BIO203 Unit 1

Learn: Match each symbol in the heat transfer equation with its definition 1. The difference between the temperature of one substance and the temperature of another substance 2. A term that takes into account the ability of the substances to transfer heat and the area of contact between the substances 3. The capacity of a substance to dissipate heat 4. The amount of heat that is transferred from one substance to another over time.

1. Driving force for heat transfer, (T2-T1) 2. Ease of movement, (K*A)/l 3. Thermal conductivity, K 4. flow of heat, dQ/dt

Learn: Choose the correct statement A. A large animal is better at retaining substances, but worse at exchanging substances, compared to a small animal. B. A large animal is better at exchanging substances, but worse at retaining substances, compared to a small animal. C. A large animal is better at both exchanging and retaining substances, compared to a small animal. D. A large animal is worse at both exchanging and retaining substances, compared to a small animal.

A. A large animal is better at retaining substances, but worse at exchanging substances, compared to a small animal.

Learn: Match each compartment name with its correct definition A. All fluid inside of cells B. All fluid inside of an organism, but outside of its cells C. the fluid in blood, but not the cells in blood D. extracellular fluid found anywhere except for the circulatory system

A. ICF B. ECF C. plasma D. interstitial fluid

Clicker: Which of the following functions would require a cell to expend energy? A. Moving sodium ions out of the cell B. Moving sodium ions into the cell C. Moving potassium ions out of cell D. Moving potassium ions into the cell

A. If a cell requires energy, then that means it is going from a low concentration to a high concentration. There are more sodium ions outside of the cell than the inside, so if the sodium ions move outside of the cell, it is going from a low concentration to a high concentration.

Verify: List in order the various fluid compartments that a glucose molecule would encounter beginning with absorption from the lumen of the intestine and ending with the glucose molecule entering a skeletal muscle cell.

Absorption from the lumen Co-transport (sodium and glucose) Active transport (sodium and potassium) Facilitated diffusion (glucose molecule entering a skeletal muscle cell)

Learn: Basic Principles (pick the incorrect statement): A group of cells of the same type that perform a specific function is referred to as a tissue. While all animals must deal with the same fundamental problems, different animals may have different solutions. A fundamental challenge for all multicellular organisms is maintaining the asymmetric distribution of ions between different compartments. All cells need energy to survive, and anaerobic metabolism is more efficient than aerobic metabolism because it is faster.

All cells need energy to survive, and anaerobic metabolism is more efficient than aerobic metabolism because it is faster.

Clicker: Pick the incorrect statement about homeostasis and feedback: A. Homeostasis is the process of maintaining the internal conditions of an organism within tolerable ranges for the cells in the organism B. All homeostatic feedback systems have the same basic components, the sensor integrator and the effector C. Homeostasis requires communication and positive feedback between the cells and the organism D. In a homeostatic feedback system, a decrease in the sensor measurement has the same effect on the output of the system as an increase in the set point

C. Homeostasis is an example of negative feedback, where the effector is opposite to stimulus.

Verify: Construct a thermal budget for an organism listing the principle sources and processes of heat gain and heat loss.

Conduction - occurring through physical contact with another object of a different temperature (ex. metal is a good conductor, therefore its temperatures can change drastically.) Convection - occurring through the physical movement of an environmental medium (ex. wind, flowing water) Radiation - absorption of heat through electromagnetic waves (ex. the sun) Evaporation - The process of water moving from a liquid phase to a vapor phase, only heat loss occurs. (ex. sweating)

Learn: Match each type of heat transfer with the example describing it. Conduction Free Convection Forced Convection Evaporation Radiation

Conduction: A seagull stands on ice and loses heat through its feet. Free Convection: A dog stands outside on a cold, but windless, day and loses heat to the air. Forced Convection: A bear stands in a cold flowing stream and loses heat to the water. Evaporation: An athlete sweats while running a race. Radiation: A lizard absorbs heat from the sun's rays.

Clicker: Pick the incorrect statement: A. Living cells in a terrestrial organisms exist in an aqueous environment B. A fundamental challenge for all organisms is to maintain a symmetry between compartments C. All life is constrained by the laws of physics and chemistry D. Organisms living in different environments have to deal with different fundamental problems

D. Organisms have to deal with the same fundamental problems even if they live in different environments. Examples include: regenerating heat, reproduction, and maintaining asymmetrical distribution of ions.

Clicker: Pick the incorrect statement about distribution of ions between compartments: A. Sodium concentration is high in plasma compared to inside red blood cells B. Calcium concentration is high in plasma compared to the intracellular fluid C. Potassium concentration in plasma is high compared to calcium concentration in intracellular fluid D. Potassium concentration in plasma is high compared to interstitial fluid

D. Potassium concentration is generally low in the ECF, and plasma is a part of the ECF. Potassium concentration is generally high in the ICF.

Learn: In cold environments, mammals and birds use counter-current heat exchange in their extremities to keep the extremities from becoming too cold.

False

Learn: In endotherms, increasing insulation facilitates heat retention in part because the range of the thermoneutral zone is reduced.

False

Clicker: Relative to body size, a larger animal has a greater surface area for heat exchange with the external environment than a small animal.

False. A bigger animal has a lower SA/V ratio compared to a small animal.

Clicker: Because anaerobic metabolism of glucose does not require oxygen, it is more efficient (more ATP per glucose molecule) than aerobic metabolism of glucose.

False. Anaerobic metabolism is not more efficient than aerobic metabolism. Aerobic respiration is the most efficient form of respiration because it can produce the most ATP molecules.

Clicker: Increasing the surface area of a contact between two objects increases the driving force of heat transfer.

False. The driving force has no effect on the ease of movement.

Learn: Which of the following organ systems is/are directly involved in the exchange of vital substances between an organism and its environment? Choose all of the correct answers. Integumentary System (skin) Immune system Nervous system Digestive system Excretory system Circulatory system Musculoskeletal system Respiratory System

Integumentary System (skin) Digestive system Excretory system Circulatory system Respiratory System

Learn: An animal has a high whole animal metabolic rate which remains constant over a large range of temperatures. Which of the following is probably true about the animal? Choose all of the correct answers. It is a large animal Its unit metabolic rate is the same as its whole animal metabolic rate It uses behavioral thermoregulation It is a small animal

It is a large animal It uses behavioral thermoregulation

Learn: For a catfish that lives in an environment that is warmer during the summer than during the winter, which of the following statements is/are correct? Choose all of the correct statements. Optimum metabolic rate is lower during the winter. Maximum critical temperature is higher during the summer. Optimum temperature is the same during the summer and the winter. Body temperature is lower during the winter.

Maximum critical temperature is higher during the summer. Body temperature is lower during the winter.

Verify: write a paragraph of 3-5 sentences describing 1) whether the following statement is correct or incorrect and 2) the reasoning for your answer. Your answer should demonstrate your understanding of the physiological concepts underlying the statement and be written professionally. Organisms living in different environments have to deal with different fundamental problems.

The statement is incorrect. All organisms have to deal with the same fundamental problems. However, organisms with different adaptations are able to deal with these fundamental problems differently.

Learn: Cells must use energy to move a substance against a concentration gradient (i.e., from a compartment with a low concentration of the substance to a compartment with a higher concentration). Which of the following processes would require a cell to expend energy? Choose all of the correct answers. Transport of sodium ions OUT OF cells Transport of sodium ions INTO cells Transport of potassium ions OUT OF cells Transport of potassium ions INTO cells Transport of calcium ions OUT OF cells Transport of calcium ions INTO the cytoplasm of a cell from the ECF Transport of calcium ions OUT OF the cytoplasm of a cell and INTO an organelle that has a high concentration of calcium ions. Transport of calcium ions OUT OF an organelle that has a high concentration of calcium ions and INTO the cytoplasm of a cell.

Transport of sodium ions OUT OF cells Transport of potassium ions INTO cells Transport of calcium ions OUT OF cells Transport of calcium ions OUT OF the cytoplasm of a cell and INTO an organelle that has a high concentration of calcium ions.

Learn: For ambient temperatures within the thermoneutral zone of an endotherm, a decrease in environmental temperature leads to increased vasoconstriction without a change in metabolic rate.

True

Learn: With respect to an animal's thermal budget, evaporation is the only type of heat transfer that cannot lead to heat gain.

True

Clicker: Evaporative cooling is effective for heat dissipation because water absorbs energy from the body surface when it moves from liquid phase to a vapor phase.

True. Evaporative cooling: when water moves from liquid to vapor, it absorbs energy from the body surface. Examples include sweating and panting.

Clicker: In the case of a seagull standing on ice, countercurrent exchange in the legs minimises heat loss by reducing the driving force of heat transfer to the environment.

True. In the countercurrent exchange system, the blood moves in the opposite direction in order to reduce heat loss to the environment. Mammals and birds use countercurrent exchange to minimize the driving force for heat loss from the extremities to keep the core temperature warm.

Clicker: With respect to the animals thermal budget, evaporation is the only type of heat transfer that cannot lead to heat gain.

True. There is no way for us to gain heat from the environment through the evaporation of the cooling process. Refer to the thermal budget: Heat gain from external environment: Conduction, convection, radiation, endogenous heat(from metabolism) Heat loss from external environment: Conduction, convection, radiation, evaporation

Clicker: For ambient temperatures within the thermal neutral zone of an endotherm, a decreased environmental temperature leads to an increased vasoconstriction without a change in metabolic rate.

True. Thermoneutral zone: The range of ambient temperatures over which an animal can thermoregulate without increasing metabolic rate.

Learn: Things required for life, including heat, water, nutrients, salts and oxygen are called "___________ substances."

Vital

Learn: Choose the INCORRECT STATEMENT. When a small fish (e.g. a goldfish) is placed in water with a temperature gradient, it will explore the environment until its optimum temperature changes to the temperature of the water. After an ectotherm has acclimated to a lower temperature, its critical temperature is lower even though its optimal metabolic rate is the same. Terrestrial ectotherms rely primarily on behavioral thermoregulation to help them achieve their optimal metabolic rates. A terrestrial ectotherm can achieve a body temperature higher than ambient air temperature using heat gain by radiation or by conduction.

When a small fish (e.g. a goldfish) is placed in water with a temperature gradient, it will explore the environment until its optimum temperature changes to the temperature of the water.

Evaluate: Regarding thermoregulation: a. In endotherms, the thermoneutral zone is the range of environmental temperatures over which the animal is able to thermoregulate without changing metabolic rate. b. Endotherms not ectotherms use behavior to thermoregulate. c. As ambient temperature gets colder, metabolic rate in an ectotherm decreases to maintain body temperature. d. Both a) and b) are correct, and c) is incorrect e. a), b) and c) are all correct

a. In endotherms, the thermoneutral zone is the range of environmental temperatures over which the animal is able to thermoregulate without changing metabolic rate.

Evaluate: Which of the following organ systems protects against environmental hazards, helps regulate body temperature, and provides sensory information? a. integumentary system b. cardiovascular system c. respiratory system d. Both a) and b) are correct, and c) is incorrect e. a), b) and c) are all correct

a. integumentary system

Evaluate: Regarding homeostasis and feedback mechanisms: a. Homeostasis requires negative-feedback mechanisms to maintain a relatively constant internal enviroment. b. Feedback systems include a sensor that measures the controlled variable, an integrator that determines how to respond to a change in the variable, and an effector that compensates for the change. c. Activation of a homeostatic feedback system will result in a It allows for widely fluctuating internal environment. d. Both a) and b) are correct, and c) is incorrect e. a), b) and c) are all correct

d. Both a) and b) are correct, and c) is incorrect

Evaluate: Basic principles states that: a. Maintaining asymmetric distribution of ions is essential for normal physiological functioning. b. Body fluids separate into different compartments, mainly intracellular fluid is the system that includes all fluid enclosed by their plasma membrane whereas extracellular fluid surrounds all cells in the body. c. All life is constrained by the laws of chemistry and physics and deal with the same fundamental problems. d. Both a) and b) are correct, and c) is incorrect e. a), b) and c) are all correct

e. a), b) and c) are all correct

Learn: The driving force for heat transfer through physical contact between two objects is determined by: the surface area of contact between the objects. the composition of the interface between the objects. the temperature gradient between the objects. the length between the objects.

the temperature gradient between the objects.