Ecology study guide –Pre-AP Biology KEY

  1. List the 8 biomes starting at the equator and traveling toward the poles. Provide a brief description of ecosystem of that area.
  1. Tropical Forest (rain forest and dry)
  • Temperature: warm to high
  • Rainfall: varied – heavy
  • Plants: thorny shrubs, deciduous trees, & succulents. (very diverse)
  • Sunlight: little reaches the forest floor.
  • Habitats: floor –> canopy.
  • Poor soil, due to high temp & heavy rains (leaching).
  • Animals: monkeys, birds, snakes, bats, frogs – tree dwelling.
  • The Rain Forest contains about 45% of all animal species
  • HIGH TEMP & HIGH WATER = LOTS OF PLANTS (PRODUCERS) SO LOTS OF ENERGY AVAILABEL FOR ANIMALS (PYRMAMID OF ENERGY, PYRAMID OF NUMBERS)

  1. Savanna
  • Temperature: warm year round
  • Rainfall: moderate rainfall (with long periods of drought)BIOME DEFINED MAINLY BY THIS
  • Plants: grasses & scattered trees.
  • growing point below ground & resistance to periods of drought.
  • Habitats: migratory
  • Poor soil, lack of moisture, grazing animals, & fires inhibit most trees.
  • Biome is dependent upon fires to keep nutrient rich enough to support life
  • Animals: large grazing mammals, insects, burrowing animals, predators (lions & cheetahs).

  1. Deserts

•Temperature: very hot,

and cold (Antarctica)

•Rainfall: dry

•Plants: none, deep rooted shrubs, succulents.

–waxy coating to prevent water loss

–many seeds that remain dormant until it rains

•Sunlight: extreme

•Habitats: burrows, active at night

•Animals: ants, birds, rodents, lizards, snakes, & hawks.

  1. Chaparral

•Temperature: mild winter, hot summer

•Rainfall: rain in winter, dry in summer

•Plants: dense shrubs with tough evergreen leaves. Seasonal plants.

–Food reserves in roots allow for rapid growth after frequent fires.

–Seeds only germinate after hot fire.

•Animals: deer, birds, rodents, lizards & snakes

  1. Temperate grasslands (Prairies)
  • Temperature: relatively cold
  • Rainfall: rain, but periodic severe droughts
  • Plants: grass, mostly treeless
  • fire & grazing prevents tree growth
  • Habitats: bird nests on ground, burrows.
  • Animals: large grazing mammals (bison, wild horses).
  • Soil supports diverse microorganisms & small animals.
  • One of the most productive agricultural regions in the world

  1. Temperate (deciduous) Forest
  • Temperature: cold winter, hot summer
  • Rainfall: high precipitation
  • Plants: deciduous trees (oak, hickory, maple)
  • Habitats: rich soil, leaf litter, burrow
  • Animals: invertebrates, mice, shrew, squirrels, birds, bobcats, foxes, bears, & mountain lions.
  • Most destroyed by loggers & urban development.

  1. Taiga (Coniferous) Forest-

•Temperature: long cold winters, short wet summers

•Rainfall: considerable precipitation (snow)

•Plants: cone bearing evergreens

–(spruce, pine, fur)

•Habitats: soil thin & acidic

•Animals: moose, elk, bears, wolves, hares, migratory birds.

•Heavily logged.

•Largest terrestrial biome

  1. Tundra

•Temperature: extremely cold

•Rainfall: little

•Plants: no trees, shrubs, grasses, mosses, and lichens.

–Permafrost prevents deep root penetration

•Sunlight: little light for much of the winter, constant daylight in summer

•Habitats: migratory (summer is a breeding ground), high altitude, permafrost, soil continually saturated due to poor drainage and slow evaporation.

•Animals: well insulated (oxen & caribou), lemmings, fox, snowy owl.

•During the summer, clouds of mosquitoes fill the air due to the marshy ground.

  1. Identify the following as biotic or abiotic factors affecting an ecosystem.
  2. Rain - Abiotic
  3. Wind - Abiotic
  4. Predation - Biotic
  5. soil nutrients - Abiotic
  6. temperature - Abiotic
  7. amount of sunlight - Abiotic
  8. competition - Biotic
  9. water availability - Abiotic
  10. living organisms – Biotic
  1. What is the difference between primary succession and secondary succession?

Both involved the progression of an ever-changing community (Plants gradually get bigger so gradually can support more animal life). The primary difference is that primary succession begins from bare rock (no life before) and secondary succession begins after a disaster that kills an already present community (fire, flood, etc.). Secondary occurs faster because there is already nutrient-rich soil to support bigger life.

  1. What are the characteristics of a pioneer species?

Autotrophic

Smaller

Able to survive very harsh conditions (there has been no other life there before so no support whatsoever).

  1. What type of interaction occurs between two different species that occupy the same niche?
  2. Complete the following table showing the positive and negative effects of interspecific interactions. Also provide and example of each.

Interspecific interaction / Effect on species 1 / Effect on species 2 / Example
Competition / - / - / Scorpion vs. Spider
Mutualism / + / + / Endosymbiosis
Predation / + / - / Snake / Mouse
Herbivory / + / - / Cow / Grass
parasitism / + / - / Tick / Human
  1. Termites have a protozoan that lives in their intestines and helps breaks down the cellulose that they consume. What type of interaction is this?Mutualism (just because it lives inside of it doesn’t make it a parasite. They both benefit. Just like the beneficial bacteria that life in/on you).
  2. What is a keystone species?

Species who has a very important niche in an ecosystem that impacts most others in the community.

  1. What is the difference in a population and a community?

Population = ONE species in one area

Community = ALL the species in one area

  1. What is the difference in a biome and an ecosystem?

Biome is bigger. It is a large geographical area that has the same typical ecosystem (same sunlight, same precipitation, same plants, same animals)

  1. Using the following diagram, list ALL of the following terms to each species. Some terms will be used more than once and some species will have more than 1 description.

Primary Consumer, Secondary Consumer, Tertiary Consumer, Producer, Herbivore, Omnivore, Carnivore, Decomposer

A:Producer (it makes its own food/doesn’t eat anything else)

B:Primary Consumer, Herbivore (A primary consumer will always be an herbivore because they are the first consumer [so they are eating the producer])

C:Primary Consumer in middle chain, Herbivore in middle chain, Secondary Consumer in bottom chain, Carnivore in bottom chain (because it is eating the primary consumer), Omnivore because eats plant and animal

D:Secondary Consumer in middle chain, Carnivore in bottom and middle chain, Tertiary consumer in bottom chain (NOT AN OMNIVORE/HERBIVORE BECAUSE DOESN’T EAT A)

E:Decomposer (everything, even the top of the food chain, is eventually broken down by this)

  1. Answer the following questions concerning the WATER CYCLE.
  2. Why do we need water?

Homeostasis, hydrolysis, etc.

  1. What is transpiration?

Plant losing water through stomata

  1. What type of bond is broken when water experiences evaporation or transpiration? Hydrogen bond between separate water molecules
  1. Answer the following questions concerning the CARBON CYCLE.
  2. Why do we need carbon?

Hydrocarbons (carbons with hydrogen bound to it) are the BACKBONE of ALL organic molecules (lipids, proteins, nucleic acids, and carbhohydrates).

  1. What two processes cycle carbon from an inorganic (CO2) form to organic (C6H12O6)?Photosynthesis converts CO2 to Glucose and Cellular Respiration converts Glucose to CO2
  2. How does burning fossil fuels lead to the Greenhouse Effect?

It ADDS more CO2 to the total amount in the cycle (because we are burning very dense material [coal, oil, etc] that is full of carbon that would’ve not otherwise been converted to CO2). There is so much CO2 that plants can’t pull it all from the air so it forms a “blanket” around the Earth. This blanket traps heat in the Earth’s atmosphere, increasing the annual AVERAGE temperature (in general, temperature is increasing. There are outliers like this year where it is on average colder).

  1. Answer the following questions concerning the NITROGEN CYCLE.
  2. Why do we need nitrogen?

DNA and proteins

  1. When atmospheric nitrogen (N2) is converted to Ammonium (NH4), this process is called what?Nitrogen Fixation (beneficial bacteria are “fixing” nitrogen to a form that plants can use it [assimilation])
  2. When ammonium (NH4) is converted to nitrite (NO2), and the nitrite (NO2) is then again converted into nitrate (NO3), this process is called what?Nitrification (the process of creating nitrates)
  3. What form does nitrogen need to be in for assimilation to occur?(Ammonion Ion [NH4+] or nitrates (NO3-)
  4. When there is an excess of nitrate, or a shortage of oxygen, nitrate (NO3) can be broken down to release the nitrogen back into the atmosphere in the form of a gas (N2). What is this process called?Denitrification (the process of getting rid of nitrates)
  5. How do animals get their nitrogen?

Eating plants to get their AMINO ACIDS. (WE GET ALL OF OUR ORGANIC MATERIAL[CARBON, PHOSPHOROUS, NITROGEN, ETC.] FROM EATING PLANTS

  1. What is eutrophication?

We OVERFERTALIZE plants which causes an excess of NITROGEN AND PHOSPHOROUS in the soil. These elements get caught in GROUND WATER where they are carried to LAKES AND PONDS. This basically means that we are FERTILIZING THE WATER which allows ALGEA (A PHOTOSYNTHETIC PROTIST) to rapidly grow. This creates an ALGAE BLANKET on the water that prevents any sunlight from getting in. This causes the DEATH OF THE PLANTS AND EVENTUALLY THE DEATH OF ALL ANIMALS in the body of water.

  1. Answer the following questions concerning the PHOSPHOROUS CYCLE.
  2. Why do we need phosphorous?

ATP, Phospholipids, DNA/RNA

  1. What process removes phosphorous from rocks?Weathering
  1. Answer the following questions about the PYRAMID OF ENERGY.
  2. How much energy is passed on to each trophic level? 10% passed on (90% used up/lost)
  3. What happens to all of the energy that is not passed on?

Each trophic level USES the energy to make ATP to maintain homeostasis, move, grow, etc. As ATP is used, energy is LOST AS HEAT.

  1. Answer the following questions concerning the PYRAMID OF NUMBERS and the PYRAMID OF BIOMASS.
  2. What does each of these demonstrate (you need a separate answer for each pyramid)?

Pyramid of Numbers = the population of a community decreases by 90% each trophic level because the energy decreases by 90% (so there isn’t enough energy to support as many organisms)

Pyramid of Biomass = the amount of biomass (dry organic weight – mostly proteins) decreases by 90% each trophic level for the same reason

  1. Why do both of these mirror (look like) the Pyramid of Energy?

Reason explained above

  1. Answer the following questions concerning the TYPES OF DISPERSION.
  2. List and describe the 3 types of dispersion.

Clumped = organisms stay in packs, herds, schools, etc.

Uniform = organisms stay equal distances from each other (everyone has their own space)

Random = some organisms are close and some are far (there is no pattern to the location)

  1. What are the benefits of each of the 3 types of dispersion?

Clumped = organisms help each other to stay alive if they’re prey, help each other to hunt if they’re predators, and for social companionship

Uniform = territorial organisms that fight to preserve their own space, food, water, etc.

Random = there is no real benefit to this dispersion. It is plants that are wind/water/animal distributed so they can’t choose where they go. they have to be able to survive close to others or far away.

  1. Which is the most/least common?

Clumped = most common because they help each other

  1. Answer the following questions concerning the POPULATION GROWTH.
  2. How are exponential and logistic growth different?

Exponential = UNREGULATED growth. Population density does not affect it. It is IDEALIZED growth where the population DOUBLES every generation.

Logistic = Growth that is affected by population density. The population reaches a CARRYING CAPACITY where there are LIMITING FACTORS (SPACE, FOOD, WATER, ETC.) that slow the population growth rate to 0 (equal birth and deaths)

  1. Draw a graph showing each of the population growth methods listed in part a. against time.

On Next Page

LOGISTIC GROWTH

EXPONENTIAL GROWTH

  1. What happens to the growth rate once it reaches the carrying capacity?

Equals 0 (equal birth and death)

  1. What are limiting factors?

Factors that LIMIT the population size (Size, Space, Food, Competition, Disease, Etc.)

  1. List and explain the three types of survivorship curves.

Type 1

Survive to old age.

Humans, large mammals

Produce few offspring & provides good care.

Type 2

Likelihood of death constant throughout life.

Lizards, rodents, birds.

A straight line on a graph = constant rate

Any prey

Type 3

Low survival rate for the very young.

Oysters, invertebrates, seed plants

Produce large numbers of offspring & little care.