processes. They need cells to specialize into
organs that do what a single cell would do in a unicellular organism. For
example, instead of having lysosomes to break down food, multicellular
organisms have digestive systems.
Pg. 45
1. Bacteria are more “primitive” due to the fact that they do not have any
organelles inside of them surrounded by membranes. In other words, they do
not have a nucleus, ribosomes, lysosomes, etc ….Having organelles form is a
marker of more modern cells.
2. They are called plant like due to the fact that they have chlorophyll inside of
them. Chlorophyll is the green pigment found in plants.
3. Euglena has chlorophyll and can make its own food just like a plant if it needs
to. It also has a large vacuole to get rid of water. However, it can “eat” like an
animal also so it kind of sits on the fence between plant and animal.
4. A paramecium uses the cilia (tiny hairs) on it to draw food into its “oral grove”.
An amoeba extends “pseudopods” also called “fake feet” around its food, creates
a membrane around the food and then digests it with lysosomes.
5. Many microorganisms cause disease if they are taken in with food or water.
Bacterial can cause infections that we need to take antibiotics to get rid of, when
travelling, amoeba’s and other protists in water often cause stomach upset and
the need to run to the bathroom.
6. All three, the amoeba, euglena and paramecium, live in fresh water. As a
result, water is continually trying to flow into the organism to maintain “balance”.
If there were not contractile vacuoles present to “squirt” out the extra water
flowing across the membrane, these organisms would burst.
7. Diagram will be different for each student. You just have to show the wall
slowly breaking down and then bacterial cell eventually bursting.
Pg. 47
1. The smaller a cell is the faster communication is inside of it. Messages travel
from the nucleus through the cytoplasm much faster than in a larger cell. This is
why cell size has a “cap” on it. Once the cell gets too large to communicate
quickly, the message to divide gets sent out and the cell splits.
2. The cell the with larger surface area – translation…largest cell membrane – is
the most efficient at getting rid of waste. This is due to the fact that there are
multiple sites on the membrane to get rid of waste as the cell pushes it out
through the membrane using vacuoles.
3. These cells are small due to the fact that they have to create such large
amounts of energy . The small size allows the cell to carry out the chemical
processes very quickly that produce the energy needed to run the rest of the cell.
The small size means that this energy can quickly be released outside of the cell
without losing too much of it.
4. a) A cell that is a cube would have a larger surface area. This is why cells are
circular. They want a large surface area, but they also do not want to waste too
much material making up the cell membrane.
b) A cell with a smooth membrane has the smallest surface area as the
projections on a cell would use up more membrane and increase the surface
area.
CELL ORGANELLES - NOTES
CELL THEORY
Cells are the basic unit of life.
The Cell Theory states that:
1) All organisms are made up of one or more cells and the products of
those cells.
2) All cells carry out life activities ( require energy, grow, have a limited
size).
3) New cells arise only from other living cells by the process of cell
division.
THE THREE MAIN COMPONENTS OF ANY PLANT OR ANIMAL
CELL ARE:
1. PLASMA MEMBRANE/ CELL MEMBRANE
Structure- a bilipid membraneous layer composed of proteins and
carbohydrates. It is fluid like.
Function - the cell membrane separates the cell from its external
environment, and is selectively permeable (controls what gets in and
out). It protects the cell and provides stability.
Proteins are found embedded within the plasma membrane, with some
extending all the way through in order to transport materials.
Carbohydrates are attached to proteins and lipids on the outer lipid
layer.
2. CYTOPLASM
Structure - The jelly-like substance composed of mainly water and found
between the cell membrane and nucleus. The cytoplasm makes up
most of the "body" of a cell and is constantly streaming.
Function - Organelles are found here and substances like salts may be
dissolved in the cytoplasm.
3. NUCLEUS
Structure - The largest organelle in the cell. It is dark and round, and is
surrounded by a double membrane called the nuclear
envelope/membrane. In spots the nuclear envelope fuses to form
pores which are selectively permeable. The nucleus contains genetic
information (DNA) on special strands called chromosomes.
Function - The nucleus is the "control center" of the cell, for cell
metabolism and reproduction.
THE FOLLOWING ORGANELLES ARE FOUND IN BOTH PLANT AND
ANIMAL CELLS.
1. "ER" OR ENDOPLASMIC RETICULUM
The Endoplasmic Reticulum is a network of membranous canals filled
with fluid. They carry materials throughout the cell. The ER is the
"transport system" of the cell.
There are two types of ER: rough ER and smooth ER.
Rough Endoplasmic Reticulum is lined with ribosomes and is rough in
appearance and smooth endoplasmic reticulum contains no ribosomes
and is smooth in appearance.
2. RIBOSOMES
Ribosomes are small particles which are found individually in the
cytoplasm and also line the membranes of the rough endoplasmic
reticulum. Ribosomes produce protein. They could be thought of as
"factories" in the cell.
3. GOLGI BODY / APPARATUS
Golgi bodies are stacks of flattened membranous stacks (they look like
pancakes!). The Golgi Body temporarily stores protein which can then
leave the cell via vesiciles pinching off from the Golgi.
4. LYSOSOMES
Lysosomes are small sac-like structures surrounded by a single
membrane and containing strong digestive enzymes which when
released can break down worn out organelles or food. The lysosome is
also known as a suicide sac.
5. MITOCHONDRIA
The mitochondria are round "tube-like" organelles that are surrounded
by a double membrane, with the inner membrane being highly folded.
the mitochondria are often referred to as the "powerhouse" of the cell.
the mitochondria releases food energy from food molecules to be used
by the cell. This process is called respiration. Some cells( muscle cells)
require more energy than other cells and so would have many more
mitochondria.
6. VACUOLES
Vacuoles are fluid filled organelles enclosed by a membrane. They can
store materials such as food, water, sugar, minerals and waste
products.
ANIMAL CELLS ORGANELLES NOT FOUND IN PLANT CELLS:
CILIA AND FLAGELLA
Both cilia and flagella are hair-like organelles which extend from the
surface of many animal cells. the structure is identical in both, except
that flagella are longer and whiplike and cilia are shorter. There are
usually only a few flagella on a cell, while cilia may cover the entire
surface of a cell. The function of cilia and flagella ionclude locomotion
for one-celled organisms and to move substances over cell surfaces in
multi-celled organisms.
ORGANELLES AND OTHER FEATURES FOUND ONLY IN PLANT
CELLS:
1. CELL WALL
The cell wall is a rigid organelle composed of cellulose and lying just
outside the cell membrane. The cell wall gives the plant cell it's box-like
shape. it also protects the cell. The cell wall contains pores which allow
materials to pass to and from the cell membrane.
2. PLASTIDS
Plastids are double membrane bound organelles. It is in plastids that
plants make and store food. Plastids are found in the cytoplasm and
there are two main types:
Leucoplasts - colorless organelles which store starch or other plant
nutrients. ( example - starch stored in a potato)
Chromoplasts - contain different colored pigments. The most important
type of chromoplast is the chloroplast, which contains the green
pigment chlorophyll. This is important in the process of photosynthesis.
3. CENTRAL VACUOLE
The central vacuole is a large fluid-filled vacuole found in plants.