HUMANITY & THE WORLD BIOMES
Unit 2-2a
The Tundra
Characteristics Of The Tundra
Tundra
Temperature
Precipitation
Biodiversity
Low
Low
Low
Locations – Tundra can be found at both poles and at the
top of the tallest mountains.
Abiotic Factors
• Temperatures range from just above freezing in the
summer to -50oF in the winter.
• In the summer, the top of the permanently frozen soil
called permafrost thaws to create some moisture during
the short growing season.
What’s It Like In Barrow, Alaska?
Imagine the
Earth rotating…
Would the north
pole get any
sunlight?
When the Earth’s axis is tilted away from the sun
it is winter & there are 30 days of night at the pole.
But in the summer, with the axis tilted toward the sun,
there are 30 days of sunlight!
Tundra Plants
Because the tundra is covered in ice, these plants must
survive without deep soil and very little moisture.
Dwarf Willow – World’s smallest tree
(~3 in tall) hides from strong winds
Moss Campion – Flower very
quickly and have short hairs on
their leaves for insulation
Lichen – A composite organism
of a producer & a fungus that
can grow on solid rock
Why aren’t there any evergreen trees in the tundra?
Tundra Animals
How do animals survive the extreme conditions of the tundra?
Arctic Fox – The short legs, ears & muzzle help conserve
heat; It’s fur changes color with the seasons.
Caribou – Have large hooves that
support them in marshes & snow;
Shorter legs & seasonal fur color.
Polar Bear – Has dark skin and clear
fur to absorb the sun’s rays; Thick
blubber & webbed feet to swim.
Penguin – Black & white color for
camouflage while swimming underwater.
Do all of these animals share a common adaptation?
Close Your Notebooks… 
What have you learned in this unit?
1. Describe the temp, precipitation
and biodiversity of the tundra.
2. Where are tundra located?
3. How many hours of daylight
does the tundra receive during
each season?
4. What adaptations have plants
developed to live in permafrost?
5. Name two animal adaptations
for the tundra.
HUMANITY & THE WORLD BIOMES
Unit 2-2b
The Savanna
Characteristics Of The Savanna
Savanna
Temperature
Precipitation
Biodiversity
High
Average
Average
Locations – Savannas are tropical grasslands located near
the equator in Africa, India, Australia & South America.
Abiotic Factors
• Temperatures average between 80-90oF all year. There
are two seasons – wet & dry.
• While most of the year is dry, the wet season brings
monsoons with ~20 inches of heavy rains.
How Is The Savanna Maintained?
Grasses dominate the
savanna because…
• Grazing animals
eat significantly each
day,
• Droughts are common
and,
• Naturally-occurring
fires are frequent
And these factors prevent larger plants from growing
Forests generally need at least 55 inches of rain/year
Savanna Plants
Bermuda Grass – Has a deep root system that stores
water during droughts and helps it re-grow after fires.
Elephant Grass – Can grow 10 ft
tall with razor-sharp blades.
Senegal Gum – A thorny tree with
sap that makes several medicines
Candelabra Tree – Has a sticky,
poisonous sap that causes blisters
Which two survival strategies are used by these plants?
Savanna Animals
Due to droughts, savanna animals have strong and/or long
legs to support migration over great distances.
African Elephant – Long trunk for reaching; Large, thin
ears that wave to dissipate heat.
Zebra – Stripes to confuse predators;
Thick hooves for defensive kicking
Wild Dog – Large ears; Strong legs;
Multicolored camouflage coat
Kangaroo – Pouch for developing young;
Powerful legs for jumping
Do all of these animals share a common adaptation?
Close Your Notebooks… 
What have you learned in this unit?
1. Describe the temp, precipitation
and biodiversity of the savanna.
2. Where are savannas located?
3. Which three factors prevent
grasslands from becoming forests?
4. List two plant adaptations for
the savanna.
5. List two animal adaptations for
the savanna.
HUMANITY & THE WORLD BIOMES
Unit 2-2c
Integumentary Adaptations
To Extreme Biomes
The Integumentary System
Comprised of hair, nails & skin
Hair & Nails - Protection & insulation. Made from mostly
keratin which makes cells tough & waterproof.
Skin - Protection from infection, injury & dehydration;
Maintains body temperature.
• Epidermis - Outer layer of skin;
Dead, flat cells of keratin.
• Dermis - Lined with nerve cells,
hair follicles, sweat glands and
blood vessels.
• Subcutaneous Layer - Deepest layer of fatty tissue
that insulates, cushions & stores nutrients.
Look At These People
Which parts of the integumentary system are visible?
Skin
Hair
Nails
The Eyes
What can you see that
is not part of the integumentary system?
Shades of Skin Color
Melanin – A pigment created by the inner layer of the
epidermis that protects the skin from UV radiation.
Higher levels of melanin, producing
darker skin, offer more protection
from the sun’s rays.
Lower levels of melanin, producing
lighter skin, allow for increased
production of Vitamin D.
Albino people cannot produce pigment.
Von Luschan’s Chromatic Scale
1
5
10
15
20
25
30
36
Integumentary System Diseases
Skin Cancer – A genetic mutation that’s caused by overexposure to UV radiation.
The ABCD’s of
skin cancer
not uniform
Carcinomas – A more common condition affecting nonpigment producing cells. It can be successfully treated.
Melanomas – A more rare cancer affecting pigment
producing cells that spread quickly and accounts for the
majority of skin cancer deaths.
Other Skin Adaptations
The average core body temperature is about 98.6°F,
To prevent hypothermia (<94°F) in extreme cold…
• The skin shivers creating warmth by muscle movement
• Goosebumps make hairs stand up to trap warm air
• Blood flow to the extremities (includes fingers, toes,
ears & nose) reduces to preserve core body temperature
What’s this called?
Other Skin Adaptations
To prevent hyperthermia (>105°F) in extreme heat…
• The skin sweats, cooling the body as it evaporates
• Blood flow to the extremities increases, releasing heat
from the body
• In serious cases, the body reduces urination & sweating
Close Your Notebooks… 
What have you learned in this unit?
1. What three parts of the body
make up the integumentary system?
2. What is the name & function
for each layer of our skin?
3. What are the results of higher
and lower levels of melanin?
4. Explain how a person can get
skin cancer & the symptoms of it.
5. How does our skin react to
extreme temperatures in order to
regulate body temperature?
Dust Mite & Dead Skin
HUMANITY & THE WORLD BIOMES
Unit 2-2d
Musculoskeletal Adaptations
To Extreme Biomes
The Skeletal System
There are 206 bones in an adult (350 in an infant) that
provides protection, gives us shape & enables movement.
The skeleton is divided into…
• Axial – Makes up the skull and trunk
• Appendicular – Makes up the limbs
A Joint, where two bones meet,
functions due to…
• Ligaments – Hold two bones together
• Tendons – Attach muscle to the bone
What is the purpose of the cartilage?
Skeletal System Diseases
Osteoporosis – Porous and brittle bones in people
Can be prevented through proper nutrition.
Arthritis – Diseases that wear
away cartilage causing painful
bone on bone contact.
Leukemia – Blood cancer in which
an overabundance of defective
blood cells are formed in the bone marrow
Calcium absorption reduces dramatically after age 35 so…
Start Building Strong Bones Today!
How Do Muscles Your Arm Move?
Muscles always work together in pairs.
Each pull in opposite directions to create movement.
Which muscles contract
to open & close your arm?
Extensor - A muscle that
opens a joint.
Flexor – A muscle that
closes a joint.
Identify these…
Joint
Extensor
Flexor
Elbow
Triceps
Biceps
These muscles create motion in all parts of your body
including your wrist, jaw, neck, and even eyelids.
Musculoskeletal Adaptations
People native to polar biomes generally have…
• Stockier bodies with shorter limbs
• Higher percentage of body fat
• Flatter faces without extruding features
How do these strategies help people survive
in polar biomes?
Musculoskeletal Adaptations
People native to tropical biomes generally have…
• Taller, slender bodies
• Carry very little fat
How do these strategies help people
survive in tropical biomes?
Close Your Notebooks… 
What have you learned in this unit?
1. Why do babies have so many
more bones than adults?
2. Name one bone in both the axial
and the appendicular skeleton.
3. What steps can you take to
reduce the risk of bone disease?
4. Estimate how many different
muscles control your neck motion.
5. Describe the most successful
body types for surviving at the
poles & the equator.