5 marksYoung mammals that are orphaned can be bottle-fed.
Fig. 1 shows a newborn tiger cub sucking on a bottle.
Fig. 1
(i)
Sucking is an example of an involuntary action observed in newborn mammals.
State the name given to involuntary actions.
[1]
(ii)
Describe the advantages of breast-feeding compared with bottle-feeding.
[4]
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3 marksFig. 1 shows a mosquito feeding on human blood.
Fig. 1
(i)
Mosquitoes can carry transmissible diseases such as malaria.
Define the term transmissible disease.
[2]
(ii)
Using information from Fig. 1, suggest how the mosquito is adapted for feeding on human blood.
[1]
4 marks(i)
The human body has a number of defences against disease.
State the name of the mechanical barrier which is broken by the mosquito.
[1]
(ii)
Some components of blood defend the body against disease.
Table 1 contains the names of three of the components of blood.
It also states three defence mechanisms.
Complete Table 1 by placing a tick (✓) in the box that matches each defence mechanism to the correct component of blood.
Table 1
defence mechanism | component of blood | ||
platelets | red blood cells | white blood cells | |
antibody production |
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blood clotting |
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phagocytosis |
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|
[3]
2 marksThe body also has chemical barriers against disease.
State the name of two chemical barriers in the body.
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3 marksVaccines provide protection against certain diseases.
(i)
State the type of immunity gained by being vaccinated against a disease.
[1]
(ii)
Describe the advantage of the type of immunity identified at part (i).
[2]
2 marksVaccines may contain one of several different substances that helps with developing immunity against disease.
Give two examples of these substances that could be found in a vaccine.
2 marksThe MMR vaccine is administered to children by the age of five and provides protection against mumps, measles and rubella.
In the year 2020 there were 693 928 children in England that celebrated their fifth birthday.
654 197 of these children had received their first MMR dose.
Calculate the percentage of five-year-old children that had received their first MMR vaccine.
2 marksIn order to prevent the outbreak of epidemics or pandemics in a population it is very important that a large percentage of the population is vaccinated.
Explain the importance of this.
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2 marksPathogens can be passed on from one host to another in different ways.
State two examples of how this happens.
3 marksHygienic food preparation methods are very important in preventing the spread of pathogens and disease.
Describe three examples of such methods.
1 markCholera is a bacterial disease that spreads through the ingestion of contaminated food or water.
State the name of the bacterium that causes cholera.
2 marksOne of the symptoms of cholera is diarrhoea, which may become life-threatening if left untreated.
Explain the reason for this.
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2 marksFig. 1 shows the response of a lymphocyte to the presence of a pathogen.
Fig. 1
Identify structure A and B in Fig. 1.
3 marksDescribe the events that occur after structure A binds to structure B.
2 marksUse the information in Fig. 1 to explain why structure A will only bind to structure B on the pathogen.
1 markDuring the response to the presence of the pathogen, the lymphocytes will also form cells that will protect the body against future infections by the same type of pathogen.
State the name of these cells.
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5 marks(i)
Describe and explain the effects of cholera bacteria on the gut.
[4]
(ii)
Suggest one treatment for cholera.
[1]
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1 markWhat term is used to describe ‘disease-causing organisms’?
2 marksFig. 1 shows some virus particles that cause the transmissible disease, influenza.
Fig. 1
Suggest how the virus particles that cause influenza are transmitted from one person to another.
3 marksDescribe the defences of the body which prevent or fight infection.
2 marksExplain why antibiotics are not successful in treating influenza.
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5 marksEating food contaminated by bacteria can cause illness.
This type of illness is called food poisoning.
Fig. 1 shows the number of cases of food poisoning per 100 000 people in the population in one country.
Fig. 1
(i)
State the year with the highest number of cases of food poisoning in Fig. 1.
[1]
(ii)
State the number of cases of food poisoning per 100 000 people in the population in the year 1996 in Fig. 1.
[1]
(iii)
Describe the trend in the number of cases of food poisoning between 2003 and 2011 in Fig. 1.
[3]
1 markFood poisoning is caused by different types of bacteria.
A common type of bacterium that causes food poisoning is Campylobacter jejuni.
State the genus of this species.
1 markFood poisoning can result in vomiting and diarrhoea.
Outline the treatment of diarrhoea.
3 marksThe body has several defence mechanisms against bacteria.
Table 1 shows three types of defence mechanism.
The word list gives examples of these defence mechanisms.
In Table 1 write the examples under the correct type of defence.
Use each word once only.
antibodies mucus nasal hairs phagocytosis skin stomach acid |
Table 1
cellular | chemical | mechanical |
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|
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2 marksWhite blood cells form part of the immune system in the human body which provides protection against infection by pathogens.
Outline the possible responses of these white blood cells to an infection by pathogens.
4 marksBeing vaccinated is another way to gain protection against infection by pathogens.
Describe how vaccines provide protection against infection by pathogens.
2 marksThe measles vaccine will not give a child immunity against the influenza virus.
Explain the reason for this.
2 marksThe flu is an example of a disease against which we typically don't build immunity; this is the main reason why we need to get vaccinated against flu regularly.
Explain why it is difficult to develop immunity against certain pathogens, such as the influenza virus.
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2 marksBreastfeeding is an example of passive immunity which provides the baby with short-term protection against pathogens.
Explain why passive immunity only provides short-term protection against pathogens.
1 markNot all babies are breastfed.
Suggest one way in which these babies may gain immunity against pathogens.
3 marksAn American TV crew visited a remote tribe in the Brazilian rainforest to make a documentary.
Two weeks after the crew's visit, six members of the tribe died of influenza and many more were seriously ill.
The members of the TV crew did not show symptoms of influenza during their visit, but members of the remote tribe died from the disease.
Suggest an explanation for this.
2 marksThe Center for Disease Control and Prevention estimated that 3.55 × 107 individuals were infected with influenza in the United States during the 2018-19 'flu season.
Of those individuals affected, an estimated 3.42 × 104 died, sadly.
Based on these estimated figures, calculate the percentage of people infected with influenza that died from the disease during the 2018-19 'flu season.
Show your working and give your answer to two decimal places.
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2 marksStreptococcus pyogenes is a pathogenic bacteria that spreads through direct contact with discharges from the nose and throat, as well as through open wounds and sores on the skin of infected people.
In the 19th century, many women died shortly after childbirth due to a disease called puerperal fever, which is caused by an infection of S. pyogenes. At the time, it was common practice for doctors to dissect dead bodies in order to study human anatomy and then move straight onto delivering babies immediately after.
Suggest an explanation for the frequent deaths of women after childbirth due to puerperal fever.
3 marksTable 1 shows the number of births and deaths at a hospital between 1841 and 1846.
Table 1
year | number of births | number of deaths |
1841 | 3036 | 237 |
1842 | 3287 | 518 |
1843 | 3060 | 274 |
1844 | 3157 | 260 |
1845 | 3492 | 241 |
1846 | 3905 | 479 |
Calculate and state the percentage change in the number of deaths between 1841 and 1846.
Show your working and give your answer to the nearest whole number.
6 marksIn 1847 a handwashing policy was introduced at the hospital from part (b) which stated that doctors should wash their hands before delivering babies in the maternity ward. This policy was strictly enforced in 1848.
Fig. 1 shows the death rate of mothers from puerperal fever between 1846 and 1848.
Fig. 1
Describe and explain the data from January 1847 to July 1848.
2 marksOther than washing their hands, suggest two other hygiene practices that doctors in hospitals should carry out in order to avoid the spread of pathogens to their patients.
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2 marksCGRP is a protein found in the human brain. High levels of CGRP has been linked to the occurrence of migraines in sufferers. A possible treatment under investigation involves injecting mice with human CGRP.
Explain how the immune system of mice would respond to the CGRP injection.
2 marksCGRP binds to receptors in the brain that triggers blood vessels to dilate. The dilation of blood vessels is responsible for the intense pain associated with migraines.
The substances produced by the immune system of mice, after the CGRP injection, are extracted and modified before being sold as medication. When administered to migraine sufferers, these substances will bind to CGRP proteins in the brain.
Suggest how this may act as a treatment for migraines.
2 marksComplete the graph in Fig. 1 to show how the number of antibodies changes when a vaccinated person becomes infected with a live pathogen.
Fig. 1
3 marksAfter many people were vaccinated against Covid-19, a new variant of the virus emerged that had different shaped antigens to the first version of the virus.
This caused the vaccine to be less effective against the virus.
Explain why having different shaped antigens caused the vaccine to be less effective against the virus.
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5 marksTable 1 shows information about the number of deaths from malaria in a particular area of Africa.
Table 1
year | number of deaths from malaria per 100 000 people |
2005 | 159 |
2007 | 136 |
2009 | 114 |
2011 | 97 |
2013 | 94 |
2015 | 92 |
Complete Fig. 1 using data from Table 1.
Fig. 1
2 marksMalaria is spread by the female Anopheles mosquito when they break through the skin of an uninfected person during a blood meal.
Explain how the skin acts as a mechanical barrier against disease.
4 marksOnce the mechanical barrier formed by the skin is broken, the malaria pathogen enters the blood.
Outline the defence mechanism that will come into effect once a pathogen enters the blood.
4 marksCompare active and passive immunity with each other.
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