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Unit 1
The Power of
Reproduction
Chapter 1 – The Cell Cycle and
Asexual Reproduction
Animal Cell
Plant Cell
1.1 The Cell (Pages 4 – 16)
1.
2.
Scientists have long been fascinated with
life. After thousands of years of studying
it we still haven’t figured out how it
works. Some history:
Assignment:
a)
b)
c)
The Cell Question Sheet
Label Cell Diagrams (1-6 & 1-7)
Cell Structures Chart
Chapter 1.1 – The Cell Question Sheet
1.
Record the date and contribution to
cell theory for the following scientists:
(22)
a)
b)
c)
Aristotle (384-322 BC) – animal and plant
kingdom (animals higher, spontaneous
generation)
Zacharias Janssen (1590) – first
compound microscope
Robert Hooke (1665) – microscope –
referred to cells as “rooms”
Chapter 1.1 – The Cell Question Sheet
1.
Record the date and contribution to
cell theory for the following scientists:
(22)
d)
e)
John Ray (1667) – “species” organism
that reproduce with their own kind
Francesco Redi (1668) – disproved
spontaneous generation (flies and
maggots)
The Redi experiment
Replica of a Leeuwenhoek microscope
The following photomicrographs were taken
through a Leeuwenhoek microscope.
f)
g)
h)
i)
Anton van Leeuwenhoek (1632 – 1723) microscope
Robert Brown - nucleus is part of the cell
Schleiden/Schwann (1838/1839) – all
animals are made of cells
Alexander Carl Heinrich Braun (1845) –
the cell is the basic unit of life
•
•
•
Charles Darwin and Alfred Wallace –
species form variations
Rudolph Virchow (1821 – 1902) – cells
come from cells
Louis Pasteur (1860) – disproved
spontaneous generation at the
microscopic level (life comes from life)
Pasteur’s
swan neck
flask
experiment
2.
Like all sciences, biology has its own
set of tools, techniques, and
investigative methods. What tools
helped scientists develop the cell
theory? (3)
3.
What methods helped scientists
develop the cell theory? (2)
4.
The internet was originally designed to
allow scientists all over the world to
communicate quickly and easily with
each other. What invention had a
similar effect on scientific
communication in earlier centuries?
(1)
5.
What can you conclude about the
relationships between scientific
discovery, tool inventions, and new
methods? (1)
Cell theory states that: (4)
6.
•
•
•
•
all living organisms are made up of one
or more cells
Cells are the basic unit of life
Cells come from cells
Activity of entire organism depends on
total activity of its independent cells
Animal Cell
Plant Cell
Assignment

BLM 1-5, 1-8, 1-9, 1-10, Investigation 1B
Cell Structures Chart
Cell Size and Scale
•
Nucleus
•
Nuclear Membrane
•
DNA Stands for:
4.
Chromatin
5.
Nucleolus
6.
Ribosomes
7.
Cell Membrane
8.
Cytoplasm
9.
Endoplasmic Reticulum
10.
Mitochondria
11.
Golgi Bodies
12.
Vacuoles
13.
Lysosomes
13.
Cell Wall (Plants only)
13.
Chloroplasts (Plants only)
1.2 Understanding the Cell Cycle


Cells grow and then divide to make new cells.
New cells are used to replace dead ones OR for
growth of the organism.



YOU started out as 1 cell!
Before a cell can divide into 2 cells it must produce
almost twice as many organelles (replication).
A cell’s stages of life are called phases.
1. Interphase
•
Most of cell’s life
•
DNA in thin strands called Chromatin
replicate.
•
Chromatin coils up to form double
stranded Chromosomes.
•
A Centromere connects the original
chromatin with its identical replicate.
•
The cell has a complete extra copy of
DNA.
A Chromosome
2. Prophase
•
Duplicate DNA is easily seen under
microscope.
•
Nucleolus and Nuclear Membrane
disappear.
•
Centrioles move to opposite sides of
the cell.
•
Spindle fibres (like a scaffold) grow out
of each centriole and attach to
centromere.
3. Metaphase
•
Spindle fibres pull on centromeres
•
Chromosomes move to line up in the
middle.
4. Anaphase
•
Spindle fibres shorten and pull
centromere apart.
•
One copy of DNA goes to each side.
5.
•
•
•
•
Telophase
A complete set of chromosomes
arrives at each centriole.
Spindle fibres disappear.
Nuclei and nucleoli form.
Chromosomes uncoil into thin
chromatin.
5.
•
•
•
Telophase
Cell membrane pinches together in the
middle
Two cells form (animal cells).
A cell plate grows across the middle of
the cell forming a new cell wall
between the two cells. (plants)
Parent Cell
Daughter Cells
Phase 1:
Prophase
Phase 2:
Metaphas
e
Phase 3:
Anaphase
Phase 4:
Telophase
Mitosis Animation Clip
http://www.pbs.org/wgbh/nova/miracle/divide.html#
http://www.johnkyrk.com/mitosis.html
http://www.dnatube.com/video/1148/Mitosis
http://www.dnatube.com/video/2380/InterpretiveMitosis
Assignment
 BLM’s 1-14, 1-15, 1-16 & 1-17
 Mitosis Crossword & Mitosis Chart
 Mitosis Quiz
1.3 The Cell Cycle in YOUR Body
Some common chromosome counts:
Dogs
Tomatoes
Humans
Black Molly (fish)
78
24
46
46
1.
Normal Cell Replacement
a)
Cells die of old age and need to be
replaced. See pg 25 for cell life spans.

b)
c)
about 3 000 000 cells die in your body every
minute.
Cells die due to damage or when they
don’t get enough food or oxygen.
Regeneration - Healing of damaged
tissue or the replacement of body parts is
called regeneration. (NOTE: see note
under Figure 1.17 – pg 26)
2.
Growth
a)
b)
As organisms grow larger, their cells stay
the same size
They just get more of them.
Aging
1.
2.
Aging is connected to the slowing of the
cell cycle.
The cells do not divide as often or as
quickly.
Cancer is caused when the DNA of a
cell becomes damaged by
1.
a)
b)
c)
d)
e)
f)
Tobacco
Asbestos
Certain chemicals
some viruses
Radioactivity
UV radiation
2.
3.
4.
5.
6.
The damage injures but does not kill the
cell.
The cell no longer functions properly and
the DNA no longer has correct information
about when and how quickly to divide.
The result: Useless cells divide often and
quickly forming a lump.
If the cancer cells can easily be transported
the cancer can spread all over.
The lump crowds out good cells and use up
a lot of food and oxygen.
Worksheet & Cancer Research
1.
Explain a process in the human body in which
there is evidence of the cell cycle at work. (1)

Growth and development
2.


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Give two reasons why cells die. (2)
Damaged
Programmed to live a certain amount of
time – no longer needed
Lack of food or oxygen
Failed mitosis
3.

How do scientists currently explain the aging
process? (2)
The cell cycle is slowing down
4.

Describe what happens when cells divide
uncontrollably. (2)
Cancer – these cells are like weeds in a
garden, choking out the healthy
plants/cells.
5.

Using your knowledge about cancer and
cell division, explain how you think
sunscreen can help reduce the risk of skin
cancer. (2)
It blocks the UV rays and prevents them
from damaging the genetic material
6.

Some cells live for years, while
others live for only a few days. Why
do you think some cells might be
replaced faster than others? (2)
Some cells are damaged more quickly
by their environments (stomach acid).
7.
The muscle cells of the heart were once thought to
stop dividing when a person reached the age of nine.
Thus, heart attacks, which kill heart cells, were
believed to cause permanent damage to the heart
muscle. New research has discovered that mitosis
does occur in the heart later in life. What do you think
this new discovery means for people who have heart
attacks? (2)

Your body is capable of regenerating
heart cells – this gives heart attack
survivors hope for recovery
What happens to our cells to bring
about cancer? (2)

Cancer is a disease that starts in our cells.
Our bodies are made up of millions of
cells, grouped together to form organs or
tissues such as the lungs, the liver,
muscles and bones. Genes inside each
cell order it to grow, work, reproduce and
die.
What is a tumor/lump made up of?
(2)

Normally these orders are clear, our cells
obey and we remain healthy. Sometimes a
cell’s instructions get mixed up and
it behaves abnormally. After a while
groups of abnormal cells form lumps or
tumours.
What is the difference between a
benign and malignant tumour? (2)

Tumours can be either benign (noncancerous) or malignant (cancerous).
Benign tumour cells stay in one place in
the body and are not usually lifethreatening.

Malignant tumour cells are able to
invade the tissues around them and
spread to other parts of the body.

Cancerous cells that spread to other
parts of the body are called metastases.

The first sign that a malignant tumour
has spread is often swelling of nearby
lymph nodes, but cancer can
metastasize to almost any part of the
body.

Malignant tumours can be dangerous.

It is important to find them and treat
them quickly, before they spread.
How are cancers named? (2)

Cancers are named after the part of the
body where they start.

For example, cancer that starts in the colon
but spreads to the liver is called colon cancer
with liver metastases.
1.4 Asexual Reproduction
- Bacteria, Protists, Fungi,
and Some Animals
Asexual Reproduction – the formation of a
new individual that has identical genetic
information to its parent.
Reproduction
Asexual
Sexual
Binary Fission
Budding
Conjugation
Spore Formation
Fragmentation
Hermaphroditic
Vegetative
Reproduction
Separate Sexes
Bacteria – see p 30
1.
2.
3.
Have no nuclear membrane
(prokaryotic)
Have only one chromosome
Reproduction asexually by the process
of binary fission.
4.
steps:
a)
b)
c)
d)
e)
cell wall ruptures
single chromosome gets copied
cell grows longer and a chromosome
moves to each end.
cell membrane pinches off.
cell wall grows to surround both cells.
Protists
1.
2.
3.
Ex) amoeba, euglena,
vorticella
unicellular organisms
with a true nucleus
(eukaryotic).
mitosis takes place
creating two identical
cells.
Fungi
1.
2.
Ex) Moulds, yeast, and mushrooms
filaments called hyphae grow over the
surface of food.
3.
have 3 methods of asexual
reproduction
a)
fragmentation – a small piece of hyphae
breaks away and grows into a new
individual. It is identical to its parent.
b)
•
budding – a copy of
the nucleus is made.
The nuclei press
against the cell
membrane, forming a
bud which grows and
breaks off. (yeast)
http://coralreefmultimed
ia.org/reef/shorts.pop?t
opic=Reproduction#
c)
spores – special cells called spores are
stored in a case called a sporangium.
The spores are released when ready and
go through mitotic cell division if they land
in suitable conditions.
Animals
Invertebrates (without backbone) make
up 97% of animal species
2.
Ex) Planaria (Flatworms) – divide in two
and replace the parts that are missing.
3.
Ex) Sponges and hydras – reproduce by
budding. see pg 35.
READ p 29-34 and do questions 1 – 6.
1.
V.
1.
2.
Asexual Reproduction in
Plants
Plants have an amazing ability to repair
themselves using mitosis. They are
often even able to regrow from a stump.
Recall: asexual means DNA is exactly
the same as its parent.
Meristem
1.
2.
3.
4.
animals stop growing at an adult size
Plants grow until they die.
Meristem – unspecialized cells in the stem
and root tips which undergo mitosis very
often.
meristem cells divide and promote growth at
the stem and root tips.
Meristem
4.
At some point some meristem cells
specialize to do only a small range of
functions. These cells no longer divide.
5.
Meristem are active at stems and root tips,
but can become active in other parts of the
plant IF repairs to the plant are needed.
Methods of Plant Asexual Reproduction
Cloning
1.


The process of making identical offspring
to the parent using a single cell or a small
amount of tissue from the parent.
Humans use “cuttings” or pieces of a
plant stem to place into soil and produce
many offspring identical to the parent.
2.
New Plants from Roots
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3.
these plants can grow from just root
cuttings – pg 38
Growers can sell just the roots.
Eg. Dandelions, asparagus
New Plants from Stems
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These plants grow from just the tips of
the runners – p 39
E.g. strawberries (runners)
Layering – A branch of the parent plant is
bent down to the ground covered with
soil.
Grafting
4.
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

one part of a plant is cut and connected to a
similar plant.
The result is a plant that is part one type and
part another.
used for apples, grapes and roses.
Tissue Cultures
5.
take a few unspecialized cells from a plant

place the cells in a special growing solution
perfect for growth.

the laboratory produces many identical plants (1
from each sample)

useful for Chrysanthemums, orchids and pine
trees.
(Note – specialized cells have been altered to be
able to carry out a few specialties very well but
cannot carry out other functions.)

See BLM 1-26, 28, 29,30, 31 and
Do BLM 1-32 & 1-33
Grafting
Grafting can add variety and bounty
to apple orchards
You have a fruit tree but you don't really like it.
Despite proper pruning and tender care, you're
getting poor apples or less-than-pretty pears.
Maybe you hate the healthy fruit -- too sour, too
squishy, too tart.
Dormant sprays might not be working to rid you
of pests.
Well, don't cut down that tree just yet.
Consider first the ultimate art of propagation -fruit tree grafting.
Grafting -- how nearly all fruitful fruit trees are
created nowadays -- means cutting a branch,
large or small, off an undesirable tree and
putting the limb of a new variety in its place.
"Really, truly it's a lost art," Master Gardener
Keith Underwood of Olympia said. "You take a
pencil-size-around diameter twig and actually
put it into the other bark of the tree."
Most apple trees are, in fact, propagated by
using strong root systems of other apple
trees.
"They're all in the apple family," said
Underwood, who grafted thousands of trees
during his days of apple farming near Yakima.
So if you have an apple variety in your yard, but
it's ugly because of scab, you might add on
more scab-resistant varieties such as
Chehalis or Liberty, or a more vigorous variety
such as the Gravenstein.
Try, eventually, up to 20 different varieties,
depending on the tree size.
Scott Stiles, a horticulturist at Raintree Nursery
in Morton, said people love the nursery's
workshops on grafting, which he'll be teaching
in part next Saturday.
"It's like magic, in a way," Stiles said. "You're
creating a new tree from some simple little
carpentry that never fails to fascinate people
who watch it."
Gardeners can take scion wood and replicate
trees from a grandparent's old homestead.
"They can just go cut a branch off that old
heirloom tree," Stiles said, "and they can
create them to pass along to their children. It's
absolutely magic."
"There's not a lot of people who do it anymore,"
Underwood said. "It's hard to find good
grafters."
Yet, Underwood does it on his farm in Olympia.
He demonstrates the cuts for a 2-inch
diameter stump on his Gravenstein, where
he's injects three Spitzenburg apple tree twigs
just under the bark.
Each twig has two or three buds above the graft
-- secured with nails and sealed with masking
tape and a homemade wax of beeswax,
Italian resin and linseed oil.
"This is called a bark graft," Underwood says, "If
you do this right, and you don't get a frost,
every single one of them will take off."
Underwood warns that gardeners borrowing
from neighbors should beware of bringing
diseases to their fruit trees.
"The problem is viruses," Underwood said. "You
have to be very aware."
Scion wood -- the twiggy branches added to
other trees -- can be purchased or gathered
with permission from a neighbor's healthy
tree.
Using special techniques and a grafting knife,
gardeners can add a different variety of fruit to
their existing tree, and that graft can produce
fruit within a few years.
"This is just a tool that you can use to get more
than one variety out of an apple tree,"
Underwood said. "I've taken 100-year-old
trees and cut all the branches back and
grafted every single stump."