Outline the chemical control of ventilation during exercise.

Describe the phenomenon of oxygen deficit.

Outline two named methods of memory improvement.

Using a sporting example, predict how a change in radius affects speed of rotation.

Explain sliding filament theory after acetylcholine (ACh) increases muscle membrane permeability.

ventilation is «chemically» regulated by blood acidity levels/low pH ✔

blood acidity levels increase/pH drops due to an increase in carbon dioxide levels ✔

blood acidity levels are detected by chemoreceptors ✔

medulla oblongata/ANS/respiratory control centre receive information from receptors ✔

increased blood acidity «and information from the proprioceptors» increases the depth / rate of ventilation ✔

Accept appropriately labelled diagram.

deficit is calculated as the difference between the oxygen required for a given rate of work and the oxygen actually consumed ✔

deficit takes place during the initial stages of exercise ✔

muscles generate ATP through anaerobic pathways ✔

oxygen transport system is not immediately able to supply the needed quantity of oxygen to the active muscles
OR
oxygen consumption requires several minutes/time before a homeostatic level is reached ✔

homeostatic level is reached when the aerobic system meets the demands ✔

is repaid after exercise is finished✔

rehearsal ✔

information is processed mentally or physically ✔

coding ✔

labelling sets of information to make it easier to access ✔

brevity ✔

giving a learner a small amount of information at a time to avoid overload ✔

clarity ✔

keeping learning / teaching simple at the beginning ✔

avoiding to teach / learn similar but distinct items in the same session «to avoid interference with the memory of the other» ✔

chunking ✔

learners retain more if the information is chunked «instead of being presented as individual items» ✔

organization ✔

we remember more easily if we organize the way in which we are to learn and ensure that the information is meaningful ✔

association ✔

ensuring that new learning is linked to what players already know ✔

practice ✔

establishes memory trace/pathway ✔

Award [1 max] for a list of methods.

Award [2 max] per memory aid.

Description must correspond to the named method to obtain the mark.

Angular momentum=moment of inertia x angular velocity ✔

angular momentum is conserved after push off/take off
OR
the magnitude of angular momentum remains constant ✔

with decrease in radius the body has lower moment of inertia ✔

the speed of rotation/rotational velocity increases with decreased radius/body being in a compact shape
OR
eg moving arms/legs closer in will increase the speed of rotation ✔

when an athlete wants to stop the spin, they increase the radius to decrease the rotational velocity ✔

Award [2 max] if no reference to an example is included.

sodium ions/Na⁺ enter the muscle and change the polarization in the myofibril ✔

the sarcoplasmic reticulum releases calcium ions ✔

calcium ions bind to troponin ✔

Tropomyosin/troponin complex exposes the binding site «on actin» ✔

myosin «head» creates a cross-bridge with the actin ✔

power stroke takes place ✔

z lines come closer together / H zone gets smaller✔

myosin releases actin if new ATP appears ✔

myosin head reattached further down the actin filament repeating the  cycle < called the ratchet mechanism>✔

process goes on until acetylcholine-esterase breaks the acetylcholine down ✔

Most candidates managed to articulate that an increase in CO₂ changes the pH which is detected by chemoreceptors.

Overall a good understanding was shown here with very few getting this mixed up with oxygen debt.

Very well articulated.

Generally well done and understood and able to use a relevant example from sport to show understanding.

Very well articulated. Candidates clearly know the sliding filament theory and the associated steps.