cell: basic unit tissue: group of cells –4 types organ: groups of tissue –ex: lung contains each...
TRANSCRIPT
• Cell: Basic unit• Tissue: Group of cells
– 4 types• Organ: Groups of
tissue– Ex: lung contains
each tissue• Organ System: Group
of organs working together– Digestive System
• Organism: all organ systems working together
Muscle Tissue• Contracting cells• Skeletal, cardiac cells
Connective Tissue• Support the body• Bone, fat, tendons
Epithelial Tissue• protection sheet of cells• skin, stomach lining
Nerve Tissue• Transmit electric signals• Brain & Spinal Cord
• Zygote: fertilized cell created by the union of the egg and sperm
• Embryonic stem cells– Created during earliest
divisions– Potential to become
any type of cell
• Average human:– 100 trillion cells– Over 200 types of
human cells
Determination• Determination
– Stem cell genes program the cell to be a specific type
– Few weeks into development
– Irreversible
Differentiation
• Differentiation– Cells acquire the
structures & functions of a specialized cell
– Specific genes activated
Quick Questions• Do your muscle cells have the same DNA as your skin
cells?
Yes• Do your skin cells have the same DNA as your brain cells?
Yes• Do your brain cells have the same DNA as your liver cells?
Yes• So if all your cells have the same DNA, how do they know
to do different jobs?
Stay tuned for the answer
Stem cell programmed to become a muscle cell
Stem cell programmed to become a nerve cell
How will the top cell know to become a muscle cell…and the bottom to become a nerve cell if they have identical genes?
Gene A Gene B Gene C Gene D Gene E Gene F Gene G
Gene A Gene B Gene C Gene D Gene E Gene F Gene G
If they have the same genes…how does one become a muscle and the other a nerve?
Stem cell programmed to become a muscle cell
Stem cell programmed to become a nerve cell
ON ON ON
ON ON ON
During “differentiation”, certain genes are activated in some cells, but deactivated in others.
Gene A Gene B Gene C Gene D Gene E Gene F Gene G
Gene A Gene B Gene C Gene D Gene E Gene F Gene G
Remember that genes tell cells to create proteins. Muscle cells create different proteins from nerve cells based on the genes that are active and these proteins are what help the cell carry out their functions.
Programmed cell death
(apoptosis) between the
fingers
Webbed Toes
YouTube Review Video for help
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1) What is a zygote?
2) What is the specific function of a stem cell?
3) How does “determination” differ from “differentiation”?
4) Cells are programmed to die during a process called ______.
5) From smallest to largest, name the 5 levels of organization.
6) Name the four types of tissues.
7) Which tissue is able to stretch and contract?
8) Which tissue transmits electric signals?
9) Which tissue covers and protects the body?
10) Which tissue connects the body?