Interactions and Ecology Day 2
Teks covered 11D, 12A, 12C, 12F, 10A, 10B
Interactions of Systems
 Plant Cell Structures: cell wall, large vacuole, chloroplast
 Chlorophyll – the pigment in chloroplast that absorb light
 Stomata – the holes on the bottom of the leaves that allow for gas exchange
 Tropisms: growth responses to stimuli
Phototropism
Gravitropism
Thigmotropism
Plant Cells
Root, Stem and Leaf
Roots are adapted to absorb
water with root hairs
Leaves are adapted for
photosynthesis by being flat
and green (spines)
Stems move water with xylem
And nutrients with Phloem
Flowers and Fruits
Flowers have bright petals to attract pollinators
Pollen (Sperm) can be transferred by animals
When egg joins with pollen, a seed is formed in the ovary
The ovary becomes the fruit
Fruit surrounds and protects seed
Fruit also helps get baby plants in seeds away from parent plant
Animal Cells
Blood, muscle, epithelial
Blood cells carry nutrients and oxygen to body tissues and waste products away
Muscle cells have three types
Skeletal muscle- work with the skeletal system to allow voluntary movement
Smooth muscle- allows internal organs to function
Cardiac muscle- allows heart to pump
Epithelial cells (skin) are the first line of immune defense. It is a part of the integumentary system.
Hormones
Auxins: Class of plant hormones (growth substances) that are essential for plant development
Insulin, oxytocin, and adrenaline: Class of animal hormones that are essential for animal function
Enzymes
Enzymes are proteins that catalyst (speed up a chemical reactions). They are made from a series of amino acids. Enzymes
are specific to a substrate. Lock and Key
Things that effect or denature (destroy) an enzyme- therefore will not function properly
 pH
 Temperature
 Concentration of salt or other molecules
Human enzymes include:
Amylase – break down carbohydrates in mouth
Lactase – breaks down milk sugar (lactose)
Pepsin – breaks down proteins in stomach
Review Questions
1. What is gravitrophism?
The ability for a plant to “feel” gravity and grow roots down to ground and stem up to sun light.
2. What are three structures that are in plants?
Chloroplast, Cell wall, large vacuole
3. What are three different cells in the human body?
Red blood cells, White blood cells, Skin cells, Muscle cells, Bone cells etc
4. What is an enzyme?
An enzyme is a protein that acts as a catalyst by speeding up the chemical reactions.
5. What are hormones and how are they transported through the organism?
Hormones are chemical messengers that allow cells to communicate with one another. The hormones are
passed through the body in blood and passed through plants in vascular tissue (xylem and phloem).
Ecological Succession
General Information:
a. Succession – constantly changing
Primary Succession: slow gradual process
a. Occurs where no soil exists
b. Volcanic eruptions, melting glaciers
c. Pioneer organism include:
i. Lichen
ii. mosses
Secondary Succession: faster process
a. Occurs when the existing community is destroyed
b. Land clearing, fire, etc.
c. Soil remains intact
d. Pioneer species
a. Weeds
b. grasses
Energy Flow
Producers:
a. Autotrophs - organisms that make their own food through either photosynthesis or chemosynthesis
Consumers:
1. Heterotrophs - organisms that depend on producers for food
2. There are 5 types of consumers
a. Herbivores – eat plants
b. Carnivores – eat animals
c. Omnivores – eat both plant and animal
d. Detritivores – eat dead material (snails, mites, maggots, earthworms)
e. Decomposers – breaks down organic material (bacteria, fungus)
f.
Saprobes- breaks down dead organisms like (fungi
Community Interaction:
1. Competition – species use the same resources at the same time
2. Predation – when one organism captures and feeds on another organism
3. Symbiosis – any relationship in which two species live closely together
a. Mutualism – both species benefit
b. Commensalism – one benefits and the other is neither helped or hurt
c. Parasitism – one organism lives on or inside another organism
d. Predation – predator vs prey
Feeding Relationships:
1. Food chain – the series of steps that show energy flow
2. Food web – feeding relationships among food chains
List producers
List primary consumers
List secondary
List tertiary
Do any belong to more than one category?
3. Energy pyramid – shows the relative amount of energy at each
trophic level
a. Only about 10% of the energy available within one trophic
level is transferred to the next trophic level
b. The other 90% is lost as HEAT a form of energy.
Some causes of ecosystem instability
--fire
-- flood -- acid rain --deforestation -- tornados -- hurricanes -- drought --construction --pollution
Ecosystems consist of…
1. Abiotic factors
2. Biotic factors
3. Limiting factor – abiotic or biotic factor that causes the growth of a populations to stop or decrease
The conditions an organism lives in AND how it uses those conditions
Habitat
a. Food
b. Water
c. Shelter
d. Space
*Different species can live in the same habitat but occupy different niches.
Practice Questions
1. Place the levels of organization in order from least complex to most complex. Ecosystems, organisms, communities,
species, populations and biomes
Organisms, Species, populations, communities, ecosystems, biomes, Bioshphere
2. What is an organism’s habitat? What is its niche?
Habitat is where an organism lives in the environment. Niche is the role the organism plays in the environment.
3. In the following chart, explain the symbiotic relationships. (Pages 92 and 93)
Relationship
Definition
Example
Mutualism
Both organisms benefit from the relationship
Moth and flower
Moth gets food and the flower gets
pollinated
Commensalism
One organism benefits the other is not helped
or harmed.
Person and shade tree
Person gets shade from the sun and the tree
gets nothing in return
Parasitism
One organism benefits and the other is harmed
Tick on a Dog
Tick gets food and dog gets harmed by the
tick sucking its blood
Predator-Prey Relationships
4. In the graph below, which organism is the prey? ____Hares_______ Which is the predator? _______Foxes_______
5. Why are predator/prey relationships important in an ecosystem? (Consider population dynamics in your answer.)
If there are more prey in the environment the number of Foxes will increase due to number of resources. If the number of
hares begin to decrease the number of foxes will decrease as well do to limited resources.
6. What is carrying capacity?
The maximum amount of a population that an environment can support
7. What are limiting factors?
These are factors that keep the number of a population at a given amount. Things such as water, shelter, food, mates,
predators, etc
Biotic and Abiotic Factors (Page 90)
8. List at least 3 biotic factors in an environment.
Biotic factors are living things- animal, plant, bacteria
9. List at least 3 abiotic factors in an environment.
Abiotic factor are nonliving things- water, soil, temperature,
10. Give an example of how biotic & abiotic factors act together to limit population growth and affect carrying capacity.
The temperature could cause things such as a drought. This in turn can cause plants not to grow limiting the number of
food resources available to the animals. This will keep the population size from over populating a given area.
Graph 1: Rabbits Over Time
11. What is the carrying capacity for rabbits?
65
12. During what month were rabbits in
exponential growth?
June
Graph 2: Mexico and US
13. In Mexico, what percentage of the
population is between 0-4 years of age?
80%
14. In the US? 40%
15. Which population is growing the fastest?
Mexico because of all of the babies
16. Which age group has the smallest number
in both countries?
80+
Primary and Secondary Succession
17. What is Primary Succession?
This occurs when no soil is present. This is the growth of ecosystem. Pioneer species are lichens and mosses. Happens
when volcanoes erupt and glacial melts.
18. What is Secondary Succession?
This occurs after a natural disaster and soil is present. Pioneer species are grasses.
19. What is a pioneer species? How are they important?
Pioneer species is the first species to grow in an ecosystem. This is important to allow soil to grow.
Food Webs
20. What are the producers in this food web?
Producers- Leaves, blossoms, nuts, bark
21. What are the primary consumers (herbivores)
in this food web?
Bees, deer, mice, rabbit, insects
22. What are the secondary consumers in this
food web?
Bear, wolf, toad, birds, red fox,
23. What are the highest level consumers in this food web?
Bear
24. How does energy move through a food web?
Only 10% of the energy moves from one trophic level to the next.
25. What is a food chain? Give an example of one from this food web.
This is a diagram that the eating patterns in an ecosystem and how energy is transferred.
26. Create an energy pyramid from the food chain:
27. Where is the most energy in this pyramid?
Leaves- producer
Bear 1
28. Where is the least energy in this pyramid?
Red fox 10
Quaternary consumer- Bear
Birds
Insects
Leaves
100
1,000
10,000
29. What happens to energy as it moves through the food chain/web?
only 10% is moved to the next level the other 90% is given off as heat
energy
30. Assume there are 10,000 kcal of energy in the leaves? Estimate
the amount of energy in each of the other levels of the energy pyramid.
31. What percent of energy is lost? __90___%
32. How much is passed on? 10_%
33. What is the ultimate source of energy for this food web? THE _____sun light____________!
34. What are the effects of bioaccumulation (biomagnification) of pesticides on a food web?
As the insects ingest the pesticides, then the birds eat the insects and the pesticides accumulate in their bodies. This can
result in death.
35. Why do some species become resistant to pesticides?
All species in a given population are exposed to pesticides. The ones that have a mutation with a resistant strand strive and
reproduce making all organisms in this species resistant to the antibiotic.