Key Idea #13

Following fertilization, cells divide and
become specialized for specific functions.
http://www.google.com/imgres?imgurl=http://image.wistatutor.com/content/feed/u2077/Multicellular%2520Organisms.jpg&imgrefurl=http://www.tutorvista.com/topic/types-of-multicellularorganisms&usg=__yq7LX05ipxlDrsajgMhnNsQiEYo=&h=600&w=714&sz=52&hl=en&start=0&zoom=1&tbnid=DKWjdNXCXbMmoM:&tbnh=127&tbnw=151&ei=hpROTfCCO8PogAffyeHzDw&prev=/images%3Fq%3Ddifference%2Bbetween%2Bsingle%2Band%2Bmulticelled%2Borg
anisms%26um%3D1%26hl%3Den%26sa%3DN%26biw%3D1003%26bih%3D567%26gbv%3D2%26tbs%3Disch:1&um=1&itbs=1&iact=rc&dur=578&oei=hpROTfCCO8PogAffyeHzDw&esq=1&page=1&ndsp=15&ved=1t:429,r:1,s:0&tx=91&ty=79
What do you want to be when
you grow up?
There are many important jobs that
grown ups do to keep our world
running smoothly.
 Whether doctors, teachers, builders,
engineers, farmers, etc, everyone
learns a specific skill which they can
then use to help everyone else.
 Just like people, cells specialize in
important jobs.

During early embryonic development, the cells of the
body became specialized for different activities in a
process called cell differentiation.
How Living Things are Structured

Following fertilization, cell division produces a
small cluster of cells that then differentiate by
appearance and function to form the basic
tissues, organs, and organ systems of multicellular organisms.
Googleimages.com
Specialized Cells

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are very different from each
other in size and structure
are only found in multicelled organisms and carry
out different functions from
each other
–

Cells that become liver cells
express a specific set of “liver
genes”
make up different kinds of
body tissues, organs, and
organ systems that function
together
Specialized Animal Cells
Specialized Animal Cells
Specialized Plant Cells
Specialized Plant Cells
Plant Book p. 145

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Epidermis and cuticle: prevents dehydration.
Green chlorophyll containing cells: perform
photosynthesis
Guard Cells: help to regulate the rate of transpiration by
opening and closing the stomata.
Xylem


Xylem tissues are
tubes that carry
materials from the
roots to the leaves.
FYI
– Roots soak up water
and minerals from
the soil.
– Cells need minerals
in their activities.
Phloem


Phloem tissues are
tubes that carry sugar
(glucose) away from
the leaves to be used
by other parts of the
plant.
FYI
– In trees, phloem located
just below the bark.
– As the phloem cells
form, they push out old
phloem which makes up
the bark.
Tissues

are made up of groups of similar
specialized cells.
http://theodoreschwann5.blogspot.com/2008_01_01_archive.html

A variety of specialized cells formed through cell
division make up different tissues, performing different
functions.
http://wpcontent.answers.com/wikipedia/commons/d/d4/Cell_differentiation.gif
Types of Animal Tissues

epithelial tissue
– outer skin cells

connective tissue
–
–
–
–
–

cartilage cells
fat cells
blood cells
bone cells
inner skin cells
muscular tissue
– muscle cells

nervous tissue
– nerve cells
Types of Plant Tissues

Vascular tissue
– transports materials
through the plant
– Made up of xylem and
phloem cells

Epidermal tissue
– protective covering
– outer surface of leaf cells

Ground tissue
– storage and support
Photosynthetic layers of
cells
http://www.progressivegardens.com/knowledge_tree/tissue.jpg

http://micro.magnet.fsu.edu/cells/leaftissue/leaftissue.html
Organs

are a group of different tissues working
together performing a specific job.
http://www.google.com/imgres?imgurl=http://bioserv.fiu.edu/~walterm/FallSpring/review1_fall05_chap_tissue5_files/image001.gif&imgrefurl=http://bioserv.fiu.edu/~walterm/FallSpring/review1_fall05_chap_tissue5.htm&usg=__GllJNQu5BxmBxbR
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Plant organs include
roots
 stems
 leaves
 flowers

Animal organs include

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stomach
liver
kidney
heart
lungs
skin
skeleton
muscles, etc…
http://www.grizzlybird.net/greenparenting/tips.gif
FYI:

The heart is an organ
that includes muscle,
epithelial, connective
(blood) tissue.

Leaves, stems, and
roots are organs made
up of dermal,
vascular, and ground
tissue.
Cells – Tissues – Organs – Organ Systems
http://plantphys.info/plant_physiology/images/anatomy.gif
Organ System
An organ system is a group of organs that
work together to perform a certain task.
Humans have multiple organ systems including:
Plants have two organ systems:
The Shoot System
 Above ground
(usually)
 Elevates the plant
above the soil
 Many functions
including:
– photosynthesis
– reproduction &
dispersal
– food and water
conduction
http://www.uic.edu/classes/bios/bios100/summer2005/plantbod.gif
The Root System
 Underground
(usually)
 Anchor the plant in
the soil
 Absorb water and
nutrients
 Conduct water and
nutrients
 Food Storage
http://www.uic.edu/classes/bios/bios100/summer2005/plantbod.gif
From atoms and molecules to organisms:

http://kentsimmons.uwinnipeg.ca/cm1504/Image48.gif
Think about it:
Why do multicelled organisms
like plants and animals make
specialized cells, considering that
every cell contains the same
genetic information?