Question 1

Studies on racehorses have shown that when the starting gate closes just prior to a race, the breathing rate of a racehorse increases, even though the horse is standing still.This response is an example of

Accepted Answer

This response is an example of feedforward control, where the horse's body anticipates the need for more oxygen and energy for the upcoming race and adjusts its breathing rate in advance, even before the physical activity begins. This is a preparatory response rather than a reaction to a change in the internal environment, distinguishing it from feedback mechanisms.

Question 2

In regulatory systems, negative feedback

Accepted Answer

Negative feedback is a process by which the body responds to a stimulus by reversing or inhibiting its effects. Negative feedback mechanisms aim to keep the body in a stable state, which is the set point. Therefore, negative feedback stimulates a return towards the set point.

Question 3

Cellular functions in most eukaryotic organisms are limited to a temperature ranging (in °C) from _______ to _______.

Accepted Answer

Cellular functions in most eukaryotic organisms are limited to a temperature ranging from 0°C to 40°C. This is because enzymes and proteins that are essential for cellular functions denature at temperatures outside this range, leading to loss of function and ultimately cell death. Some extremophile organisms, however, are able to survive and even thrive in temperatures outside this range.

Question 4

The value of Q₁₀, which describes the sensitivity of a reaction to temperature, is calculated as the

Accepted Answer

Q₁₀ is the activation energy, which is the energy required for a chemical reaction to occur. Q₁₀ is calculated as the ratio of the rate of a reaction at a certain temperature to the rate of the same reaction at a temperature 10°C lower. This is known as the Arrhenius equation. Therefore, choice B is the correct answer.

Question 5

Which Q₁₀ value indicates that a reaction is not temperature sensitive?

Accepted Answer

A Q₁₀ value of 1 indicates that the reaction rate does not change with temperature, meaning it is not temperature sensitive.

Question 6

The upper temperature limit at which cells can function is determined by the _______ point of _______.

Accepted Answer

The denaturation point of proteins determines the upper temperature limit at which cells can function. Denaturation refers to the irreversible change in the shape of a protein, which can occur at high temperatures and disrupt the protein's function.

Question 7

Which statement about positive feedback is true?

Accepted Answer

Sexual behavior is an example of positive feedback, as it leads to the release of hormones (such as oxytocin) that increase the desire for more sexual behavior. The other options are incorrect - negative feedback is more commonly observed in biological systems, positive feedback typically does not have a limit and can cause exponential growth, it enhances a response rather than diminishing it, and a thermostat regulating a furnace is an example of negative feedback.

Question 8

Homeostasis refers to the tendency

Accepted Answer

Homeostasis refers to the process by which living organisms regulate their internal environment to maintain a stable, constant condition, despite changes in the external environment. This involves varying the activity of body systems as necessary to keep internal conditions within certain physiological limits.

Question 9

Which of the following would serve to change the set point of a regulatory system?

Accepted Answer

Feedforward information can inform the regulatory system of a future change in the internal or external environment, prompting the system to adjust its set point accordingly. Negative feedback, sensitivity that amplifies a response, and positive feedback all serve to maintain the system's set point once it has been established. Insensitivity to information would not change the set point at all.

Question 10

You measure metabolic rates of several four-toed salamanders at 20°C and at 30°C and calculate a Q₁₀ equal to 2 for the species.Based on this information, which statement is true?

Accepted Answer

According to the Q₁₀ of 2 for the species, metabolic rate increases by a factor of 2 when temperature increases from 20°C to 30°C. Therefore, metabolic rate at 20°C must be half that at 30°C for this species. Choice E is correct. The other choices are not supported by the information given in the question.

Question 11

At the end of the summer you notice that a cool breeze signaling the approach of autumn is actually at a temperature that felt warm when you encountered it the previous winter.Which hypothesis best explains this observation?

Accepted Answer

This phenomenon can be explained by acclimatization to temperature. Our bodies adjust to the temperature range we experience over time, so the same temperature may feel different depending on whether we've been exposed to colder or warmer temperatures recently.

Question 12

Most biological Q₁₀ values are between _______ and _______.

Accepted Answer

Most biological Q₁₀ values, which indicate the rate of change in a biological or chemical system with a 10°C temperature increase, typically range between 2 and 3. This suggests that the rate of reaction or process doubles or triples with a 10°C rise in temperature.

Question 13

The reactions that make up animal metabolism are not equally sensitive to temperature.Which value reflects that fact?

Accepted Answer

The correct answer is E) Q₁₀, which likely represents Q10, a value that reflects the rate of increase in metabolic reactions for a 10-degree Celsius increase in temperature. This value indicates how sensitive biological processes are to changes in temperature.

Question 14

A Q₁₀ value of 3 indicates that a reaction rate has _______ over a rise in temperature of 10°C.

Accepted Answer

The Q₁₀ value indicates the temperature coefficient of a reaction rate. A Q₁₀ value of 3 means that for every 10°C increase in temperature, the reaction rate triples. Therefore, the correct answer is C, tripled.

Question 15

Most physiological processes

Accepted Answer

Most physiological processes speed up as the temperature increases, due to the increased kinetic energy of molecules, which enhances the rate of chemical reactions. However, there is a limit to this effect; beyond a certain temperature, proteins can denature, leading to a decrease in physiological function.

Question 16

Mechanical systems, like physiological systems, can be regulated to maintain homeostasis.Imagine an automated system that allows water to flow from a storage tank into a water bowl for your pet.In this system, the valve that opens when the water level drops below the desired water level is the

Accepted Answer

The valve that opens when the water level drops below the desired level is the effector, as it is responsible for regulating the water flow and maintaining the desired water level in the bowl. The sensor would detect changes in the water level, while the error signal would communicate the difference between the desired water level and the actual water level. Feedforward information would provide information to the system before any changes occur, while the set point would be the desired water level that the system is trying to maintain.

Question 17

Suppose an airline pilot sets an aircraft's engines to produce a velocity of 450 mph and measures that speed using an instrument on the outside of the plane.When another pilot reports turbulence ahead, the pilot changes the velocity set point to 350 mph.The instrument on the outside of the plane is providing

Accepted Answer

The instrument on the outside of the plane is providing feedback to the pilot, allowing them to adjust the set point for the velocity based on external factors.

Question 18

Positive feedback responses

Accepted Answer

Positive feedback responses amplify changes and tend to reach a limit and then terminate, unlike negative feedback which stabilizes around a set point.

Question 19

What is the difference between negative feedback mechanisms and positive feedback mechanisms?

Accepted Answer

Negative feedback mechanisms work to return a system to a set point by reversing the direction of the initial stimulus, while positive feedback mechanisms amplify the response of a system and move it further away from its set point, reducing stability.

Question 20

Suppose an airline pilot sets an aircraft's engines to produce a velocity of 450 mph and measures that speed using an instrument on the outside of the plane.When another pilot reports turbulence ahead, the pilot changes the velocity set point to 350 mph.The other pilot is providing

Accepted Answer

The other pilot is providing feedforward information, which is a proactive measure to adjust the system (in this case, the plane's speed) in anticipation of a change in conditions (turbulence), rather than reacting to the change after it occurs. This helps in maintaining or adjusting performance before the external change affects the system.

Quiz 39: Physiology, Homeostasis, and Temperature Regulation

Studies on racehorses have shown that when the starting gate closes just prior to a race, the breathing rate of a racehorse increases, even though the horse is standing still.This response is an example of

In regulatory systems, negative feedback

Cellular functions in most eukaryotic organisms are limited to a temperature ranging (in °C) from _ to _.

The value of Q₁₀, which describes the sensitivity of a reaction to temperature, is calculated as the

Which Q₁₀ value indicates that a reaction is not temperature sensitive?

The upper temperature limit at which cells can function is determined by the _ point of _.

Which statement about positive feedback is true?

Homeostasis refers to the tendency

Which of the following would serve to change the set point of a regulatory system?

You measure metabolic rates of several four-toed salamanders at 20°C and at 30°C and calculate a Q₁₀ equal to 2 for the species.Based on this information, which statement is true?

At the end of the summer you notice that a cool breeze signaling the approach of autumn is actually at a temperature that felt warm when you encountered it the previous winter.Which hypothesis best explains this observation?

Most biological Q₁₀ values are between _ and _.

The reactions that make up animal metabolism are not equally sensitive to temperature.Which value reflects that fact?

A Q₁₀ value of 3 indicates that a reaction rate has _______ over a rise in temperature of 10°C.

Most physiological processes

Mechanical systems, like physiological systems, can be regulated to maintain homeostasis.Imagine an automated system that allows water to flow from a storage tank into a water bowl for your pet.In this system, the valve that opens when the water level drops below the desired water level is the

Positive feedback responses

What is the difference between negative feedback mechanisms and positive feedback mechanisms?

Suppose an airline pilot sets an aircraft's engines to produce a velocity of 450 mph and measures that speed using an instrument on the outside of the plane.When another pilot reports turbulence ahead, the pilot changes the velocity set point to 350 mph.The other pilot is providing

Quiz 39: Physiology, Homeostasis, and Temperature Regulation

Studies on racehorses have shown that when the starting gate closes just prior to a race, the breathing rate of a racehorse increases, even though the horse is standing still.This response is an example of

In regulatory systems, negative feedback

Cellular functions in most eukaryotic organisms are limited to a temperature ranging (in °C) from _______ to _______.

The value of Q10, which describes the sensitivity of a reaction to temperature, is calculated as the

Which Q10 value indicates that a reaction is not temperature sensitive?

The upper temperature limit at which cells can function is determined by the _______ point of _______.

Which statement about positive feedback is true?

Homeostasis refers to the tendency

Which of the following would serve to change the set point of a regulatory system?

You measure metabolic rates of several four-toed salamanders at 20°C and at 30°C and calculate a Q10 equal to 2 for the species.Based on this information, which statement is true?

At the end of the summer you notice that a cool breeze signaling the approach of autumn is actually at a temperature that felt warm when you encountered it the previous winter.Which hypothesis best explains this observation?

Most biological Q10 values are between _______ and _______.

The reactions that make up animal metabolism are not equally sensitive to temperature.Which value reflects that fact?

A Q10 value of 3 indicates that a reaction rate has _______ over a rise in temperature of 10°C.

Most physiological processes

Mechanical systems, like physiological systems, can be regulated to maintain homeostasis.Imagine an automated system that allows water to flow from a storage tank into a water bowl for your pet.In this system, the valve that opens when the water level drops below the desired water level is the

Positive feedback responses

What is the difference between negative feedback mechanisms and positive feedback mechanisms?

Suppose an airline pilot sets an aircraft's engines to produce a velocity of 450 mph and measures that speed using an instrument on the outside of the plane.When another pilot reports turbulence ahead, the pilot changes the velocity set point to 350 mph.The other pilot is providing

Cellular functions in most eukaryotic organisms are limited to a temperature ranging (in °C) from _ to _.

The value of Q₁₀, which describes the sensitivity of a reaction to temperature, is calculated as the

Which Q₁₀ value indicates that a reaction is not temperature sensitive?

The upper temperature limit at which cells can function is determined by the _ point of _.

You measure metabolic rates of several four-toed salamanders at 20°C and at 30°C and calculate a Q₁₀ equal to 2 for the species.Based on this information, which statement is true?

Most biological Q₁₀ values are between _ and _.

A Q₁₀ value of 3 indicates that a reaction rate has _______ over a rise in temperature of 10°C.