Chapter 50● Biosphere

○ Anywhere you can find life● Biomes

○ Characterized by biotic factors (food chains) and abiotic factors ( temp, amount of rainfall)

● Vertical stratification○ Canopy○ Permafrost

■ Root layer in arctic tundra● Terrestrial biomes- found on land

○ Tropical■ Between the 23’s■ Large amount of rainfall,■ Weather changes rapidly→ from sun to rain■ Climate is stable■ Most diverse wildlife and plant life■ Most dangerous animals

○ Savanna■ Grassland w/ scattered trees (diff. species)■ 3 seasons

● Cool dry● Wet dry● Warm wet

■ Frequent fires○ Desert

■ Classified by amount of moisture■ 30 cm rainfall/yr■ Cool: no sand, west of rockies■ Hot: northern africa, middle east

○ Chaparral■ Spiny, tough plants, low-lying■ Foggy, rainy, hot climate■ Along coastline (cali)■ Seattle, oregon■ Periodic fires

○ Temperate grasslands■ Plains of US■ Colorado, nebraska, oklahoma■ Rich soil, most farms

○ Deciduous Forest■ Leaves fall off trees■ Huge range in temperature

○ Coniferous Forest (in the taiga)

■ Cone-breading trees■ Harsh winds■ North america■ Not great soil

○ Tundra■ According to elevation■ Limited plant life■ arctic→ north pole, limited light, permafrost layer

■ alpine→ not as cold, towards equatorFreshwater Biomes

● Vertical Stratification○ Photic

■ Upper zone, light for photosynthesis■ Plankton, zooplankton, phytoplankton

○ Aphotic ■ Lower, little light, cold■ Broken down plant material

○ Thermocline layer■ Can sometimes be in the middle

○ Benthic zone■ Bottom■ Occupied by communities of organisms called benthos■ Major source of food is called detritus

● Broken down leaves and stuff● Sometimes, when lake heats up, it rises up● Helps circulate material to plankton and organisms● Called convection

● Freshwater Biomes○ Littoral zone

■ Rooted and floating plants flourish here■ Shallow, well-lit, close to the shore

○ Limnetic zone

■ Well-lit, open surface■ Farther from the shore■ Occupied by phytoplankton

○ Profundal zone

■ Lower ○ Streams and rivers

■ Moving● River, stream

■ Not moving● Lake, pond (freshwater)

○ Ponds and Lakes■ Oligotrophic

● deep water● No phytoplankton● Nutrient poor lake

■ Eutrophic● Dark life● Shallow● A lot of life, phytoplankton

■ Mesotrophic ● Somewhere in between

■ Changing from one to the other● Oligo→ Eutroph● Due to runoff excessive amounts of nitrogen and phosphorous● Makes water unusable

○ Rivers and Streams■ Starts off

● narrow, straight ● cold

■ Starts to ● neander, curve, slow down

● valley widens○ Wetlands

■ Aquatic plants○ Estuary

■ Where freshwater stream merges with ocean■ Bordered by wetlands■ Algae, phytoplankton

● Marine Communities○ Stratification

■ Photic zone and aphotic zone■ Intertidal

● Where land meets water■ Neritic zone

● Shallow region over the continental shelves■ Oceanic zone

● Reaches very great depths■ Pelagic zone

● Open water of any depth■ Benthic zone

● Bottom of seafloor

● Abyss○ Intertidal zones

■ Twice-daily cycle of tides■ Organisms are subject to mechanical forces

● Some bury themselves in the sand● Some are scavengers on these organisms

○ Coral reefs■ Formed by cnidarians■ Forma substrate on which algae can grow■ Obtain nutrients from photosynthesis of symbiotic algae that live in their

tissue○ Oceanic pelagic Biome

■ 75% of earth■ Produce rainfall, climate conditions, wind patterns■ Organisms in it produce 02

● Phytoplankton■ Creatures absorbing CO2

● Zooplankton■ Examples of abiotic factors

● Temp, amount of available water● Available sunlight, ,Wind patterns, periodic disturbances

○ Benthos■ Nutrients rain down in the form of detritus■ Cold, dark■ Very productive■ Deep-sea hydrothermal vents

Chapter 52● Population ecology

○ Individuals of the same species that occupy the same area and use same resources

○ All blue whales in Pacific Ocean● Density

○ # individuals per unit area● Dispersion

○ Pattern of spacing○ Can measure the quadrants○ Gives you density; cant do this for birds, must capture and tag them○ Mark-recapture method

■ Mark the birds, let them go, recapture them

○ Patterns of dispersion■ Spacing takes place on range■ Clumping

● Advantage in many ways

● Schools of fish make them seem like a large organism● Scares off prey● Mating can take place● Friendly form of spacing

■ Uniform● Birds are very territorial● Emperor penguins

■ Random● More for plants than to animals

● Demography○ Study of vital statistics that affect population size○ Age structure

■ If v. young better than older, high death rate■ If old: can’t reproduce

○ Generation overlap■ generation : time between birth and reproduction

○ Sex ratio■ Number males to females■ More females beneficial

● Life table○ Describe how mortality varies with age over certain time period○ Mortality summaries○ Cohort

■ A group of individuals of the same age○ Survivorship Curve

■ Plot of the number of cohorts still alive at each age■ 3 types■ Type 1

● Flat at start, drops steeply as death rates increase● Humans● K

■ Type 2● Somewhere in between● Squirrels

■ Type 3● Very high death rate as young

○ Clams

○ R ● Biotic Potential

○ Maximum growth rate of a population under ideal conditions■ Number of reproductive episodes■ Survivorship of young

○ Opportunistic life history ■ Based on large number of offspring ■ Size of population fluctuates because of environmental factors, survival

rate, etc○ Equilibrial life history

■ Repeated production of small number of offspring ■ Sizes vary less dramatically

● Change in population size○ Births-deaths

● Population growth○ Exponential

■ Population increases rapidly■ r selected populations■ Human pop growth

○ Logistic population growth■ Rate slows as N approaches K■ K selected populations■ Carrying capacity

● Regulation of population size○ Density dependant factors

■ Intensifies as population size increases■ resources

○ Density independent factors■ Natural disasters

Communities● Multiple populations in a given area● Coevolution

○ Change in one species bring on change (is a selective force) on another○ Most are predator-prey relationships○ Some are symbiotic relationships

■ Parasitism, commensalism, etc● Predation

○ organisms feed off of each other○ Predators have specific characteristics

■ Acute senses■ Owls makes sound waves ■ Birds have binocular vision ■ Claws, sharp teeth, poison

○ Prey defense■ Plants have thorns and poison■ Cryptic coloration (camo)

● Makes prey difficult to spot● Prey go for back part, fish swims away

■ Mechanical defense ● Monarch butterfly● Porcupines have quills

■ Chemical Defense ● skunk ● Plants have poison

■ Aposematic Coloration● Brightly colored means it is poisonous

■ Mimicry: one looks like the other● Predator knows it tastes bad → won’t want to eat it● Batesian: palatable/unpalatable resembles unpalatable● Mullerian: two unpalatable resemble each other: similar warning

systems● Attracting prey by the predator

○ Alligator snapping turtle○ Look like alligator○ Their tongues attract prey to them

● Interspecific Competition○ Two or more species rely on the same limiting resource○ Competitive exclusion principle : two organisms can’t reply on same resource set

w/out it being detrimental to both○ Ecological niche

■ What an organism carves out for itself/needs■ Fundamental: ideal, w/out worrying about impact on other organisms■ Realized: actual space/resources utilized

○ Resource partitioning■ Organism with more options shifts to the available option■ Partition resources into different areas so everyone can survive

○ Dominant species■ highest abundance, most prominent

○ Keystone species exert strong control on community structure■ Not particularly abundant, not dominant■ Remove them, community falls apart

● Niche○ Total organism's use of resources: abiotic and biotic○ Have a role in community (prey, predator, producer, decomposer)○ Fundamental Niche

■ Resources the organism is capable of using under ideal circumstances (won't run out)

○ Realised Niche■ Have to fight for it■ Realistic

○ Resource partitioning■ Division of land depending on diff resources■ Each is a niche, very stable community, organisms occupy each niche

● Symbiotic○ E-coli in body, parasite on animal○ Host and symbiont-3 possibilities○ Parasite

■ +/-■ One goes inside body

● Endoparasitic● Tapeworm

■ One lives outside● Tick● Ectoparasitic

○ Commensalism■ +/0 ■ Barnicle on whale

○ Mutualism■ +/+ ■ Lichen on rocks

● Fungi and pants■ Pioneer organisms

● Stable community○ Is vegetation produced>○ What is trophic structure?○ Species richness○ Ability to resist change and recover

● Ecological Succession○ Lichen turns rock into soil○ Grow into low lands○ Grows into different environments until climax community○ Primary succession

■ 2nd succession is after natural disasterChapter 45 Ecosystems

● Ecosystem consists of all organisms in a given area sharing their abiotic factors○ No real boundaries○ 2 major processes: energy flow; chemical cycling

● Energy flow○ Trophic levels//feeding patterns○ Food chains

■ Sunlight hits primary producers● They get the most energy

■ It’s energy gets passed along to a primary consumer● They eat only plants (herbivores)

■ Primary consumer eaten by primary consumer● Situation 1: carnivore● Situation 2: omnivore

■ Tertiary consumer eaten by secondary consumer■ Eventually, detrivore (decomposers)

● Breaks down things● Bacteria, fungi● Scavengers

■ Food webs are food chains put together■ Organisms use 90% of energy, 10% is passed on

○ E-budget■ Sunlight hitting earth organisms absorb 1% of sunlight■ Energy pyramid

● Primary producers have most organisms, keeps going less as you go up

● AKA: pyramid of biomass, pyramid of energy, pyramid of numbers● Numbers decrease as you go along

■ Primary Productivity● GPP : gross primary productivity

○ Determined by measuring total amount of oxygen made from a photosynthetic process

● NPP : net primary productivity○ Equal to the GPP-RS (cell respiration reactions)○ Accounts of organic mass, or biomass

■ Mass of the biological material○ Varies among ecosystems

■ Rain forests are the most productive ecosystems, followed my estuaries and coral reefs

■ Lowest are oceans● Cycles

○ Nutrient cycling■ Resevoir: way to store certain types of chemicals

● Put them in storage and take them out of storage■ 1) available organic reservoir

● This contains all the living organisms and their nutrients● When one animals eats another, it's using the available organic

reservoir■ 2) unavailable organic reservoir

● Carbon based structures that cannot be used● Cannot be directly assimilated, but go through many steps to be

used● Coal, oil

■ 3) available inorganic reservoirs● Elements, ions, molecules present in the soil, air, or water● Assimilate these when we take the into our bodies

■ 4) unavailable inorganic● Rocks● Made up of minerals: limestone● Cannot be assimilated but can be released by 1 process called

weathering■ Can transfer this energy from reservoir to reservoir

● Help transfer btwn unavailable inorganic to available organic● Weathering

○ Break down of material○ Rainfall, temperatures can do this

● Erosion ○ Taking those weathered pieces of rock and moving them

from one place to another○ Wind erosion, water erosion○ Can help w/ transfer of materials from unavailable

inorganic to available inorganic○ Carbon-Oxygen cycle

■ Relationship between photosynthesis and cell respiration● Energy coupling

○ Nitrogen cycle■ 80% of air is nitrogen■ Nitrogen is water soluble: raindrops gather nitrogen into them, goes into

the ground■ 1) nitrogen fixation

● nitrogen fixing bacteria● Found in roots of legumes● Live in nodules● Absorb nitrogen, change into

■ 2) ammonification● Organisms and Fungi

○ Break down into ammonia

○ Then change into another substance that can be used easily

■ 3) Nitrifying Bacteria● Passes this along to nitrifying bacteria● Change nitrogen in one form N03 into N02● This can be absorbed by plants all over the earth

■ 4) denitrifying ● Decomposers that put nitrogen back into the atmosphere● As they are breaking things down, nitrogen is released and turned

into gas● Phosphorous Cycle

○ 3 reasons why we need phosphorous ■ ATP■ Lipid bilayer■ DNA

○ Stored in rocks○ There is weathering of rocks, broken down by smaller pieces○ Absorbed by plants○ Follows groundwater, deepest parts of the oceans, becomes rock again

● Water cycle● Human disturbance

○ DDT ■ Was a highly toxic substance used to kill bugs on crops■ Got into groundwater, which emptied into lakes rivers and streams■ Went through the foodchain, got amplified■ Highly toxic in large quantities■ Bald eagles got affected; decalcified the eggs of the female

Chapter 51 Animal Behavior● Behavior

○ Instinct■ Innate■ Born with it

○ FAP (fixed action pattern)■ Innate■ Initiated by specific stimulus■ Behavior carried out to completion■ Type of bird nests on the ground; if by chance an eggs falls out of nest,

mother will take certain amount of steps to roll it back■ If u put a little rock on the ground, it will tap the rock back into the nest

○ Imprinting■ Innate behavior; gets passed along during critical period■ When hatchlings are born, first thing they see they learn is their mom and

will follow it○ Associative

■ AKA classical conditioning■ Pavlov’s dogs■ When animals understand their is an action that follows a stimulus■ Recognize connected events■ Ringing of bell and food

● Salivate at the ringing of the bell○ Trial and error

■ Operant conditioning■ Type of learning■ 2 types of learning: negative and positive■ Reinforcement■ Mouse going down maze: two diff kind of feedback in the maze, learn the

desirable and undesirable actions○ Habituation

■ So used to do something it's habit forming○ Observational learning

■ Copying■ Monkey see monkey do

○ Insight■ Exposed to a situation, have to figure out how to solve the problem

● Behavior○ Kenisis

■ Adding a stimulus and animals respond to it in a random direction■ When you lift a rock and the bugs scatter all over the place

○ Taxis■ Moving in a specific direction depending upon stimulus■ Phototaxis: moth going towards light■ Sharks: chemotaxis–towards blood

○ Migrational■ Seasonal■ Responding in change in season

● Communication○ Chemical

■ Insects gives off pheromone, communicates to other animals○ Auditory

■ Sounds■ Whales make the sounds■ crickets

○ Visual■ Diff displays can be given that other animals of the same species

understand■ Aggression■ submissive

○ Tactile

■ Animals touching each other in certain ways■ Honeybees clamor around a single bee

● Bee does a dance in a figure 8● Social behavior

○ Feeding■ animals come together in a pack■ Animals that are travelling in groups

○ Altruistic■ Certain animals give off alarm calls■ Prairie dogs

○ Territoriality ○ Dominance hierarchies

Sample Essays1. Organisms rarely exist alone in the natural environment. The following are five

examples of symbiotic relationships. Chose four of the below examples and, for each: identify the participants involved in the symbiosis and describe the symbiotic relationship. Discuss the specific benefit or detriment, if any, that each participant receives from the relationship

● Plant root nodules○ Plants/bacteria○ Mutualism - both benefit○ Plants receive nitrogen while bacteria receive CHOs and other nutrients/water and

shelter/protection from the environment● Digestion of cellulose

○ Termites/bacteria○ Mutualism - both benefit○ Microorganism breaks down cellulose because termites cannot; host gets

energy and nutrients from cellulose, microorganism gains food and shelter/protection from the environment

● Epiphytic plants○ Large trees (plants)/epiphyte/bromeliads/orchids/some mosses/ferns○ Commensalism - one benefits, the other is not affected○ Smaller plant grows upon another (larger) plan (tree) t; it benefits but does not

affect the larger one○ Host is not affected (neither a negative nor positive impact on it), symbiont has a

substrate for anchoring/access to sunlight & pollinators● AIDS (acquired immune deficiency syndrome)

○ Human/(retro)virus (HIV)○ Parasitism - parasite (virus) benefits at the expense of the host

○ HIV uses host cell to replicate while the host/immune system is harmed or killed by the reproduction and spread of the virsus -- HIV kills helper T cells and as a result the body cannot activate the proper cells needed to kill invaders, so the body becomes very susceptible to disease and dies from a common one

● Anthrax○ Human or cow or horse/bacteria or spores○ Parasitism - parasite benefits at the expense of the host○ Bacterial disease affecting skin and lungs - happens in sheep or cattle, can be

transmitted to human○ Bacteria receives nutrients from and a habitat in the host, which becomes ill

or dies2. In many ways, all organisms in a food web can be said to be solar-powered. The producer level of the food web is responsible for the transformation of the solar energy into a form that can be used by other living organisms.

a. Discuss the role of green plants in transforming the Sun’s energy into a form that can ultimately be used by heterotrophs.

i. Plants undergo photosynthesis in which they use light energy (from the sun) to convert CO2 into organic molecules (sugar)

1. Light dependent reactions produce NADPH and ATP which are used in subsequent light independent reactions (calvin cycle) in which the CO2 from the atmosphere is fixed into sugar

2. The chloroplast is required for photosynthesis - location of processes, captures light energy and starts processes

ii. Sugar produced in photosynthesis is what heterotrophs use as fuel and nutrients; eat plants to obtain the sugar

b. Discuss the flow of energy from producers through top carnivores in a food web in terms of the laws of thermodynamics.

i. First law of thermodynamics: energy cannot be created nor destroyed, only converted; second law: as energy is transferred/transformed, more and more of it is wasted

ii. Primary producers create food and are eaten by primary consumers (herbivores) which are eaten by secondary consumers (carnivores) which are eaten by tertiary consumers (carnivores)

iii. Only around 10% is actually passed onto the next level; the higher the trophic level you go, the less energy there is

iv. Producers have the highest amount of energy; carnivores, and specifically tertiary consumers, have the least amount of energy

3. Compared with other terrestrial biomes, deserts have extremely low productivity.a. Discus how temperature, soil composition, and annual precipitation limit productivity in

deserts.i. Temp: increase in evaporation/transpiration lowers

photosynthetic rates; not optimal temps → metabolic enzymes/proteins hindered

ii. Soil composition : low organic content/nutrients lowers photosynthetic rate/plant growth; low water retention lowers photosynthetic rate/plant growth

iii. Annual precipitatio n: low rainfall means there is not a lot of water available for photosynthesis

b. Describe a four-organism food chain that might characterize a desert community, and identify the trophic level of each organism

i. Primary producer: cactusii. Primary consumer: mouseiii. Secondary consumer: snakeiv. Tertiary consumer: hawk

c. Describe the results depicted in the graph. Explain one anatomical feature and one physiological difference between species A and B that account for the CO2 uptake patterns shown. Discuss the evolutionary significance of each difference.

i. Plant A takes up CO2 during day, plant B takes up CO2 at nightii. Stomata location (pits/crypts, underside stems) is linked to CO2 uptakeiii. Physiological: stomata of species A opens during the dayiv. Increased evolutionary significance due to decrease in water loss in desert

environment; adaptation to open at different times of day based on when it will be more productive (?)

4. According to fossil records and recent published observations, two species of leaf-eating beetles (species A and B) have existed on an isolated island in the Pacific Ocean for over 100,000 years. In 1964 a third species of leaf-eating beetle (species C) was accidentally introduced on the island. The population size of each species has been regularly monitored as shown in the graph above.

a. Propose an explanation for the pattern of population density observed in species C.i. Exponential growth - J shaped curve ii. Lack of limiting factors, low competition for resources, abundant

food, low predation, ideal environmental conditions, access to matesb. Describe the effect that the introduction of beetle species C has had on the population

density of species A and species B. Propose an explanation for the patterns of population density observed in species A and in species B

i. Species C had little to no effect on species A, as its population size stayed roughly the same throughout

1. Little to no competition between the two species, no niche overlap

ii. Species C had an effect on species B; as species C increased, species B decreased

1. Competition and high niche overlap - species C, as is typical of invasive species, outcompeted species B and was more able to obtain resources

c. Predict the population density of species C in 2014. Provide a biological explanation for your prediction.

i. The population will continue to increase because of its access to resources, which are/will be abundant, and the lack of competition (barely any w/ species A, species B will be extinct by then)

d. Explain why invasive species are often successful in colonizing new habitats.i. Have a new evolutionary advantage brought to new habitat from their

old one; chemical defense, flight advantage, novel enzyme, etc

5. Many populations exhibit the following growth curve:

a. Describe what is occurring in the population during phase A.i. Population growth slows as population reaches carrying capacity -

levels offii. Exponential phase - period of rapid growthiii. Lag phase - population grows slowly/does not grow

b. Discuss THREE factors that might cause the fluctuations shown in phase B.i. Change in availability of resources - may be harder to obtain at some

times and easier at othersii. Predation - more prey, more predators → less prey; less

prey, less predators → more prey

iii. Reproduction - varying number of offspring produced/survived in different periods

c. Organisms demonstrate exponential (r) or logistic (K) reproductive strategies. Explain these two strategies and discuss how they affect population size over time.

i. Exponential reproductive strategies: many offspring, higher reproductive capacity, rapid sexual maturation -- allow more animals to mate and reproduce quickly; great fluctuations in population size

ii. Logistic strategies: few offspring, lower reproductive capacity, slow sexual maturation -- mating and reproduction takes longer and yields fewer offspring; population stabilizes around carrying capacity (k)

7. Interactions among populations may have an effect on densities of the species that interact. Predation represents an important interaction among populations, the curves below depict the population densities of three species: a small herbivore, a larger herbivore, and a carnivore.

Identify which curve represents which of the species listed, and justify your answer by describing the changes in the population densities of these three species over time.

● Curve A: large herbivore, pop not affected by predators in curve c, food sources constantly available - eats diff food than small herbivore

● Curve B: small herbivore, largest pop size, shortest generation time, pop decreases as predator increases

● Curve C: predator, smallest pop size, increase follows increase of prey (herbivores), which drives decrease of prey (herbivores)

8. The energy flow in ecosystems is based on the primary productivity of autotrophs.

a. Discuss the energy flow through an ecosystem and the relative efficiency with which it occurs.

i. Primary producers create food through photosynthesis, in which light energy is utilized to create cellular energy

ii. Primary producers are eaten by primary consumers (herbivores) which are eaten by secondary consumers (carnivores) which are eaten by tertiary consumers (carnivores)

iii. Only around 10% is actually passed onto the next level; the higher the trophic level you go, the less energy there is

iv. Producers have the highest amount of energy; carnivores, and specifically tertiary consumers, have the least amount of energy

b. Discuss the impact of the following on the energy flow on a global scale.i. Deforestation

1. Trees are cut down, habitats destroyed -lowers food supply-, getting rid of a lot of primary producers, aka the first source energy

2. Interrupts ecosystem and natural processes3. Less producers → less energy available → primary

consumers have less food → die off → secondary have less food → die off → tertiary have less food → die off; CHAIN RXN

ii. Global climate change1. Climate change is the alteration of climate/global warming or

cooling2. Increase/decrease in number of producers → increase or

decrease in energy → ecosystems are less productive (changed)