chapter 46 - ecosystems - (lecture 6)

Question 1

a community interacting with its environment via the ongoing flow of energy and a cycling of nutrients

Answer 1

ecosystem

Question 2

autotrophs

Answer 2

• producers (primary)
• capture sunlight or chemical energy
• are the catalyst to energy flow

Question 3

heterotrophs

Answer 3

• get energy and organic nutrients by feeding on tissues, wastes or remains of other organisms
• also known as consumers

Question 4

herbivore

Answer 4

eats plants (90%)

Question 5

carnivore

Answer 5

eats meat (90%)

Question 6

omnivore

Answer 6

eats both plants and meat (≤ 89%)

Question 7

parasite

Answer 7

relies on other organisms by siphoning their host’s nutrients or consuming directly from them

Question 8

decomposer

Answer 8

consumes remains, dead body parts, breaks things down

Question 9

detritivores

Answer 9

consume particulate organic matter; turn organics into inorganics

Question 10

how are lines between types of consumers blurry? give an example

Answer 10

many animals consume both plants and meat, in different stages of life, and in different seasons.

ex: foxes consume largely fruit in the summer, and more rodents and birds in the winter. the ratio of their diet changes, so it becomes a question on how to define that

Question 11

trophic level

Answer 11

the position of an organism in a food chain

Question 12

within each trophic level…

Answer 12

• all the organisms are the same number of steps away from the energy input into the system

Question 13

which trophic group is closest to the energy input?

Answer 13

producers

Question 14

the highest predator, typically a tertiary or quaternary consumer, is sometimes called…

Answer 14

an apex predator

Question 15

should we use the term food web or food chain? why?

Answer 15

food webs are better to use because they include all the possible paths for energy flow within the trophic levels

Question 16

the rate at which producers capture and store energy (varies between ecosystems and producers)

Answer 16

primary production

Question 17

stored glucose in plants is called…

Answer 17

starch

Question 18

ecological efficiency is low because…

Answer 18

• some energy is always lost at each step
• only 5-30% of energy is transferred, we standardize this as 10%
• these factors limits the number of tropic levels

Question 19

calorie

Answer 19

the amount of heat needed to raise 1 mL of water 1 degree celsius

Question 20

why doesn’t each trophic level transfer all of its energy to the next level?

Answer 20

the organism’s metabolism uses up a lot of energy, energy lost in heat, waste products, shedding of cells, etc.

Question 21

a kilocalorie is…

Answer 21

1000 calories

Question 22

the stacked trophic levels with autotrophs at the base and heterotrophs at each subsequent level is called…

Answer 22

a trophic pyramid

Question 23

the sun hits and generates ___ million kilocalories per square meter per year, and 98.8% of it is lost to heat and not absorbed by photosynthetic producers

Answer 23

1.7