Class 12 VBQs Biology Human Health and Diseases
Very Short Answer Type Questions
Question. How does smoking tobacco in human lead to oxygen deficiency in their body ?
Answer : Smoking increases the carbon monoxide (CO) content in the blood which has greater affinity to haemoglobin than oxygen. CO forms a stable bond with haemoglobin and does not allow binding of oxygen. It reduces concentration of haem bound oxygen and causes oxygen deficiency in the body. Smoking also damages alveolar walls, which reduces respiratory surface (emphysema).
Question. Name one plant & the addictive drug extracted from its latex. How does this affect the human body ?
Answer : Morphine & Heroin are the addictive drug obtained from a plant called Papaver somniferum. Morphine is used as sedative but harmful when used as opioids.
Heroin is a depressant and slows down body functions.
Short Answer Type Questions
Question. Name two drugs obtained from poppy plant.
“These drugs are medically useful but are often abused“. Taking the mentioned examples justify by giving reasons.
Answer : Heroin / smack, morphine; morphine obtained from latex of unripe capsules of poppy plant (Papaver somniferum) is an effective pain killer and sedative, heroin (a derivative of morphine) is used as drug. If these drugs are taken for the purpose other than medicinal or taken in larger doses that may impair the physical and mental state of a person. Then it is said to be abused.
Question. What is “withdrawal syndrome” ? List any two symptoms, it is characterized by.
Answer : Manifestation of unpleasant characteristic when a regular dose of drugs / alcohol is abruptly discontinued or reduced.
Unpleasant feeling, Anxiety, shakiness, nausea, sweating.
Question. Name the plant source of ganja. How does it affect the body of the abuser ?
Answer : Ganja is obtained from Cannabis sativa / hemp plant.
It is hallucinogenic, alters perception, causes illusion and damages cardio vascular system.
Question. (i) HIV and Hepatitis-B are STDs. Mention the two other ways by which they can be transmitted to a healthy person.
(ii) Why is early detection of STD essential ? What can it lead to otherwise ? Explain
Answer : (i) HIV can also be transmitted to a healthy person by :
(a) Sharing of infected needles and surgical instruments.
(b) From infected mother to the foetus.
(c) Transfusion of infected Blood.
(ii) Leads to complication in life later; pelvic inflammatory disease (P/D) / abortion /infertility / cancer of reproductive tract, still birth, ectopic pregnancies. STDs are curable if detected early and treated properly otherwise they may lead to death.
Question. Prior to a sports events blood and urine samples of sports persons are collected for drug tests.
(i) Why is there a need to conduct such tests ?
(ii) Name the drugs the authorities usually look for.
(iii) Write the generic names of two plants from which these drugs are obtained.
Answer : (i) To detect drug abuse / use of banned drugs / use of cannabinoids / anabolic steroids / narcotic analgesic diuretics / hormones / drugs used to accelerate performance /
increase muscle strength / bulk / promote aggressiveness / to ensure fair game.
(ii) Cannabinoids / cocaine / coca alkaloid / coke / crack / hashish / charas / ganja / hemp plant extract.
(iii) Cannabis / Atropa / Erythroxylum / Datura.
Detailed Answer :
(i) The blood test is conducted to check the level of certain drugs in the blood which are banned by sports authorities.
(ii) Authorities look for certain drugs like narcotic analgesics, anabolic steroids, diuretics and certain hormones.
(iii) The generic name of the plants from which drugs are obtained are Cannabis sativa and Papaver somniferum.
Question. (i) Why is there a fear amongst the guardians that their adolescent wards may get trapped in drug/ alcohol abuse ?
(ii) Explain ‘addiction‘ and ‘dependence‘ in respect of drug / alcohol abuse in youth.
Answer : (i) Adolescents are easily affected by (Vulnerable to) peer pressure, adventure, curiosity, excitement, experimentation and media.
(ii) Addiction : Psychological attachment to certain effects such as Euphoria or temporary feeling of well – being.
Dependence : Tendency of the body to show withdrawal syndrome or symptoms if regular doses of drug or alcohol is abruptly discontinued.
Question. A team of students are preparing to participate in the interschool sports meet. During a practice session you find some vials with labels of certain cannabinoids.
(i) Will you report to the authorities ? Why ?
(ii) Name a plant from which such chemicals are obtained.
(ii) Write the effect of these chemicals on human body.
Answer : (i) Yes
May be abused by sports persons.
(ii) Cannabis sativa / any other relevant plant.
(iii) Effects cardio vascular system of the body.
Detailed Answer :
(i) Yes, I would report the matter to the authorities because vials might have been abused by the sports persons. Moreover, cannabinoids are classified under drugs and drug abuse is an illegal practice.
(ii) Cannabinoids can be obtained from a plant called Cannabis sativa.
(iii) Although these chemicals increase athletic performance of the sports persons but they have many harmful side effects. The cannabinoids bind to cannabinoid receptors present in the brain and affect the cardiovascular system.
Question. Write the source and the effect on the human body of the following drugs :
Answer : (i) Morphine : poppy plant / Papaver somniferum, depressant.
(ii) Cocaine : Erythroxylum coca, stimulates CNS / causes euphoria / hallucination.
(iii) Marijuana : Cannabis sativa, affects cardiovascular system of the body.
Detailed Answer :
(i) Morphine :
(a) Source : Latex of unripe capsules (fruits) of poppy plant (Papaver somniferum).
(b) Effect on human body : It has a sedative, analgesic and a calming effect. It is a depressant. It decreases blood pressure and depresses respiratory center.
(ii) Cocaine :
(a) Source – Erythroxylum coca
(b) Effect on human body : It is a powerful stimulant of CNS. Its higher doses causes hallucination and euphoria.
(iii) Marijuana :
(a) Source : Cannabis sativa
(b) Effect on human body : It is hallucinogenic, affects cardiovascular system of the body and may even cause psychosis.
Question. Why is tobacco smoking associated with rise in blood pressure and emphysema (Oxygen deficiency in the body) ? Explain.
Answer : Tobacco stimulates the release of adrenaline hormone due to the presence of nicotine in it. This raises the blood pressure. Smoking releases carbon mono-oxide. This reduces the haem bound oxygen concentration and causes the oxygen deficiency in the body.