Science 8 Unit – Cells, Tissues, Organs and Systems
In this unit, we will review the structure and functions of all cell components. The next step will be to
learn how molecules move in and out of the cells, as well as how energy is used within the cells. To
discuss how energy is used, we also have to discuss and learn about where the energy comes from and
how it is produced.
Lesson 1: The History of Cells
Have you ever heard of the cell theory??? A quick timeline:
1590 – Believed to be the first microscope developed
1665 – Robert Hooke views the first cells through his microscope studying dead cork cells – only seeing
the hard outer walls of the cells. He did not link that the cells were the building block of all living things.
1670’s – Antoni van Leeuwenhoek not only improved microscopes (a glass shaper, lens cutter by trade),
but then was the first to discover red blood cells and has become known as the Father of Microbiology.
1839 - German botanist Matthias Schleiden and German zoologist Theodor Schwann, working together,
recognize the fundamental similarities between plant and animal cells and propose that all living things
are made up of cells.
1858 – Rudolf Virchow suggested that cells come from preexisting cells.
These discoveries led to the creation of the Cell Theory which was stated as:
1. All living things are made of cells
2. Cells come from preexisting cells
3. Cells are the basic building units of life
The Modern Interpretation of the Cell Theory has as many as nine points, but the basis of the theory is
found in these three early points as determined by the early scientists. Additional points include
information on cells containing DNA, and that energy flow and metabolism takes place in the cells. The
advances in cytology (the study of cells) furthered with the introduction of electron microscopes, and
more recently, scanning probe microscopy. Scientists continue to push microscopes further and we will
continue to learn more about cells in the future.
Lesson 2 – Cells and their Organelles
There are numerous organelles in cells, each of which has a specific purpose. The following page
contains two pictures, one of a plant cell and one of an animal cell. Please go through and write down
each organelle along with the function of that organelle. In some cases, an organelle has the same
purpose in both cells so you do not have to repeat the organelle or its function. Please also take special
note of the organelles that are specific to a cell type, either animal or plant. The following link is an
excellent place to get the definitions: http://www.cellsalive.com/cells/cell_model.htm
Cell Project
Purpose: The purpose of this project is to make a 3D model of a cell in order to better understand
the parts and workings of a cell.
Using household items make a three-dimensional model of a plant or animal cell that meets the
criteria listed below. (Sample items: cereal, balloons, gummi worms, mints, fruit slices, dried fruit,
matches, gum balls, peanuts, rope licorice, jelly beans, sesame seeds, other candies, toothpicks.
Craft packages also may work: clay, beads, pipecleaners..etc)
Choose what type of cell you will build, a typical plant or animal cell. Include this label somewhere on
your model.
Create a KEY or label in some way each part on your model and its function.
Cell Project Rubric
Category
Scoring Criteria
Excellent
(3 pts)
Satisfactory
(2 pts)
Model cell is creative and shows effort
Craftsmanship
The model is 3 dimensional
Model stays together, is not too messy or
cumbersome to move around
Type of cell and student name are found on
both the key and the model
Key, legend, or labeling easy to use to
identify the parts on your model
Cell Parts
Accurate description of the function of each
cell part is provided
Appropriate material is used (item looks like
the cell part)
Shape corresponds to the type of cell: plant
or animal
Written word
Grammar, spelling
Score
Total Points (out of 30)
Lesson 3 – Observe Cells
Please complete the Lab Activities to view Cells. These will be handed to you and the number will
depend on your experience using microscopes.
Intro to Microscopes: http://www.biologycorner.com/worksheets/microscope_use.html
Please complete Microscope handout.
Needs Work
(1 pt)
Lesson 4 – Cell Functions
All cells need to take in food, remove wastes, reproduce and survive to be successful. As well, we need
cells to be successful for us to grow and maintain our own health over our lives. When you grow, is it
because your cells get bigger, or is it because more you end up with more cells?
In Grade 8, we only need to concern ourselves with how food and wastes are passed in and out of cells
to help cells maintain their health. We know that cells have a outer membrane, or even an outer wall,
that all must pass through. For our purposes, we are only going to concern ourselves with a type of
transport that is called passive transport, meaning that energy is not required for movement.
Diffusion is the movement of molecules from an area of high concentration to an area of low
concentration. It can occur with water, oxygen, food, or any type of molecule in nature. Can you think
of an example of diffusion that could occur in this room? Osmosis is a special type of diffusion that only
considers the movement of water. So, osmosis is the diffusion of water.
In both cases, diffusion and osmosis, the movement of particles is from an area of higher concentration
to an area of lower concentration. Where the concentration is high, the particles will bump into each
other and spread themselves out over time, meaning that they have moved to an area of lower
concentration. The boundary between the two areas of concentration is the cell membrane.
Please complete the OsmosisDiffusion assignment.
Lesson 5 – Single Celled Organisms vs. Multi Celled Organsisms
Organisms that are single celled are made up of one cell and must depend on that one cell to perform all
required actions to survive. So, the cell must be able to move and collect its own food without the
assistance of others, or the chance of survival will go down. To begin this lesson, we will try to look find
some single celled organisms in the water sample that we have in class. Please look at the following link
to see some of the organisms that you might find:
http://www.microscopy-uk.org.uk/index.html?http://www.microscopyuk.org.uk/ponddip/paramecium.html
Biodiversity of Ponds
Objective: Students will observe and record data on 2-3 ponds, with
emphasis on the types and numbers of organisms in each. Students will
prepare a report that discusses the biodiversity of each pond.
Materials:
Pond Water from 2 different places (prepared in advance)
Microscopes (light and stereoscope)
Slides and Cover slips
Pond Identification Sheet or website access to ID organisms
Instructions:
1. Place a few drops of the water into a petri dish and observe under the stereoscope. Record and
sketch any living thing you see.
2. Use a pipette to withdraw a sample from the water and prepare a wet mount on a slide. Observe this
slide using the light microscope and record your observations.
3. Observe the drop of pond water under Low Power to scan and find the organisms. High Power is
useful once you have found something to determine details not clear in Low Power. If you use High
Power, make sure to add a coverslip.
4. If the organisms are moving too fast and therefore difficult to observe: place 2or 3 strands of cotton
on the slide
YOU MUST BE PATIENT FINDING THEM
*Prepare a slide of each of the pond water (you may even want to prepare multiple slides)
*Make sure you keep track of which pond water sample you are observing
Construct Data Table and Observations
-- illustrations of organisms and/or descriptions
-- identify of organisms (don’t worry if you can’t ID everything, but get as many as you can and group the
rest as “unknowns”
-- record numbers of each type of organism found
--any other information, such as what the organism appears to eat, or how it moves
-- evidence of responses to stimuli, does it avoid light or obstacles?
-- make sure your indicate which pond sample your observations came from
Prepare Project Report
1. Introduction :
Include what you are studying and how you are studying it. Written in paragraph form, overview of the
lab
2. Data: Include your observations (data table)
--please rewrite if they are messy from the lab, most data tables start off messy as you take down notes
as you go, but a completed lab report should have a final “clean” version
-- This part does not actually have to be a table, you can simply draw organisms and list observations for
each underneath it
-- Choose at least 4 organisms that you have good counts for and create a graph that compares the
populations of the organisms in each of the ponds. (A bar graph for each pond will probably work best)
3. Report conclusions.
-- Compare data with other classmates and make a list of generalizations about what type of organisms
are found in pond water
-- List organisms that are assumed to be producers and consumers and construct a food web of the pond
ecosystem
-- Answer the question: Which pond has the greatest biodiversity?
-- Use your data to defend the answer to this question
Single celled can move in a couple of ways. The first way is by simple contraction, stretching or simply
moving. The second way is by having some sort of propulsion tools like cilia to move on or a flagella to
whip like a tail. Many of these single-celled organisms live in water to make it easier for them to be
mobile and to obtain food. Food can enter the body through diffusion across the membrane, or by
surrounding the food and engulfing it like an ameba does. Please note that we are not talking about
bacteria or viruses right now, they are something different that you will learn about in future years.
Multi-celled organisms are different because they are made of numerous cells that are specialized for
the job that they perform in the body. So, there are different types of cells, that all still have the same
needs for food, water and oxygen, but all with different jobs. These cells need to depend on each other
to survive in a successful manner. Can you think of any reasons why it would be advantageous to be
multicellular? Can you think of any different cells found in the human body?
Lesson 6 – Cell Specialization into Tissues
Because the cells specialize in multicellular organisms, we get different kinds of cells each with a specific
purpose. What kinds of cells do you think are in the human body?
The following info has been taken and adapted from:
http://www.edquest.ca/component/content/article/181/
Different cells have different structures and functions:
Type of Cell
Shape (Structure)
Muscle
Elongated and tapered on
either end
Skin
Flat and thin, brick-shaped or
honeycomb
Nerve
Long branched fibres running
from the main part of the cell
Blood
Thin, disc-like
Bone
Thick, mineral matrix
Function
Move parts of the body
Fit closely together to form a continuous
protective layer
To carry nerve signals from one part of the
body to another
Carry oxygen in the bloodstream
(giving them a large surface area to collect
oxygen)
To provide support
http://faculty.sdmiramar.edu/kpetti/bio160/TissueHistology/CardiacMuscle.jpg
http://camillasenior1.homestead.com/files/human_skin_cells.jpg
http://www.biology-online.org/images/neurone.gif
http://t0.gstatic.com/images?q=tbn:ANd9GcQAaL6NxWTt7OkVSmbiwr59_U_A8gfcNhvC4vOe7OXS7ogR
iD-N
http://www.azom.com/work/LZa2TZ1lqZ22O09M4pCh_files/image010.jpg
There are many other cell types in the body, we have only looked at 5. Please understand that these
cells work with others that are similar to create tissues. These tissues work together to form organs,
which work with other organs to form an organ system. Organ systems work with each other to form an
organism. So, one of those single muscle cells in the first picture works with other muscle cells to form
muscle tissue. These tissues work together to form an organ, like a heart, which works with other
organs to form a system. Putting all the systems together leaves with an organism like us!
There are four major types of tissue found within the human body. All are important and play important
roles in various organs systems of the body.
1. Muscle Tissue – Used for strength and support in all areas of the body.
2. Nerve Tissue – Carries messages around the body, used to create organs like the brain
3. Epithelial Tissue – The outer covering of your body, commonly known as skin. It is your first
defense against all intruders.
4. Connective Tissue - Can be used for structure (like in your ears or nose) or to connect your
muscles to bones or bones to bones. Think of your knee.
Lesson 7 – Organ Systems
To study organ systems we are only going to look at 5 specific systems within our body. These systems
are the respiratory, circulatory, digestive, excretory and nervous. In our study, we are going to create
groups and each group will be responsible to learn about, and then teach the rest of the group about
their system by answering the questions given. Each group will have to make a quick presentation, will
need some sort of graphic (can be on the computer or a poster) and a short write up that can be shared
with the rest of the class. The questions to answer are:
1.
2.
3.
4.
5.
What is your organ system?
What is the main function of the system?
What organs, tissues and cell types are involved in the systems function?
How do they all function together?
A graphic of the system within the human body
Please look at the following rubric that will be used for your assessment.
Science 8 : Organ Systems
Teacher Name: Mr. Schlosser
Student Name:
________________________________________
4
3
2
1
Objectives
All Objectives are
met and exceeded.
All Objectives are
met.
One Objective was
not completely met.
More than one Objective
was not completely met.
Content
Covers topic indepth with details
and examples.
Subject knowledge
is excellent.
Includes essential
knowledge about the
topic. Subject
knowledge appears
to be good.
Includes essential
information about
the topic but there
are 1-2 factual
errors.
Content is minimal OR there
are several factual errors.
Presentation
Well-rehearsed with
smooth delivery that
holds audience
attention.
Rehearsed with fairly
smooth delivery that
holds audience
attention most of the
time.
Delivery not smooth, Delivery not smooth and
but able to maintain audience attention often
interest of the
lost.
audience most of the
time.
CATEGORY
Organization
Content is well
organized using
headings or bulleted
lists to group related
material.
Uses headings or
bulleted lists to
organize, but the
overall organization
of topics appears
flawed.
Content is logically
organized for the
most part.
There was no clear or
logical organizational
structure, just lots of facts.
Mechanics
No misspellings or
grammatical errors.
Three or fewer
misspellings and/or
mechanical errors.
Four misspellings
and/or grammatical
errors.
More than 4 errors in
spelling or grammar.
Originality
Product shows a
large amount of
original thought.
Ideas are creative
and inventive.
Product shows some
original thought.
Work shows new
ideas and insights.
Uses other people's
ideas (giving them
credit), but there is
little evidence of
original thinking.
Uses other people's ideas,
but does not give them
credit.
Lesson 8 - How do all the systems work together?
Consider for a moment all that must be going on in your body for you to accomplish any task during the
day. All of your systems must not just perform their own task, but must do so in unison with all other
systems so that your body works effectively. How do your body systems work together to accomplish
eating? If I gave each of you a piece of chocolate right now, what would all systems be doing? How
about to run?
Do you have an impact on how all the systems work based on your choices? For instance, do you take
vitamins? Do you drink energy drinks? Do you exercise? Drugs, alcohol or smoking?
http://abcnews.go.com/Health/sports-drinks-choice-kids/story?id=13704953
What if an organ in an organ system begins to fail? Will the system still function? What if a kidney fails?
What do you believe about people having a transplant? How about an artificial joint like a hip or knee
replacement?
Lesson 9 – Heart Rate Experiment
To begin we need to be able to determine our heart rate at rest. To do this, you must find your pulse
(either on your inner wrist or on the side of your neck). Once you find your pulse, please count how
many times your heart beats in 10 seconds and then multiply by 6. This will tell you how many beats per
minute your heart is taking. Will this stay the same if you are active? Exercising?
Our job is to create an experiment in which we will exercise at different rates and check what our heart
rates are, and if they change. We will then retry the experiment and see if you get the same results.
What kinds of variables will we need to control?