Exam 1

Question 1

What is ecology?

Answer 1

study of the interactions between organisms and their environment

Question 2

What kind of interactions does ecology look at?

Answer 2

Energy loss/gain, population dynamics, etc.

Question 3

How do ecologists answer their questions? (2)

Answer 3

Mathematical models and manipulative experiments

Question 4

Explain the difference in warmth between the equator and the poles of the earth

Answer 4

At the poles sunlight hits the earth at an angle and thus the rays are spread over a larger area, making the energy less concentrated while at the equator the rays hit the earth near to perpendicular, so there is more solar energy per unit area.

Question 5

How do the angles the sun hit the earth (equator vs. poles) influence air currents?

Answer 5

Since the equator is warmer, this causes air to lift towards the atmosphere, creating a low pressure area (Hadley cell), while in the poles the cold air pulls air downwards creating a higher pressure (polar cell). The movement of air between these two cells is driven by the the movement of the cells and by the exchange of energy at the polar front

Question 6

How do the cells described earlier in combination with the earths spin create the patterns of air movement at the earths surface?

Answer 6

the air at the equator will flow in the opposite direction of the earths spin and the combination of air currents moving away from high pressure or towards low pressure areas creates weterlies and easterlies as shown in figure 2.9 (pg 28)

Question 7

Climate

Answer 7

Long term description of weather at a given location

caused by earth’s tilt (latitudinal climate patterns) and proximity to oceans

Question 8

potential evapotranspiration (PET)

Answer 8

max amount of water expected to be lost from the landscape by evaporation and/or transpiration under climatic conditions (assuming NO water limitation)

Primary driver = temperature

Question 9

actual evapotranspiration (AET)

Answer 9

water actually lost from a landscape by evaporation and transpiration

Primary drivers = temperature and percipitation

Question 10

What type of biomes have the most PET?

Answer 10

Those that are hot

Question 11

What type of biome will have the most AET?

Answer 11

Those that are hot and wet (have more water to lose) ie.// tropical rainforest has a higher AET than a desert since there is less water available to lose in a desert

Question 12

What if the earth did not have a tilt?

Answer 12

No seasons, there would be less land at a liveable temperature

Question 13

What if the earth had a more dramatic tilt?

Answer 13

Seasons would be more extreme and it would be harder to survive year round in a given area

Question 14

what determines ocean currents?

Answer 14

surface winds

Question 15

Local factors that influence climate (5)

Answer 15

Rain shadow, continent size, elevation, vegetation, topography (slope direction)

Question 16

Tropical rainforests

Answer 16

High growth rates multiple layers (diversity)

Precipitation outweighs water loss due to temperature all of the year

Question 17

Polar regions

Answer 17

scattered cover, low temperatures, high winds, dry, low growth rates

Question 18

Tropical seasonal forests/savannas

Answer 18

Some of the year low precip, some high. Wet and dry seasons. Somewhat lower diversity and growth rate. Frequency of fires in dry season influences plant life. more shrubs etc than trees

Question 19

Deserts

Answer 19

Sparse populations, high temp, low water availability, usually around 30* latitude N and S (high pressure areas)

Question 20

Temperate grasslands

Answer 20

seasonal variability (warm wet, cold dry), frequent fires, grass dominant

Question 21

Temperate shrub and woodlands

Answer 21

seasonality of precipitation, somewhat diverse, some fires

Question 22

aquatic biomes

Answer 22

Fresh or saltwater-> influences strategy to minimize water loss/gain

Deep vs shallow water (temperature more influenced by air temp in shallow water), available light changes as well

Moving vs. still water

Tidal zones: variation in wet vs. dry and temperature

Question 23

Lotic

Answer 23

moving freshwater

Question 24

lentic

Answer 24

still freshwater

Question 25

Estuarine

Answer 25

at river junctions, salinity varies due to proximity of ocean and tidal behavior

Question 26

Salt marshes

Answer 26

Often next to estuaries, salinity gradients based on plant tolerance to salinity, flood often

Question 27

Mangroves

Answer 27

shallow estuaries inhabited by salt tolerant trees and shrubs

Question 28

coral reefs

Answer 28

warm shallow ocean waters, slow growth but very diverse, production rate highest on earth

Question 29

rocky intertidals

Answer 29

influenced by tides (species need to be able to deal with temperature change and change from wet to dry environments)

Question 30

Acclimation

Answer 30

individual’s response to a factor

Question 31

Adaptation

Answer 31

evolutionary response across generations

Question 32

Acclimatization

Answer 32

individual’s response to many factors

Question 33

endotherm

Answer 33

animal capable of internal generation of heat

Question 34

ectotherm

Answer 34

animal dependent of external sources for heat

Question 35

homeothermy

Answer 35

organism maintains body temp at constant level

Question 36

poikilothermy

Answer 36

organism’s body temp adjusts depending on the environment

Question 37

osmoconformation

Answer 37

Allowing salt levels to change with environment (strict osmoconformers cannot regulate their salt levels)

Question 38

osmoregulation

Answer 38

Using energy to regulate internal salt levels (strict regulators maintain a constant salt level no matter what environment)

Question 39

isosmotic

Answer 39

two areas with same osmotic pressure (concentration solutes)

Question 40

hypoosmotic

Answer 40

solution of lesser concentration (freshwater is hypoosmotic compared to sea water)

saltwater fish lose water to osmisis because they are hypoosmotic compared to their environment and this must drink more water to compensate for water loss, excrete more concentrated urine, and have transporters that actively transport Cl- and Na+ out of their cells

Question 41

hyperosmotic

Answer 41

solution of greater concentration (sea water is hyperosmotic compared to freshwater)

freshwater fish are hyperosmotic compared to their surroundings (must take in more salt and excrete dilute urine)

Question 42

Light curves (incident light vs. photosynthetic rate of plants)

Answer 42

plants in shady environments will plateau sooner as not used to getting much light

Question 43

Shade vs. Sun leaves

Answer 43

Sun leaves thicker and less broad to fit more photosynthetic machinery and less pigment as sunlight is not the limiting factor

Question 44

Competitive species

Answer 44

dominate under low disturbance and stress conditions

Question 45

Ruderals

Answer 45

dominant under conditions of high disturbance and low stress

Question 46

Stress tolerant

Answer 46

dominant under high stress and low disturbance conditions