Topic 6: Energy and Nutrient Relationships

Question 1

Autotroph

Answer 1

an organism that can synthesize organic molecules using inoragnic molecules and energy from either sunlight or from inorganic molecules, such as hydrogen, sulphide

Question 2

C3 photosynthesis

Answer 2

the photosynthetic pathway used by most plants and all algae, in which the product of the initial reaction is phosphoglyceric acid, or PGA, a 3 carbon acid

Question 3

C4 photosynthesis

Answer 3

photosynthesis in which CO2 is fixed in mesophyll cells by combining it with phosphoenolpyruvate, or PEP, to produce a 4 carbon acid. Plants using C4 photosynthesis are generally more drought tolerant than plants employing C3 photosynthesis

Question 4

CAM photosynthesis

Answer 4

a photosynthetic pathway largely limited to succulent plants in arid and semiarid environments, in which carbon fixation takes place at night, when lower temperatures reduce the rate of water loss during CO2 uptake. the resulting 4 carbon acids are stored until daylight, when they are broken down into pyruvate and CO2.

Question 5

Carnivore

Answer 5

organisms that consume flesh - approximately synonymous with predator.

Question 6

chemosynthetic autotroph

Answer 6

autotrophs that use inorganic molecules as a source of carbon and energy

Question 7

detritivore

Answer 7

organisms that feed on non living organic matter

Question 8

functional response

Answer 8

an increase in animal feeding rate, which eventually levels off, that occurs in response to an increase in food availability

Question 9

handling time

Answer 9

the amount of time it takes the predator to handle the food, beginning from the time the predator finds the prey item to the time the prey item is eaten.

Question 10

herbivore

Answer 10

organism that eats plants

Question 11

heterotroph

Answer 11

an organism that uses organic molecules both as a source of carbon and a source of energy

Question 12

light compensation point

Answer 12

the amount of light necessary for a plants respiration rate to equal its photosynthetic rate

Question 13

light saturation point

Answer 13

is the intensity at which additional increases in light do not increase photo-synthesis

Question 14

marginal value theorem

Answer 14

developed by Eric Charnov, a theory based on optimality, which describes the “optimal” time for a forager to move from one food patch to another

Question 15

mixotroph

Answer 15

the ability to gain energy both from photosynthesis and from consuming organic or inorganic compounds

Question 16

omnivore

Answer 16

hetertorophic organisms that eat a wide range of food items, usually including both animals and plant matter

Question 17

optimal foraging theory

Answer 17

attempts to model how organisms feed as an optimizing process, a process that maximizes or minimizes some quantity, such as energy intake or predation risk

Question 18

PA (photosynthetically active radiation)

Answer 18

wavelengths of light between 400 - 700 nm that photosynthetic organisms use as a source of energy

Question 19

photosynthetic autotroph

Answer 19

describes organisms capable of photosynthesis

Question 20

P max

Answer 20

the maximum rate of photosynthesis

Question 21

prey switching

Answer 21

is the frequency dependent predation, where the predator preferentially consumes the most common type of prey

Question 22

primary producer

Answer 22

autotrophs or primary producers are organisms that acquire their energy from sunlight and materials from nonliving sources

Question 23

primary predator

Answer 23

predators such as birds and foxes join the food chain by eating the plant eaters and are known as primary consumers. These predators may become food for the next animal up the chain

Question 24

search cost

Answer 24

the time, energy, and money that buyers and sellers in a market expend in tying to find one another in order to engage in transactions

Question 25

secondary predator

Answer 25

occurs when one predator feeds on a second predator, which has in turn eaten a target prey.