MODULE 8 | NON-INFECTIOUS DISEASE AND DISORDERS646

Non-infectious disease and disordersMultiple choice1 Identify the best description of homeostasis.

A Homeostasis is controlling pH and temperature within all the cells of the body.

B Homeostasis is keeping conditions within the body relatively stable and constant.

C Homeostasis is reducing metabolism when conditions are not ideal for functioning.

D Homeostasis is maintaining identical temperatures under different conditions.

2 Feedback mechanisms are important in the homeostatic control of the body’s internal conditions. In a feedback system of control, which of the following is true?

A The stimulus alters the original response.B The response alters the original stimulus.C The response reduces the effect of the original

stimulus.D The response increases the effect of the original

stimulus.

3 Which of the following describes paracrine signalling?

A The signalling molecule is carried to the target cell through the bloodstream.

B The signalling molecule acts on the same cell that secretes the molecule.

C The signalling molecule acts on target cells near the cell that secreted it.

D The signalling molecule acts on target cells distant from the cell that produced it.

4 A person is swimming in water that has a temperature of 20°C. What actions happen to regulate that person’s body temperature?

blood circulation to the skin

sweat glands

skeletal muscle

A increased blood flowincreased secretion

decreased shivering

B decreased blood flowdecreased secretion

increased shivering

C decreased blood flowincreased secretion

increased shivering

D increased blood flowdecreased secretion

increased shivering

5 Four adaptations of the Australian red kangaroo for regulating their body temperature are:

i a dense network of blood vessels close to the skin in the forelimbs

ii licking the forelimbs in hot weatheriii a powerful tail that acts as a counterbalance when

hoppingiv the blood vessels in the forelimbs widen (dilate) in

hot weatherWhich one of the following groups correctly classifies these four adaptations?A i = physiological, ii = behavioural, iii = structural,

iv = physiologicalB i = structural, ii = behavioural, iii = structural,

iv = physiologicalC i = structural, ii = behavioural, iii = structural,

iv = behaviouralD i = physiological, ii = behavioural, iii = physiological,

iv = structural

6 Which feature is common to endotherms found in cold climates?

A a small SA/Volume ratioB a large SA/Volume ratioC large external organs such as earsD a large blood supply

7 Plants growing in areas of water scarcity need adaptations to reduce water loss. Select the adaptation that conserves water:

A ability to close stomates during very hot conditionsB leaves with a thick, waxy cuticleC hairs on leavesD all of the above

8 Select the list that contains only non-infectious diseases:

A lung cancer, diabetes, Down syndrome, asthmaB cystic fibrosis, anaemia, heart disease, hepatitis BC rickets, warts, scurvy, cancerD lead poisoning, heart disease, diphtheria, cancer of

the cervix

MODULE 8 • REVIEW

REVIEW QUESTIONS

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647REVIEW QUESTIONS

9 Identify the best summary description for control of the cell cycle.

A Tumour suppressor genes produce proteins that slow down cell growth and cell division.

B Damaged or mutated genes are inactivated by special genes at set points in the cycle.

C Proto-oncogenes and tumour suppressor genes repair any chromosomal damage throughout the cell cycle.

D A balance of stimulation and suppression of cell divisions results in control of the cell cycle.

10 Cancer refers to a group of diseases caused by some common malfunctions at the cellular level. Identify the processes that result in cancer.

A very rapid cell division and growth B uncontrolled meiosis and growth of abnormal cellsC production of mutant cells that do not differentiate

normally D activation of oncogenes and tumour growth

11 An expectant mother gave birth to a baby that was severely jaundiced and anaemic. The baby recovered after a blood transfusion, but concerned doctors tested the blood of both the baby and its mother. It was discovered that the baby and her older brother were positive to the Rhesus factor while their mother was Rhesus negative. The baby’s haemolytic disease occurred because:

A The mother’s antigens recognised the baby’s antibodies as foreign and attacked them.

B The mother’s antibodies to the Rhesus factor developed in response to the blood of her first child, and then caused the immune response to the blood of her second child.

C The baby developed antibodies in response to the mother’s Rhesus negative blood and this caused the second baby’s haemolytic disease.

D The Rhesus antigen present on the mother’s red blood cells caused an immune response to the baby’s blood, which was free of the antigen.

12 Blood glucose levels rise after a meal is eaten, then fall again as the body uses the energy provided by the glucose, or stores the excess for later use. Diabetes is a condition that results in excess glucose in the blood. When compared to a ‘normal’ person, the blood glucose levels in a diabetic rise higher after eating a meal and fall at a slower rate. If the glucose levels do not fall, this would suggest the diabetic is suffering from:

A type 1 diabetesB type 2 diabetesC hyperglycaemiaD hypoglycaemia

13 Identify the main features of epidemiology.

A Epidemiology is the collection and statistical analysis of large volumes of data on health and health services.

B Epidemiology is the study of epidemics of infectious diseases in humans.

C Epidemiology is useful for identifying the causes of infectious and non-infectious diseases.

D Epidemiology studies the patterns and causes of diseases in groups of people.

14 In 2006, residents of the mining town of Mt Isa in Queensland expressed concern at rising rates of childhood learning disabilities and the possible link with exposure to environmental lead. Queensland Health tested 400 children between September 2006 and December 2007 and the results are displayed in the graph.

Levels of lead in the blood greater than 10 micrograms (μg) per decilitre (dL) are considered potentially dangerous. Note: To compare with international standards it was convenient to use the dL unit: 1 dL = 100 mL.

indigenousnon-indigenous

Blood lead levels μg/dL

Perc

enta

ge o

f chi

ldre

n te

sted

25

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2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32

10

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20

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648 MODULE 8 | NON-INFECTIOUS DISEASE AND DISORDERS

MODULE 8 • REVIEW

Select the most accurate interpretation of this graph. A Fewer than half the children tested had dangerous

levels of lead in their blood. B There is a causal relationship between lead exposure

and learning disabilities. C 15% of Indigenous children and 5% of

non-Indigenous children had levels >10 μg/dL. D All Mt Isa children have some level of lead in their

blood.

15 Identify the correct set of labels for structures of the human ear.

Y

X

Z

label X label Y label Z

A outer ear semicircular canals oval window

B middle ear auditory nerve ossicles

Ctympanic membrane

middle ear inner ear

D outer ear cochlea round window

16 Hearing aids are particularly suitable for which of the following groups of people?

A people with sensorineural hearing lossB all hearing-impaired individualsC totally or profoundly hearing-impaired peopleD people with poorly formed cochlea

17 Select the correct way to complete the sentence. Photoreceptors in the human eye:

A are located only in the foveaB include rods and conesC only work in dim lightD control the amount of light entering the eyes

18 Select the correct way to complete the sentence:

In myopia, light entering the eye is focused:A before the retinaB on the retinaC behind the retinaD before the lens

19 An athlete who has just completed a 20km run will have lost an excessive volume of water through sweating. To regulate water and salt balance, which of the following occurs?

A Dilute urine will be produced. B An increased volume of urine will be produced. C ADH will be released into the bloodstream, increasing

the reabsorption of water from the collecting ducts in the kidney.

D Vasopressin will be released into the bloodstream, decreasing the reabsorption of water from the collecting ducts in the kidney.

20 Dialysis treatment for chronic loss of kidney function requires:

A surgical removal of the diseased part of the kidneyB insertion of artificial replacement filters into the

kidneyC a complete blood transfusion once a weekD lengthy treatment to cleanse the blood three to four

times a week

Short answer21 a Explain why homeostasis is important in organisms,

using an example to support your answer.

b Describe the stages of homeostasis, again using an example to support your answer.

22 The following diagram shows how the body regulates the glucose concentration in blood.

glucose normal

glucose increase

glucose decrease

X released

Y released

a Identify X and Y.b Explain how the body regulates the glucose

concentration in blood.c Draw a circle on the diagram to show which process

is stopped when a person suffers from type 1 diabetes.

d List the parts of the diagram that represent negative feedback.

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23 Choose one plant adapted to arid conditions that you have studied in this course.

a Describe the features of the plant that make it suited to conditions of water scarcity.

b Explain how the features you have described assist the plant in maintaining water balance.

24 a Distinguish between infectious and non-infectious diseases.

b List three types of non-infectious disease and name one example of each.

25 Acetylcholine is produced by neurons and binds to receptors on the muscle cell membrane. This initiates a sequence of steps that result in muscle contraction. When acetylcholine receptors on muscle cells are blocked by an individual’s own antibodies, it results in myasthenia gravis, which is characterised by weakness in the skeletal muscles.

a Which group of diseases does myasthenia gravis belong to?

b i Which group of signalling molecules does acetylcholine belong to?

ii How would the blocking of acetylcholine receptors on the muscles cause muscle weakness?

c Some patients with myasthenia gravis have an abnormally large thymus gland. What role does the thymus gland play in the adaptive immune response?

26 Hay fever is an allergic response in which the immune system overreacts to the presence of a previously encountered foreign antigen. The diagram below illustrates the key steps that occur in an allergic reaction.

foreign antigen B lymphocyterecognises antigen aspreviously encountered

antibody histaminemast cell

releaseproduces

a Define the term ‘antigen’.b Identify the type of antibody involved in allergic reactions.c Where in the body are mast cells located?d Describe the event that causes mast cells to release

histamine.e Describe two symptoms resulting from the release of

histamine.

27 Medical authorities spend large amounts of time and money on epidemiological studies.

a Explain the term epidemiology and outline its value. b Describe how epidemiology has contributed to the

effective treatment or management of a named non-infectious disease.

28 Explain how public education campaigns can benefit the health of the community at large, as well as individuals. Use at least two specific examples in your answer.

29 Account for the following:

a A colour-blind person with excellent visual acuity has difficulty finding a red object lost in the grass.

b The cause of colour blindness in humans.

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650 MODULE 8 | NON-INFECTIOUS DISEASE AND DISORDERS

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30 As part of your study in this course you investigated the structure and function of the human kidney. Use your knowledge and the diagram to answer the following questions.

I

II

III

IV

a Name structures I, II and III.b Name the substance transported by structure IV.c Describe the function of the kidney.d Compare the composition of blood leaving the kidney

with that of blood entering.

31 The diagram shows the changes in the core body temperature and skin surface temperature of a jogger. He jogged from t = 0 to t = 60 minutes. From t = 60 to t = 90 minutes, the jogger stopped and sat on a chair.

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30 45 60 75 90150

323334353637383940

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core bodytemperaturetemperatureof skin

Time (mins)

Tem

pera

ture

(°C

)

Core body temperature and skin surface temperature of jogger

a Describe the changes in core body temperature and temperature of the skin from t = 0 to t = 60 minutes.

b Explain the patterns described in part a.

c Suggest why the temperature of the jogger’s skin started to rise after t = 60 minutes.

d Outline the thermoregulation mechanisms in the human body that control temperature.

32 RAS is a family of proteins that are involved in cell signalling. When RAS proteins are switched on they promote cell division and growth. Mutations in the genes that encode the RAS proteins can result in these genes being permanently switched on. Normal RAS proteins are also important in the initiation of cell apoptosis (natural programmed cell death).

a Explain how mutations in RAS genes lead to cancer.b Another cause of cancer in humans is the

overproduction of certain proteins. One human breast cancer variant is caused by a mutation that results in the overproduction of the HER2 protein. This protein forms part of a receptor found on the surface of cell membranes. This receptor is involved in the signalling pathway that results in cell division.

Suggest how overproduction of HER2 leads to breast cancer.c One important treatment for HER2-positive breast

cancer is a drug called trastuzumab, marketed in Australia as Herceptin. This medication is a monoclonal antibody. It binds to the external domain of the HER2 receptor.i What are monoclonal antibodies?ii Herceptin is a humanised monoclonal antibody.

What does this mean?iii Why do scientists humanise monoclonal

antibodies?d A drug company has invented a new monoclonal

antibody that it claims will be effective against HER2-positive breast cancers that have been shown to be resistant to current therapies. The company is ready to begin human trials of its proposed treatment. i Describe an experiment to test the effectiveness of

the new treatment.ii What results would suggest that the drug

company’s claims are justified?iii Outline some issues that the researchers could

face in performing human trials?iv Many human trials enlist only a few individuals.

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33 Severe Combined Immune Deficiency (SCID) is an inherited disease. The most common form of the disease has been linked to mutations in the gene IL2RG, which is found on the X chromosome, so this form of the disease is called SCID-X1. Because of the mutation the body lacks the ability to make natural killer (NK) cells, T cells and B cells, effectively resulting in a total absence of the adaptive immune response and a depleted innate response to viruses. Typically, individuals die from viral infections within the first year of life. As girls need to inherit the trait from both parents and boys with SCID-X1 do not survive to maturity, this condition is only seen in boys.

Genetic engineering was used in 1999 for the first trials of a new treatment for SCID-X1. Bone marrow stem cells were collected from the patients and the active form of IL2RG was inserted into the nuclei of the cells using a viral vector.a i What is a vector in this context?

ii Why is a virus used as a vector?b By 2002, 20 boys had been treated and 18 of them

actually developed the ability to make effective lymphocytes. Long-term monitoring of the patients showed that eventually five of the boys developed leukaemia and, of those, one eventually died. Further research into the causes of the leukaemia discovered that the cancer developed because the IL2RG gene inserted into the chromosomes by the virus was inserted in such a way as to activate a cancer-causing gene.How might the insertion of a virus cause a cancer-causing gene to become activated?

c Gene therapy trials recommenced after the cause of the leukaemia was identified and the vector was subsequently modified to better regulate its insertion into the chromosomes. Even so, there are issues associated with the use of this therapy, especially because the recipients are all infants.What issues may arise in gene therapy of infants that do not arise when the patients are adults?

d How would you evaluate the effectiveness of this treatment and its future directions?

34 Sound is an important means of communication for humans. Hearing disorders affect personal safety, learning and social abilities.

a Draw a large, clearly labelled flow diagram to show the path of a sound wave through the ear. Use different colours to identify the different forms of energy involved as the sound is transmitted.

b If you damaged your hair cells in the organ of Corti near the oval window, explain the effect this would have on your hearing.

c Evaluate one hearing aid and one cochlear implant in terms of how they function, their value and their limitations.

35 Summarise the causes of two disorders of the human eye that cause vision problems and compare technologies that could assist.

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