7.5.2 Effects of too much and too little exercise Quiz: Pearson Edexcel Biology A (Salters-Nuffield), Unit 7

The 20 questions

1. Which of the following is a recognised disadvantage of exercising too much?

   • Increased risk of type 2 diabetes, which develops when the body becomes resistant to the action of insulin over time
   • Reduced blood pressure from chronic inactivity, which lowers the force with which the heart pumps blood round the body
   • Increased risk of obesity, which develops when energy intake consistently exceeds the energy expended during activity
   • Wear and tear on joints, such as cartilage damage, which can build up with repeated high-impact loading over years

2. Which of the following is a recognised effect of very prolonged, strenuous exercise on the immune system?

   • It has no effect on immune function, since the immune system is independent of physical activity levels
   • It produces more antibodies in every case, which protects athletes from infection for many months afterwards
   • It is strengthened permanently, so athletes become more resistant to all infections as their training volume rises
   • It is temporarily suppressed, increasing susceptibility to infection for a period after very intense training

3. Which of the following is a risk of exercising too little?

   • Increased risk of obesity, which develops when energy intake regularly exceeds energy expended through physical activity
   • Increased risk of stress fractures, which develop when bones are loaded repeatedly without sufficient time to recover
   • Increased wear and tear on joints, which occurs when the body is loaded beyond its capacity to recover
   • Suppression of the immune system, which is caused by a lack of rest between periods of intense physical activity

4. Which condition is most closely linked to a sedentary lifestyle, along with obesity and high blood pressure?

   • Phenylketonuria, a genetic condition in which the body cannot break down the amino acid phenylalanine
   • Haemophilia, an inherited disorder in which blood fails to clot normally because a clotting factor is missing
   • Cardiovascular disease, which affects the heart and blood vessels and is strongly associated with physical inactivity
   • Sickle cell anaemia, an inherited condition in which red blood cells take an abnormal crescent shape

5. A study finds that people who exercise less have a higher rate of type 2 diabetes. Which statement is the best interpretation?

   • There is no relationship between the two variables, since the differences in rates could be due entirely to chance
   • Exercise causes diabetes, because the activity places stress on the pancreas and damages its insulin-producing cells
   • There is a correlation, which does not on its own show that low exercise causes diabetes, since other factors may be involved
   • Diabetes causes people to exercise more, because the condition makes people feel more energetic during the day

6. Which statement correctly distinguishes correlation from causation?

   • Causation means two variables change together, but one does not necessarily cause the other to change in any way
   • Causation and correlation mean the same thing, so the two terms can be used interchangeably in scientific writing
   • Correlation means one variable causes the other to change, so a strong correlation always proves a direct cause
   • Correlation shows that a relationship exists between two variables, but does not prove that one causes the other

7. A researcher finds that people who spend more hours on exercise have a lower body mass index. What is the most appropriate conclusion?

   • The data show no relationship at all, because the measurements of exercise and body mass index are not linked
   • Exercise always causes a lower body mass index, so every person who exercises more will lose weight over time
   • Body mass index causes people to exercise more, since people with a lower body mass find activity more enjoyable
   • There is a negative correlation between exercise time and body mass index in this sample, which may have other causes

8. A runner's knee cartilage is damaged after many years of running long distances. Which mechanism best explains this?

   • Lactate build-up permanently dissolves the bone, weakening the joint so the cartilage can no longer be held in place
   • Cartilage is a muscle that becomes fatigued and tears, after the muscle has been worked too hard during the run
   • Inactivity causes the cartilage to swell and burst, since the joint is not moved enough to keep the tissue healthy
   • Repeated high-impact loads gradually wear the cartilage, reducing its protection of the joint over many years of training

9. Which pair correctly matches an exercise extreme with a disadvantage?

   • Too much exercise: increased risk of type 2 diabetes, which develops when the body is overloaded by continuous training
   • Too much exercise: increased risk of obesity, which develops when the body is overloaded with energy during training
   • Too little exercise: increased risk of obesity and cardiovascular disease, which develop with prolonged physical inactivity
   • Too little exercise: increased suppression of the immune system, which develops after long periods of physical inactivity

10. A large epidemiological study finds a positive correlation between hours of inactivity and risk of cardiovascular disease. Which factor is the best example of a confounding variable?

    • Age, if older people were more likely to be inactive and also more likely to develop cardiovascular disease
    • The number of cars owned by the participants, which may reflect transport habits but is unlikely to affect either factor
    • The colour of the participants' clothing, which might differ between the groups but has no link to either variable
    • The ambient temperature at the time of data collection, which is unlikely to be related to either inactivity or disease

11. What does a control group allow researchers to do in a study of exercise and disease?

    • Compare outcomes with a group that does not receive the factor, to help establish whether the factor has an effect
    • Guarantee that all results will be identical across every participant in the study, regardless of individual differences
    • Prove that the exercise caused the disease, since the comparison group shows exactly what would have happened otherwise
    • Eliminate the need for statistical analysis, because the control group shows the result without any calculation at all

12. A person exercises very intensively for many hours each day. Which combination of effects is most likely?

    • Strengthened immunity and reduced joint wear, since the body adapts to the load by becoming more resistant to damage
    • Increased obesity and increased bone density only, since the activity stores energy as fat and strengthens the bones
    • Wear and tear on joints and suppressed immunity, since very high training loads damage joints and reduce immune function
    • No change to joints and enhanced recovery of the immune system, since the body copes well with any level of activity

13. Which statement about the health effects of exercise is most accurate?

    • Moderate regular exercise has no benefits for cardiovascular health, since any activity beyond rest is equally harmful
    • Both too little and excessive exercise can carry health risks, so the amount of exercise matters for health
    • The only effect of exercise is a change in body colour, which is caused by increased blood flow to the skin
    • Exercise is only harmful and never beneficial, since the physical stress it places on the body always outweighs gains

14. A study of 1000 adults compares those who are physically inactive with those who are active. Which design would best show whether inactivity causes cardiovascular disease?

    • A single case study of one person, followed closely for a short period to record every change in their health
    • A questionnaire completed only by people who already have heart disease, asking about their activity before diagnosis
    • An observation of how many people visit a gym on one day, recording the numbers at a single location
    • A prospective cohort study following people over time with measured activity levels and recorded disease outcomes

15. Why are the effects of exercise on health usually shown in data as frequency tables or bar charts?

    • They replace the need for a hypothesis, since the data set answers the question without any prediction being made
    • They prove causation automatically, because the layout of the table shows which variable produces the other
    • They show the exact genetic code of athletes, which can be read directly from the bars of the chart
    • They allow comparison of numbers of people in different categories, such as activity levels, for interpretation

16. A researcher reports that 30 per cent of inactive adults develop type 2 diabetes compared with 10 per cent of active adults. What is the relative risk of diabetes in inactive adults compared with active adults?

    • 3, which is the ratio of the risk in the inactive group to the risk in the active group
    • 1.3, which is found by adding the two percentages and dividing by the active group figure
    • 0.3, which is simply the percentage of inactive adults who develop the condition, as a decimal
    • 20, which is the difference between the two percentages multiplied by ten

17. An athlete's immune cell counts fall during a period of very heavy training. What is the most reasonable conclusion from this observation alone?

    • Immune cells are destroyed by all exercise, so any form of physical activity will reduce the body's defences
    • The athlete has definitely caught an infection, since a fall in immune cells always shows that an infection is present
    • Heavy training may be associated with temporary immune suppression, but other causes must be considered before concluding
    • Heavy training causes permanent immune deficiency in every athlete, since the reduction in cells is never reversed

18. Which statement best describes a risk of exercising too much for a young person with still-developing bones?

    • Excessive load may cause stress injuries, so training must be balanced with rest to allow healthy bone development
    • Bones stop growing completely as soon as any exercise is started, which prevents the skeleton from reaching adult size
    • Bone density always increases without limit, so the bones become stronger the harder the young person trains
    • Joint cartilage is strengthened at the cost of muscle, which means the young person loses strength as training continues

19. Which evaluation is most appropriate for a claim that exercise prevents all cardiovascular disease?

    • The claim is correct, because exercise is the only cause of cardiovascular disease and removing it removes all risk
    • The claim is overstated, because exercise reduces risk but other factors such as genetics and diet also affect outcome
    • The claim is correct, because all correlations between exercise and health prove that exercise causes the benefit
    • The claim is incorrect, because exercise has no effect on any disease and any benefit comes from other sources

20. Which statement correctly describes the link between sedentary behaviour and cardiovascular disease?

    • Inactivity is associated with a higher risk of cardiovascular disease, and this association is seen across many populations
    • There is no association between inactivity and cardiovascular disease in any population that has been studied
    • Inactivity lowers the risk of cardiovascular disease in all people, since rest reduces the work done by the heart
    • Cardiovascular disease causes people to become more active, which is why active people are less often affected

Related quizzes

• Why animals need a circulation and the role of water Quiz · 1.1.1 · 20 questions
• Gas exchange surfaces and Fick's Law Quiz · 2.1.1 · 20 questions
• Common features of living cells Quiz · 3.1.1 · 20 questions
• Biodiversity, endemism and threats to variety of life Quiz · 4.1.1 · 20 questions
• Ecosystems, communities, populations and biotic and abiotic factors Quiz · 5.1.1 · 20 questions
• Time of death, decomposition and forensic entomology Quiz · 6.1.1 · 20 questions
• Structure and function of blood vessels Quiz · 1.1.2 · 20 questions
• Cell membrane structure and the fluid mosaic model Quiz · 2.1.2 · 20 questions
• Eukaryotic ultrastructure and electron micrographs Quiz · 3.1.2 · 20 questions
• Measuring biodiversity: heterozygosity and diversity index Quiz · 4.1.2 · 20 questions