Specialized Animal

Cells

cell specialization/stem

cells/levels of organization

In the beginning….. You began life as a

single fertilized egg

cell

This cell quickly

divided and produced

two cells

After about 10 days

and many cell

divisions the cells

started to differentiate

(become different

from each other)

Cell Specialization

Cells develop in different

ways to perform

particular functions

EX. Animal cells may

become lung cells or skin

cells

Your body is a collection

of more than 200

different types of cells

doing specialized jobs

Each type of specialized cell is a

particular shape and size and has

unique features that let the cell perform

its special function.

Specialized Cells

and Hearing

Inside our ears are

cells with cilia

The cilia detect

vibrations that we

interpret as sound

Very loud noises can

permanently damage

these cells, leading to

hearing loss and

deafnesshttp://www.youtube.com/watch?v=1EJ4g3J6cJM

Question #1

Why are our bodies made up of specialized

cells?

We have over 200 different kinds of

specialized cells to perform all the

functions needed to keep us alive.

Growing New Cells from Stem Cells

Sometimes specialized

cells can no longer divide

Stem cells can often

replaced these damaged

cells

In some organs, like bone

marrow, stem cells divide

regularly. These bone

marrow stem cells can

become red blood cells,

white blood cells or

platelets

STEM CELLS

Are unspecialized

cells

They can divide

repeatedly

Can form specialized

cells

Types of Stem Cells

There are two types

of stem cells:

1. Embryonic stem

cells

2. Adult stem cells

Embryonic VS Adult Stem Cells

EMBRYONIC

Found in embryos (and to

a small extent umbilical

cords or placentas)

Able to undergo

differentiation

ADULT

Found in adults

Can undergo limited

differentiation

Used by the body to

replace damaged tissue

Putting Stem Cells to Work

Many medical experts believe stem cells can be

used to treat a variety of illnesses and injuries

Ex. Bone regeneration, cancer, heart disease,

diabetes and Parkinson’s disease

Question #2How do stem cells differ from other body

cells?

They are not specialized and can divide

repeatedly.

Levels of Organization1

Animals are

organized in a

hierarchy

The most simple level

of the hierarchy

consists of cells, the

basic unit of living

things

Levels of Organization2

Any group of

similar cells that

perform the same

specific function

is called a tissue

Ex. Muscle, bone,

blood and nerve

tissue

Types of Tissues

There are 4 main

types of animal

tissues

1. Epithelial

2. Connective

3. Nervous

4. Muscle

Epithelial Tissue

Tightly packed cells

that cover body

surfaces and line the

internal organs

Connective Tissue

Supports, protects

and connects the

body’s organs

Ex. Bone, blood,

cartilage

Nervous Tissue

Transmit signals

throughout the body

Most complex tissue

in the body

Makes up the brain,

spinal cord and

nerves

Muscle Tissue Made up of cells that

contract (get shorter)

Skeletal muscle

attaches bone to

bone so we can move

Smooth muscle

causes most body

organs to contract

Cardiac muscle

pumps blood through

the heart

Levels of Organization3

Groups of tissues

(two or more types)

working together form

an organ

Ex. Stomach, heart

Levels of Organization4

An organ system

consists of one or

more organs and

other structures that

work together to

perform a body

function

Ex. circulatory system,

digestive system

Levels of Organization5

Many different organ

systems working

together makes an

organism

Ex. human

Question #4

Think of your circulatory system as

pictured above. Name one type of cell,

tissue and one organ found in this organ

system.

Cell – red blood cell

Tissue – cardiac muscle

Organ - heart