Homeostasis and Response Mechanisms in Human Biology

What can test anxiety and stress trigger in the human body?

Increased heart and respiratory rates and increased sweating.

Which reaction helps maintain homeostasis when the body becomes dehydrated?

The kidneys produce concentrated urine.

What do changes in external temperatures often result in?

Sweating or shivering to maintain dynamic equilibrium.

What helps dogs stay cool on a hot day?

Sweating through their paw pads and panting.

What is anhidrosis?

The inability to sweat normally.

What does anhidrosis interfere with?

A feedback mechanism that maintains homeostasis.

What happens if body temperature is too high?

Blood vessels increase in size and sweat glands excrete sweat.

What is an example of maintaining dynamic equilibrium?

Insulin is released when glucose levels in the blood are high.

Why is decreased urine production important during a long-distance run?

It allows the body to conserve water.

During which condition does shivering help bumblebees maintain homeostasis?

Low environmental temperature.

What is an example of bumblebees regulating their body temperature?

Warming their flight muscles by shivering.

What happens to red onion cells when placed in salt water?

They undergo changes due to water moving out of the cells.

How do fish behaviors help them survive in different salt environments?

By maintaining a water balance inside and outside their bodies.

What happens to a potato cube in distilled water after 20 minutes?

The mass increases due to water moving into the cells.

What causes red onion cells to change when transferred from distilled water to salt water?

Water moving out of the cells.

What process is limited by cyanide in a cell?

The ability to manufacture ATP.

What happens to a potato cube in a concentrated salt solution?

The mass remains the same due to the cell wall preventing molecule movement.

What change occurs to red onion cells when transferred from distilled water to salt water?

Cells undergo plasmolysis.

Which process requires cellular energy?

Active transport.

What explains the net movement of water into a cell?

Osmosis when water is 90% inside and 95% outside.

Why did freshwater fish die in a saltwater aquarium?

They became severely dehydrated due to diffusion.

What two processes are represented in the glucose movement diagram?

Molecule transport and energy use.

What process is indicated by the arrow in the cell membrane diagram?

Active transport.

What describes the particles crossing a cell membrane in a time-lapse diagram?

They do not require added energy and could be water or oxygen.

What mechanism helps a person adjust from a cool to a hot environment?

Regulation of water loss by guard cells in plant leaves.

What maintains a stable internal temperature in humans?

Detection of and reaction to stimuli in the environment.

What process could move sodium out of a cell if its concentration is greater outside?

Active transport.

What happens to glucose molecules in solution A after 20 minutes?

Solution A will contain approximately the same number of glucose molecules as solution B.

What explains the changes in the beaker with water and food coloring?

Molecules moved across the membrane without additional energy being supplied.

What does the chart about single-celled organisms illustrate?

Single-celled organisms contain structures that function in maintaining homeostasis.

What structure in paramecia helps remove excess water?

Contractile vacuole.

What is the function of a flagellum in single-celled organisms?

Movement.

What is the function of chloroplasts in single-celled organisms?

Food production.

What occurs when a cell is placed in a hypertonic solution?

Water moves out of the cell.

What is the result of placing a cell in a hypotonic solution?

Water moves into the cell.

What is osmosis?

The movement of water across a selectively permeable membrane.

What is diffusion?

The movement of molecules from an area of higher concentration to an area of lower concentration.

What is active transport?

The movement of molecules against their concentration gradient using energy.

What is passive transport?

The movement of molecules across a membrane without the use of energy.

What is homeostasis?

The maintenance of a stable internal environment.

What role do guard cells play in plants?

They regulate water loss.

What is the significance of selectively permeable membranes?

They allow certain substances to pass while blocking others.

What happens during cellular respiration?

Cells convert glucose and oxygen into energy.

What is the primary function of the contractile vacuole in paramecia?

To maintain water balance.

What effect does a higher concentration of salt have on the contractile vacuole of a paramecium?

It causes the contractile vacuole to contract fewer times.

What is the normal urine output for an average adult?

Approximately 0.5-1 mL/min.

What is the most likely result of drinking an excessive amount of water on urine flow?

Homeostatic feedback.

Why do onion cells not burst in distilled water while red blood cells often do?

Red blood cells have only a cell membrane, while onion cells have a cell wall.

What does the student's experiment with plastic bags and sucrose solutions demonstrate?

Water movement into the cell is dependent on the percent concentrations of solutes inside and outside the cell.

Which solution is most similar in concentration to the normal internal environment of the human circulatory system?

Solution B.

How is the higher concentration of potassium in red blood cells maintained?

By active transport.

What happens to red blood cells placed in a hypertonic solution?

Water moves out of the cells.

What is the response of the body to increased temperature?

Sweating to cool the body.

What causes muscle cramps during dehydration?

Depletion of electrolytes.

What is a response to insufficient oxygenation of tissues?

Increased heart rate.

What physiological change occurs due to increased breathing rate?

More oxygen is supplied to muscles.

What triggers increased thirst in the body?

Dehydration caused by sweating.

What is the effect of increased temperature on muscle activity?

It may cause a person to slow down or stop.

What is the role of homeostasis in response to dehydration?

It helps stabilize the body's internal environment.

What is the relationship between solute concentration and water movement in cells?

Water moves to balance solute concentrations inside and outside the cell.

What is the primary function of the contractile vacuole in paramecium?

To regulate water balance.

What happens to red blood cells in a hypotonic solution?

They may burst due to excess water intake.

What is the consequence of increased heart rate during exercise?

Faster delivery of oxygen to muscles.

What does the evaporation of sweat do for the body?

It cools the body and lowers temperature.

What is the effect of lactic acid build-up during intense exercise?

It can lead to muscle cramps.

How does the body respond to a rise in temperature?

By increasing sweating and heart rate.

What is the primary process that maintains electrolyte balance in cells?

Active transport.