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STATION 1 - 11B
The phenomenon you are observing above is called phototropism.
The prefix "photo" means "light", and the suffix "tropism" means
"turning". So, phototropism is when plants turn or bend toward
light.
Plants need light to make food (sugar = glucose) and oxygen gas
from carbon dioxide and water during a process of
photosynthesis. Phototropism is likely a survival mechanism
adopted by plants so that they can get as much light as possible.
When plant leaves open toward light, more photosynthesis can
take place, allowing for more solar energy to be absorbed and
food made.
a. What is the external factor in this example? Sunlight
availability
b. How do plants respond to this external factor? Bend toward
light
c. Why? Need sunlight energy for photosynthesis
STATION 2 - 11B
Many animals migrate. Birds do it. Fish do it. Mammals, insects
and reptiles do it. Animals across the globe fly, swim, walk or drift
in their effort to find food, a more hospitable climate or places to
breed.
Migration is driven by a simple fact: Resources on Earth fluctuate.
Warm summer months may be followed by inhospitable cold.
Plants – or other meals – may be abundant, but only for a short
time. The best place to give birth or hatch young may not be a
good place to find food.
a. What is the external factor(s) in this example? Food
availability decreases; shift in temperature (seasons);
space/shelter for breeding.
b. How do animal populations respond to the external
factor(s)? Migrate to more hospitable environments.
STATION 3 - 11B
When the temperature around us becomes too warm, we sweat. As
sweat evaporates, it carries away heat from the surface of our skin. We
cool off. This brings our body temperature back to normal.
When we feel cold, tiny sensors in our skin send messages to the brain
telling us to warm up. The brain sends messages to nerves all over our
body telling our muscles to tighten and loosen really fast, which is what
we call shivering. It does this because when muscles move they
generate heat. We warm up and this brings our body temperature to
normal.
a. What external factor is described in this example? Temperature
b. How do our bodies respond when we feel hot and cold? Hot- sweat;
Cold-shiver
c. What type of response does the “fan” in the picture above
represent? Sweating
d. What type of response does the “heater” represent? Shivering
e. What do we call the tendency of our body to maintain balance
(stability)? Homeostasis
STATION 4 – 11C
Some microorganisms help keep us
healthy by performing many jobs.
Sometimes helpful bacteria are called
“natural flora”. An example of this is the E.
coli bacteria found in our large intestine
(colon). These bacteria help us get
nutrients out of some foods that we
wouldn’t be able to digest all on our own.
They also produce some of our vitamins,
such as Vitamin K, which aids in blood clotting. Lactobacilli help us
digest milk proteins.
a. What role do microorganisms play in maintaining the health
of organisms? Give an example. Help get nutrients; produce vitamin K
(E.coli); help digest milk (Lactobacilli)
Some microorganisms, such as bacteria and fungi, are pathogenic
which means these microbes cause disease. An example of this is
Streptococcus pyogenes causes strep throat.
b. What role do microorganisms
play in disrupting the health of
organisms? Give an example.
Cause diseases.
STATION 5 – 11C
Bacteria and fungi are both very important in
nutrient recycling. For example, when food
starts to rot often you will see fungus grow on it.
Think about a rotting orange. The greenish
colored organism that grows on a rotting orange
is a fungus. It’s job is to decompose or
chemically breakdown the orange recycle its
nutrients that the orange still has in its tissues
so that those nutrients can be used by other
organisms (to help them grow). In this respect bacteria and fungi are
decomposers in all ecosystems. Without them, nutrient recycling
would not occur.
a. What role do microorganisms play in maintaining the health of
ecosystems? Give an example. Recycle nutrients.
The Chestnut blight fungus was accidentally introduced to the
United States around 1900. Here it caused the death of chestnut
trees throughout the eastern United States. The nuts of chestnut
trees were consumed by both humans and animals. Chestnut leaves
provided much nutrient (glucose) content to the forest ecosystem.
Chestnut trees were replaced by oak, hickory, and maple trees.
Other animal species moved in.
b. What role do microorganisms play in disrupting
the health of ecosystems? Give an example.
Make-up of the ecosystem has changed - other
trees replaced Chestnut trees. Other animals
moved in.
STATION 6 – 12C
An adaptation (or adaptive feature) is an inherited trait of an organism
that enables it to survive and reproduce in its habitat.
Biome - TUNDRA
a. What is an adaptation? Inherited trait
b. How do small extremities such as limbs and ears help animals
survive in tundra? Limit heat loss
c. How is hibernation (deep sleep) help some animals in tundra to
survive? To save energy
d. How does having blubber (fat) help animals
such as seals survive in tundra? Fat is
source of long-term energy.
e. How does turning fur white in the winter help animals survive in
tundra? Camouflage them in the snow – avoid predators.
f. How does growing close to the ground help plants survive in
tundra? Keep them from freezing
g. How does having shallow roots help plants survive in tundra? No
need to penetrate ice (permafrost).
STATION 7 – 12C
Biome - DESERT
a. How does having large ears help animals survive in desert?
To give off heat
b. Why do animals in the desert active only at night? To avoid the
heat of the day
c. Animals in the desert produce little urine. How does this adaptation
help them survive in the desert? To save water
d. Plants in the desert have either needle like leaves or no leaves.
How is this adaptation help plants survive in the desert? Help
reduce water loss
e. Why does having shallow roots in the desert is an advantage?
Shallow roots soak up water over a large area closer to the surface.
f. Some plants have deep roots. How does this adaptation help these
plants survive in the desert? Long roots get to water stored
underground
STATION 8 – 12D
There two types of factors that affect population size:
 Density-dependent factors affect a population because
the population is “dense or crowded”.
 Density-independent factors –affect a population
regardless of how dense or crowded it is or not.
How do these factors affect a species’ ability to survive?
a. Competition –The more crowded a population, the higher/lower
the competition.
b. Disease –The more crowded a population, the more/less disease
will spread.
c. Parasites –The more crowded a population, the more/fewer
parasites will spread.
d. Predation –The more crowded or dense a population is, the
more/fewer predators will be successful.
e. Give examples of density-independent factors.
Drought; weather; fire; flood; drought.
f. Does bad weather hit Houston because it is a crowded city? No
g. Pacific mussels, Mylillus sp., are largely limited by competition for
space on rocky outcrops. Occasionally, disturbance by floating logs
decimates populations.
 Which of the factors in this example is density – dependent?
Competition
 Which of the factors in this example is density –independent?
Floating logs
Name _____________
Student Answer Sheet
STATIONS (11B; 11C; 12C; 12D)
Station 1
a. _______________________________________
b. _______________________________________
c. _______________________________________
Station 2
a. _______________________________________
b. _______________________________________
Station 3
a. _____________
b. _____________
c. _____________
d. _______________
e. _______________
Station 4
a. _______________________________________
b. _______________________________________
Station 5
a. _______________________________________
b. _______________________________________
Station 6
a.
b.
c.
d.
e.
f.
g.
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Station 7
a. _______________________________________
b. _______________________________________
c. _______________________________________
d. _______________________________________
e. _______________________________________
f. _______________________________________
Station 8
a. _______________________________________
b. _______________________________________
c. _______________________________________
d. _______________________________________
e. _______________________________________
f. _______________________________________
g. _______________________________________
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