practice quiz

Question 1

use the example of the California sea otter to explain why ecologists must study multiple hierarchical levels to understand most environmental problems

Answer 1

• they are a predatory and prey trophic level
• when their predators (whales) can’t find seals, they’ll eat otters
• when the sea otters can’t find food, they eat fish
• sea otters are usually herbivores, but they can be carnivores
• food availability above and below

Question 2

explain how increased atmospheric carbon dioxide can affect the ability of coral to build their exoskeletons?

Answer 2

• atmospheric CO2 is absorbed by the ocean, causes acidification
• acidification reduced the availability of carbonate ions (CO2 + H2O –> carboxyl acid –> bicarbonates–> none left), less available to form calcium carbonate for exoskeletons

Question 3

how does size affect heat exchange in animals?

Answer 3

• larger bodies can retain heat better (cold environments)
• increase in surface area = increase in heat loss

Question 4

how could you measure the success of a diet?

Answer 4

biomass (how much nutrients you actually get)

Question 5

what are the two ways that vertical mixing of waters in lakes and oceans affects the primary production?

Answer 5

INCREASE PRODUCTIVITY:
- it can bring the deep, nutrient-rich water to the surface where phytoplankton can use it
DECREASE PRODUCTIVITY:
- it can also carry phytoplankton down to the deep water, where they will die because of the low light conditions
- When phytoplankton die, primary production may shut down in the deep water and little primary production will occur in the nutrient-rich waters at the surface.

Question 6

why do giraffes have long necks?

Answer 6

sex- fighting for mates

Question 7

Hadley cells cause:

Answer 7

• major effects on weather patterns
• why equator/deserts are hot
• why tropics have moisture

Question 8

Apex predator

Answer 8

top predator in food chain; highest trophic level

Question 9

do freshwater fish need to drink water?

Answer 9

no, they have a higher solute concentration than the water around them
- net influx of water over entire surface (osmosis)
- hypertonic
- sodium and chloride ions diffuse out, gills move them up gradient to maintain concentration

Question 10

do saltwater fish need to drink water?

Answer 10

yes, they have a lower solute concentration than the water around them (hypotonic)
- water flows out, drink water

Question 11

freshwater fish have more __ cells in their lamellae than saltwater fish

Answer 11

chloride
- keeps sodium levels high (hypertonic)

Question 12

freshwater excrete ___ urine, while saltwater fish excrete ___ urine.

Answer 12

• freshwater = lots of diluted urine
• saltwater = concentrated urine

Question 13

as water flows over fish gills, they extract ___ from the water.

Answer 13

some O2, diffuses into blood

Question 14

as water flows forward over gills in one way, ___ flows in the opposite direction because…

Answer 14

blood flows in the opposite direction because O2 concentration in higher in the water
- most oxygenated blood exchanges w/ most oxygenated water

Question 15

lots of bacteria doing decomposition in water causes decreased ___ availability

Answer 15

O2

Question 16

freshwater holds more ___ than salt water

Answer 16

O2

Question 17

where is the highest productivity? also the higher O2 levels?

Answer 17

the ocean

Question 18

“oikos” means…

Answer 18

house

Question 19

C4 occurs in the

Answer 19

bundle sheath