Unit 6 Ecology – Biotic Factors
Environmental Factors that Influence Organisms
· Ecology is the study of how living things interact with another and with their environment.
· An organism interacts with and responds to both the living and nonliving things in its environment
ABIOTIC vs. BIOTIC FACTORS
Abiotic factors
· the nonliving parts of an ecosystem
· Abiotic factors include:
Water: All living things need water to carry out their life processes
Sunlight: Necessary for photosynthesis in plants
Oxygen: Most living things require oxygen to carry out their life processes
Temperature: The temperatures that are typical of an area determine the types of organisms that can live there
Soil: The type of soil in an area influences the kinds of plants that can grow
Biotic factors
· living or once living organisms in the environment
· Biotic factors include:
Bacteria, Protists, Fungi, Plants, and Animals
· Organisms depend on other organisms for food, shelter, protection, and reproduction
o Ex: The biotic factors in the prairie dogs’ ecosystem include the grass and plants that provide seeds and berries.
· The hawks, ferrets, badgers, and eagles that hunt the prairie dogs
are also biotic factors. In addition, worms, fungi, and bacteria are biotic factors that live in the soil underneath the prairie grass. These organisms keep the soil rich in nutrients as they break down the remains of other living things.
· Name a biotic factor in your environment: people, dogs, plants, birds
Nature’s Cycles
· Nature’s cycles help the earth renews itself.
· The living things within an ecosystem interact with each other and also with their non-living environment to form an ecological unit that is largely self-contained. Sometimes this renewal process is violent and destructive. Sometimes it is gradual and gentle. Nevertheless, ecosystems contain within themselves the resources to regenerate themselves.
Cycles in nature include:
life cycles of plants and animals seasonal cycles
lunar cycles nitrogen cycle
oxygen-carbon cycle water cycle
rock cycle
geophysical cycles (plate tectonics,
earthquakes and volcanoes)
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POPULATIONS
Population Size
· the number of individuals in the population
· always changing
· List how a population may change:
1. birth rates
2. death rates
3. movement of organisms into or out of an area
Limiting Factors
· populations cannot continue to grow larger forever
· any ecosystem has limits to the amount of biotic or abiotic factors available
· List limiting factors that would change a population’s size:
1. food availability
2. water availability
3. amount of available living space
4. available mates
Carrying Capacity
· the largest number of individuals of a species that an environment can support and maintain
· if a population gets bigger than the carrying capacity of the environment, individuals are left without the biotic and abiotic resources they need
Biotic Potential
· the maximum rate at which a population can increase when there are unlimited biotic and abiotic resources
RELATIONSHIPS BETWEEN LIVING THINGS
Mutualism
A relationship between in which both species benefit
Ex: tick bird/rhino, honey badger/honey guide bird, mushrooms
near the tree roots, bacteria/termites
Parasitism
A relationship in which one species benefits
and the other species is harmed
The parasite hurts the host
but does not necessarily kill it
Ex: tick/rhino, heartworm/dog, lice/human, termite/tree
Commensalism
A relationship in which one species benefits
and the other species is not affected
It is neither helped nor harmed
Ex: bird living in a tree, remora/shark, crab carrying sea urchin
Predator/ Prey
A relationship between two animal species in which one animal hunts the other animal for food
The hunter is the predator
The prey is hunted by the predator
Ex: penguin/fish, snake/mouse, shark/sea turtle,
hawk/rabbit, bear/fish
Label the following relationships:
Predator/prey: bird and worm Predator/prey: fox and rabbit
Commensalism: bird and tree Commensalism: moss on a tree
Mutualism: cow bird and cow Mutualism: clown fish and sea anemone
Parasitism: cow and West Nile mosquito
Parasitism: tree fungus and tree Mutualism: pollination between a bee
and a flower
WHO EATS WHAT?
I. Producers
Producers are organisms that do not have to eat anything to obtain their nutrients. They produce their own food through a process called photosynthesis.
In this chemical reaction, sunlight helps make complex substances such as proteins and starches.
Ex: plants
II. Consumers
Consumers are organisms that must eat other organisms to obtain their nutrients.
A. Herbivores eat plants
Ex: rabbit, deer
B. Carnivores eat other animals
Ex: hawk, mountain lion
C. Omnivores eat both plants and animals
Ex: humans
D. Scavengers
Scavengers are carnivores that eat animals that are already dead.
Scavengers usually wait until other animals are done feeding, and then they come in for leftovers.
Ex: vultures, hyenas, ants
E. Decomposers
Decomposers are nature’s recyclers. They help break down organic molecules into materials that go back into the soil to help fertilize the producers.
Ex: bacteria, maggots, fungi, worms
F. Parasites
Parasites are organisms that feed on animals that are still living.
Ex: tick, fungi, tapeworm
vulture pig deer worm flower
scavenger omnivore omnivore decomposer producer
THE FLOW OF ENERGY THROUGH A COMMUNITY
· A community is made up of all of the organisms that live together in an area.
· The energy that flows through a community begins with solar energy.
· The energy from the sun is transferred to producers and then to consumers.
· A food web, food chain, or energy pyramid can show the transfer of energy.
1. FOOD WEB
shows the transfer of energy throughout all of the members
of a community
Ex:
Draw the missing arrows:
2. FOOD CHAIN
shows only one of the paths in the food web
Ex:
Draw the arrowheads in the correct direction:
acorn squirrel owl
3. ENERGY PYRAMID
diagram that shows the amount of energy available
at each level of the feeding order in a food chain
Ex:
Label the pyramid: 1%
producers
hawk _10%
rabbits
ADAPTATIONS
Traits that help a species to survive
A. Structural Adaptations
A body part aids in survival
Examples:
Survival Skill / Plants / AnimalsFood Acquisition / Roots, leaves / Sharp teeth, claws
Movement / n/a / Wings, hooves, fins
Reproduction / Seed shape / Shell of eggs, pouch
Protection / Needles, thorns / Antlers, quills, odor
Conserve Water and Heat / Thick, waxy leaves / Blubber, thick fur
B. Coloration Adaptations
· The coloring of a plant or animal aids in survival
· 2 types camouflage and warning coloration
Camouflage- characteristics that enable the organism to blend in with their surroundings (4 types of camouflage)
1. Protective coloration - camouflage in which colors and patterns of organisms match the surroundings
Ex: polar bear appears white to blend in with snow; chameleon
2. Protective resemblance - camouflage in which the shape and color of an organism match other objects in the surroundings
Ex: caterpillar resembles bird droppings; seahorse looks like coral
3. Mimicry - camouflage in which a species resembles another species in the same habitat
Ex: viceroy moth resembles monarch butterfly
4. Eye spots - camouflage in which an animal has a spot that resembles an eye in order to fool predators
Ex: fish eyespots on tail confuse predators
Warning Coloration- bold patterns and colors
that serve as a warning signal to other species and predators
Ex: dart frog
C. Behavioral Adaptations
Behaviors aid an animal species in survival
Examples:
Survival Skill / BehaviorFood Acquisition / Spinning a spider web
Birds call out when they find food
Protection (escaping danger) / Deer flips tail
Elephants surround their young
Reproduction (finding mates) / Cockroaches raise their wings and pose
Types of Behavior
1. Learned Behavior - an action that is not inherited from a species’ parent
Ex: skunk squirting; lion cubs hunting
2. Instincts - an inherited behavior; the species’ parent does not have to teach its offspring the behavior
Ex: wolves howling; puffer fish inflating its body
Behavioral Responses
1. Stimulus – a change in an organism’s surrounding that causes the organism to respond
2. Response – an action or change in behavior to the stimulus
Internal stimuli – signals inside an organism that cause a response
Example of internal stimuli:
Internal Stimulus / Responsedry mouth (thirst) / Drink water
growling stomach / Eat food
brain’s signal to lungs / Breathe
External stimuli – signals outside an organism that cause a response
Examples of external stimuli:
External Stimulus / ResponseHeat on a snake / Move to a cooler location
Light on a plant / Grows toward light
Sudden movement behind a door (seen by you) / Scream
Seasons (changing temperature) on animals / Store food, migrate, hiberbnate
Sound of a fox to a rabbit / Run away
UNIT 7: ABIOTIC FACTORS
Label the water cycle diagram using the words below:
Evaporation - the process in which liquid water becomes water vapor (a gas). Water vaporizes from the surfaces of oceans and lakes, from the surface of the land, and from melts in snow fields.
Transpiration - the process in which some water within plants evaporates into the atmosphere. Water is first absorbed by the plant's roots, then later exits by evaporating through pores in the plant.
Condensation - the process in which water vapor (a gas) in the air turns into liquid water. Condensing water forms clouds in the sky. Water drops that form on the outside of a glass of icy water are condensed water. (This term appears twice in the diagram.)
Precipitation - the process in which water (in the form of rain, snow, sleet, or hail) falls from clouds in the sky.
Subsurface Runoff - rain, snow melt, or other water that flows in underground streams, drains, or sewers.
Surface Runoff - rain, snow melt, or other water that flows in surface streams, rivers, or canals.
Accumulation - the process in which water pools in large bodies (like oceans, seas and lakes).
Components of Water
The chemical formula for water is H2O. It contains 2 Hydrogen atoms and 1 oxygen atom.
Rivers, lakes and oceans have natural salts in them that have dissolved out of rocks.
Problem: What happens to salt when water evaporates?
Hypothesis: If water containing salt evaporates, then the salt will be left behind.
Experiment:
Materials: Beaker, teaspoon, water, salt, heat source
Procedure: Boil 250mL of H2O and 2 tsp of salt. Observe and record data.
Conclusion: My hypothesis was correct. When water containing salt evaporates, salt is left behind.
Water Pollution
Unfortunately, besides H, O and salts, pollutants also exist in water.
Types of water pollution:
1. Acid rain
2. Wastes
3. Oil
4. Chemicals
Burning the fossil fuel, coal, can release SO2 (sulfur dioxide) into the air. SO2 combines with rain (H2O) to make H2SO4, or acid rain. Acid rain enters the water cycle by ending up in the lakes and rivers.
Burn coal release SO4 combine with rain enter H2O cycle
Mini Lab – Part 1: Cleopatra’s Needle
Cleopatra’s Needle was a monument in the Sahara Desert in Egypt. It was being eroded by wind blown sand. After 2000+ years it was moved to the United States to save it. In just over 15 years, our acid rain has nearly destroyed it!
Problem: How does an acidic liquid affect a solid object?
Hypothesis: If certain objects are exposed to acid, then they will weather away.
Experiment:
Materials: chalk, vinegar, dropper, container
Procedure: Add a few drops of acid (vinegar) to a solid object (chalk).
Conclusion: My hypothesis was correct. The chalk “weathered” away when exposed to acid.
Mini Lab – Part 2: Acid Rain in Lakes
The bedrock under lakes is not the same. Explore the effect of acid rain on different rock types.
Effect on granite: Does not affect MOST types of granite, only granite with feldspar.
Effect on limestone: Limestone weathers away (fizz)
If “fizzing means the acid is neutralized, what would the effects of acid rain be in a limestone lake versus a granite lake?
With a limestone lake, the acid will be neutralized. However, the lake’s limestone is eaten away. With a granite lake, the lake water will become more acidic.
Therefore, Cleopatra’s Needle is made of (granite/ limestone). It’s a trick question. BOTH, because it is made of limestone and granite with feldspar.
CHALLENGE: Can you label this diagram of the water cycle?
WATERSHEDS
1. Watershed – a land area in which surface runoff drains into a lake or a system of rivers and streams. They come in all shapes and sizes and cross county, state, and national boundaries. We all live in a watershed!
2. The largest watershed in the United States is the Mississippi River watershed.
3. Surface Water includes lakes, rivers, streams and ponds.
4. Water beneath Earth’s surface, found in spaces in the soil, sand, and rocks, is called groundwater.
5. The upper zone of this underground area is called the unsaturated zone, or zone of aeration. (pore spaces are filled with air)
6. Farther down, water collects in the saturated zone or zone of saturation. (pore spaces are filled with water)
7. The top of the saturated zone is known as the water table.
8. Groundwater dissolves rocks to create caves.
9. An aquifer is a rock layer that stores ground water and allows it to flow. Aquifers and surface water occur in watersheds.
10. If the water table reaches Earth’s surface, water will flow out from the ground and form a spring.
11. When springs do not occur, wells must be dug or drilled to obtain water.
12. In the United States, 23% of the water used by people comes from groundwater.
13. Water (from a source such as a reservoir) is cleaned at a water treatment plant.
14. Wastewater is used water and is cleaned at a wastewater treatment plant.
AIR
Main components of air
· Earth’s air contains 78% Nitrogen
20% Oxygen
1% Carbon Dioxide
≤1% Argon
Problem: Determine the percent of oxygen inside a small container.
Experiment:
Materials: candle, matches, pie pan, graduated cylinder
Procedure: