The Missing Loonie Riddle
Animals:
From
Cells to
Systems
Agenda

Anticipation guide

Cell differentiation/specialization

Abnormal Development

Chernobyl (video)

Break (5 min)

Types of tissues

In class work
Anticipation Guide
A or D
Question
All cells in the body of an animal are
specialized
The environment has little to no impact
on cell specialization.
It is possible for an animal to be born a
Cyclops.
Like some plants, animals have four main
tissues.
Cells that are near one another may
impact cell specialization
A or D
3.1 Cells and Tissues

The adult human body is estimated to
have between 75 to 100 trillion cells!

Some of these cells are non-specialized
while most of the cells are specialized
(i.e. differentiated)
Cell Differentiation/Specialization

There are 3 main factors that influence
cell specialization
1. The contents of the cell’s cytoplasm
2. Environmental conditions
3. The influence of neighbouring cells

Let’s look at each of these factors
individually
Factor 1: Influence of the
Cytoplasm on Cell Specialization

In mitosis each daughter cell receives identical sets of
chromosomes.

However, each cell will contain a different cytoplasmic
content (i.e. larger vacuole, more ribosomes, etc)
◦ This results in the production of different signals for cell
specialization.
Factor 2: Environmental Influence
on Cell Specialization

Some environmental factors that can impact
cell specialization are:
◦ Temperature
 E.g. Siamese Cats dark feet, tails, ears and nose due to
cold temperatures
◦ Presence or lack of nutrients
◦ Toxins
Factor 3: The Effect of Neighbouring
Cells on Cell Specialization

Neighbouring cells tend to have the
largest impact on cell specialization.
◦ They send signals to nearby
cells which alters their DNA.
◦ E.g. Digit (finger) formation
during development.
The Effect of Neighbouring Cells on
Cell Specialization

E.g. 2: 12 Day Old Chick Embryo
Abnormal Development

The environment plays a critical role in normal
development of the embryo.

If exposed to toxins, contaminants, radiation, or
other harmful chemicals the embryo may
develop abnormalities.
Cyclops lamb:
Veratrum Californicum
(contains cyclopamine)
Human Abnormal Development
Approximately 6% of
worldwide babies born each
year are born with an
abnormality!
◦ With increasing abnormalities, it will be
“normal” to have an abnormality.
Fetal Alcohol Syndrome
Cleft Palate
Anencephaly
Chernobyl (Radiation
Abnormalities)
Break Time (5 min)
From Cells to Tissues

When a group of cells come together to
carry out a specific function they form a
TISSUE

Animals have four main
tissues:
◦
◦
◦
◦
Epithelial
Muscle
Nervous
Connective
Epithelial Tissue

Lines the inner and outer surfaces of the
human body (including organs)
◦ Functions of epithelial cells include secretion,
absorption, protection and transcellular
transport.

Can be subdivided into skin epithelia and
columnar epithelia
Types of Epithelial Tissue
◦ Skin Epithelia: Creates a
barrier between the inside
and the outside of the body
 Mainly for protection
◦ Columnar Epithelia: Found
in the small intestine, stomach
and glands. It functions to
absorb nutrients and secrete
mucus.
Muscle Tissue

Consists of elastic-like cells that contract.

Can be subdivided into skeletal muscle,
smooth muscle, and cardiac muscle.
Types of Muscle Tissue

Skeletal Muscle: Connects to the bone
allowing movement.
◦ Voluntary

Smooth Muscle: Found along the walls of
blood vessels and internal organs (i.e.
oesophagus and stomach)
◦ Involuntary

Cardiac Muscle: Found only in the heart
Nervous Tissue

Made of cells called neurons. Function to
receive and conduct electrical signals.
◦ Relay signals to the central nervous system
(brain and spinal cord).
◦ Detects and responds to external stimuli.
Connective Tissue

Tissue that functions to strengthen,
support, protect, bind, or connect cells
and other tissues.
◦ Can be subdivided into Bone Tissue, Fat
(adipose tissue), and Blood Tissue.
Types of Connective Tissue

Bone: Made of many cells
enveloped in calcium.

Fat: A collection of large,
tightly packed cells found
under the skin and around
organs.

Blood: A collection of red
and white blood cells,
platelets, and plasma.
Anticipation Guide Revisited
A or D
Question
All cells in the body of an animal are
specialized
The environment has little to no impact
on cell specialization.
It is possible for an animal to be born a
Cyclops.
Like some plants, animals have four main
tissues.
Cells that are near one another may
impact cell specialization
A or D
Test Your Knowledge

Which tissue prevents harmful bacteria from
entering your body?

Which tissues are responsible for supporting and
forming bone?

Imagine you are opening a water tap in your
washroom. Immediately after touching the water,
you realized the water was boiling. Which tissues
are involved in moving your hand away quickly?

Which tissue is responsible for controlling the
contraction of blood vessels?
Homework/ In Class Work
Read pages 85-92.
 Practice Questions 1,3, 4 (page 90)

DAY 2
Agenda

Story Time

Stem Cells

Pluripotency vs Totipotency

Use of Embryonic Stem Cells

Controversy of Stem Cells

Pros and Cons of Embryonic Stem Cells (T-Chart)

Different types of Stem Cells

In-class work/Assignment
Story Time
Stem Cells
Analogous to the meristematic cells in
plants
 Are unspecialized non-differentiated
cells

Totipotent Stem Cell
Toti- : Means Total
-potent : Means Potential

By combining the prefix and suffix we can
make sense of the meaning of the word.

Totipotent cells are therefore cells that
have the potential of forming all total cells
possible
Pluripotent Stem Cells
Pluri- : Means plural or multi
-potent : Means Potential

By combining the prefix and suffix we can
makes sense of the meaning of the word.

Pluripotent cells are therefore cells that
can make many different types of cells
(but not all).
Pluripotent vs Totipotent
Early Embryo Embryo (Day 5)
Trophoblast
Blastocyst
Fertilized egg
Embryonic Stem (ES) Cells
Found in early embryo’s (<1 week old)
 Are pluripotent
 Are used by scientists to treat various
illnesses and conditions

E.g. 1 Use of ES Cells

Cardiovascular disease

Lack of oxygen kills
heart cells

Heart cells cannot
replenish themselves

ES cells can be inserted
into the heart to
regenerate new heart
cells
E.g. 2 Type 1 Diabetes

Cells in the pancreas that produce insulin
(controls blood sugar) are attacked by the
own body’s immune system
◦ ES Cells help replenish insulin producing cells
Controversy

Attaining a sample of ES cells involves
destroying an embryo.
◦ These embryo’s are usually in vitro (fertilized
in a test tube)
Is it ethically right to kill an
embryo for the sake of
medical advancement?
T-Chart: Pros & Cons
Additional Types of Stem Cells
Adult Stem Cells
•
Are tissue specific stem cells. (i.e. Neural
stem cells can produce all types of nerve
cells
•
Commonly used to restore bone marrow
cells in patients that have received
chemotherapy.
Additional Types of Stem Cells
Fetal Stem Cells
Taken from fetus (10 weeks old)
 Are tissue-specific

Cord Blood Stem Cells
Taken from umbilical cord at
birth
 Used to treat the blood system
after cancer treatments (i.e.
chemo)

Additional Types of Stem Cells
Induced Pluripotent Stem Cells (iPS)

Reprogramming of specialized cells (i.e. skin
cells) into an embryonic stem cells.
◦ Are pluripotent
◦ Behave slightly different that ES cells.
Assigned Work

Reread section 3.1

Answer questions #4-8

Assignment
◦ Create a newspaper article documenting one use
(treatment) for embryonic stem cells.
◦ The article should include the 5W’s and the How
component.
◦ Due Monday
E.g. Burn Victims and Stem Cells

Burned tissue takes up to 30 days to begin
healing in patients with 2nd degree burns

By placing ES cells at the region that is burned
using a spray on method, the recovery can be
reduced by over 3 weeks.