USABO OPEN Exam 5 Questions with 100%
Correct Answers Latest Versions 2025 Graded
A+
1. collagenous fibers: made of collagen, nonelastic and do not tear easily
2. reticular fibers: made of collagen, joins connective tissue to adjacent tissues,
continuous with collagenous fibers
3. elastic fibers: made of elastin, easily stretched but bounce back to original
shape
4. sarcomeres: repeating units in muscles
5. glial cells or glia: located in nervous tissue; nourish, insulate, and replenish
neurons
6. regulator: manages internal conditions to combat changes caused by external
conditions
7. conformer: allows internal conditions to conform to external conditions
8. normal range (of a variable - homeostasis): range for which action is taken to
maintain homeostasis
9. acclimatization: when an animal changes certain aspects of its metabolism,
,behavior, etc. to temporarily conform to changing external conditions
10. endothermic (animal): maintain the temperature inside the body through their
internal metabolism
11. ectothermic (animal): gain their heat from external sources, do not perform
internal mechanisms to maintain temperature
12. poikilotherm: animal whose body temperature varies with its environment
13. homeotherm: animal whose body temperature does not vary with its environ-
ment
14. radiation: emission of heat in the form of electromagnetic waves
15. evaporation: removal of heat along with liquid being turned into gas
16. convection: transfer of hear by the movement of air or liquid past a surface
17. conduction: the direct transfer of heat between objects in direct contact
18. vasodilation: increasing the diameter of blood vessels as to bring it closer to the
surface of the body and warm it
19. vasoconstriction: decreasing the diameter of blood vessels as to take it farther
away from the surface of the body and cool it
20. countercurrent exchange: the flow of adjacent fluids in opposing directions that
maximizes transfer rates of heat or solutes
21. thermogenesis: heat production
, 22. non-shivering thermogenesis: heat production without moving
23. brown fat: tissue specialized for heat production
24. hypothalamus: part of the brain that acts like a thermostat for the body, control-
ling the internal mechanisms that control internal temperature
25. bio-energetics: the overall flow and transformation of energy in an animal
26. metabolic rate: the sum of all the energy-requiring biochemical reactions over
a given time interval
27. basal metabolic rate (BMR): in an endotherm, the minimum metabolic rate at
rest with an empty stomach without any stress
28. standard metabolic rate (SMR): in an ectotherm, the minimum metabolic rate
when resting, nonstressed, and fasting
29. torpor: a physiological state in which activity is low and metabolism decreases
30. hibernation: long term torpor that is an adaptation to winter cold and food
scarcity
Correct Answers Latest Versions 2025 Graded
A+
1. collagenous fibers: made of collagen, nonelastic and do not tear easily
2. reticular fibers: made of collagen, joins connective tissue to adjacent tissues,
continuous with collagenous fibers
3. elastic fibers: made of elastin, easily stretched but bounce back to original
shape
4. sarcomeres: repeating units in muscles
5. glial cells or glia: located in nervous tissue; nourish, insulate, and replenish
neurons
6. regulator: manages internal conditions to combat changes caused by external
conditions
7. conformer: allows internal conditions to conform to external conditions
8. normal range (of a variable - homeostasis): range for which action is taken to
maintain homeostasis
9. acclimatization: when an animal changes certain aspects of its metabolism,
,behavior, etc. to temporarily conform to changing external conditions
10. endothermic (animal): maintain the temperature inside the body through their
internal metabolism
11. ectothermic (animal): gain their heat from external sources, do not perform
internal mechanisms to maintain temperature
12. poikilotherm: animal whose body temperature varies with its environment
13. homeotherm: animal whose body temperature does not vary with its environ-
ment
14. radiation: emission of heat in the form of electromagnetic waves
15. evaporation: removal of heat along with liquid being turned into gas
16. convection: transfer of hear by the movement of air or liquid past a surface
17. conduction: the direct transfer of heat between objects in direct contact
18. vasodilation: increasing the diameter of blood vessels as to bring it closer to the
surface of the body and warm it
19. vasoconstriction: decreasing the diameter of blood vessels as to take it farther
away from the surface of the body and cool it
20. countercurrent exchange: the flow of adjacent fluids in opposing directions that
maximizes transfer rates of heat or solutes
21. thermogenesis: heat production
, 22. non-shivering thermogenesis: heat production without moving
23. brown fat: tissue specialized for heat production
24. hypothalamus: part of the brain that acts like a thermostat for the body, control-
ling the internal mechanisms that control internal temperature
25. bio-energetics: the overall flow and transformation of energy in an animal
26. metabolic rate: the sum of all the energy-requiring biochemical reactions over
a given time interval
27. basal metabolic rate (BMR): in an endotherm, the minimum metabolic rate at
rest with an empty stomach without any stress
28. standard metabolic rate (SMR): in an ectotherm, the minimum metabolic rate
when resting, nonstressed, and fasting
29. torpor: a physiological state in which activity is low and metabolism decreases
30. hibernation: long term torpor that is an adaptation to winter cold and food
scarcity
