Bio 2 exam 3

What symmetry is this?

Bilateral

What symmetry is this?

radial

What symmetry is this?

porifera/asymmetric

Whats the definition of a biome?

major type of habitat characterized by distinctive plant and animal life

What are the abiotic factors that affect terrestrial and aquatic organisms:

light, wind, temperature, water availability, pH, and salinity

How can temperature affect organisms?

inability to regulate body temperature

How can low temperatures affect organsims?

can be lethal if cells rupture and plants with poisonous chemical defenses

How can high temperatures affect terrestrial organisms?

fire

How can high temperatures affect aquatic organisms?

coral bleaching

How can wind affect aquatic organisms?

intensify ocean waves

How can wind affect terrestrial organisms?

increase rate of heat loss leading to water loss in organisms

How does light affect organisms?

necessary for photosynthesis, photic zone

Whats the photic zone?

a narrow zone close to the surface of an aquatic environment, where light is sufficient to allow photosynthesis to occur

How does salinity affect aquatic organisms?

Fresh water fish cannot survive in salt water because they have a greater concentration of solutes and vice versa.

How does salinity affect terrestrial organisms?

salt in the soil affects plant growth, halophytes

What are halophytes?

a plant that can survive in higher salinity

How are aquatic organisms affected by pH?

Optimal pH for freshwater fish is between 6.0-9.0. Acidity increases amount of toxic metal like mercury

What is the normal pH for rain water?

5.6

What pH do plants grow best in?

6.5

How can pH affect terrestrial organisms?

Acid rain- precipitation with a pH less than 5.6 results from burning fossil fuel

Whats the definition of population?

same species same environment

What the definition of community?

different species interacting in the same environment

Whats the definition of population density?

the number of organisms of a given species in a given unit

What are the techniques to calculate population density?

visually counting, quadrat, line transect, mark-recapture, collar with tracking devices, and drones

Population density: visually counting

calculate density of small aera and then used to estimate large area, use amount of ground covered to estimate

Population density: Quadrat

sampling device with a square frame that often enclosed an area of 0.25m^2, not effective for larger plants

Population density: Line transect

number of plants located along the string are counted

Population density: mark-recapture

capture animals then release them, mix freely with unmarked, animals learn to avoid traps

Whats the equation equation for the mark-recapture technique?

Total population size = (number of marked individuals in first catch x total number of second catch)/number of marked recaptures in second catch

What are the patterns of spacing?

clumped, uniform, random

What is clump pattern spacing?

most common, individuals gather in small groups

What is uniform pattern spacing?

individuals maintain a certain minimum distance between themselves to produce an evenly spaced distribution

What is random pattern spacing?

rarest pattern, location of an individual lacks a pattern

What does it mean when r=0?

exponential growth is reached

What does exponential growth look like on a graph?

J-shaped

When does exponential growth occur?

when resources are unlimited

What happens to the line on the graph when the r value becomes larger?

the stepper the line

When does logistic growth occur?

when resource are limited

What is the equation for logistic growth?

(r x N) ((k-n)/k)

What does each letter mean in the logistic growth equation?

k-carrying capacity, r-per capita growth, N-population size

What does logistical growth look like on a graph?

S-shaped

What happens to populations when r>0?

increases

What happens to populations when r<0?

decreases

Whats the definition of dispersion?

the extend to which individuals in a population are clustered together or spread out

Whats the definition of carrying capacity?

maximum amount of organisms that can be supported by resources present

What is density independent?

a morality factor whos influence is not affected by changes in the population size or density

What is density dependent?

 morality factor whos influence decreases as population size increases

What is resource partitioning?

similar species coexist by using resources in different places or at different times

What are the types of species interactions?

predation, competition, parasitism, mutualism, commensalism, and amensalism

Species Interaction: predation

an interaction in which the action of a predator results in the death of its prey

Species Interaction: Competition

interaction that affects two or more species negatively, compete over food or resources

Species Interaction: Parasitism

symbiotic association in which one organisms feeds off another but does not normally kill it

Species Interaction: Mutualism

both species benefit

Species Interaction: Commensalism

one species benefits and leave the other unaffected

Species Interaction: Amensalism

 one sided competition between species, detrimental to one species but not the other

What are pathogens?

agents that cause disease symptoms in humans and other species

How are pathogens spread?

number of susceptible hosts (Ns), transmission rate (B), and the period of time a host remains infected (L)

What is the equation for calculating the spread of pathogens?

R0=(Ns)(B)(L)

what does R0 mean when calculating the spread of pathogens?

basic reproduction number, the average number of new cases of a disease that arise from each infected host

What is herd immunity?

A pathogen will die out within a population when a certain percentage of individuals become immune to the pathogen

Whats bottom up?

plants are controlling how many of each, If you have a lot of plants you’re going to have a lot of herbivores, then carnivores

Whats top down?

controls the hypothesis saying predators are controlling how much prey are present, the more predators the less prey

Whats the definition of an ecosystem?

system formed by interactions between abiotic and biotic community of organisms in an area and the abiotic environment affecting the community

What are primary consumers?

herbivores

What are secondary consumers?

eat primary consumers, carnivores

What are tertiary consumers?

eat secondary consumers, secondary carnivores

What is the facilitation mechanism?

Early species help others grow, until stronger species take over

How is facilitation mechanism determined?

climate, soil conditions, frequency disturbance

What is the inhibition mechanism?

where early colonists exclude subsequent colonists

What is the tolerance mechanism?

Any species can begin succession, and early species don’t affect later species

Example of food chain

Plant (primary producer autotroph) → Caterpillary (primary consumer herbivore)  → Lizard (secondary consumer carnivore) → snake (tertiary consumer secondary carnivore)

Whats a food web?

interconnected food chains, multiple links among different species

What species richness?

the number of different species in a community

Whats the species-time hypothesis?

Temperate regions have fewer species than tropical ones because they’re younger

Whats the species-area hypothesis?

Bigger areas have more species because they have more space and habitats

Whats the species-productivity hypothesis?

proposes that greater production by plants result in greater overall species richness

how is productivity influenced?

factors like rainfall and temperature

Definition of asymmetric

no plane of symmetry like sponges

Definition of radially symmetric

divided equally by any longitudinal plane passing through the central axis; jelly fish

Definition of bilaterally symmetric

 divided along a vertical plane at the midline to create two halves

What are the body cavities?

coelom, coelomate, pseudocoelom, and acoelomates

Whats the coelom?

fluid filled in an animals

Whats the function of the coelom?

cushions internal organs and prevents injury

Whats the coelomate?

an animal with true coelom, completely lined with the mesoderm

Whats the Pseudocoelom?

not completely lined by mesoderm

Whats the Acoelomates?

an animal that lacks fluid filled body cavity

Whats the definition of germ layer?

embryonic cell layer such as ectoderm, mesoderm, or endoderm. No sponges

Whats the endoderm?

inner layer of cells that line the primitive digestive tract

Whats the ectoderm?

outer layer; differentiates into the epidermis and the nervous system

Whats the mesoderm?

middle layer of bilageria and forms muscles and most organs

What does segmentation allow?

specialization of body regions

What are the characteristics of animals?

heterotrophs, capacity to move, ability to reproduce sexually, lack cell wall, and multicellularity.