2. Levels of Organization

3. Levels of Organization What are the levels from smallest to largest?1
Species: can breed and produce fertile offspring
Population: same species in same area
Community: different populations in same area
Ecosystem: all organisms in particular place; includes nonliving surroundings
Biome: group of ecosystems with same climate and similar communities
Biosphere: all portions of the planet where life exists (land, water, air, atmosphere)

4. Ecology—the scientific study of interactions between different organisms and between organisms and their environment or surroundings 2

5. Biotic—living factors that influence an ecosystem3
Abiotic—non-living factors that influence an ecosystem

6. Producers A. Sunlight is the main energy source for life on earth
Also called autotrophs
C. Use light or chemical
energy to make food
1. Plants
2. plant-like protists (algae)
3. Bacteria 4

7. (Remember: 6CO2 + 6H2O 6O2 + C6H12O6)
D. Photosynthesis—use light energy to convert carbon dioxide and water into oxygen and carbohydrates
(Remember: 6CO2 + 6H2O O2 + C6H12O6)
E. Chemosynthesis—performed by bacteria, use chemical energy to produce carbohydrates
Light Energy 5

8. B. Also called heterotrophs
Consumers
Organisms that rely on other organisms for their energy and food supply
B. Also called heterotrophs 6

9. Herbivores—obtain energy by eating only producers7
Carnivores—eat only consumers

10. Omnivores—eat both producers and consumers8
Decomposers—breaks down dead organic matter

11. Feeding Interactions
A. Energy flows through an ecosystem in one direction—from the sun or inorganic compounds to autotrophs (producers) and then to heterotrophs (consumers) 9

12. Arrows go in the direction of how energy is transferred10
Food Chain—series of steps in which organisms transfer energy by eating and being eaten
Arrows go in the direction of how energy is transferred
Start with producer and end with top consumer
or carnivore
Ex: grass cricket frog raccoon

13. C. Food Web—network of food chains within an ecosystem11
Hawks
Weasels
Raccoons
Mice
Grass
Grass
Which of the organisms above is the producer?
Which of the organisms above is the top consumer?
Hawks

14. Trophic Levels—each step in a food chain or food web
1. Level 1—Producers (autotrophs)
2. Level 2—Primary Consumers (herbivores)
3. Level 3—Secondary Consumers
(carnivores or omnivores)
4. Level 4—Tertiary Consumers
(carnivore—usually top carnivore) 12

15. Hawks
Weasels
Raccoons
Mice
Grass
Food Webs 13

16. 14
Ecological Pyramids
A. Diagram that shows the relative amount of energy or organisms contained within each trophic level of a food chain or web

17. 15
Energy Pyramid shows relative amount of energy available at each trophic level
1. Organisms in a trophic level use the available energy for life processes (such as growth, photosynthesis, cellular respiration, metabolism, etc.)and release some energy as heat
Remember: Every chemical process that happens in your body releases heat as a byproduct (ex: burning calories).
2. Rule of 10—only about 10% of the available energy within a trophic level is transferred to the next higher trophic level
C. Biomass Pyramid—represents the amount of living organic matter at each trophic level

18. 100%
10% 1%
0.1%
Energy Pyramid
Biomass Pyramid

19. Energy and Biomass Pyramid (together)
Represents amount of energy available at each level as well as amount of living tissue—both decrease with each increasing trophic level

20. Heavy metals
Ex: mercury
Pesticides
Ex: DDT (dichlorodiphenyltrichloroethane)
Organochlorides:
Ex: PCBs

21. V. Ecological Interactions between organisms
Competition—when two organisms of the same or different species attempt to use an ecological resource in the same place at the same time.
Ex: food, water, shelter

22. Monkeys compete with each other and other animals for food.
Rams compete with each other for mates.

23. Until Americans introduced gray squirrels into parts of England in the early 20th century, red squirrels had been the only species of squirrel in the country. The gray squirrels were larger and bred faster and successfully competed for resources. Within a couple years of overlap in an area, the red squirrels disappeared.

24. B. Niche—the ecological niche involves both the
B. Niche—the ecological niche involves both the place where an organism lives and the roles that an organism has in its habitat.
Example: The ecological niche of a sunflower growing in the backyard includes absorbing light, water and nutrients (for photosynthesis), providing shelter and food for other organisms (e.g. bees, ants, etc.), and giving off oxygen into the atmosphere.

25. “Address”—Soil, Ground, etc.
The ecological niche of an organism depends not only on where it lives but also on what it does. By analogy, it may be said that the habitat is the organism’s “address”, and the niche is its “profession”, biologically speaking.
“Address”—Soil, Ground, etc.
Worm’s Niche
“Profession”– Mix-up soil

26. C. Predation—one organism captures and feeds on another organism
1. Predator—one that does the killing
2. Prey—one that is the food

28. 1. Mutualism—both species benefit (WIN-WIN) a. Ex: insects and flowers
D. Symbiosis—any relationship in which two species live closely together
1. Mutualism—both species benefit (WIN-WIN)
a. Ex: insects and flowers
Can you think of any other examples that we’ve talked about in class?

29. Example: barnacles on a whale
2. Commensalism—one member of the association benefits and the other is neither helped nor harmed.
(WIN-0)
Example: barnacles on a whale

30. Birds build nests in trees.
The Remora fish attaches to the shark and gets a free ride.
Commensalism
Birds build nests in trees.

31. 3. Parasitism—one organisms lives on or inside another organism (host) and harms it.
The parasite obtains all or part of its nutritional needs from the host. (WIN-LOSE)
Example: fleas on a dog

32. Parasitism Wasp eggs on back of caterpillar.
Sea lampreys feed on fluids of other fish.
Mosquito biting a human.

33. Mutualism, Commensalism or Parasitism??

35. Tropisms
Plants have adapted to survive in their environments over time.
Some of the ways we call tropisms –
Thigmotropism – grow by touch (ex. Vines)
Phototropism – grow towards the light (ex. A sunflower bending towards the light)
Gravitropism – growing down because of gravity (ex. Root

36. What happens to a garden or field when plants are removed in the fall and not replanted in the spring?

37. Succession
Succession- the series of changes that take place in a community; either as initial growth or new growth Link

38. Primary succession- growth in a lifeless area, soil not yet formed Ex: new volcanic island/the land under a retreating glacier Lichen and mosses will grow first and create small pockets of soil from which small grasses can grow

39. Secondary Succession- the regrowth of an existing community after a disturbance that leaves the soil intact

40. Figure 53.18x2 Forest fire

41. Figure 53.18 Patchiness and recovery following a large-scale disturbance

43. Succession in a Pond- Eutrophication

47. Ecology Review

48. What is Ecology?
Ecology is the study of interactions among organisms and between organisms and their environment.
There are many levels of organization ecologists study…

49. Energy Flow Energy flows in
Sun to producers (make own food) to levels of consumers (get food from other organisms)
one direction

50. Energy Flow Producers: Autotrophs Consumers: Heterotrophs
Photosynthesis Vs. Chemosynthesis
Consumers: Heterotrophs
Herbivores - eats only plants
Carnivores – eats only other animals
Omnivores – eat both
Detritivores – eat remains of plants/animals
Decomposers – break down dead organisms

51. Feeding Relationships
Food chain: series of steps
Food web: links all food chains together
Trophic level: each step in a chain or web

52. Ecological Pyramids Energy Pyramid Shows the relative amount of
energy available at each trophic
level. Most of the energy at the bottom - plants
Biomass Pyramid
Represents the amount of
living organic matter at each
trophic level. Typically, the
greatest biomass is at the
base of the pyramid.

53. Recycling in the Biosphere
Unlike the one-way flow of energy, matter is recycled.
Matter moves through an ecosystem in biogeochemical cycles.
Matter is recycled because systems do not use up matter, they transform it.

54. Nutrient Cycles
Every organism needs nutrients to grow and function. Like water, nutrients are also transferred in cycles.
3 Nutrient Cycles:
Carbon
Nitrogen
Phosphorus-mostly in rocks and soil minerals

55. Carbon Cycle
CO2 in
Atmosphere
CO2 in Ocean

56. Nitrogen Cycle
N2 in Atmosphere
NO3-
and NO2-
NH3

57. Nitrogen Cycle
Bacteria that live in the soil and on the roots of legume plants convert nitrogen gas to ammonia through nitrogen fixation.
When organisms die, their ammonia can be converted back to nitrogen gas through denitrification.

58. How do humans impact their environment?
Human Impact
How do humans impact their environment?

59. Populations
Some people say there are too many of us and the earth is overcrowded, but……. nobody wants to leave.

60. Growth of populations
The growth rate of any population depends on the birth rate and the death rate.
If the birth rate > death rate, then pop. will increase.
If birth rate < death rate, pop. will decrease.
If birth rate = death rate, then pop. stays the same.

61. J-Curve/Exponential Growth: shows growth under ideal conditions
Unlimited resources:
Plenty of food and space
No disease
No predators
Favorable temperatures
No such place exists; eventually resources will be limited

62. However, organisms under ideal conditions are said to reach their biotic potential:
the highest rate of reproduction under ideal conditions

63. S-Curve/Logistic Growth: a typical population growth curve
The first stage shows little pop. growth since there are few organisms to reproduce.
A rapid increase follows due to plentiful food and few predators.
The population growth eventually slows and stops. Controlled by limiting factors- circumstances which keep organisms from reaching their biotic potential
Eventually the carrying capacity of this population will be reached

64. Carrying Capacity- the maximum number of organisms an environment can support
The number of organisms tends to rise above and below the carrying capacity depending on the limiting factors that are present. Why is this beneficial?

65. Limiting Factor Examples
Density-dependent
(impact determined by population size)
Food
Water
Space
Predation
Disease
Density–independent (same effect regardless of population size)
Temperature
Natural Disaster
Disease

66. Changes in a Population’s Size
Births and immigration add individuals to a population.
Births
Immigration
Population size
Emigration
Deaths
Deaths and emigration remove individuals from a population.
Immigration – The movement of individuals into a population from another population.
Births – An increase in births increases the population size.
Emigration – The movement of individuals out of a population into another population.
Death – When individuals die, the population decreases.

67. Population Density
Population Density is a measurement of the number of individuals living in a defined space.

68. Geographic Dispersion:
Population Dispersion is the way in which individuals of a population are spread in an area or a volume.
There are three types of population dispersion:
1. Clumped Dispersion – individuals may live close together in groups in order to facilitate mating, gain protection, or access food resources.
2. Uniform (even) Dispersion – Territoriality and intraspecies competition for limited resources lead to individuals living at specific distances from one another.
3. Random Dispersion – Individuals are spread randomly within an area or volume. They have almost no competition or predators.
Important

69. Geographic Dispersion

70. Population Dispersion Patterns
This is a highly social group of animals such as baboons which must live near a watering hole and food source. This is also the most common distribution
found in nature.
A. Uniform (even) dispersion
B. Random dispersion
C. Clumped dispersion
C. Clumped dispersion

71. VIDEO ON CARRYING CAPACITY AND DISPERSION PATTERNS
VIDEO ON CARRYING CAPACITY AND DISPERSION PATTERNS

72. What part would be MOST affected by a Density Independent Limiting Factor3 2
It is limiting no matter the size of the population 1

73. Human Impact can take several forms
Resource Use
Land abuse
Pollution
Loss of Biodiversity
Ozone Depletion
Greenhouse Effect
Global Warming

74. Resource Use
Whether a resource is “renewable" or “nonrenewable" is about how long nature takes to renew it.
Renewable – can be renewed by nature, includes energy sources that do not consume fuel
Renewable resources are NOT unlimited, they can be abused
Plants, animals

75. Resource Use cont. Nonrenewable Resources –
cannot be replenished by nature within our lifetimes - are limited in supply
fossil fuels, metals, other minerals
Sustainable Use – using natural resources at a rate that does not deplete them

76. Land Abuse Soil Erosion
Desertification – farming and drought turn dry grasslands into desert
Deforestation

77. Pollution
Acid Rain - burning of fossil fuels release N2 & S which combine with water vapor to form nitric and sulfuric acid
Acid Rain

79. Pollution – Biological Magnification
Biological Magnification – concentration of harmful substances increase in organisms as chemical travel in the food web

80. Loss of Biodiversity Biodiversity is the variety of living things.
CAUSES of Loss:
Endangered species – species that is highly vulnerable to extinction
Habitat loss – physical reduction in suitable places to live

81. Ozone Depletion
layer of ozone (O3) is normally present in Earth’s upper atmosphere
prevents much of UV light emitted by sun from reaching Earth’s surface
Chlorofluorocarbons (CFCs) – in polar atmosphere, CFCs act as catalyst that enable UV light to break apart ozone materials

82. What does the Ozone Layer do?
Ozone absorbs 99% of the harmful ultraviolet (UV) radiation.
Without the Ozone Layer
Most of the harmful UV radiation will penetrate the atmosphere.
This can cause skin cancer and eye problems but DOES NOT cause Global Warming!

83. Greenhouse Effect
heat is retained by the layer of gases (CO2, CH4, etc) forming the atmosphere. This is a Natural Process!

84. Global Warming Increase in average temperature of biosphere
over past 120 years, global temp. has risen .5o C
CAUSES – human activities have caused global warming by adding CO2 and other greenhouse gases to the atmosphere
RESULT – atmospheric greenhouse gases retain more heat and average temp rises. Can cause sea level to rise and disrupt weather patterns

85. Population Review
What factor listed below has NOT contributed to the explosive human growth seen in the last 100 years?
Advancements in medicine.
Improved sanitation.
More available jobs.
Global Warming
2. Which factor listed below is NOT considered scientific evidence for global warming?
A. Data from retreating glaciers
B. Average increase in global temp.
C. Increase in storm intensities.
D. Increased rate of extinction. D D

86. Population Review C D How many people currently live on planet Earth?
A. 1 million
B. 1 billion
C. 7 billion
D. 100 billion
What is the carrying capacity for humans on planet Earth?
A. 1 million
B. 6 billion
C billion
D. unknown C D

87. Population Review
5. How are human populations NOT likely to be impacted by global warming?
A. Frequent intense storms
B. Rising power costs
C. Rising sea levels
D. Increased temperature B

88. Population Review
6. Why do humans need more potent pesticides over time?
A. Because the target population soon develops a resistance to the chemical.
B. Because pesticide salesman need to make more money.
C. Because plants begin to eat the pesticides.
D. Because the explosive growth of the human population places increased demands on current farmers. A

89. Population Review D 7. Where are pesticides found in the environment?
A. In the soil only
B. In the water only
C. In the air only
D. Everywhere D

90. Population Review
8. Which of the following activities requires the most commercially produced power?
A. Heating a new home.
B. Heating an old home.
C. Heating a car.
D. Building a fire. B

91. Population Review
9. Which of the following is an environmentally responsible water consumption technique?
A. Washing your favorite outfit by itself in the washing machine.
B. Watering your garden between 10 pm and 10 am.
C. Leaving the hose running the entire time you wash your car.
D. Taking 2 showers per day. B

92. Population Review
10. How much power in the U.S. is produced by fossil fuels?
A. Under 40%
B. About 50%
C. Over 60%
D. 100% C