Objective 3 Taks Review
Bacteria and Viruses, Ecology,
Evolution and Adaptations
TEK 4C and 4D: Bacteria and
Viruses
Characteristic
Bacteria
Viruses
Cell Wall
Cytoplasm
Shape
Crystalline
structure
Crystalline
structure.
Ribosome
Characteristic
Living
Bacteria
Yes
Viruses
NO-nonliving particle
DNA or RNA but not both.
Genetic
material
Metabolism
DNA not inside a nucleus
Yes
NO metabolism- does not use
energy
Yes-asexual (binary
fission)
Not on own- must reproduce inside
a living host cell
After viral reproduction, the host
cell is killed /destroyed as new
virus particles break out.
Reproduction
Yes –but only some do
like Streptococcus,
Cause disease
Tuberculosis and
Diphtheria
Yes –all are parasites
Characteristic
Helpful
Can it be
treated with
antibiotics?
Bacteria
Viruses
Some- aid in digestion
NO
like E. Coli
Aid body in maintaining
health
Decomposers (recyclers)
YES- #1 treatment for
NO-antibiotics do not work for
bacterial infections is
viruses.
antibiotics
Some viruses are forever (HIV,
warts, herpes).
Some viruses must run their course
(cold, influenza) until the body
learns how to fight it off.
There are vaccines for some
viruses (polio, small pox,
chickenpox, influenza)
How does a vaccine work?
• A vaccine is a dead or weakened virus
or bacteria that are injected into the
person so that the immune system learns
how to recognize and fight off future
infections.
What disease is caused by HIV (Human
Immunodeficiency Virus)?
• AIDS or Acquired Immune Deficiency Syndrome
which weakens the immune system by
destroying a particular white blood cell called the
helper T cell knocking out the body’s ability to
recognize new infections.
TEK 9D & 12E Food Chains, Food
Webs, and Food Pyramids
Vocab Review
• Abiotic factors: (nonliving)-air,
soil, water
• Biotic factors: all living
organisms
• Producer: produce own food
• Consumer: must eat food
• Herbivore: eat only producers
• Carnivore:eat only consumers
• Primary Consumer:1st to eat in food
chain; eat producers
• Secondary Consumer: 2nd to eat in
food chain; eat 1st consumers
(herbivores)
• Biomass: Total amount of mass of
all living organisms living in an
ecosystem. (Ex. There is more
biomass in the rainforest than the
desert)
Food Chain: shows one feeding relationship in an
ecosystem.
• It shows the direction of energy flow as
organisms eat other organisms to obtain energy
to live.
• Where do plants ultimately get their energy
from?
– solar energy from the sun
Food Web:
• Shows many feeding relationships within
an ecosystem.
• It also shows the direction of energy flow
as organisms eat other organisms to
obtain energy.
• It can be used to show how changes in
population numbers of one species, like
the grasshopper, could affect many other
populations in the environment.
Sample Problem:
• If a pesticide kills many of
the grasshoppers in the
area, then the frog
population would
decrease, which would
cause the snakes to eat
more mice.
3
3
3
3
2
2
3
22
22
1
1
1
1
1
1
3
• 1’s in diagram represent
producers.
• 2’s represent primary
consumers.
• 3’s represent secondary
consumers.
Energy Pyramids:
• Show the available
amount of energy at each
feeding level.
• Producers are always
found in greater numbers
than consumers and are
placed on the bottom of
the pyramid.
• Which level contains the
highest available amount
of energy?
– Producers (bottom)
• 10% rule: Only 10% of
the available energy at
each feeding level can be
transferred up to the next
level.
1%
10 %
100 %
• What % of energy is lost
as heat or kinetic energy
by the organisms in that
level?
– 90%
Biological Magnification:
• Increasing the
concentration of toxic
chemicals (such as DDT
and mercury) in each
higher level of a food
web. DDT is a pesticide
that was used worldwide
to kill disease-causing
insects like mosquitoes.
• These chemicals can be
found in high
concentrations in which
level?
– top carnivores
Sample Problem:
• Which organism
would have the
highest concentration
of pollution?
– Gulls
Symbiosis describes the close relationships
between 2 different populations in which at least
one organism is helped.
*Types of symbiosis:*
• Parasitism – one benefits & one is harmed (Ex.
heartworms and a dog) Parasites only take
nutrition from the host organism, its intent is not
to kill. (-Parasites are not predators.)
• Commensalism – one benefits and the other is
not harmed. (Ex. barnacles attach themselves to
whales – the whale is not harmed and the
barnacle has a place to live and a means of
transport)
• Mutualism – both organisms benefit (Ex. You
and bacteria (E. coli) in your intestines)
Parasitism
• 1. ____________A
human losing blood to a
feeding mosquito
Commensalism
• 2. __________Birds
nesting in trees
Parasitism
• 3. ____________An
oakworm caterpillar feeds
on the leaves of an oak tree
Mutualism
• 4. ____________An
orchid being pollinated by a
nectar collecting hummingbird
Parasitism
• 5. ____________A
tapeworm absorbing
nutrients from the intestine of a dog.
A
Mutualism
B
Commensalism
C
Parasitism
TEKS 7A, 7B & 13B Evolution and
Adaptations
Natural Selection:
• Nature selects those individuals with
favorable traits to live longer and
reproduce more fit offspring. Those things
that can limit/pressure a population include
predator/prey relationships, limited habitat,
food & water.
Decent with Modification/ Speciation:
• Idea that today’s species are descendants
of ancestral species with slight changes
(due to mutations) that help them survive
in an ever-changing environment.
An adaptation is the physical or behavioral trait an
individual has that helps them survive and reproduce
in a particular environment.
Examples of adaptations:
This leaf exchanges gases with
the atmosphere using
openings in the leaf called
stomata (“T” in picture above.)
Because water is also lost in a
process called transpiration
through these leaf openings,
some plant adaptations to
prevent water loss include less
stomata per leaf in drier
more arid environments.
Other Plant adaptations:
• Mangroves and other fresh/saltwater plants
must be able to tolerate high levels of salt.
Mangroves pump out the extra salt onto their
leaves.
• Water lilies have stomata only on the top
surface of their leaves.-(the part exposed to the
air.)
• Desert plants because they live in arid (drier)
regions, have long and extensive root systems
to access water deep underground. Desert
plants also have water retaining stems that can
photosynthesize.
• The pitcher plant and venus fly trap use
insects to get nutrients that are not available in
the poor soils that they live in.
• Tropical rainforest plants have broad leaves to
capture sunlight. Being broad/large these
leaves can hold a lot of water. Rainforest leaves
have a thick waxy coating to prevent too much
water from being lost or absorbed.
• Deciduous trees of the also have broad leaves
that hold water. These leaves can be destroyed
by freezing temperatures. To conserve energy
these leaves fall off in fall, storing energy in the
form of sap in the roots until spring.