Bio Lecture Exam 4

conservation, population, community, and biomes

 Define Extinction

The complete loss of a species

List a few of the examples mentioned in the learning module on Bb

EX Dodo bird, Golden toad, Tasmanian tiger

 Describe the Endangered Species Act of 1973

Made after public concern due to increasing numbers of extinction use to prevent loss of biodiversity and maintain variety of living organisms

Define mass extinction and its causes

Species loss that is global, affects large numbers of species and is dramatic in impact 50-90% of all living species lost, caused by changes in sea levels, climate fluctuations, shifts in ocean and land from continental drift, and asteroid impact.

How many previous mass extinctions have there been?

5

What is the background extinction rate?

Rate of which species are lost from normal evolution (to be considered extinct there must be no sight of the species in 50 years)

What is the current extinction rate?

0.005%

What is Habitat destruction

the natural home/environment of an animal, plant, or other organism

What is Species-area curve

The relationship between the size of an area and the number of species that it can support, and predicting the loss of species that would correspond to a loss of habitat area

What is Habitat fragmentation

Subdividing one large habitat into several smaller sections

What is an Invasive species

An organism that is not native and has negative effects on our economy, our environment, or our health (not all introduced species are invasive)

What is Over-harvesting/over-exploitation

Cultures using animal parts for medicine, rituals, etc (tiger skin rug, rhino horn medicine)

 What is Pollution

Release of poisons, excess nutrients, and other waste into the environment (fertilizer runoff leading to algae bloom)

What is Eutrophication

depletion of oxygen in water resulting in large fish death

 Describe a food web and know what impact a break in this web (via extinction) can cause

Complex linkage among organisms within a community

Describe a food chain

The flow of energy in one direction within an ecological system

What is a Producer

Photosynthetic organisms (plant)

What is a Primary consumer

Feeds on the producer (mouse)

What is a Secondary consumer

Predators feed on the primary consumers (snake)

What is a Tertiary consumer

Feeds on secondary consumer (hawk)

Mutualism

Association increases the growth or population size of both species

Competition

Two species of organisms both require the same resources in a habitat

Commensalism

Increases the growth or population size of one species and does not affect the other species.

Predation

Consumption of one organism by another

Parasitism

Consumption of one organism by another

Define keystone species and give a few examples.

A single species that indirectly affects more than one other species to the extent that if removed the community collapses EX (Yellowstone Wolves)

What is a biological hotspot and why do we want to protect them?

Regions contain a high level of species diversity, many endemic species (species not found anywhere else in the world), and a significant number of threatened or endangered species.

What is ecotourism, what are the benefits?

Responsible travel to natural areas which conserves the environment and improves the welfare of local people

What is genetic drift and how does this relate to extinction?

The chance change in the frequency of an allele within a population, the more a population decreases the increase of genetic drift occurs 

What is so great about genetic variability within a species?

High genetic variability = high fitness

Define ecology

The study if the interactions that living things have with each other and with their environment

 How does ecology differ from conservation biology?

Ecology studies the interactions that living things have with each other and their environment while conservation biology is concerned with preserving natural resources

Define the following important levels of biological organization:

1. Biosphere

2. Ecosystem

3. Community

4. Population

What is Population

All the members of a single species that live together in a specified geographic region

What is Community

Populations in a given area that potentially interact with one another

What is Ecosystem

Community of organisms and the physical environment with which they interact

What is Biosphere

Interactive collection of all the Earth’s ecosystem

What is Population distribution

How organisms are distributed in a space

What is Population abundance

How a population changes across space and time

What is Clumped distribution

High densities in resource-rich areas, low densities elsewhere (most common)

What is Uniform distribution

Individuals are equally spaced out (seen in bird nesting)

What is Random distribution

Occurs when no compelling factor is bringing individuals together or pushing them apart (seen mostly in plants)

 Describe the following ways ecologists estimate population size

Droppings count,  Mark-recapture method, and Transect sampling

What is Droppings count

Counting animal droppings within a defined area

What is Mark-recapture method

Capturing animals and leaving a mark such as a ring or a number on them before releasing

What is Transect sampling

Points are located at specific distances along a transect, sampling is then done at the point itself.

  Describe how exponential growth and logistic growth differ.

Exponential Growth: J-shaped growth curve

Logistic Growth: S-shaped growth curve

Define carrying capacity (k)

The maximum population that can be supported by a given environment, because food supplies and space are limited.

Describe why a population might have a slower growth

Environmental Resistance

What is environmental resistance?

All the forces of the environment that act to limit population growth

What are density dependent factors?

Food supply, increased risk of disease, and increased risk due to waste accumulation

What are density independent factors?

Severe weather, and extreme temperatures

 How do ecologists estimate population growth?

Using birth rates and death rates

Define growth rate

Percent change in population size in a given time period

If a population of 200 birds produces 15 chicks, what is the birth rate? If 5 birds die that year, what is the death rate? What is the growth rate?

What is the intrinsic rate of increase?

The rate at which a population would grow if there were no external limits on its growth

What are K-selected species

Equilibrium species

Population size: limited by carrying capacity, density dependent, relatively stable

Organisms: large, long lived, fewer offspring, greater parental care

What are R-selected species

Opportunist species

Population size: limited by reproductive rate, density independent, relatively unstable

Organisms: small, short-lived, many offspring, no parental care

What is a population crash and what causes it?

A steep decline in population can be caused by number of deaths being too high while birth rates are low after a too large population competes for too few resources

 What is a population cycle and at what point does it eventually (hopefully) stabilize at? 

When a population crashes over and over again as a result of a tendency to grow beyond carrying capacity it may stabilize at carrying capacity.

Define community.

It is an assemblage of species living close enough together for potential interaction

What is species richness?

The number of species found in a community

What is relative abundance?

The percentage composition of an organisms of a particular kind relative to the total number of organisms

Interspecific interactions

Relationships between the species of a community

What is Competition

Occurs when resources are limited

Interspecific competition 

Occurs when resources are limited

Predation

A predator eats prey

Mutualism

Both species involved benefit to some extent with neither species being harmed.

Commensalism

an association between two organisms in which one benefits and the other derives neither benefit nor harm

Describe an ecological niche and give some examples. 

The role a species plays in the ecosystem EX the habitat in which the organism lives or organism use of biotic and abiotic resources in its enviroment

 Describe the competitive exclusion principle. 

No two similar species occupy the same niche at the same time

What are the possible outcomes of competition and how does this affect the individual species? 

Extinction of one species, resource partitioning (splitting the niche), character displacement ( two similar species evolve in such a way as to become different from each other by accentuating their initial minor differences

Describe resource partitioning. 

Sympatric species consume slightly different resources or use resources in slightly different ways

What is the difference between allopatric populations and sympatric populations? 

allopatric speciation occurs in geographically separated populations while sympatric speciation occurs in populations that could share a geographical area within the range of the ancestral population. EX beak depth

What are Predators

Animals that eats prey

What are Herbivores

Animals that eats plants

What are Parasites

Predator live on/in a host and depend on the host for nutrition

What are some predator adaptations? 

Claws, teeth, fangs, poison, heat sensing organs, speed and agility

What are the outcomes of predator-prey interactions?

Offset oscillations in the population size of the predator and pray

 Describe the lynx and hare oscillation. Why do you suppose the spikes in lynx and hare populations are always in harmony? 

They have a predator-prey relationship, as hare numbers start to decline, lynx numbers would go up however when hares become scares lynx numbers also decline.

What are some plant and animal defenses from predation?

Plants: Chemical compounds that are toxic

Animals: Behavioral defenses include fleeing, hiding, self-defense, noises, and mobbing.

What are Endoparasites

Lives inside the host

What are Ectoparasites

Lives on the surface of the host

What are Parasitoidism

A special type of parasitism where the parasite eventually kills the host

Describe the trophic levels (again) all the way up to quaternary consumers

A community is determined by the feeding relationships between organisms

1. primary producers (plant)

2. primary consumers (bug)

3. secondary consumers (mouse)

4. tertiary consumers (snake)

5. quaternary consumers (hawk)

Be able to describe the keystone species examples

Sea otters in kelp forest, Wolves in Yellowstone

Paine’s study on Piaster and blue mussels

With Pisaster number of species is on a steady rise, however without the number declines

Describe the various stages of ecological succession

1. New bare land

2. Colonizing stage (herbs & grasses)

3. Successionist stage (shrubs)

4. Climax stage (pine forest)

Forests and Scrubslands

•Forests are communities dominated by trees and other woody plants

•Occupy about 1/3 of Earth’s surface

•Account for 70% of

  Earth’s biomass

Tropical Rain Forests

•At or near equator

•High biodiversity

•Rapid decomposition

•Lots of water

•Warm temperatures

•Nutrient poor soil

•Central/South  America,

 Central Africa, India,

Southeast Asia, Indonesia

Temperate Forests

•Seasonal changes

•Large trees w/ broad leaves - deciduous

•Nutrient rich soil

•Mostly in Eastern N. America, Central Europe, Eastern China

Boreal Forests

•Largest biome on earth

•Long, cold, snowy winters

•Coniferous trees dominate/evergreens

•Short growing season

•Not too many humans

•N. America, N. Asia/Europe
(close to poles)

Chaparral

•Not a forest; mainly shrubs

•Long, dry summers

•Frequent/essential fires

S. California, Mediterranean

Grasslands

•Dominant plants are grasses

•Few shrubs/trees

Tropical grasslands

•Called savannas

•Africa, India, S. America, Australia

•Support huge herds

   of large mammals

Temperate grasslands

•Tallgrass – prairies

•Shortgrass – steppes

•Central N. America, C. Asia, Southern S. America

•Vegetation height correlates w/rain amt.

Desert

•Less than 20 in. rain/year

•Usually close to the equator

•Sahara, Gobi, SW US, Australia

•Plants and animals have adaptations to conserve water

Tundra

•Coldest temperatures

•Areas closest to poles

•Permafrost – frozen ground

•Small plants/Grazing animals

•Growing season: 50 to 60 days/year

•Animal adaptations:

–Extra fur/feathers

–Hibernation

–Fat storage

–Migration

Freshwater Biome

•Low salt concentration (> 1%)

•3 types:

–Lakes and ponds

–Rivers and streams

–Wetlands

 Lakes and Ponds

•Inland bodies of water

•Different zones: Surface/shore, Deep water

•Algal blooms caused by excess nutrients