Q: Which equation correctly represents the aerobic breakdown of glucose in respirometry experiments?

$$\mathrm{C_6H_{12}O_6$} + 6\mathrm{O_2$} \rightarrow 6\mathrm{CO_2$} + 6\mathrm{H_2O} + \text{Energy}$$

Q: If an adult human is laying down and has a metabolic rate of 1400 cal/min, what is their approximate daily energy expenditure in kilocalories?

$$1400 \times 60 \times 24 = 2,016,000$$ cal, which is $$\approx 2,000$$ kcal

Question 1

Which of the following best defines an organism's metabolic rate?

Accepted Answer

The rate at which chemical reactions occur in every cell of the body.

Question 2

According to Hess's Law, what is true about the total energy released from the breakdown of glucose?

Accepted Answer

It is the same regardless of the intermediate chemical steps or pathways used.

Question 3

Which equation correctly represents the aerobic breakdown of glucose in respirometry experiments?

Accepted Answer

$$\mathrm{C_6H_{12}O_6$} + 6\mathrm{O_2$} ightarrow 6\mathrm{CO_2$} + 6\mathrm{H_2O} + 	ext{Energy}$$

Question 4

A biologist uses calorimetry to measure the metabolic rate of a human. What is being measured directly in this experiment?

Accepted Answer

The amount of heat produced by the body.

Question 5

If an adult human is laying down and has a metabolic rate of 1400 cal/min, what is their approximate daily energy expenditure in kilocalories?

Accepted Answer

$$1400 	imes 60 	imes 24 = 2,016,000$$ cal, which is $$\approx 2,000$$ kcal

Question 6

Which of the following statements about poikilotherms is correct?

Accepted Answer

They are dependent on external sources of heat to warm up.

Question 7

What is the standard metabolic rate (SMR) in poikilotherms?

Accepted Answer

The minimum metabolic rate of a poikilotherm at rest at a given temperature.

Question 8

How does enzyme activity typically change with increasing temperature in poikilotherms, and what is the consequence for metabolic rate?

Accepted Answer

Enzyme activity increases up to an optimal temperature, then decreases, causing metabolic rate to peak and then drop.

Question 9

A poikilotherm is suddenly exposed to cold temperatures. If its metabolic rate at $$20^\circC is 10 $$units and at $$10^\circC is 4 $$units, what is its $$Q_{10}$$ value?

Accepted Answer

$$Q_{10} = \frac{10}{4} = 2.5$$

Question 10

Which of the following is a benefit of poikilothermy?

Accepted Answer

Poikilotherms can allocate more energy to growth and reproduction.

Question 11

Which group of animals are homeotherms?

Accepted Answer

Birds and mammals

Question 12

What is the basal metabolic rate (BMR) in homeotherms?

Accepted Answer

The minimum metabolic rate of a homeotherm at rest.

Question 13

Why is BMR measured in the thermal neutral zone (TNZ) for homeotherms?

Accepted Answer

Because metabolic rate is unaffected by temperature in the TNZ.

Question 14

Homeotherms are also classified as endotherms. What does this mean?

Accepted Answer

They generate heat metabolically to raise body temperature.

Question 15

Which of the following changes would NOT be necessary to evolve a poikilotherm cell into a homeotherm cell?

Accepted Answer

Decrease in cellular respiration efficiency.

Question 16

A eurythermal poikilotherm is exposed to a wide range of temperatures. What is a likely adaptation compared to a stenothermal species?

Accepted Answer

It will tolerate a wide range of environmental temperatures.

Question 17

Which of the following best describes acclimation in poikilotherms?

Accepted Answer

An adaptive adjustment in physiology and/or biochemistry in response to changes in well-defined variables.

Question 18

If a homeotherm and a poikilotherm of similar size are compared, which statement is true regarding their minimum metabolic rates?

Accepted Answer

The homeotherm's BMR is about 10 times higher than the poikilotherm's SMR.

Question 19

Which of the following is a direct consequence of poikilothermy for an organism's activity level?

Accepted Answer

Poikilotherms tend to be inactive in cold environments and active in warm environments.

Whole Organism Metabolism and Metabolic Rate in Animals

Study Guide - Practice Questions

Study Guide - Flashcards