The Missing Loonie Riddle

Animals: From Cells to System

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AgendaAnticipation guideCell differentiation/specializationAbnormal DevelopmentChernobyl (video) Break (5 min)Types of tissuesIn class work

Anticipation GuideA or D

Question A or D

All cells in the body of an animal are specializedThe 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

3.1 Cells and TissuesThe 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/SpecializationThere are 3 main factors that

influence cell specialization 1. The contents of the cell’s

cytoplasm2. Environmental conditions3. 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 nearbycells which alters their DNA.

◦E.g. Digit (finger) formationduring development.

The Effect of Neighbouring Cells on Cell Specialization

E.g. 2: 12 Day Old Chick Embryo

Abnormal DevelopmentThe 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 TissuesWhen 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 TissueLines 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 TissueConsists of elastic-like cells that

contract.Can be subdivided into skeletal

muscle, smooth muscle, and cardiac muscle.

Types of Muscle TissueSkeletal 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 TissueMade 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 TissueTissue 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 TissueBone: 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 RevisitedA or D

Question A or D

All cells in the body of an animal are specializedThe 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

Test Your KnowledgeWhich 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 WorkRead pages 85-92.Practice Questions 1,3, 4 (page

90)

DAY 2

AgendaStory TimeStem CellsPluripotency vs TotipotencyUse of Embryonic Stem CellsControversy of Stem CellsPros and Cons of Embryonic Stem Cells (T-

Chart)Different types of Stem Cells In-class work/Assignment

Story Time

Stem CellsAnalogous to the meristematic

cells in plantsAre unspecialized non-

differentiated cells

Totipotent Stem CellToti- : Means Total-potent : Means PotentialBy 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 CellsPluri- : Means plural or multi-potent : Means PotentialBy 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

Fertilized egg

Early EmbryoEmbryo (Day 5)

Blastocyst

Trophoblast

Embryonic Stem (ES) CellsFound in early embryo’s (<1

week old)Are pluripotentAre used by scientists to treat

various illnesses and conditions

E.g. 1 Use of ES Cells Cardiovascular diseaseLack of oxygen kills

heart cellsHeart cells cannot

replenish themselvesES 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.

Fetal Stem CellsTaken from fetus (10 weeks

old) Are tissue-specific

Cord Blood Stem Cells Taken from umbilical cord at

birthUsed 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.

Additional Types of Stem Cells

Assigned WorkReread section 3.1Answer questions #4-8Assignment

◦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.