science 14 unit c: from life to lifestyle chapter 8 · 6 8.2 – cell theory pp. 164-165...
TRANSCRIPT
Science 14 Unit C: From Life to Lifestyle
Chapter 8
Structure and Function of Plant and Animal Cells
WORKBOOK
Name: _____________________________
1
8.1 – A Closer Look pp. 158-164
Read pp. 158-159
Before the invention of microscope technology, scientific studies were rudimentary. Much of the work was based on trial and error.
The development of microscopes allowed scientists to see organisms that were previously invisible to the naked eye
o Early microscopes were pieces of curved glass (convex lens) that could bend light and focus it on one spot, much like a magnifying glass
o Originally able to view objects 30 times their actual size (Figure 8.1 – p. 158)
o saw “beasties” (bacteria) when magnified 200 times (Figure 8.3 – p. 158)
Modern compound microscopes have a stronger magnification than earlier devices
and use light to illuminate objects being viewed. (Figure 8.5 – p. 160)
o magnifies objects 400 to 1000 times their actual size
There are two types of electron microscopes that magnify more than 600 000 times by relying on a beam of electrons rather than light
o Object or specimen must be dead and covered in chemicals to observe using a transmission electron microscope (TEM)
o living organisms are examined with a scanning electron microscope (SEM) where electrons pass over the specimen to produce a 3D image
o see microscopic images on Figure 8.4 – p. 159
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Contrast and Staining o Scientists learned that staining cells improved the contrast between internal
cell parts. o Unstained cells are virtually colorless with little contrast between parts. o Manipulating the light source (diaphragm) allows you to alter the contrast of
different structures in a cell.
Properly Handling a Microscope o Be Careful!! o Carry it with 2 HANDS: one on the arm and the other on the base o Clean only with a soft cloth/tissue o Make sure it’s on a flat surface o Don’t bump it
Using a Microscope o Start on the lowest magnification and use the course adjustment knob to focus. o Never use the coarse adjustment knob on high magnification
you’ll break the slide!! o Increase the magnification and only use the fine adjustment to focus on medium
and high power.
What scientists learned from their observations, and the questions they continued to ask about cells, have led to many technological advances that depend on knowledge from microscopy.
The development of the microscope was a great boost for science. It allowed scientists who studied cells (referred to as cytologists) to observe details in plant and animal cells. These observations allowed them to develop greater understanding of the living world. Such advances include:
o blood work to identify disease mechanisms o urine analyses to detect various substances (Example: sugar) that are indicators
of disease (Example: diabetes) o the development of hybrid plants that have defenses against certain plant
diseases and parasites o genetic developments, such as cloning
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Discuss Figure 8.5 – p. 160
Use the following diagram to label the parts of a compound microscope.
hand lens curved glass for magnifying
dissecting scopes microscope consisting of two eye pieces, a low power lens, and a medium power lens
4
Calculating Magnification Practice BLM 8-3
p. 163
Eyepiece magnification multiplied by magnification of the objective lens indicates the
total magnification of an object under a microscope.
Total Magnification = Ocular Lens x Objective Lens
Example:
Magnification of eyepiece: 5X
Magnification of objective lens: 4X
Total magnification: 5 x 4 = 20X
Complete the following chart for practice. Use the information to determine
the magnification of the specimens you are observing.
Eyepiece Objective Lens Show Your
Calculations Total
Magnification
(a) 5X 4X 5 x 4 = 20 20X
(b) 5X 10X
(c) 5X 40X
(d) 10X 4X
(e) 10X 10X
(f) 10X 40X
(g) 20X 4X
(h) 20X 10X
(i) 20X 40X
5
Microscope Word Challenge BLM 8-8
1.
2.
3.
4.
5.
Clues
1. equipment used to examine specimens at 100X or more
2. often used to study the internal organs of lab specimens
3. improved by two Canadians named Prebus and Hillier
4. a magnifying device used in most schools
5. earliest form of the microscope
The letters in the boxes spell the name of a piece of magnifying equipment. What is it?
Piece of magnifying equipment: ___ ___ ___ ___ ___
Discuss CYU – p. 164 #1-3
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8.2 – Cell Theory pp. 164-165
Organization of Life
(cell hierarchy)
Atom – smallest unit of matter for both living and non living
Molecules – atoms grouped together form molecules
Organelle – part of a cell that carries out a specific function or role
Cell – smallest unit of life; the building block of all living organisms
from the Latin word cella, meaning small room
Tissue –cells combined to perform a specific task or function
Organ – two or more tissues combined work together to do a specialized role
System – any group of organs working together to perform a specialized role
Organism – any living thing that carries out all 7 activities necessary to survive
Cell Theory – accepted explanation supported by repeated experimental results
1. Cells are responsible for function and structure in all organisms. 2. All living things are made up of cells. 3. All cells reproduce from other living things.
i.e. cells are the smallest unit of life and come from other cells
Bacteria and amoebas are made of one cell
Humans are multi-cellular organisms
Discuss CYU – p. 165 #1-4
7
Word Scramble BLM 8-12
Unscramble the letters to discover these key terms from your study of cell theory.
Use the definitions as clues to help you along.
Definition Scrambled Word Answer
a) when life processes are
present, an organism is
called this
V I G L I N
b) tissues combined to perform
a specialized role
G R O A N
c) activities necessary in
order to survive
F I L E S P E C S O R E S
d) part of a cell that carries
out a particular function
or role
L E G L A N O R E
e) cells combined to perform a
specific task or function
S U T I E S
f) the smallest unit of life
L C E L
g) life processes are not present
in this kind of object
G I N – V I N L O N
______________________
h) an explanation supported
by repeated experimental
results
H E R T O Y
i) made up of organs working
together
M E S S Y T
j) may consist of only one cell,
or many cells
S N A R G I O M
8
8.3 – Plant & Animal Cell Structures pp. 166-173
A) Cell Membrane
separates inner cell from surrounding environment
semi-permeable (allows some materials in and keeps harmful materials out)
B) Cytoplasm
jellylike fluid
holds organelles in place
C) Nucleus
“brain” or control centre
directs overall cell activity
contains DNA
D) Vacuole
stores food, water, and waste materials
looks like an empty sac
E) Endoplasmic Reticulum (ER)
transports food, water, and waste materials
F) Mitochondrion
“powerhouse” releases energy in the cell
uses oxygen and digested food for energy
G) Golgi Apparatus
holds waste products until cell removes it
packages and transports proteins
specialized part of the ER
H) Cell Wall (only in plant cells)
protection and strength for cell.
non-living.
I.) Chloroplast (only in plant cells)
contains chlorophyll (green color)
helps collect sunlight for photosynthesis.
Discuss CYU – p. 173 #1-4
Animal
Plant
⇒Organelles
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Parts of the Cell BLM 8-13
Complete the chart by placing the missing information in the correct box. Identify
whether you were using the plant or animal cell, and which letter identifies the part. Use
the list of cell parts to label the diagrams below.
Cell Part Diagram Letter Function
cytoplasm
outer covering of a plant cell
outer covering of an animal cell
chloroplast
mitochondrion
transportation system inside the cell
Golgi Apparatus
control centre of the cell
vacuole
Animal Plant
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Organelle Crossword BLM 8-17
Across 1. semi-permeable; separates contents of cell from surrounding environment
4. collects sunlight; found only in plants
5. stores food, water, and waste
7. the “powerhouse”; releases energy in cell
Down 1. jelly-like substance
2. transports materials; known by initials
3. non-living; provides protection and strength
6. the control centre
Read pp. 174-175
Discuss CYU – p. 175 #1-4
11
Word Search BLM 8-18
Complete the word search puzzle by finding the 23 key terms listed below.
Circle the words as you find them.
Hint: The words may be hidden in any direction, but they will always be in a straight line.
microscope
organelle
theory
vacuole
compound microscope
living
organism
ER
electron microscope
non-living
life processes
cell membrane
hand lens
tissue
nucleus
cell wall
dissecting scope
organ
cytoplasm
chloroplast
cell
system
mitochondrion
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Chapter 8 Review Questions
1. Who played a leading role in the development of the microscope? (8.1)
2. Sketch a microscope. Label its parts. (8.1)
3. State the cell theory. (8.2)
4. List the life processes of all living things. (8.2)
5. Use a chart to show the difference between living and non-living things. (8.2)
6. Identify the parts of an animal cell. (8.3)
7. Identify the parts of a plant cell that are not part of an animal cell. (8.3)
8. What two parts of the cell handle transportation of materials? (8.3)
9. How are the functions of a cell similar to the functions of a city? (8.4)