Bio 100
Bio 100 exam 4 AHC Exam Questions and Answers
2025
List the organized hierarchy of most animal bodies (begin with cells) - Cells, tissues,
organs, organ systems, organism.
Explain the concept of homeostasis. - Homeostasis is the ability of an organism to
maintain a stable internal environment despite external changes.
What is a negative feedback loop? Give an example in the human body. - A negative
feedback loop is a mechanism that reduces or stops a process to maintain homeostasis.
An example is the regulation of body temperature: if the body gets too hot, mechanisms
like sweating are activated to cool it down.
Describe the thermoregulation of endothermic and ectothermic animals. - Endothermic
animals generate their own heat internally, while ectothermic animals rely on external
sources for heat.
How are homeotherms different than heterotherms? - Homeotherms maintain a constant
internal body temperature, while heterotherms can have variable body temperatures.
What is the function of the digestive system? - The function of the digestive system is to
break down food, absorb nutrients, and eliminate waste
List the pathway of food as it moves through the digestive system. - Mouth, esophagus,
stomach, small intestine, large intestine, rectum, anus.
Where does the majority of absorption occur during digestion? - The majority of
absorption occurs in the small intestine.
Bio 100
, Bio 100
Explain the structure and function of the villi and microvilli in the small intestine. - Villi
are finger-like projections and microvilli are even smaller projections on the villi. They
increase the surface area of the small intestine for efficient nutrient absorption.
Describe the passage of air from the outside environment to the lungs. - Air enters
through the nasal cavity or mouth, passes through the pharynx, larynx, trachea, bronchi,
bronchioles, and finally reaches the alveoli in the lungs.
Describe the characteristics of alveoli that make them effective at gas exchange. - Alveoli
have thin walls, a large surface area, and are surrounded by capillaries, which facilitates
efficient diffusion of oxygen and carbon dioxide.
Describe the functions of the circulatory system - The circulatory system transports
oxygen, nutrients, hormones, and waste products throughout the body, and helps regulate
body temperature and fight infections
What is the function of the semilunar and atrioventricular valves? - Valves in the heart
prevent the backflow of blood. Semilunar valves are located between the ventricles and
arteries, while atrioventricular valves are located between the atria and ventricles
What is an EKG and where does the electrical impulse of the heart begin? - An EKG
(electrocardiogram) is a test that measures the electrical activity of the heart. The
electrical impulse begins in the sinoatrial (SA) node
Compare and contrast arteries, veins, and capillaries. - Arteries carry blood away from the
heart (usually oxygenated), veins carry blood towards the heart (usually deoxygenated),
and capillaries are tiny vessels where exchange of substances occurs between blood and
tissues. Arteries have thicker, more elastic walls than veins.
Bio 100
Bio 100 exam 4 AHC Exam Questions and Answers
2025
List the organized hierarchy of most animal bodies (begin with cells) - Cells, tissues,
organs, organ systems, organism.
Explain the concept of homeostasis. - Homeostasis is the ability of an organism to
maintain a stable internal environment despite external changes.
What is a negative feedback loop? Give an example in the human body. - A negative
feedback loop is a mechanism that reduces or stops a process to maintain homeostasis.
An example is the regulation of body temperature: if the body gets too hot, mechanisms
like sweating are activated to cool it down.
Describe the thermoregulation of endothermic and ectothermic animals. - Endothermic
animals generate their own heat internally, while ectothermic animals rely on external
sources for heat.
How are homeotherms different than heterotherms? - Homeotherms maintain a constant
internal body temperature, while heterotherms can have variable body temperatures.
What is the function of the digestive system? - The function of the digestive system is to
break down food, absorb nutrients, and eliminate waste
List the pathway of food as it moves through the digestive system. - Mouth, esophagus,
stomach, small intestine, large intestine, rectum, anus.
Where does the majority of absorption occur during digestion? - The majority of
absorption occurs in the small intestine.
Bio 100
, Bio 100
Explain the structure and function of the villi and microvilli in the small intestine. - Villi
are finger-like projections and microvilli are even smaller projections on the villi. They
increase the surface area of the small intestine for efficient nutrient absorption.
Describe the passage of air from the outside environment to the lungs. - Air enters
through the nasal cavity or mouth, passes through the pharynx, larynx, trachea, bronchi,
bronchioles, and finally reaches the alveoli in the lungs.
Describe the characteristics of alveoli that make them effective at gas exchange. - Alveoli
have thin walls, a large surface area, and are surrounded by capillaries, which facilitates
efficient diffusion of oxygen and carbon dioxide.
Describe the functions of the circulatory system - The circulatory system transports
oxygen, nutrients, hormones, and waste products throughout the body, and helps regulate
body temperature and fight infections
What is the function of the semilunar and atrioventricular valves? - Valves in the heart
prevent the backflow of blood. Semilunar valves are located between the ventricles and
arteries, while atrioventricular valves are located between the atria and ventricles
What is an EKG and where does the electrical impulse of the heart begin? - An EKG
(electrocardiogram) is a test that measures the electrical activity of the heart. The
electrical impulse begins in the sinoatrial (SA) node
Compare and contrast arteries, veins, and capillaries. - Arteries carry blood away from the
heart (usually oxygenated), veins carry blood towards the heart (usually deoxygenated),
and capillaries are tiny vessels where exchange of substances occurs between blood and
tissues. Arteries have thicker, more elastic walls than veins.
Bio 100
