# Lesson Worksheet: Biomass in Ecosystems Biology

In this worksheet, we will practice constructing pyramids of biomass and calculating the efficiency of biomass transfers.

Q1:

Which of the following is a disadvantage of calculating the dry biomass of an organism?

• AThe organism must be killed.
• BThe organism must be captured.
• CThe organism must be tranquilized.
• DThe dry biomass is not as accurate as the wet biomass.

Q2:

The table provided shows the different processes biomass is used for in a consumer. Complete the table.

 Process Percentage of Biomass Used Converting to new body tissue Respiration Lost in feces/urine 10 50 ⋯

Q3:

A student calculates the efficiency of a biomass transfer between a herbivore and the carnivore that eats it to be . Why must this answer be incorrect?

• AThe efficiency of a biomass transfer is always less than .
• BThe efficiency of a biomass transfer must be given in grams rather than a percentage.
• CEfficiencies of biomass transfers are not usually whole numbers.
• DThis statement is incorrect; there is no reason that answer would be wrong.

Q4:

The table provided shows a set of organisms in a food chain and their total dry biomass (grams).

 Organism Dry Biomass (g) Phytoplankton Polar bear Seal Arctic cod 600,000 1,000 5,000 10,000

Which of the following pyramids would represent their biomass? Bars are not to scale.

• A
• B
• C
• D

Q5:

The table provided shows a set of organisms in a food chain and their total dry biomass (grams).

 Organism Dry Biomass (g) Oak tree Ladybugs Aphids Sparrow 500,000 500 1,000 60

Which of the following pyramids would represent their biomass? (Bars are not to scale.)

• A
• B
• C
• D

Q6:

The following organisms are in a food chain: a cod (a species of fish), a seal, a killer whale, and phytoplankton (marine algae). The diagram provided shows a simple pyramid of biomass for this food chain, with the different organisms represented by letters A–D.

Which organism in this food chain is represented by the letter A?

• ACod
• BPhytoplankton
• CSeal
• DKiller whale

Which organism in this food chain is represented by the letter D?

• ACod
• BSeal
• CKiller whale
• DPhytoplankton

Q7:

The following organisms are in a food chain: sea lions, fish, and algae. The diagram provided shows a simple pyramid of biomass for this food chain, with different organisms represented by letters A–C.

Which organisms in this food chain are represented by the letter A?

• AFish
• BAlgae
• CSea lions

Which organisms in this food chain are represented by the letter B?

• AFish
• BSea lions
• CAlgae

Which organisms in this food chain are represented by the letter C?

• AFish
• BAlgae
• CSea lions

Q8:

The following organisms are in a food chain: rabbits, foxes, and wildflowers. The diagram provided shows a simple pyramid of biomass for this food chain, with different organisms represented by letters A–C.

Which organisms in this food chain are represented by the letter A?

• ARabbits
• BFoxes
• CWildflowers

Which organisms in this food chain are represented by the letter B?

• ARabbits
• BWildflowers
• CFoxes

Which organisms in this food chain are represented by the letter C?

• AWildflowers
• BFoxes
• CRabbits

Q9:

The table provided shows the organisms present in a food chain, their average individual biomass, and their number.

OrganismAverage Biomass of Individuals (g)Number of Individuals PresentTotal Biomass (g)
Heather (plant)2,0003
Caterpillar (insect)218
Robin (bird)111

Calculate the total biomass (g) of heather in this food chain.

Calculate the total biomass (g) of caterpillars in this food chain.

Calculate the total biomass (g) of robins in this food chain.

Q10:

The following organisms are in a food chain: caterpillars, an oak tree, sparrows, and a hawk. The diagram provided shows a simple pyramid of biomass for this food chain, with the different organisms represented by letters A–D.

Which organism in this food chain is represented by the letter A?

• ASparrow
• BOak tree
• CCaterpillar
• DHawk

Which organism in this food chain is represented by the letter B?

• AHawk
• BOak tree
• CCaterpillar
• DSparrow

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