Distinguish the characteristics of smooth and cardiac muscle.

Describe the resynthesis of adenosine triphosphate (ATP) by the lactic acid (anaerobic glycolysis) system.

Outline how the body responds when an athlete’s skin is exposed to injury or infection.

An attacking football player moves in one direction and immediately changes to the opposite direction. This deceives the defender.

Explain the concept the attacking player is using to evade the defender.

Explain the function of the diencephalon.

Candidates must distinguish muscle characteristics to be awarded a mark.

Accept any suitable example location of smooth muscle.

Accept any accurate additional structural difference.

system can only use glycogen/glucose as a fuel source;

glucose is converted into pyruvate;

system produces a low yield / 1 glucose produces 2ATP <net>;

in the absence of oxygen pyruvate is converted to lactate/lactic acid;

byproducts of lactic acid system are lactic acid, <hydrogen ions, lactate>;

system resynthesizes ATP at a rapid rate;

physical barriers: e.g. increase of epithelial linings, mucous secretions;

chemical: change pH of body fluids e.g. increasing adrenalin / cortisol;

leucocyte/white blood cells fight pathogens;

antibodies are produced to fight the antigen/pathogen;

inflammation to protect area / heat;

clotting <by platelets> reduces blood loss / repair physical barrier;

Max [2] if mechanisms listed without examples.

psychological refractory period;

is the increase in response time(RT) to a second stimulus caused when the second stimulus has been delivered while the performer is responding to the first stimulus

OR

time delay in RT caused by the arrival of a second stimulus before the first is processed

OR

when a second stimulus arrives before the first response is completed;

reaction to the second stimulus is longer as the first response is still being processed

OR

player has to sort out new and correct stimulus, but first they have to disregard the old and now useless stimulus and this causes the delay;

hoping the defender has been distracted by the fake move as they cannot respond until the full reaction/response 1 has been processed by the brain;

brain processes one action at a time causing a time delay in responding to the second stimulus

OR

the single channel hypothesis states that each stimulus can only be processed one at a time

OR

a second stimulus must wait until the first has been processed

OR

each stimulus we process has to progress through a single track

OR

any subsequent stimulus must wait for the one before it to be processed before it can be dealt with;

Award [1] stating for the concept.

Accept diagram to assist with explanation.

thalamus AND hypothalamus form <part of> the diencephalon;

thalamus functions:

sensory input <except smell> received from receptors is relayed through the thalamus to the cerebral cortex;

regulation of sensory input that reaches the conscious brain which is important for motor control

OR

thalamus plays a role in awareness/consciousness;

regulation of sleeping/wakefulness by suppressing sensory information which may wake an individual;

connection to the amygdala demonstrates a role in emotions and awareness of danger;

hypothalamus functions:

hypothalamus maintains homeostasis by controlling the internal environment through neuroendocrine control;

e.g. fluid balance/food intake/thirst/body temperature;

circadian rhythms are controlled by the release of melatonin from the pineal gland;

autonomic nervous system/ANS e.g. heart rate/respiration/digestion/ fight or flight response;

neuroendocrine control of growth;

Max [2] for a list of functions.

Max [2] per function if detailed explanation given.

Only credit sleep–wake cycle once, unless correctly explained for each part.

Many candidates were able to clearly identify a location of cardiac muscle within the heart. Many candidates correctly identified that smooth muscle is found within organs such as the stomach or intestines. However, many candidates just identified organs as the location and therefore were not credited the mark. Most candidates correctly identified cardiac muscle fibres have striations whereas smooth does not. Very few referred to nuclei and appeared to have a misconception that smooth muscle was multinucleated. As the question was 'distinguish' nuclei were not included in the mark scheme as both cardiac and smooth are uninucleate, although we appreciate some cardiac muscle can be binucleated therefore if candidates correctly distinguished between the two muscles, credit would have been provided.

Of the candidates who selected question 12, many chose not to respond to this question. Surprisingly many candidates struggled to access full marks for this question. Most were able to identify glucose as the fuel and a net of 2ATP and a by-product of lactic acid.

Most candidates who attempted question 12 addressed this question. Many were able to explain that an athlete must complete their response to the first stimulus before they can respond to the second stimulus and that the introduction of a dummy fake as the first stimulus causes a delay in response. However few candidates referred to the single channel hypothesis or were able to identify the concept.

Most candidates who attempted this question understood the main structures involved in the diencephalon and in the most part explained the role of the hypothalamus. However, many listed functions of the thalamus or diencephalon without much detail. Therefore, further depth of understanding of these areas is required.