Homeostasis exam questions with verified detailed solutions || || || || || ||
Suggest one way of measuring metabolic rate (1)
|| || || || || || ||
Production of carbon dioxide || || ||
The graph shows the affect of increasing the environmental temperature on the metabolic
|| || || || || || || || || || || || ||
rate of a small mammal.
|| || || ||
The small mammal has ears which are usually pink but they appear pale when the
|| || || || || || || || || || || || || || ||
environmental temperature is low. Explain the pale appearance of the mammals ears when || || || || || || || || || || || || ||
the environmental temperature is low (3)
|| || || || ||
-arterioles constrict/narrow -vasoconstriction || ||
-so that there less blood flows to the capillaries
|| || || || || || || ||
-which reduces heat loss due to convection
|| || || || || ||
What is meant by homeostasis? Nd give one example explaining why homeostasis is
|| || || || || || || || || || || || ||
important in mammals (2) || || ||
-maintaining a constant internal environment || || || ||
-keeping an optimum temperature for enzyme activities || || || || || ||
Cross channel swimmers experience a large decrease in external temperature when they
|| || || || || || || || || || || ||
enter the water, describe the process involved in thermoregulation in response to this large
|| || || || || || || || || || || || || ||
decrease in external temperature (6) || || || ||
-hypothalamus which contains the thermoregulatory centre has receptors which detect the || || || || || || || || || || ||
temperature change in the blood || || || ||
-impulses are also received from the skin || || || || || ||
-nerve impulses are transmitted from hypothalamus resulting in
|| || || || || || ||
-vasoconstriction
-and the diversion of blood to the core
|| || || || || || ||
-muscular contractions generate heat through respiration through shivering
|| || || || || || ||
-and adrenaline is released which increases metabolic rate
|| || || || || || ||
A person swimming in cold water may not be able to maintain their core body temperature
|| || || || || || || || || || || || || || || ||
and begins to suffer from hypothermia. Explain why a tall thin swimmer is more likely to
|| || || || || || || || || || || || || || || ||
suffer from hypothermia than a short stout swimmer with the same body mass (2)
|| || || || || || || || || || || || ||
, -Larger surface area to volume || || || ||
-less insulation and more heat loss by conduction
|| || || || || || ||
Cross channel swimmers may suffer from muscle fatigue during which the contraction
|| || || || || || || || || || || ||
mechanism is disrupted. One factor thought to contribute to muscle fatigue is a decrease in
|| || || || || || || || || || || || || || ||
the availability of calcium ion channels within muscle fibres.
|| || || || || || || ||
Explain how a decrease in the availability of calcium ions could disrupt the contraction
|| || || || || || || || || || || || || ||
mechanism in the muscles (3) || || || ||
-cannot move tropomyosin from the binding sites on actin
|| || || || || || || ||
-so myosin heads do not binds and actinomyosin is not formed
|| || || || || || || || || ||
-does not activate ATPase || || ||
How does maintaining a constant body temperature allow metabolic reactions in cells to
|| || || || || || || || || || || || ||
proceed with maximum efficiency (5) || || || ||
-37 degrees (body temp) is optimum temp for enzymes
|| || || || || || || ||
-excess heat can denature enzymes so substrate cannot bind
|| || || || || || || ||
-so reactions are slowed
|| || ||
-lower temperatures reduces kinetic energy of molecules so they move more slowly
|| || || || || || || || || || ||
-fewer collisions take place so fewer ES complexes formed
|| || || || || || || ||
One reason that reaction time is slower when body temperature falls is because nerve
|| || || || || || || || || || || || || ||
impulse conduction is slower. || || ||
Explain how a lower temperature leads to slower nerve impulse conduction (2)
|| || || || || || || || || || ||
-slower diffusion of Na+ and k+ ions || || || || || ||
Insulin is a polypeptide molecule, state where in the pancreatic cell insulin molecules are
|| || || || || || || || || || || || || ||
synthesised (1) ||
Ribosome
Outline the events that occur after the synthesis of an insulin molecule until it is ready to be
|| || || || || || || || || || || || || || || || ||
secreted from the pancreatic cell (3)
|| || || || || ||
-transported to the Golgi || || ||
-modified in the golgi || || ||
-packaged into golgi vesicles and transported towards the cell surface membrane
|| || || || || || || || || ||
Explain why the events shown in the diagram can be described as an example of negative
|| || || || || || || || || || || || || || || ||
feedback (1) ||
A change to the normal level initiates a response which acts against the change
|| || || || || || || || || || || || ||
Suggest one way of measuring metabolic rate (1)
|| || || || || || ||
Production of carbon dioxide || || ||
The graph shows the affect of increasing the environmental temperature on the metabolic
|| || || || || || || || || || || || ||
rate of a small mammal.
|| || || ||
The small mammal has ears which are usually pink but they appear pale when the
|| || || || || || || || || || || || || || ||
environmental temperature is low. Explain the pale appearance of the mammals ears when || || || || || || || || || || || || ||
the environmental temperature is low (3)
|| || || || ||
-arterioles constrict/narrow -vasoconstriction || ||
-so that there less blood flows to the capillaries
|| || || || || || || ||
-which reduces heat loss due to convection
|| || || || || ||
What is meant by homeostasis? Nd give one example explaining why homeostasis is
|| || || || || || || || || || || || ||
important in mammals (2) || || ||
-maintaining a constant internal environment || || || ||
-keeping an optimum temperature for enzyme activities || || || || || ||
Cross channel swimmers experience a large decrease in external temperature when they
|| || || || || || || || || || || ||
enter the water, describe the process involved in thermoregulation in response to this large
|| || || || || || || || || || || || || ||
decrease in external temperature (6) || || || ||
-hypothalamus which contains the thermoregulatory centre has receptors which detect the || || || || || || || || || || ||
temperature change in the blood || || || ||
-impulses are also received from the skin || || || || || ||
-nerve impulses are transmitted from hypothalamus resulting in
|| || || || || || ||
-vasoconstriction
-and the diversion of blood to the core
|| || || || || || ||
-muscular contractions generate heat through respiration through shivering
|| || || || || || ||
-and adrenaline is released which increases metabolic rate
|| || || || || || ||
A person swimming in cold water may not be able to maintain their core body temperature
|| || || || || || || || || || || || || || || ||
and begins to suffer from hypothermia. Explain why a tall thin swimmer is more likely to
|| || || || || || || || || || || || || || || ||
suffer from hypothermia than a short stout swimmer with the same body mass (2)
|| || || || || || || || || || || || ||
, -Larger surface area to volume || || || ||
-less insulation and more heat loss by conduction
|| || || || || || ||
Cross channel swimmers may suffer from muscle fatigue during which the contraction
|| || || || || || || || || || || ||
mechanism is disrupted. One factor thought to contribute to muscle fatigue is a decrease in
|| || || || || || || || || || || || || || ||
the availability of calcium ion channels within muscle fibres.
|| || || || || || || ||
Explain how a decrease in the availability of calcium ions could disrupt the contraction
|| || || || || || || || || || || || || ||
mechanism in the muscles (3) || || || ||
-cannot move tropomyosin from the binding sites on actin
|| || || || || || || ||
-so myosin heads do not binds and actinomyosin is not formed
|| || || || || || || || || ||
-does not activate ATPase || || ||
How does maintaining a constant body temperature allow metabolic reactions in cells to
|| || || || || || || || || || || || ||
proceed with maximum efficiency (5) || || || ||
-37 degrees (body temp) is optimum temp for enzymes
|| || || || || || || ||
-excess heat can denature enzymes so substrate cannot bind
|| || || || || || || ||
-so reactions are slowed
|| || ||
-lower temperatures reduces kinetic energy of molecules so they move more slowly
|| || || || || || || || || || ||
-fewer collisions take place so fewer ES complexes formed
|| || || || || || || ||
One reason that reaction time is slower when body temperature falls is because nerve
|| || || || || || || || || || || || || ||
impulse conduction is slower. || || ||
Explain how a lower temperature leads to slower nerve impulse conduction (2)
|| || || || || || || || || || ||
-slower diffusion of Na+ and k+ ions || || || || || ||
Insulin is a polypeptide molecule, state where in the pancreatic cell insulin molecules are
|| || || || || || || || || || || || || ||
synthesised (1) ||
Ribosome
Outline the events that occur after the synthesis of an insulin molecule until it is ready to be
|| || || || || || || || || || || || || || || || ||
secreted from the pancreatic cell (3)
|| || || || || ||
-transported to the Golgi || || ||
-modified in the golgi || || ||
-packaged into golgi vesicles and transported towards the cell surface membrane
|| || || || || || || || || ||
Explain why the events shown in the diagram can be described as an example of negative
|| || || || || || || || || || || || || || || ||
feedback (1) ||
A change to the normal level initiates a response which acts against the change
|| || || || || || || || || || || || ||
