VBQs Class 12 Biology Human Health and Diseases
Very Short Answer Type Questions
Question. How are morphine & heroin related ? Mention their effects on human body.
Answer : Both are obtained from a plant ‘Papaver somniferum’.
Heroin is related to morphine as it is obtained by acetylation of the later. Morphine is a sedative while heroin is a depressant.
Question. Mention the useful as well as harmful drug obtained from latex of poppy plant.
Answer : Morphine.
Question. Certain pathogens are tissue/organ specific. Justify the statement with suitable example.
Answer : Certain pathogens are tissue/organ specific as they are adapted to overcome the resistance mechanisms of those tissues and organs, e.g., the pathogens that enter the gut
must know a way of surviving in the stomach at low pH and resistant to various digestive enzymes.
Question. The immune system of a person is suppressed. In the ELISA test, was found positive to a pathogen.
(a) Name the diseases the patient is suffering from.
(b) What is the causative organisms?
(c) Which cells of body are affected by the pathogen?
Answer : The immune system of a person is suppressed. In the ELISA test, he was found positive to a pathogen.
(a) The patient is suffering from AIDS.
(b) AIDS is caused by Human Immuno deficiency Virus (HIV). It is a retro virus containing RNA as genetic material.
(c) Macrophages and helper T-cells are affected by the pathogen.
Question. Where are B-cells and T-cells formed? How do they differ from each other?
– Thinking Process
Lymphocytes are of two types i.e., T-lymphocytes or T-cells and B-lymphocytes or B-cells.
Answer : Both type of lymphocytes and other cells of the immune system are produced in the bone
B and T-cells are different from each other in the following aspects
Question. Given below are the pairs of pathogens and the diseases caused by them.
Which out of these is not a matching pair and why?
(a) Virus Common cold
(b) Salmonella Typhoid
(c) Microsporium Filariasis
(d) Plasmodium Malaria
Answer : (c) Wuchereria species bancrofti and W malayi), the filarial worms cause a slowly developing chronic inflammation of the organs in which they live for many years,usually the lymphatic vessels of the lower limbs and the disease is called elephantiasis or filariasis.
Fungi belonging to the genera Microsporium, Trichophyton and Epidermophyton are responsible for ringworms which is one of the most common infectious diseases in man.
Question. What would happen to immune system, if thymus gland is removed from the body of a person?
– Thinking Process
Thymus is the primary lymphoid organ. In thymus gland, immature lymphocytes differentiate into antigen-sensitive lymphocytes.
Answer : If thymus gland is removed from the body of a person, his immune system will become weak. As a result the person’s body becomes prone to infectious diseases.
Question. Many microbial pathogens enter the gut of humans along with food. What are the preventive barriers to protect the body from such pathogens? What type of immunity do you observe in this case?
Answer : Many microbial pathogens enter the gut of humans along with food.
The preventive barriers to protect the body from such pathogens are as follows
(i) the mucus coating of the epithelium lining of the gut helps in trapping microbes entering the body.
(ii) saliva in the mouth and hydrochloric acid in gastric juice secreted by stomach prevent microbial growth.
This type of immunity is innate immunity. It is present from birth and is inherited from parents. The innate immunity remains throughout life.
Question. Why is mother’s milk considered the most appropriate food for a new born infant?
– Thinking Process
Colostrum is the first yellowish milk secreted during initial days of lactation.
Answer : Colostrum contains several antibodies (especially IgA) which are absolutely essential for developing resistance for the new-born babies.
Question. What are interferons? How do interferons check infection of new cells?
Answer : In response to viral infections our body produces glycoproteins called interferons. Such type of barriers of innate immunity is called cytokine barrier. Interferons protect the non-infected cells from further viral infection.
Question. In the figure, structure of an antibody molecule is shown. Name the parts A, B and C.
Question. If a regular dose of drug or alcohol is not provided to an addicted person, he shows some withdrawal symptoms. List any four such withdrawal symptoms.
Answer : The withdrawal symptoms are
Question. Why is it that during changing weather, one is advised to avoid closed, crowded and air conditioned places like cinema halls etc?
Answer : During changing weather one is advised to avoid crowded places, because changing seasons are the time when infectious agents are more prevalent as moist condition
favoures pathogen to grow fast and people are more vulnerable as their body system is busy in adapting the changing environmental conditions of temperature humidity, etc and they get infected to there pathogen easily.
Question. The harmful allele of sickle-cell anaemia has not been eliminated from human population. Such afflicted people derive some other benefit. Discuss.
Answer : Sickle-cell anaemia still persists in the population despite being harmful because this mutation can also be beneficial in certain conditions.
The mutant Hb5 type haemoglobin is found at high frequencies (up to 20% and above) in the tropical Africa.
It is known that heterozygotes (Hbs /HbA), having both types of haemoglobin show resistance to malarial infection because the body targets the Plasmodium falciparum infected cell for destruction. In contrast, individuals homozygous for normal haemoglobin (HbA/HbA) suffer high mortality rates in early childhood due to malarial infection.
Thus, the allele for sickle cells has been maintained because heterozygotes have a higher reproductive success than either of the two possible homozygotes.
Question. Lymph nodes are secondary lymphoid orgAnswer : Explain the role of lymph nodes in our immune response.
Answer : Lymphoid Organs immune system of human beings consists of lymphoid orgAnswer : The organs whereas callid the maturation and proliferation of lymphocytes occurs are called lymphoid orgAnswer : Lymphoid organs are of two types. These are
Lymph nodes are small solid structures present at different points along the lymphatic system. They trap the microorganisms or other antigens that enter the lymph and tissue
fluid. Antigens trapped in the lymph nodes activate the lymphocytes and produce an immune response.
Question. Why is an antibody molecule represented as H2L2?
Answer : Each antibody molecule has four peptide chains, two small called light chains (represented by L) and two longer called heavy chains (represented by H).
Hence, an antibody is represented as H L 2 2.
Question. What does the term ‘memory’ of the immune system mean?
Answer : When the body encounters a pathogen for the first time, it mounts an immune response by generating antibodies. This response is of low intensity. Subsequent encounter with the same pathogen elicits a highly intensified secondary response.
This is ascribed to the fact that our body appears to have memory of the first encounter. This type of secondary immune response is elicited by memory T-cells, B-cell which keep ready to mount a rapid and vigorous attack as soon as the same pathagen infects the body again
Question. If a patient is advised anti restroviral therapy, which infection is he suffering from? Name the causative organism.
Answer : The patient is suffering from AIDS. The causative agent is HIV virus, a member of ‘retrovirus group’.
Short Answer Type Questions
Question. Why are adolescents especially advised not to smoke ? How does smoking affect the functioning of the body ?
Answer : Because smoking paves the way to hard drugs, increased chances of cancer particularly of lungs, cause oxygen deficiency in the body (any two);
Nicotine (in cigarette) stimulates adrenal gland, which raises blood pressure / increases heart rate. It increases carbon monoxide (CO) in blood and reduces oxyhaemoglobin. This causes O2 deficiency in the body. Therefore, the adolescents are advised not to smoke.
Question. What happens to an individual when a regular dose of drugs/alcohol is abruptly discontinued?
What characteristics, manifest in the individual under such a situation ?
Answer : Withdrawal syndrome.
Manifestation of unpleasant characteristics and feelings.
Anxiety, shakiness, nausea and sweating.
Question. (a) Name the source plant of heroin drug. How is it obtained from the plant?
(b) Write the effects of heroin on the human body.
Name the plant source of the drug popularly called “smack”. How does it affect the body of the abuser ?
Name an opioid drug and its source plant. How does the drug affect the human body ?
Answer : (a) Papaver somniferum / Poppy plant.
Extracted from latex of the plant / acetylation of morphine (obtained from the latex of plant).
(b) Depressant, slows down body function.
Detailed Answer :
(a) Heroin, commonly called smack (chemical name diacetylmorphine) is a white, odourless, bitter crystalline compound. This is obtained by acetylation of morphine, which is extracted
from the latex of poppy plant (Papaver somniferum).
(b) Opioid drugs bind to a specific opioid receptor present in our central nervous system and gastrointestinal tract. Heroin is a depressant and slows down body functions.
Question. Name and state the effect of a drug that is often medically prescribed, but its over use leads to drug dependence and drug abuse.
Answer : Morphine, barbiturate, amphetamines, benzodiazepines, lysergic acid diethyl mides (LSD) Affects the central nervous system, acts as a pain killer, acts as a sedative, treats depression, treats insomnia, creates hallucinogenic effect.
Question. A doctor prescribed morphine as a sedative and pain killer to your cousin who had undergone surgery. Even after recovery, he craved for the prescribed medicine. What do you conclude about his condition, had he continued with the same medication? After appraising yourself, what measures will you suggest to him to overcome this problem? Briefly explain any two.
Answer : Drug dependence is the tendency of the body to manifest a characteristic and unpleasant
withdrawal syndrome. If regular dose of drugs is abruptly discontinued / because of perceived benefits, drugs are frequently used repeatedly from which the person may not be able to rid off.
(i) Education and counselling-to face problems and stresses / to channelize the energy into healthy pursuits like reading, music, yoga and other extracurricular activities.
(ii) Seeking help from parents-to guide the person appropriately and immediately.
(iii) Seeking professional and medical help-to help the person to get rid of the problem completely with sufficient efforts and will power.
Question. A group of youth were having a ‘rave party‘ in an isolated area and was raided by police. Packets of ‘smack‘ and syringes with needles were found littered around.
(i) Why is taking ‘smack‘ considered an abuse ?
(ii) Write the chemical name of ‘smack‘ and the name of its source plant.
(iii) Syringes and needles used by the youth for taking the drug could prove to be very fatal. Why ?
Answer : (i) Because an addictive substance causes drug dependence and affects nervous system / used in amounts or frequencies that impairs ones physical and physiological or psychological functions.
Papaver somniferum / poppy plant / opium poppy.
(iii) They can acquire serious infections i.e. transmission of HIV infections or AIDS or Hepatitis.
Question. Explain the following with reference to drug/ alcohol abuse : (i) Addiction, (ii) dependence and (iii) withdrawal symptoms.
Answer : (i) Addiction – Frequent use of drugs or alcohol leads to increase in the level of tolerance of receptors present in our body, thus making these receptors respond to only higher doses of drugs and alcohol.
Psychological attachment to certain effects such as euphoria and temporary feeling of well being associated with drugs and alcohol.
(ii) Dependence – Due to inherent addictive nature and its psychological attachment to drugs or alcohol and are unable to live without them.
(iii) Withdrawal syndrome – When a person is taking drugs / alcohol regularly and the intake of drugs is abruptly discontinued it leads to various characteristics symptoms (nausea, anxiety, shakiness, sweating etc.).
Question. ‘Prevention is better than cure’ is an apt slogan to safeguard adolescents from drug abuse. List any six steps that could be taken in this regard.
Answer : Six steps that can be taken for prevention and control of drug abuse among adolescents are :
(i) A regular monitoring of the activities of adolescents by parents.
(ii) Avoiding undue peer pressure as every child has his own stamina and personality.
(iii) Educating and counselling about the dangers of drug abuse.
(iv) Channelizing the child’s energy into healthy pursuits like sports and other extra-curricular activities.
(v) Seeking professional and medical help for those who have unfortunately got in the quagmire of drug.
(vi) Identifying the motivations for alcohol and drug abuse in children.
Question. (i) Name the drug used
(a) As an effective sedative & pain killer.
(b) For helping patients to cope with mental illness like depression but often misused.
(ii) How does the moderate & high doses of cocaine affect human body?
Answer : (i) (a) Morphine.
(b) LSD (Lysergic acid dimethylamide) or Barbiturates.
(ii) Moderate dose of cocaine have stimulating action on central nervous system. It produces a sense of euphoria and increased energy. High dosage of cocaine causes hallucinations.
Question. Differentiate between active immunity and passive immunity.
Answer : Differentiate between active immunity and passive immunity
Question. Differentiate between bening tumour and malignant tumour.
Answer : Differentiate between bening tumour and malignant immunity
Question. Do you consider passive smoking is more dangerous than active smoking? Why?
Answer : Passive smoking can be equally dangerous because it exposes the persons to the same harmful effect of smoke.
Passive or second hand smoking means being in the same room or place, where some one is smoking and getting exposed to smoke in the surrounding air.
Once inhaled, the smoke can trigger release of mucus in the bronchioles that blocks the airways. This induces coughing. But prolonged exposures can lead to bronchitis emphysema, respiratory tract infections and eventually lung cancer.
Question. ‘Prevention is better than cure’. Comment.
Answer : Prevention is always better than cures because some diseases cause extensive damage to the body tissues or organs and have a
(i) Negative effect on their capacity to function.
(ii) Permanent or long term debilitating effect.
(iii) Negative mental and psychological effect.
(iv) Financial burden.
Prevention, therefore is easier and effective, than cure of a disease.
Question. Explain any three preventive measures to control microbial infections.
Answer : Preventive measures to control microbial infection include
(i) Maintenance of personal and public hygiene by
(a) Proper cleanliness standards and practices .
(b) Proper disposal of waste.
(c) Periodic cleaning of water reservoirs, etc.
(ii) Control or elimination of vectors that transmit diseases by
(a) Checking water stagnation and garbage accumulation.
(b) Using disinfectants or biological methods to check their breeding and spread.
(iii) Proper immunisation by vaccination, wherever available to control or completely eradicate infectious diseases.
Question. In the given flow diagram, the replication of retro virus in a host is shown. Observe and answer the following questions.
(a) Fill in (A) and (B)
(b) Why is the virus called retrovirus?
(c) Can the infected cell survive, while viruses are being replicated and released?
(b) The virus is called retro virus because it does not follow the central dogma of biology (DNA® RNA® Proteins).
Its genetic material is RNA that is transcribed to DNA using enzyme reverse transcriptase.
(c) Yes, the infected cell can survive, while viruses are being replicated and released.
Question. ‘Maintenance of personal and public hygiene is necessary for prevention and control of many infectious diseaes. Justify the statement giving suitable examples.
Answer : Diseases which are easily transmitted from one person to another, are called infectious diseases.
For prevention and control of such diseases, maintenance of personal and public hygiene is necessary, for this purpose, some common preventive measurer should be taken as follows
(i) Education People should be educated about communicable disease to protect themselves from such diseases.
(ii) Isolation The infected person should be kept isolated to minimise the spread of infection.
(iii) Vaccination People should get vaccination on time to avoid infection.
(iv) Sanitation The sanitation should be improved to avoid infection from polluted water, contaminated food, etc.
(v) Eradication of Vectors The breeding places of vectors must be destroyed and adult vectors should be killed by suitable methods.
(vi) Sterilisation The patient’s surroundings and articles of use should be completely sterilised to reduce the chances of infection.
Question. The following table shows certain diseases, their causative organisms and symptoms. Fill the gaps.
Question. The outline structure of a drug is given below.
(a) Which group of drugs does this represent?
(b) What are the modes of consumption of these drugs?
(c) Name the organ of the body which is affected by consumption of these drugs.
Answer : (a) It represents cannabinoids group of drugs.
(b) Mode of consumption−nasal inhalation or oral in take.
(c) Organs affected−heart and cardiovascular system.
Question. Give the full form of CT and MRI. How are they different from each other? Where are they used?
Answer : CT-Computed Tomography. It uses X-rays to generate 3-D images of internal orgAnswer :
MRI−Magnetic Resonance Imaging. It uses strong magnetic fields and non-ionising radiations to detect pathological and physiological changes in the living tissue accuratily.
Both are used in cancer detection.
Question. Many secondary metabolites of plants have medicinal properties. It is their misuse that creates problems. Justify the statement with an example.
Answer : Drugs like barbiturates, amphetamines, benzodiazepines, lysergic acid diethylamides (LSD) and other similar drugs, that are normally used as medicines to help patients coping
with mental illnesses like depression and insomnia. Morphine is a very effective sedative and painkiller and is very useful in patients who have undergone surgery.
Misuse of plant metabolites fruits and seeds in amounts/frequency more than prescribed for medicinal purposes can impair one’s physical, physiological or functional behaviour creating problem for the society and slowly moves towards the eaternal truth (death).
Question. Why cannabinoids are banned in sports and games?
Answer : Cannabinoids are banned in sports, as athletes misuse these drugs to enhance their performance. But drugs obtained from cannabinoids can cannatnads have, a serious negative effect on their general health and in long term can hamper the normal functioning of organ system.
Question. What is secondary metabolism?
Answer : Secondary metabolism (also called specialised metabolism) is a term for pathways and metabolites are small molecule produced by metabolism that are not absolutely required
for the survival of the organism.
In case of plant, metabolites aid in the growth and development of plants. It also facilitates the primary metabolism.
Question. Drugs and alcohol give short-term ‘high’ and long-term ‘damages’.
Answer : Curiosity, need for adventure and excitement and experimentation, constitute common causes, which motivate youngsters towards drug and alcohol use.
The frequent use of drugs/alcohols drive people to take them even when these are not needed, or even their use becomes self-destructive.
Short-term effects of drugs/alcohols
→ A relaxing effect l Reduced tension
→ Lowered inhibitions l Poor concentration
→ Slow reflexes l Slow reaction time
→ Reduced coordination l Slower brain activity
→ Sensations and perceptions that are less clear
Long-term effects of drugs/alcohols
→ Disrupts normal brain development
→ Liver damage and cirrhosis of the liver
→ Brain cells die, decreasing brain mass
→ Stomach and intestinal ulcers and destroyed organs
→ Blood pressure increases, causing heart disease, heart attack or stroke
→ Male sperm production decreases
→ Lower levels of iron and vitamin-B, causing anaemia
→ Death and
→ Fetal alcohol syndrome in unborn children
Question. Diseases like dysentery, cholera, typhoid, etc., are more common in over crowded human settlements. Why?
Answer : Dysentery, cholera and typhoid are more common in crowded settlements because these are infectious diseases and spread from person to person contact. Water gets contaminated with the excreta of infected people and causes the spread of infection to other people.
Question. From which plant cannabiniods are obtained? Name any two cannabinoids.
Which part of the body is effected by consuming these substances?
Answer : Cannabinoids are obtained from the inflorescence of the plant Cannabis sativa.Marijuana, hashish, charas, ganja are some cannabinoids. These chemicals interact with cannabinoid receptors of the body, mainly present in the brain. Cardiovascular system of the body is effected adversly by consuming these substances.
Question. In the metropolitan cities of India, many children are suffering from allergy/asthma. What are the main causes of this problem. Give some symptoms of allergic reactions.
– Thinking Process
Allergy is the exaggerated response of the immune system of certain antigens present in the environment.
Answer : In metropolitan cities life style is responsible in lowering of immunity and sensitivity to allergens. More polluted environment like dust in surroundings increases the chances of
allergy in children. Some symptoms of allergic reactions are sneezing, watery eyes,running nose and difficulty in breathing.
Question. What is the basic principle of vaccination? How do vaccines prevent microbial infections? Name the organism from which hepatitis-B vaccine is produced.
Answer : The principle of vaccination is based on the property of ‘memory’ of immune system.
In vaccination, a preparation of antigenic proteins or inactivated/live but weakened pathogens is introduced into the body. The antigens generate primary immune response by producing antibodies along with memory B-cells and T-cells.
When the vaccinated person is attacked by the same pathogens, the existing memory B-cells and T-cells recognise the antigen and overwhelm the invaders with massive production of lymphocytes and antibodies.
Hepatitis-B vaccine is produced from yeast.
Question. What is cancer? How is a cancer cell different from the normal cell? How do normal cells attain cancerous nature?
Answer : An abnormal and uncontrolled division of cells is termed as cancer. Genes called cellular oncogenes (c-onc) or proto-oncogens present in normal cells when activated under certain conditions lead oncogenic transformation of the normal cells leading cancer.
A cancer cell is different from the normal cell in following ways
Question. A person shows strong unusual hypersensitive reactions when exposed to certain substances present in the air. Identify the condition. Name the cells responsible for such reactions. What precaution should be taken to avoid such reactions.
Answer : If a person is hypersensitive to certain substance present in the air, he may be allergic to it.
Mast cells release certain chemicals, e.g., histamine and serotonin, in response to this substance, that result in allergic reaction.
Precaution taken to prevent such reaction is to avoid the allergens responsible for particular allergy.
Question. For an organ transplant, it is an advantage to have an identical twin.Why?
Answer : For an organ transplant, it is an advantage to have an identical twin because the organ will have same surface markers and therefore, the recipient’s immune system will not identify it as foreign and will not react against it. In case of different surface markers, the immune system starts a reaction, kills the foreign tissue or rejects it.
Question. What are lifestyle diseases? How are they caused? Name any two such diseases.
Answer : Life style disease are caused by specific food habits, work related posture or exposure to harmful radiations or substances, lack of physical exercise, mental stress, etc. e.g., cancer, alcoholism, heart disease, etc.
Question. If there are two pathogenic viruses, one with DNA and other with RNA,which would mutate faster? And why?
Answer : RNA mutates faster than DNA.
DNA is more stable and also has better repair mechanisms that correct the changes in base pairs as soon as it is introduced.
Long Answer Type Questions
Question. Represent schematically the life-cycle of a malarial parasite.
Answer : The life-cycle of a malarial parasite
Question. Compare the life style of people living in the urban areas with those of rural areas and briefly describe how the life style affects their health.
Answer : People think that the city life is better than village life. However, there are so many advantages as well as disadvantages of urban life and rural life
Advantages of Urban (city) Life
The city life is more comfortable as there are lot of facilities in the city. There are more opportunities for people to progress their lives and they have more opportunities for making money.
Children living in the city can get a good education, in the town than in the village. When a person falls ill, there are good government and private hospital in the city to get treatment.
There are large shopping complexes, banks, offices, cinemas, clubs, hospitals, etc., in and around the city for recreations. People in the city have better transport facilities than the village. There is electricity, highway,communication, telecommunication, plumb facilities in the city. So, people can lead a comfortable and enjoyable life in the city.
Disadvantages of Urban (city) Life
Although living in the city has many advantages there are some disadvantages too. The cost of living is very high in the city. Goods are expensive, no fresh air and pure water is present.The environment is polluted with dust, smoke, garbage and gases from factories.Most of the people who live in the city are corrupted, so there are lots of crimes in the city.
Many thefts and murders often take place in the city.
The city is always busy and noisy. There are a lot of vehicles and people in the road. The streets are dusty and unclean. So, it is hard to lead a healthy life in the city.
Advantages of Rural (village) Life
The people of the village live in unity and peace. The villagers earn money enough for live.
very hardly. So, they live in less competition with each other. They have more friends in the community.
The village people always try to protect their traditional habits and culture. The village has clean air and the environment is very beautiful. The village has less noise and rush. So, the
pollution is less.
The village do not have lot of vehicles. So, roads are less dangerous for driving or cycling.
They can get fresh vegetables and fresh fruits. The environment of the village is pleasant and silent and it has scenic beauty.
Disadvantages of Rural (village) Life
People living in rural area have to face many problems like lack of good education, proper medical facilities, transportation, electricity, telecommunication, etc.
Life style affects human health and cause many diseases due to specific food habits, work related posture or exposure to harmful radiation or substances, lack of physical exercise, mental stress, etc. Some life style diseases are cancer, alcoholism, heart diseases, etc.
Question. Why do some adolescents start taking drugs. How can this be avoided?
Answer : The reasons why adolescents and youngsters starts consumption of drugs are
(i) Curiosity of child motivates him/her to do experiment.
(ii) For adventure and excitement.
(iii) Peer group pressure.
(iv) Desire to do more physical and mental work.
(v) To overcome frustration and depression, due to failure in examinations or in other activities.
(vi) Unstable or unsupportive family structures.
The following measures can be taken to avoid drug abuses
(i) Avoid undue pressure on child to perform beyond his/her capability in studies, sports or any other activities.
(ii) Education and counselling are very important to face problem of stress and failure in life.
(iii) Seeking help from parents, elders and peers. This would help the young to share their feelings and concern.
(iv) Looking for danger signs and taking appropriate measures to treat them.
(v) Seeking professional and medical help for de-addiction and rehabilation.
Question. In your locality, if a person is addicted to alcohol, what kind of behavioural changes do you observe in that person? Suggest measures to over come the problem.
Answer : If a person is addicted to alcohol, it will give rise to some behavioural changes in that person. Alcoholic drinks are costly and most drinkers, because of their selfish habits, deprive their children and other members of the family of the basic needs.
The drinking of alcohol is invariably associated with social crimes and dissolution of moral and cultural inhibitions. Violence and other corrupt practices in the community are often
directly or indirectly due to the consumption of alcohol.
Measures that should be taken to overcome the above mentioned problem are
(i) Avoid Undue Peer Pressure Every person has his/her own choice and personality, which should be kept in mind. So he/she should not be pressed unduly to do beyond his/her capacities, in work condition and other in social get together or activities.
(ii) Education and Counselling Helps to overcome the problems, like stresses, disappointments and failure in life. One should utilise a himself/herself energy in some beneficial activities like sports, music, reading, yoga and other extra curricular activities.
(iii) Seeking Help from Parents and Peers In case of minors, whenever, there is any problem, one should seek help and a guidance from parents and peers. Help should be taken from close and trusted friends. This would help young to share their feelings of anxiety and wrong doings.
(iv) Looking for Danger Sings If friends find someone using drugs or alcohol, they should bring this to the notice of parents or teacher so that appropriate measures can be taken
to diagnose the illness and the causes. This would help in taking proper remedial steps or treatment.
(v) Seeking Professional and Medical Helps Highly qualified psychologists, psychiatrists and de-addiction and rehabilitation programmes can help individuals who are suffering
from drug/alcohol abuse.
If such help is provided to the affected persons, with sufficient efforts and will power, the patient could be completely cured and lead normal and healthy life.
Question. What are the methods of cancer detection? Describe the common approaches for treatment of cancer.
Answer : Early detection of cancer is essential. The methods of cancer detection and diagnosis are as follows.
(i) Biopsy and histo-pathological studies of the tissue/ blood/ bone marrow.
(ii) Tests for increased cell counts (in the case of leukaemia blood cancer).
(iii) Techniques like radiography (use of X-rays), CT (computed tomography) and MRI (Magnetic Resonance Imaging) to detect cancers of the internal orgAnswer :
(iv) Detection of cancer specific antigens.
(v) Molecular biology techniques to detect genes in individuals with inherited susceptibility to certain cancers.
The common approaches for treatment of cancer
(i) Surgical removal of tumour.
(ii) Irradiation of tissue to kill cancerous cells.
(iii) Immunotherapy using interferon to boost cancer cell killing.
Question. Drugs like LSD, barbiturates, amphetamines, etc., are used as medicines to help patients with mental illness. However, excessive doses and abusive usage are harmful. Enumerate the major adverse effects of such drugs in humAnswer :
Answer : Harmful effects of drugs like LSD, barbiturates, are
(i) Anxiety, shakiness, nausea and sweating, loss of mind control.
(ii) Reckless behaviour, vandalism and violence.
(iii) Lack of interest in personal hygiene, fluctuations in weight and appetite.
(iv) Withdrawal, isolation, depression, fatigue, aggressive behaviour.
(v) Social adjustment problems
(vi) Withdrawal symptoms can be severe and life threatening.
(vii) Excessive doses of drugs may lead to coma and death may occur due to respiratory failure, heart failure or cerebral haemorrhage.
Question. What is Pulse Polio Programme of Government of India? What is OPV?
Why is it that India is yet to eradicate polio?
Answer : Pulse Polio is an immunisation campaign established by the Government of India in 1995-96 to eradicate poliomyelitis (polio) in India by vaccinating all children under the age
of five years orally against polio virus.
This project deals with the ways to fight poliomyelitis through a large scale immunisation programme, co-operating with various international institutions, state governments and
Non-Governmental Organisations. In 1995, following the polio eradication initiative of World Health Organisation (1988), India launched Pulse Polio Immunisation Program along with Universal Immunisation Program which aimed at 100% coverage.
Having mate on unprecedented progress in polio eradication, India is now gearing up to be declared polio free by 2014 by guarding itself against the import of polio virus from neighbouring countries and by boosting routine immunisation.
Oral Polio Vaccine
Oral Polio Vaccine (OPV) is a live-attenuated vaccine, produced by the passage of the virus through non-human cells at a sub-physiological temperature, which produces spontaneous
mutations in the viral genome.OPV also proved to be superior in administration, eliminating the need for sterile syringes and making the vaccine more suitable for mass vaccination campaigns. OPV also provides long lasting immunity than the salk vaccine.
One dose of OPV produces immunity to all three poliovirus serotypes in approximately 50% of recipients. India is yet to eradicate polio because inspite of many initiatives taken by government, few cases has been reported.
The last reported cases of polio in India was in West Bengal and Gujarat on 13 January 2011. Earlier this year, the World Health Organisation (WHO) had removed India from the list of polio-endemic countries. If no fresh case is reported till 2014, the country will be declared polio free.
July 30, 2013 a nine-month old boy from Navi Mumbai has been found positive for Vaccine-Derived Polio-Virus(VDPV) type 2 and was on ventilator at BJ Wadia Hospital in Parel. This is the fourth such case recorded in the country that year.
In India the main obstacle in the eradication of polio had been the refusal of polio vaccine by certain communities on account of illiteracy and misinformation.
Question. What are recombinant DNA vaccines? Give two examples of such vaccines.
Discuss their advantages.
Answer : Recombinant DNA vaccines are made up of a small circular DNA (plasmid) that has very tiny piece of pathogen DNA incorporated in it to produce one or two specific proteins of the pathogen.
This recombinant DNA is introduced in to the bacteria or yeast cells, where it can use cell’s machinery to produce polypeptides of pathogen. These are used as vaccine to trigger a
range of immune responses.
Vaccines produced by using this approach allow large scale production. e.g.,
(i) Hepatitis-B vaccine produced from yeast.
(ii) Bird flu DNA vaccine.
(i) Recombinant DNA vaccines are advantageous over killed or attenuated vaccines since,they does not get virulent or mutated again as it is seen in case of attenuated vaccines.
(ii) Secondly these are highly pure, specific and elicits strong immune response