Date | November 2016 | Marks available | 5 | Reference code | 16N.2.SL.tz0.5 |
Level | Standard Level | Paper | Paper 2 | Time zone | time zone 0 |
Command term | Outline | Question number | 5 | Adapted from | N/A |
Question
Outline the structural components of skeletal muscle.
Analyse the systolic blood pressure response of an endurance runner.
Explain the importance of reliability and validity in fitness testing, for a sport of your choice.
Markscheme
epimysium is the outer surrounding layer «which consists mainly of collagen fibres» ✔
perimysium surrounds bundles of muscle fibres ✔
muscle fibres which are surrounded in a layer called the endomysium ✔
these all connect to a tendon which attaches to the bone to allow muscles to move ✔
the muscle cell/fibre is composed of smaller units called myofibrils ✔
a myofibril is composed of contractile components «protein filaments» known as myosin and actin ✔
sarcomere is a basic/functional unit of the muscle cell ✔
Do not award for reference to striped/striated appearance.
Award [3 max] if they draw and label a diagram.
during endurance running, systolic BP increases ✔
systolic BP increases in direct proportion to the increase in running intensity ✔
increased systolic BP results from increased CO ✔
increase in systolic BP helps increase in blood flow «to muscles involved in running» ✔
increase in systolic BP aids substrate delivery to working muscles/muscles involved in running ✔
fitness tests can be reliable even if they are not a valid test ✔
valid inferences cannot be made from a fitness test unless it is reliable ✔
Validity:
is the extent to which a method/measurement of an investigation possesses the property of doing what it has been designed to do/measure ✔
eg testing the sprint speed of a cyclist using a running test such as a 40m sprint would not yield valid results of the cyclist’s cycling sprint speed as it employs a different mode of transport not applicable to the sport ✔
achieving external validity would enable your experimental results to be applicable to real situations/generalized to the population as a whole/reliant «in part» upon the adequacy of the sample ✔
internal validity is the extent to which the outcome/result of an investigation is a function of the variables that are measured/controlled/manipulated ✔
Award [3 max] for validity.
Award [2 max] if there is no reference to sport of choice.
Reliability:
a test is reliable when you undertake a retest under the same conditions as the original and a similar result is obtained ✔
it is important for tests to be repeatable so that any improvements in performance can be identified and tracked/the effect of the manipulated variable can be clearly seen ✔
reliability in any kind of testing questions the accuracy of test results ✔
Award [2 max] if there is no reference to sport of choice.
Examiners report
For those candidates who had selected Q5 many confused the requirements of the question with the characteristics of muscle. Candidates should develop their ability to describe anatomical structures as those who attempted this question found it difficult to express their understanding coherently. Some candidates drew a diagram to demonstrate their knowledge and this helped to provide evidence to support their response.
Many candidates were able to identify that systolic pressure rises with endurance running. However very few candidates were able to access further marks for this question. Overall this was a poorly answered question.
This was a poorly answered question. Candidates struggled to relate the concept of validity and reliability to a sport of their choice. Many candidates confused validity with accuracy and many candidates were unable to access more than one mark per term.