biology test 3

Biology 107 with Gardner at Boston University

About this deck

By: catherine carchedi
Textbook: Life + Bioportal + Lecture 9th Ed
Created: 2010-11-10
Size: 94 flashcards
Views: 50

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What are the levels of biological organization

molecule, organelle, cell, tissue, organ systems, organism
organism, population, community, ecosystem, biosphere

Solar Energy

determines climate
-depends on angle of sun gives seasonality
variation with latitude

What is causes certain seasons?

earth's axis
-different parts of the earth are pointed towards the sun and away from the sun depending on the month

which part of earth gets the most solar energy

equator
-because of the sunlight on the equator- it rains a lot- because the sun causes the air to be warm, this warm air rises, and it loses its moisture

cool dry air descends and absorbs moisture from the surface of the earth
-at 30 S and 30 N of equator dry air descends towards earth --> desert

What is 60 degrees north and south of the equator?

forests

Solar radiation

causes the patterns of the winds, ocean circulation and air circulation

What are prevailing winds?

they cause upwelling in the ocean--> deep water is brought to the top
-this brings a lot of nutrients to the top --> a lot of diversity

What causes a rain shadow?

on mountain ranges, warm air rises and releases moisture and then that air crosses the mountain with no more moisture and then there is a desert on the other side of the mountain

What are the typical global air patterns?

in the northern hemisphere- the winds go clockwise
in the southern hemisphere- the winds go counterclockwise
the winds converge along the equator

Fact

Abiotic factors tell who or what lives in a certain area or doesn't live in that particular area

Biome

area characterized by similarity
-overtime there can be convergent evolution because of similar selective pressures in a biome

Trend in all biomes except one exception (tropical evergreen forests)

the more southern the biome is located- the richer the soil and more species abundance

Tundra

most north - arctic circle; permafrost- permanently frozen; poor soil; poor species richness; not a lot of rain

Boreal Forest

2- evergreen trees- with adaptation= don't drop needles which allows photosynthesize

Temperate Deciduous forest

3- us ; on coastline - migration

Temperate grasslands

4 midwest ; rich soil

Hot desert

5; 30 N and 30 S
does have species abundance; adaptations of animals

cold desert

seeds--> food for birds

chapparal

thrives with fire
smaller biome
rich soil

Tropical savannah

disturbance is necessary unless it becomes a thorn forest

tropical deciduous forest

very rich soil; stopping ground for migratory birds

Tropical evergreen forest = rain forest

on equator- low soil richness; all nutrients within plants **exception to trend

Borneo experiment

logging- does it cause damage to populations?
they looked at bird and beetles
result: 75% of species still present; some even further diversified
=anthropogenic changes may not be that bad!

novel ecosystem

modified by people but not managed by them; this is about 30 % of land on the planet

What is Wallace's line? what did this lead to?

it divides malaysia
- on either side of the islands there are extremely different species
this discovery led to the study of biogeography

What is biogeography?

the study of where species, populations and communities are located
how and why things are where they are

Endemic animals

only in certain regions
-hot spots- a lot of endemic species

What is biotic interchange?

it occurs when changes in sea levels alter access to different areas
-this and continental drift affect where species disperse

What is vicariance and dispersal

both of these explain the discontinued range
-vicariance: when a physical barrier splits species
-dispersal: species cross a barrier

Fact

Humans are helping the movement of plants and animals

Hibernation

winter sleep

Estivation

summer sleep

Diapause

insect sleep

biological antifreeze

how animals deal with the cold

migration

get out of an area to a better climate

morphological adaptations

they evolve so that they can best fit with a certain climate- like penguins

behavioral adaptations

change how you act so that you can live in different climates; iguana sits in sun to get hot; jumps off rock to get cool = stilting

What is the benthic zone?

the bottom of the ocean; it is very cold, has very high pressure; animals that live there need to be very well adapted; there is no light and therefore no photosynthesis; bioluminescence is very prevalent

Freshwater enviroments

have great diversity
-have 10 percent of all aquatic species

estuaries

where salt and fresh water meet; species diversity

population

animals of the same species that interact with one another in a certain place at a certain time

studying populations

density: # of individuals per unit area
+birth and immigration; -death and emigration

What are the characteristics that change in a population

age structure: shows individuals across age categories
-a cohort is made of individuals of the same age
reproductive capacity: varies with age; we can tell if a population will grow based on how many organisms are in reproductive years

Organization within a population (3 types)

clumped : when the presence of one individual causes all the others to come to the same place- social environment- like a human environment
regular: one individual causes others to stay away- maybe because of competition
random: rare! equal probability of occupying a certain region or not

How do ecologists study behavior- how do you calculate the second method

-census--- counting all individuals (know ages and the rates they come and go)
-mark-recapture method- mark organisms ; the number of organisms is equal to: total number captured in first sample x total captured in 2nd / #of marked in 2nd

What are ecologists concerned with with populations?

the rate at which they grow or decrease

equation to describe population changes

N1= N0 + (b-d) +(i-e)
N1= organisms at a certain time
N0= original number of organisms
b=births
d=deaths
i=immigration
e=emigration

life tables

keeps track of demographic events; predict future trends
shows survivorship (Ix) - organisms alive at a later date - shows probability of given cohorts to survive
mortality- proportion of each age class that is going to die before it reaches the next class

fecundity

number of offspring each female has; shows what age has the most fecundity
-greater fecundity can be linked to an increase in rainfall which led to an increase in vegetation

fact about life tables

the values in life tables are determined by an organism's environment, population density, and life history

Survivorship curve- Type 1

high survival rate through adulthood- they have parental care and a low fecundity (this is like humans)

Survivorship curve- Type 2

its a diagonal- so there's an equal change of mortality at all ages
birds

Survivorship curve type 3

they die pretty young; they produce many offspring but have no parental care- this explains the death of the young - but mortality levels off as age increases

intrinsic growth rate (r)

the max rate of increase of a population per individual; r= births - deaths

Reproductive rate

it is a part of life history ;
parity = how often reproduction occurs
semelparous- they produce once but in big numbers of offspring (type 3 S.C curve)
iteroparity:- they produce many time in their lifetime but they only have small numbers of offspring every time (Type 1 or 2 S.C curve)

exponential growth

even when the intrinsic rate is constant- if population size increases than the population density increases - half a u shape curve

unrestricted growth

like the reindeers- this growth could have long term effects on an environment

calculating exponential growth

change in individuals/change in time= birth - death
dN/dT = (b-d)N (b-d)=r --> rN = potential of the population when no limits are present

carrying capacity

for a short time organisms can have exponential growth but then it levels off because of external factors; has an S shaped curve

calculating carrying capacity

dN/dt = rN (K-N) / K K is the preemption of resource
growth will stop when N=K when dN/dt = 0

limits to growth rate- the two factors

density dependent : depends on how many are in a certain area- food
density independent- has nothing to do with the amount of organisms- climate

life history strategies - r

r - strategists: high intrinsic rate of increase--> unstable; want exponential growth so they have a lot of offspring one time (semelparity) with little or no parental care; can inhabit a lot of different places; develop quickly; short life;

k strategists

specific habitat; long maturation; reproduce many times with few offspring - iteroparity; long life; slowly rising population growth- levels off ; stable

Why do some species reach high densities?

non specific resources
small body size - they take up less space so more people can inhabit one place
social organization- help them to come together in one place
new species that come into the area exist in high densities

facts

birth rate is highest when a population is below carrying capacity so reducing a population may just make it increase faster

having a predator come into an area could result in the predator taking over

human population pyramids

in 3rd world- there's a lot of young people but there is a high mortality rate when you are older so this could lead to population growth because more are in their reproductive ages

in germany- there is an inverted structure so the population would decline

coevolution arms race

a change in one species is caused by having to change because of another species
stepwise reciprical adaptations

Antagonistic interactions

predation (+,-) - one species kill the prey
-predators have certain adaptation and tricks to catch prey

defensive adaptations for prey to avoid predation

chemical defense
cryptic coloration: you can't tell them apart from certain environments
homotypy: the organism tried to resemble something else like poop
aposeomatic coloration- animals try to signify to others that they are inedible with their colors
batesian mimicry- an harmless(palatable) creature will mimic a harmful creature
mullerian mimicry- two or more unpalatable- harmful creatures resemble each other so it gives them a better chance of being avoided by predators

herbivory

plant is eaten - two types
polyphagus- many different plants are eaten by one type of species
oligophagous - a herbivore only eats a singly type of plants- most insects are this

how can oligophagous herbivores help the environment

they can maintain a population - like if they only like a certain tree- it can cause the tree population to exists in small numbers

fact

if chemicals reduce herbivory than that genotype is favored but sometimes the herbivore can adapt resistance to that chemical and then the resistant herbivore can take in that chemical and use it to hurt other organisms--> this is a sign of coevolution

Parisitism

(+,-) a parasite is able to thrive in a host- but a host can end up being depleted by the parasite

mutualism

(+,+) both species benefit- like a tree is protected by ants and the ants are able to eat the plant
- this particular tree wouldnt even survive without the ants

intraspecific interactions

nonrelated species interact
1. reciprocity- you do for me and i will do for you
2. mutualism- shared benefit
3. manipulation- to get one species to interact in a certain way for it to be beneficial to the other species

competition mechanisms

competitive exclusion: when 2 species are trying to get the same resource one of them might prevent the other species from using that resource
resource partitioning; this is when two species share resources- coexistence
interference competition: you have 2 species- one physically stops the other from reaching the resource
exploitation competition: 2 species one uses up all the resources before the other can get to it

how can species that are competing live together?

if there is a predator that gets rid of the better competitor
or if if they only are able to use a different part of a resource like a different area

character displacement

competition effects this - like darwin's finches with the beak size- when they live together the resources are divided up because they evolved so that they each could use their own type of seed
or like when bees arnt present the birds with have wings that are really small to get nectar from flowers

Niches

fundamental : physiological capability
realized niche: from the interactions with other species

rare relationships in nature

Commensalism : one benefits the other isnt harmed or hurt- like a buffalo stir bugs to come above ground and then the egrets can get them- doesnt affect buffalo
amensalism- one species is harmed , the other is neither harmed or hurt ; when a herd steps on grass

Community

group of organisms that interact and share an environment
they revolve around energy flow - trophic levels

ancient agro ecosystem

leaf cutter ants have a very complex cycle of gathering food - they have evolved to grow bacteria themselves because without it their whole community would have no food source

what is the main source of energy for most communities

SUN! but not all cases because like deep see vents

trophic level

as you go up- you lose energy ; metabolism gives of the most energy through heat

gross and net primary productivity

gross- the rate that primary producers turn the energy from the sun into chemical energy through photosynthesis
net primary productivity: the amount of primary producer biomass is available for heterotrophs **this is what matters because the producers lose energy
GPP - R(energy lost)= NPP

transfer of energy in trophic levels

inefficient- because only 10 percent is transferred because it is mostly heat loss because of the biomass may not be available maybe because of a chemical that inhibits from being consumed and even indigestibility- like if it was a piece of bark

ecological efficiency

the transfer of energy from one trophic level to the next; ratio of consumer production to producer production
it shows the proportion of energy consumed that is put to use (more in carnivores) and the proportion of energy that is put into growth
-the growth is what moves on to the next trophic level

FACT

the majority of the energy organisms consumes goes into self maintenance
successive loss of energy is why biomes can only really support 3 -5 trophic levels

Trophic cascades

abiotic and biotic influences the trophic cascades

happens when there are direct correlations between the interactions of species or/and the environment like wolves and moose

causes restructuring of the community

an outside community can have an affect too

keystone species

strong control over structure of the community; it doesn't have to be the most dominant species; they just have a lot of control because of their niches

measures of diversity

alpha diversity- within a single community
beta diversity- between- habitat diversity ; change from one community to another
gamma diversity- regional diversity over a range of communities in a region

what is species diversity determined by ?

1. species richness- total number of species in a community
2. relative abundance (evenness) : proportion of each species to the entire community - shows if there is a dominant species

if there is evenness there it is more diverse

Species richness trend with latitudes

highest at equator
if you go up in latidude- north or south- species richness declines

4 hypotheses for the trend across latitudes

1. time: species in tropics have had a constant climate for such a long time that they were able to adapt
2. spatial heterogenity- tropics are complex; so more niches--> more species diversity
3. specialization: more competition--> narrower niches--> more total species
4. predation: with high predation population are small so there is less competiton which leads to more species richness

About this deck

By: catherine carchedi
Textbook: Life + Bioportal + Lecture 9th Ed
Created: 2010-11-10
Size: 94 flashcards
Views: 50

About StudyBlue

“I have been getting MUCH better grades on all my tests for school. Flash cards, notes, and quizzes are great on here. Thanks!”
Kathy