©GRACEAMELIA 2024/2025 ACADEMIC YEAR. ALL RIGHTS RESERVED
FIRST PUBLISH OCTOBER 2024
PNB 2250 Exam 3 Questions and Answers
– Updated 2024
Of the following, which is NOT a strategy by which endotherms generate internal heat: - Ans:✔✔-
Panting
The minimal metabolic activity required to maintain bodily functions in a mammal is known as the -
Ans:✔✔-basal metabolic rate.
Which of the following thermoregulatory mechanisms can be used to restrict blood flow to the skin, and
thus decreases heat loss by keeping the warmed blood closer to the core of the body? - Ans:✔✔-
vasoconstriction
Poikilothermic ectotherms that live in thermally variable environments manage to maintain a relatively
stable body temperature. - Ans:✔✔-False
Which of the following statements is NOT true? - Ans:✔✔-Endotherms gain all their heat from internal,
biochemical reactions.
According to the second law of thermodynamics, as life become more organized the environment
becomes disorganized. - Ans:✔✔-True
Page 1/25
, ©GRACEAMELIA 2024/2025 ACADEMIC YEAR. ALL RIGHTS RESERVED
FIRST PUBLISH OCTOBER 2024
Which of the following is true for LARGER animals in comparison to SMALLER animals? - Ans:✔✔-Mass-
specific BMR is lower in larger animals, because of a low Surface Area:Volume ratio
With respect to thermal adaptation, amphibians are considered to be - Ans:✔✔-ectothermic
Almost all expended energy eventually becomes heat, in accordance with the: - Ans:✔✔-Second law of
thermodynamics
The transfer of energy from the sun to the earth is ____________ . - Ans:✔✔-radiation
Ectotherms are always poikilotherms, and endotherms are always homeotherms - Ans:✔✔-false
Metabolism is __________ . - Ans:✔✔-reactions that consume ATP
reactions that produce ATP
anabolic reactions
reactions that break molecules down into smaller molecules
Page 2/25
, ©GRACEAMELIA 2024/2025 ACADEMIC YEAR. ALL RIGHTS RESERVED
FIRST PUBLISH OCTOBER 2024
ALL OF THE ABOVE
Respiratory Quotient is ____________ . - Ans:✔✔-Ratio of CO2 produced / Oxygen consumed
Non-shivering thermogenesis, a strategy used by many small mammals involves: - Ans:✔✔-Oxidizing BAT
to produce heat
Temporal heterotherms such as the ____________ regulate heat by ____________ . - Ans:✔✔-
Hummingbird; going into daily torpor to reduce energy demands
The direct transfer of energy from objects of differing temperature that are in contact with each other is
_______________ . - Ans:✔✔-conduction
The swordfish's heater organ involves all of the following EXCEPT ___________ . - Ans:✔✔-Oxidation of
brown adipose tissue
The principal role of calcium in skeletal muscle contraction is to - Ans:✔✔-bind troponin, which in turn
permits tropomyosin to uncover the cross-bridge binding site on the thin filament.
A vertebrate motor unit is - Ans:✔✔-a motor neuron and the muscle fibers it innervates
When a skeletal muscle contracts, ___________ - Ans:✔✔-Actin filaments slide inward along myosin
filaments, making the I band more narrow
Page 3/25
FIRST PUBLISH OCTOBER 2024
PNB 2250 Exam 3 Questions and Answers
– Updated 2024
Of the following, which is NOT a strategy by which endotherms generate internal heat: - Ans:✔✔-
Panting
The minimal metabolic activity required to maintain bodily functions in a mammal is known as the -
Ans:✔✔-basal metabolic rate.
Which of the following thermoregulatory mechanisms can be used to restrict blood flow to the skin, and
thus decreases heat loss by keeping the warmed blood closer to the core of the body? - Ans:✔✔-
vasoconstriction
Poikilothermic ectotherms that live in thermally variable environments manage to maintain a relatively
stable body temperature. - Ans:✔✔-False
Which of the following statements is NOT true? - Ans:✔✔-Endotherms gain all their heat from internal,
biochemical reactions.
According to the second law of thermodynamics, as life become more organized the environment
becomes disorganized. - Ans:✔✔-True
Page 1/25
, ©GRACEAMELIA 2024/2025 ACADEMIC YEAR. ALL RIGHTS RESERVED
FIRST PUBLISH OCTOBER 2024
Which of the following is true for LARGER animals in comparison to SMALLER animals? - Ans:✔✔-Mass-
specific BMR is lower in larger animals, because of a low Surface Area:Volume ratio
With respect to thermal adaptation, amphibians are considered to be - Ans:✔✔-ectothermic
Almost all expended energy eventually becomes heat, in accordance with the: - Ans:✔✔-Second law of
thermodynamics
The transfer of energy from the sun to the earth is ____________ . - Ans:✔✔-radiation
Ectotherms are always poikilotherms, and endotherms are always homeotherms - Ans:✔✔-false
Metabolism is __________ . - Ans:✔✔-reactions that consume ATP
reactions that produce ATP
anabolic reactions
reactions that break molecules down into smaller molecules
Page 2/25
, ©GRACEAMELIA 2024/2025 ACADEMIC YEAR. ALL RIGHTS RESERVED
FIRST PUBLISH OCTOBER 2024
ALL OF THE ABOVE
Respiratory Quotient is ____________ . - Ans:✔✔-Ratio of CO2 produced / Oxygen consumed
Non-shivering thermogenesis, a strategy used by many small mammals involves: - Ans:✔✔-Oxidizing BAT
to produce heat
Temporal heterotherms such as the ____________ regulate heat by ____________ . - Ans:✔✔-
Hummingbird; going into daily torpor to reduce energy demands
The direct transfer of energy from objects of differing temperature that are in contact with each other is
_______________ . - Ans:✔✔-conduction
The swordfish's heater organ involves all of the following EXCEPT ___________ . - Ans:✔✔-Oxidation of
brown adipose tissue
The principal role of calcium in skeletal muscle contraction is to - Ans:✔✔-bind troponin, which in turn
permits tropomyosin to uncover the cross-bridge binding site on the thin filament.
A vertebrate motor unit is - Ans:✔✔-a motor neuron and the muscle fibers it innervates
When a skeletal muscle contracts, ___________ - Ans:✔✔-Actin filaments slide inward along myosin
filaments, making the I band more narrow
Page 3/25
