Energy Transfers - B13

Question 1

Define producer

Answer 1

Photosynthetic organisms that make organic substances using light energy, water, CO2 and minerals

Question 2

Define consumer

Answer 2

Any organisms which feeds to gain it’s energy(primary/ secondary/tertiary)

Question 3

Define saprobiont

Answer 3

Digest dead organisms into simple molecules

Question 4

Define food chain

Answer 4

Describes a relationship where the producer is eaten by the primary consumer which is then eaten by the secondary consumer etc. Each stage in the chain is known as a trophic level

Question 5

What is a food web

Answer 5

Shows how all the food chains within a single habitat/ecosystem link together

Question 6

What is the definition of biomass?

Answer 6

The mass of living material
=chemical energy(stored in a plant)

Question 7

What compounds make up the biomass?

Answer 7

Producers synthesise biological compounds during photosynthesis

Question 8

How is energy transferred through an ecosystem?

Answer 8

When organisms are eaten

Question 9

What is biomes measured as?

Answer 9

Biomass can be measured in terms of the mass of carbon that an organism contains or the dry mass(water removed) of its fissure per unit area per time

Question 10

How is biomass measured?

Answer 10

-to measure dry mass, sample organism is dried in an oven at a low temperature
-weigh regularly and when weight becomes constant, all the water has been removed
-generally half the dry weight is the mass of carbon

Question 11

What is dry mass measured in?

Answer 11

kgm^-2

Question 12

Why do we use dry mass?

Answer 12

Dry mass is used to measure biomass because dry mass measures biological material as the water content varies between organisms.
-dry mass is a measure of production of organic material
-a way of measuring growth other than length
-water content of seedlings varies

Question 13

What is calorimeter used for?

Answer 13

-Used to estimate the amount of chemical energy stored in the biomass by burning the biomass in a calorimeter
-the amount of heat given off is how much energy is stored measured in Joules(J)

Question 14

What is gross primary production(GPP)?

Answer 14

The total amount of chemical energy, converted from light energy by a plant, in a given area, in a given time.
It is a fixed value.

Question 15

What is respiratory loss?

Answer 15

Approximately 50% of GPP is lost to the environment as heat when plants respire.
The remaining chemical energy is called the net primary production(NPP).

Question 16

What is the Net Primary Production(NPP)?

Answer 16

The energy available to plants Rory growth and reproduction, also energy available to next organisms in food chain.

Question 17

What is the equation for net primary production?

Answer 17

NPP= GPP-R
As the R is lower, NPP is higher, increasing biomass, so the plant can grow more.