Download AP Biology Summer Assignment Ecology Unit Chapter 52 1. Define

AP Biology Summer Assignment
Ecology Unit
Chapter 52
1. Define the following words:
Population -a group of individuals of the same species living in an
area
Community -a group of populations of different species in an area
Ecosystem -the community of organisms in an area and the physical
factors with which those organism interact
Biosphere - The part of the earth and its atmosphere in which living
organisms exist or that is capable of supporting life.
Habitat -place where an organism or a biological population normally
lives or occurs
Niche -the specific area that on organism inhabits; the role or
function of an organism or species in an ecosystem
2. In seeking to find out why species are found in certain areas of the world,
ecologists focus on two kinds of factors, abiotic and biotic. Describe both of
them.
Abiotic: non living factors- all the chemical and physical factors
such as temp, light, water, and nutirents.
Biotic: living factors- all the organisms that are part of an individual's
environment (competition, predators, disease)
3. The biosphere is divided into regions called biomes. Biomes exhibit common
environmental characteristics. Unique communities or ecosystems of plants and
animals occupy them. The following is a list of major biomes. Give a summary
of their characteristics.
Tropical rain forest
-about 200-400 cm of rain annually
-high air temperatures year-round
-canopy blocks much sunlight
-high animal diversity
Desert
-precipitation is low and highly variable
-temperature is variable seasonally and daily
-dominated by low, widely scattered vegetation; much bare ground
-animals include snakes, lizards, scorpions, ant, beetles, etc.
-many nocturnal species
Savannas
-seasonal rainfall; averages 30-50 cm a year
-warm year-round
-scattered trees, often thorny with small leaves
-fires are common in the dry season
-large plant-eating mammals, but dominant herbivores are insects
Chaparral
-precipitation is highly seasonal; rainy winters, long dry summers; annual
precipitation is 30-50 cm
-fall, winter, and spring are cool; average summer temperature can reach 30°C
-dominated by shrubs and small trees, along with many kinds of grasses and
herbs; high plant diversity
-native mammals include browsers (like deer and goats) and a high diversity of
small mammals; also support many species of amphibians, birds, and other
reptiles and insects
Temperate grasslands
-precipitation: often highly seasonal; relatively dry winters and wet summers;
annual precipitation is between 30 and 100 cm; periodic drought is common
-winters generally cold, summers are hot
-dominant plants are grasses and forbs; many are adapted for periodic drought
-native mammals include large grazers; wide variety of burrowing mammals
Northern Coniferous Forest (Taigas)
-annual precipitation ranges from 30 to 70 cm; periodic droughts are common;
however some are temperate rain forests that may receive over 300 cm
-winters usually cold and long; summers may be hot
-cone-bearing trees
-many migratory birds nest here; mammals include moose, brown bear, and
Siberian tigers; periodic outbreaks of insects that feed on dominant trees
Temperate Broadleaf or Deciduous forests
-precipitation can average from about 70 to over 200 cm annually; significant
amounts fall during all seasons
-winter temperatures average around 0 degrees Celsius; summer are hot and
humid
-distinct vertical layers; few epiphytes, dominant plants are deciduous trees
-many mammals hibernate in winter, while many bird species migrate to warmer
climates
Tundra
-precipitation averages from 20 to 60 cm annually but may exceed 100 cm in
alpine tundra
-winters are long and cold; summers are short with low temperatures
-vegetation is mostly herbaceous; permafrost restricts the growth of plant roots
-animals include large grazing musk oxen; caribou and reindeer are migratory;
predators include bears, wolves, and foxes; many bird species migrate to the
tundra for summer nesting
4. List some freshwater biomes.
-lake, pond, streams, rivers, wetlands
5. Describe the following marine biomes:
Intertidal zones
-oxygen and nutrient levels generally high
-substrates generally rocky or sandy
-high diversity and biomass of attached marine algae inhabit rocky
areas; sandy areas generally lack attached plants or algae
-rocky: many animals have structural adaptations allowing them to attach to the
hard substrate
-sandy: many animals bury themselves and feed as the tides bring sources of
food
Oceanic Pelagic zone: includes those waters further from the land, basically the
open ocean. The pelagic zone is generally cold though it is hard to give a general
temperature range since, just like ponds and lakes, there is thermal stratification
with a constant mixing of warm and cold ocean currents. The flora in the pelagic
zone include surface seaweeds. The fauna include many species of fish and
some mammals, such as whales and dolphins. Many feed on the abundant
plankton.
Coral reefs: are widely distributed in warm shallow waters. They can be found
as barriers along continents (e.g., the Great Barrier Reef off Australia), fringing
islands, and atolls. Naturally, the dominant organisms in coral reefs are corals.
Corals are interesting since they consist of both algae (zooanthellae) and tissues
of animal polyp. Since reef waters tend to be nutritionally poor, corals obtain
nutrients through the algae via photosynthesis and also by extending tentacles to
obtain plankton from the water. Besides corals, the fauna include several species
of microorganisms, invertebrates, fishes, sea urchins, octopuses, and sea stars.
Marine Benthic zone: area below the pelagic zone, but does not include the
very deepest parts of the ocean (see abyssal zone below). The bottom of the
zone consists of sand, slit, and/or dead organisms. Here temperature decreases
as depth increases toward the abyssal zone, since light cannot penetrate through
the deeper water. Flora are represented primarily by seaweed while the fauna,
since it is very nutrient-rich, include all sorts of bacteria, fungi, sponges, sea
anemones, worms, sea stars, and fishes.
Chapter 53
1. Population ecology is the study of the growth, abundance, and distribution of
populations.
Population abundance and distribution are described by the following
terms: Define them.
A. Size of the population: the number of individuals living inside the
boundaries of the population
B. Density of the population: number of individuals per unit area or volume
C. Dispersion (which of the three type is most common): the pattern of
spacing between the individuals within the boundaries of the population;
clumped is the most common
D. Age structure: the relative number of individuals of each age in a
population
E. Survivorship curves: plot of the proportion or numbers in a cohort still
alive at each age
2. One species of forest bird is highly territorial, while a second lives in
flocks. Predict each species' likely pattern of dispersion and explain.
The bird that is territorial will most likely have uniform dispersion because
each individual has its own section of territory
The flocked birds will most likely be clumped because they will gather where
the resources are favorable for living
3. Draw a chart showing the three types of survivorship curves.
Distinguish between Survivorship curves Type I, II, and III. Give an
example of an organism that displays each of these types of curves.
Large mammals that provide good care for offspring are a type I curve. Type II
has a constant death rate throughout the lifespan of the organism such as some
rodents. Type III is when the organism produces large amounts of offspring and
does not care for them such as many fishes do.
4. The traits that affect an organism's schedule of reproduction and
survival make up its life history.
Life history traits are products of natural selection.
There are two main types of life history traits:
Describe and give an example of each type.
1. Big-bang reproduction or semelparity: the organism tries one time to
reproduce and then dies afterward; Pacific salmon and agave plants do this
2. Repeated production or iteroparity: reproduce annually for several years;
some lizards do this
5. How do the following terms describe population growth?
biotic potential-plenty of resources means maximum reproductive capacity
leading to exponential growth
carrying capacity- the maximum population size that can be supported by the
available resources, this means the population is going to level
off
limiting factors- density-dependent
if they are density dependent then the death rate will rise and the
birth rate will fall with a rising density
If population density is high it means the population will be
decrease due to disease, competition etc.
density-independent
birth or death rate that does not change with population density
Population size is not affected by increase in population number.
6. Describe and diagram the two general patterns of population growth.
They are
exponential growth-growth of a population in an ideal,
unlimited environment, represented by a J-shaped curve
when population size is plotted over time
logistic growth- per capita rate of increase approaches zero as
the carrying capacity is reached
7. The logistic model and life history p. 1185
Compare the two life strategies of r-select and K-select organisms.
-K selected species live in populations that are at or near equilibrium conditions
for long periods of time. Competitive for limited resources is very important for
the environment.
ex. lemurs, giraffes, elephants, bats
-R selected species live in populations that are highly variable. The fittest
individuals in these environments have many offspring and reproduce early.
ex. mosquitoes, Daphnia, goldenrod
Chapter 54
1. Interspecific interactions are interactions of organisms with individuals of
other species in the community.
Describe the following interspecific interactions.
Use the following symbols (+, -, o) to show how these interactions affect
the survival and reproduction of two species that are involved.
Competition -/- occurs when individuals or different species
compete for same resources
Predation +/- occurs when one species the predator kill and
eats the other the prey
Herbivory- ( +/- ) interaction in which an organism eats parts of a
plant or alga
Parasitism- ( +/- ) symbiotic interaction in which one organism, the
parasite, derives its nourishment from another organism, its
host, which is harmed in the process
Mutualism- ( +/+ ) interaction that benefits both species
Commensalism- ( +/0 ) benefits one of the species, but neither harms
nor helps the other
2. The following concepts describe the two ways in which competition is
resolved.
The competitive exclusion princeple (Gause's principle)- two species
competing for the same limiting resources cannot coexist in the same place. in
the absence of disturbance, one species will use the resources more efficiently
and this reproduce more rapidly than the other. even a slight reproductive
advantage will eventually lead to local elimination of the inferior competition, an
outcome called competitive seclusion
Resource partitioning- the differentiation of niches that enables similar species
to coexist in a community; “the ghost of competition past”- the indirect evidence
of earlier interspecific competition resolved by the evolution of niche
differentiation; when competition between species with identical niches does not
lead to local extinction or either species, it is generally because one species'
niche becomes modified- evolution by natural selection can result in one of the
species using a different set of resources
Character displacement (niche shift)- the tendency for characteristics to be
more divergent in sympatric populations (geographically overlapping) of two
species then in allopatric (geographically separate) populations of the same two
species; example: variation in beak size between different populations of the
Galapagos finches
Realized niche- the portion of its fundamental niche that it actually occupies in a
particular environment
3. Coevolution
In the contest between predator and prey, some prey may have unique
heritable characteristics that enable them to more successfully elude predators.
Similarly, some predators may have characteristics that enable them to more
successfully capture prey. The natural selection of characteristics that promote
the most successful predators and the most elusive prey leads to coevolution of
predator and prey. Coevolution is the evolution of one species in response to
new adaptations that appear in another species.
These are some import examples of coevolution.
Define these terms and tell how they have helped predators or prey to
become more successful.
Secondary compounds- are found in plants as products from bio-chemical
pathways that are offshoots of basic metabolism. They are called secondary
compounds because the compounds were not part of primary metabolism
Camouflage (cryptic coloration)- makes prey difficult to spot; this is helpful to
the prey so the predators have a harder time finding the prey to eat them
Aposematic coloration (warning coloration)- animals with effective chemical
defenses exhibit this; ex. poison of dart frog; seems to be adaptive: there is
evidence that predators are particularly cautious in dealing with potential prey
having bright color patterns
Mullerian mimicry- two or more unpalatable species resemble each other; ex.
cuckoo bee and yellow jacket; each species gains an additional advantage
because the more unpalatable prey there are, the more quickly and effectively
predators adapt, avoiding any prey with that particular appearance
Batesian mimicry- palatable or harmless species mimics an unpalatable or
harmful model; involves behavior; ex. larva of the hawkmoth puffs up its head
and thorax when disturbed to look like the head of a small poisonous snake
4. Two dominant features of community structure are species diversity and
feeding relationships.
A. Describe the two components of species diversity.
Species richness: number of different species in a community
Relative abundance: proportion each species represent of all the
individuals in the community
B. Feeding relationships or the trophic structure of the community
Describe each trophic level in the food chain
Primary producers: plants and other autotrophic organisms
Primary consumers: herbivores that eat the plants
Secondary consumers: carnivores that eat the herbivores
Tertiary consumers: carnivores that eat the previous carnivores
Quaternary consumers: carnivores that eat the precious carnivores
Decomposers: break down the dead organic matter
5. How does a food web differ from a food chain?
food webs are made up of food chains that are linked together
6. Why are food chains relatively short?
-energetic hypothesis: the length is limited by the inefficiency of energy transfer
along the chain
-dynamic stability hypothesis: long food chains are less stable than short
chains
7. Why do dominant species and keystone species exert strong controls on
community structure?
dominant species:because they are the most abundant or collectively have the
highest biomass
-keystone species: have pivotal ecological roles, or niches
8. Distinguish between primary and secondary succession.
-primary succession: when ecological succession begins in a virtually lifeless
area where soil has not yet formed
-secondary succession: when an existing community has been cleared by
some disturbance that leaves the soil intact
9. Give an example of primary succession.
-when ecological succession begins on a new volcanic island or on the rubble left
by a retreating glacier
10. Give an example of secondary succession.
-Yellowstone following the 1988 fires