Question 1

Suppose that heterotrophs ingested 1,560 kilograms of plant biomass over a month's period. Respiration of these heterotrophs was the equivalent of 900 kilograms, and they egested 420 kilograms. What is the net secondary production?

Accepted Answer

Net secondary production is calculated as the amount of biomass ingested minus the sum of respiration and egestion. Here, it is 1,560 kg - 900 kg - 420 kg = 240 kg.

Question 2

Suppose that the net secondary production in a community is 530 kilograms. The respiration of heterotrophs is 1,400 kilograms, and the egestion is 350 kilograms. Plant respiration is 2,700 kilograms. How much plant material did the heterotrophs ingest?

Accepted Answer

The amount of plant material ingested by heterotrophs is calculated by adding net secondary production, respiration, and egestion: 530 + 1,400 + 350 = 2,280 kilograms.

Question 3

Suppose that net secondary production in an ecosystem is only 15% of the total amount of plant material ingested by heterotrophs. If herbivores egest 20% of what they ingest, what percentage of what they ingest goes to heterotroph respiration?

Accepted Answer

Net secondary production is 15% of the total amount of plant material ingested by heterotrophs. Herbivores egest 20% of what they ingest. Therefore, the percentage of what herbivores ingest that goes to heterotroph respiration is 100% - 15% - 20% = 65%.

Question 4

Which statement about net secondary production is false?

Accepted Answer

The answer of Which statement about net secondary production is...

Question 5

By means of a process called _______, some bacteria can use forms of _______ as electron donors to take up CO₂ and convert it to carbohydrates.

Accepted Answer

Chemosynthesis is a process by which some bacteria use inorganic substances like sulfur as electron donors to convert CO2 into carbohydrates.

Question 6

In the symbiotic relationships among the organisms living near hydrothermal vents, the chemosynthetic bacteria supply _______ for the invertebrates, and the invertebrates provide _______ for the bacteria.

Accepted Answer

Chemosynthetic bacteria produce carbohydrates through chemosynthesis, which they supply to invertebrates. In return, invertebrates provide CO₂ for the bacteria to use in chemosynthesis.

Question 7

In hydrothermal vent communities, colonization begins with chemoautotrophic bacteria, which often are followed by

Accepted Answer

Tube worms are typically among the first animals to colonize hydrothermal vent communities after chemoautotrophic bacteria, as they have a symbiotic relationship with these bacteria.

Question 8

Refer to the table. Table 1 You are studying the movement of energy through an ecosystem. You collect data on energy use at the same site across four years, measured in g/m²/year. Assume that the site is sampled at the same location on the same date each year. Based on the data you collected (Table 1), create a completed table (this will be referred to as Table 2) with values in all of the cells.

Accepted Answer

The answer of Refer to the table.
Table 1
  You...

Question 9

Refer to the table. Table 2 You are studying the movement of energy through an ecosystem. You collect data on energy use at the same site across four years, measured in g/m²/year. Assume that the site is sampled at the same location on the same date each year. Use the data in Table 2 to graph GPP, NPP, and NEE as a line graph (this will be referred to as Figure 1). The x-axis should be years 1-4 and the y-axis should be productivity in g/m²/year from 0-7,000.

Accepted Answer

The answer of Refer to the table.
Table 2
  You...

Question 10

Refer to the table and the figure.
Table 2
  Figure 1
  You are studying the movement of energy through an ecosystem. You collect data on energy use at the same site across four years, measured in g/mS1U1P12S1S1P0/year. 
-Assume that the site is sampled at the same location on the same date each year.Answer the following questions:
a) In which year was GPP the highest?
b) Were NPP and NEE also highest when GPP was highest?
c) In which year was GPP the lowest?
d) Were NPP and NEE also lowest when GPP was lowest?
e) In which year was the difference between GPP and NPP the greatest?
f) In which year was NEE the smallest?

Accepted Answer