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Turbo TAKS
Week 3
Lesson 1: Plants
Lesson 2: Energy Flow in Ecosystems
Lesson 3: Evolution and Adaptations
Lesson 4: Viruses and Bacteria
Lesson 1: Plants
Photosynthesis Review
6CO2 + 6H2O  C6H12O6 + 6O2
Plants convert solar energy
into useable chemical energy
(sugar)
Since plants make their own
food, they are AUTOTROPHIC!
Occurs in the chloroplasts
Leaf Structures
Leaves absorb energy from the sun
(Broader/ bigger leaves absorb more sunlight!)

Epidermis- covers the upper and lower surfaces and
secretes a waxy coating called a cuticle

Veins- vascular tissues (like the circulatory system) of the
plant and run from the leaves through the stems and the
roots to supply leaf cells with water and nutrients
 Phloem: takes sugars down, remember “Phlo low”
 Xylem: brings water up, remember “Xy high”

Stomata/ stoma- allow gases (CO2 and O2) in and out
of the cell
Transpiration

Transpiration – loss of water vapor from a plant

If a plant has adequate water, water exerts turgor pressure against
cell walls

If a plant loses too much water, cells lose water and become
flaccid, and the plant wilts
Stomata let CO2 in and control
water loss

Each stomata is surrounded
by guard cells

When plants have plenty of
water, stomata open and CO2
can diffuse into the leaf

When plants lose too much
water, guard cells become
flaccid and stomata close –
this prevents more water loss
Stems and Roots

Stems for conduction
 Phloem-
transports sap containing sugars and amino
acids through the cytoplasm in the tube
 Xylem- transports water from the roots to the leaves

Roots for water absorption
 Fibrous
root system: has many branching
roots and are usually close to the surface
which helps prevent erosion, like corn and beans
 Taproot
system: roots penetrate into deep
soil and are usually long and slender with
short side branches, like oak and carrots
Lesson 2: Energy Flow
Through Ecosystems
Physical Aspects in an Ecosystem
BIOTIC FACTORS
Bio means “life”
Living organisms
Ex: plants, animals
ABIOTIC FACTORS
“a” means “not”
Non-living things
Ex: rocks, wind, sun,
water, dirt
Symbiotic Relationships

Mutualism: both partners benefit

Commensalism: one partner benefits and the
other partner is not affected

Parasitism: one partner benefits and the other
is harmed

Predatory: predator/prey - one organism eats
the other
Wheat
Mouse
Snake
A food chain shows one path energy can take
A food web is a
collection of
several food
chains, linked
together
Owl
Trophic Levels = feeding level



Producers are at the bottom, they make their own food
Primary consumers eat producers (herbivores)
Secondary consumers eat primary consumers (carnivores)
10 % Rule


Only 10 % of the energy at one trophic level is passed
on to the next
90% is lost as heat
The greatest amount of energy
in the ecosystem is stored in
the producers. There is more
grass than grasshoppers, and
there are more grasshoppers
than frogs. There are very few
tertiary consumers in an
ecosystem because it takes a
lot of energy to feed one.
BIOMAGNIFICATION
Toxins (poisons) can
build up in the food
chain. The toxin
becomes more and
more concentrated as
you go up the trophic
levels.
Lesson 3: Evolution and
Adaptations
All organisms have adaptations that help
them survive in their environment
Examples of Plant Adaptations:
 Support/food storage: Stiff cell walls in
stems and trunks, vascular tissue that
carries water and food, Starch storage
in roots.
 Prevention of water loss: Waxy cuticle,
stomata on leaves, reduced leaf surface
area (cactus), seed coats
 Reproduction: Seed dispersal by wind
and animals, colors to attract
pollinators, pollen, co-evolution with
insects
 Defense: Toxins, thorns, bark
Examples of Animal Adaptations:

Protection and prevention of dehydration:
exoskeletons, armor, scales, skin, kidneys

Defense/Predation: Claws, teeth, well
developed eye lens, sense of smell, speed,
camouflage, armor, mimicry

Reproduction: Eggs, internal fertilization,
placentas, care of young, nesting
Which one is
venomous?
Looks like owl eyes! This
butterfly scares away
potential predators
Life is very Diverse
Diversity is a measure of how
many different types of
organisms live in an area
A rainforest is a very diverse
habitat (many different species of
plants, animals, fungi, etc.)
A desert is not very diverse
(Cacti and a few species of animals)
A species is a group of
animals that can breed and
produce fertile offspring.
(Cocker spaniel and poodle produce a
cockapoo. Lion and tiger producing a
liger. Elephant and a rabbit can not
produced a rabbant!- not same species)
Five basic components of
1. All species have genetic variation.
Variation can be caused by mutations.
Every species is different,
even within itself.
Look around you…are
you all the same?
2. Organisms produce more offspring than can
survive.
The female green sea turtle lays a clutch of about
110 eggs. She may lay several clutches.
It is likely that less than 1%
of the hatchlings will ever
reach sexual maturity.
3. Since more organisms are produced than can
survive, there is competition (struggle for
existence).
Within and Among Species for
food
water
shelter
space
And Within a Species for
mates
4. The constant struggle for survival is affected
by changes in the environment (hurricanes,
earthquakes, floods, etc.)
5. SURVIVAL OF THE FITTEST
Individuals that are best adapted to their
environment survive and leave more offspring
Over time, genes for favorable
characteristics will be more common
Example: giraffes and their
increasingly longer necks
Speciation
If two populations of the same species become
separated by a barrier, each group may change
in different ways. Eventually they may become
different enough that they are no longer the
same species (can’t produce offspring together).
Phylogenetic Trees are diagrams that show
relationships
C
Present
D
E
F
G
B
100mya
A
A is the common
ancestor. B is
extinct. E and F
are the most
closely related.
Lesson 4: Viruses and Bacteria
Viruses

ARE NOT LIVING!

Can only reproduce inside host cell

Cell Specific- will only bind to certain cells
Polio virus only attaches to human
nerve cells
Viruses destroy host cell!
Viruses

Viral infection must run their course- NO
ANTIBIOTICS!

There are vaccines that prevent some viral
infections, like polio, influenza and chicken
pox.

An organism’s immune system fights
viruses with fever & antibodies.
Viral diseases

HIV
 Destroys
Helper T cells of the immune system
 Causes AIDS

Influenza and common cold
 spread
by contact
Bacteria shapes
A.
B.
C.
Coccus: round or spherical
Spirillum: spiral-shaped
Bacillus: rod-shaped
Coccus
Bacillus
Spirillum
Bacteria
Good Types
 Nitrogen-fixing bacteria
(Nitrogen cycle)
Bad Types
 Cause disease



In food (Lactobacillus in
yogurt)

In digestive system
(E. coli)

Decomposers



Strep throat
Diphtheria
Staph infection
Food poisoning
Bacterial infections
can be treated with
antibiotics