Human Health and Diseases Class 12 Biology Exam Questions

Please refer to Biology For Human Health and Diseases Class 12 Biology Exam Questions provided below. These questions and answers for Class 12 Biology have been designed based on the past trend of questions and important topics in your class 12 Biology books. You should go through all Class 12 Biology Important Questions provided by our teachers which will help you to get more marks in upcoming exams.

Class 12 Biology Exam Questions Human Health and Diseases

Multiple Choice Questions

Question. In vaccination which of the following is introduced in the body
(a) Antigenic proteins of pathogens
(b) Inactivated pathogen
(c) Weakened pathogen
(d) All of these

Question. Antitoxin is
(a) Antigen as toxin
(b) Antibody as toxin
(c) Representation of antitoxin
(d) Antibody to toxin

Question. In tetanus for quick immune response injection is given containing
(a) Antibody to the toxin
(b) Antigen toxin
(c) Penicillin
(d) None of these

Question. Antigenic polypeptides of pathogens are produced in large scale using which technology
(a) Ultracentrifugation
(b) Chromatography
(c) Protein sequencing
(d) r-DNA Tech

Question. Which type of antibody is produced during allergic reactions?
(a) IgG
(b) lgM
(c) IgA
(d) None of these

Question. Allergy is due to chemicals released by
(a) Eosinophils
(b) Neutrophils
(c) RBC
(d) Mast cells

Question. Which of the following drug is used to reduce the symptoms of allergy?
(a) Anti-histamines
(b) Adrenaline
(c) Steroids
(d) All of these

Question. Which of the following is an autoimmune disease?
(a) Cancer
(b) Pneumonia
(c) Common cold
(d) Rheumatoid arthritis

Question. Which of the following is not a secondary lymphocyte?
(a) Thymus
(b) Spleen
(c) Peyer’s patches
(d) Both (b) and (c)

Question. Which of the statement is not true for spleen?
(a) The spleen is very small bean shaped organ
(b) It mainly contains lymphocytes and phagocytes
(c) It acts as a filter of the blood by trapping blood-borne microorganisms
(d) Spleen also has a large reservoir of erythrocytes

Question. Use of vaccines and immunization programs has enabled us to eradicate which disease
(a) Polio
(b) Diphtheria
(c) Small pox
(d) Malaria

Question. Which of the following does not come under physical barrier of innate immunity?
(a) Skin
(b) Saliva in mouth
(c) Mucous coating of epithelium lining of respiratory tract
(d) Mucous coating of epithelium lining of urogenital tract

Question. Which of the following does not come under cellular barrier of innate immunity?
(a) Neutrophils
(b) Macrophages
(c) Natural killer lymphocyte
(d) Mucous coating of epithelium lining of gastrointestinal tract

Question. Adaptive immunity is
(a) Non specific
(b) Pathogen specific
(c) Characterized by memory
(d) Both (b) and (c)

Question. An antibody molecule have
(a) 1 light chain and 3 heavy chain
(b) 2 light and 2 heavy chains
(c) 3 light and 1 heavy chain
(d) All heavy chain

Question. Response elicited by antibodies is
(a) Cell mediated immunity
(b) Innate immuity
(c) Active immunity
(d) None of these

Question. Antigen binding site is at which end of antibody heavy chain
(a) C terminal
(b) N terminal
(c) In the middle
(d) May be on any end

Question. Which type of immune response is responsible for graft rejection?
(a) Humoral immune response
(b) Cell mediated immune response
(c) Both (a) and (b)
(d) None of these

Question. The yellow fluid secreted by mother during initial phase of lactation is called
(a) Colostrum
(b) Sylvestrum
(c) Sternum
(d) None of these

Question. During pregnancy foetus receives antibodies from mother’s
(a) Milk
(b) Placenta
(c) Uterus
(d) Fallopian tube

Question. Which one of the following is not correctly matched?
(a) Glossina palpalis – Sleeping sickness
(b) Culex pipiens – Filariasis
(c) Aedes aegypti – Chikungunya
(d) Anopheles culicifacies – Dengue

Question. Which of the following is a symptom of ringworm?
(a) Chronic inflammation
(b) Abdominal pain
(c) Dry and scaly lesions on skin
(d) Muscular pain

Question. Transplantation of organs in a patient is declared failed.
Choose the option which indicates the type of immune response responsible for this reaction.
(a) Autoimmunity
(b) Humoral immunity
(c) Cell-mediated immunity
(d) Cytotoxins

Question. Which of the following types of vaccine matches with its correct examples?
I. Toxoids –Tetanus vaccine
II. Attenuated vaccine – BCG vaccine
III. Inactive vaccine – MMR vaccine
IV. Combinations – DPT vaccine
Codes
(a) I, II and III
(b) II, III and IV
(c) I, II and IV
(d) I, III and IV

Question. Which one of the following is correct match?
(a) Heroin – Depressant
(b) Cocaine – Opiatic narcotic
(c) Morphine – Hallucinogenic
(d) Tobacco – Psychedelic drug

Assertion-Reasoning MCQs
Each of these questions contains two statements, Assertion (A) and Reason (R). Each of these questions also has four alternative choices, any one of which is the correct answer. You have to select one of the codes (a), (b), (c) and (d) given below.
(a) Both A and R are true and R is the correct explanation of A
(b) Both A and R are true, but R is not the correct explanation of A
(c) A is true, but R is false
(d) A is false, but R is true

Question. Assertion (A) Interferons are a type of antibodies produced by body cells infected by bacteria.   
Reason (R) They interfere with viral replication at the site of injury.

Question. Assertion (A) AIDS is a disorder caused by HIV.          
Reason (R) HIV is a virus that damages immune system of its host.

Question. Assertion (A) Cancer cells are virtually immortal until the body in which they reside, die.     
Reason (R) Cancer is caused by damage to gene regulation of the cell division cycle.

Assertion-Reasoning MCQs

Direction : Each of these questions contains two statements, Assertion (A) and Reason (R). Each of these questions also has four alternative choices, any one of which is the correct answer. You have to select one of the codes (a), (b), (c) and (d) given below.
(a) Both A and R are true and R is the correct explanation of A
(b) Both A and R are true, but R is not the correct explanation of A
(c) A is true, but R is false
(d) A is false, but R is true

Question. Assertion (A) Interferons help to eliminate the viral infections.
Reason (R) They released by infected cells, reach the nearby uninfected cells and make them resistant to viral infection.

Question. Assertion (A) Repeated use of drugs, increases the tolerance level of receptors in our body.
Reason (R) Addiction occurs as receptors respond only to higher doses of drugs.

Question. Assertion (A) Antibody mediated immune response is provided by B-cells.
Reason (R) B-cells work chiefly by secreting substances called antibodies into the body fluids.

Question. Assertion (A) Dope test is used to estimate the level of alcohol by analysing the breathe of alcohol drinking person.
Reason (R) Athletes undergo dope test before major tournaments or a match.

Question. Assertion (A) AIDS and hepatitis-B are sexually transmitted diseases.
Reason (R) There is no permanent cure for both of them.

Case Based MCQ

Question. Drugs that are normally used as medicines to help the patients cope with mental illness are
(a) barbiturates
(b) amphetamines
(c) benzodiazepines
(d) All of these

Question. Observe the type of plant shown below and ans the questions that follows.
(image) 12
(i) A type of drug is obtained from the plant whose one flowering branch is shown above.
Choose the correct statement(s) regarding the figure.
I. It is a hallucinogen.
II. It is a stimulant.
III. It produces euphoria and increased energy.
IV. It induced behavioural abnormalities by changing thoughts, feelings and perceptions.
Codes
(a) I and III
(b) II and IV
(c) I and IV
(d) II and III

Question. Which one of the following fungi-contains hallucinogens?
(a) Morchella esculenta
(b) Amanita muscaria
(c) Neurospora sp.
(d) Ustilago sp.

Question. Nicotine intake stimulates the release of hormones known as ………… .
(a) adrenaline and nor-adrenaline
(b) thyroxine and parathyroxine
(c) oestrogen and progesterone
(d) All of the above

Question. The diagram shown above represents the flowering branch of which plant?
(a) Cannabis sativa
(b) Datura
(c) Opium poppy
(d) None of these

Short Answer (SA) Type Questions

Question. Name the blank spaces A, B, C and D in the table given below.
(image) 18
Answer : A–Cocaine, B–Central nervous system, C–Cannabis sativa, D–Cardiovascular system

Question. ‘Many secondary metabolites of plants have medicinal properties. It is their misuse that creates problems’. Justify the statement with an example.
Answer : Many secondary metabolites obtained from plants are used for their medicinal properties, e.g. opiates derived from poppy plant are used as drugs to relieve pain. The problem starts when these metabolites are misused for having pleasure and are taken in doses above the prescribed limit, e.g. opium addict loses weight, fertility and interest in work.

Question. Explain why using tobacco in any form is injurious to health.
Answer : Consumption of tobacco is injurious to health in the following ways
(i) It can cause cancer of lungs, throat, urinary bladder and oral cavity.
(ii) Emphysema, bronchitis and coronary heart diseases can be caused.
(iii) Gastric ulcer can occur.
(iv) Smoking tobacco increases carbon monoxide levels in the blood, which leads to the oxygen deficiency in body.

Question. The tobacco smoking is associated with the rise in blood pressure and emphysema (oxygen deficiency in the body). Explain.
Answer : Tobacco smoking increases the concentration carbon monoxide (CO) in blood and reduces the concentration of haemoglobin bound oxygen. Thus, leading to oxygen deficiency (emphysema) and high blood pressure in the body.

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?
Or
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 : If the regular dose of drug or alcohol in an addicted person is discontinued abruptly, the body exhibits characteristic and unpleasant symptoms called ‘withdrawal syndrome’.
The ‘withdrawal syndrome’ is characterised by symptoms like anxiety, shakiness, nausea and excessive sweating.

Question. Do you support ‘dope test’ being conducted on sports persons participating in a prestigious athletic meet? Give three reasons in support of your answer.
Answer : Yes, the ‘dope test’ should be conducted on sports persons participating in prestigious athletic meet. This is done to find out whether any participant had taken any kind of performance enhancing drugs.
The use of drugs in sports should be banned as
(i) they increase muscle strength.
(ii) promote aggressiveness.
(iii) increase athletic performance.
Because of above reasons, use of such drugs, e.g. steroids, analgesics, diuretics should be banned for participants as it would be unfair to the other participants (not consuming such drugs).

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 : Both morphine and heroin are extracted from the latex of plant Papaver somniferum. Morphine acts as an effective sedative and painkiller, while heroin acts as depressant and slows down body functions. When taken in excess amounts, these drugs alter the moods or induce sleep.

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) The age between 12-18 years of age is called adolescent period. There is always a fear amongst guardians that their adolescents may get trapped in drug/alcohol abuse due to following reasons
(a) Adolescence is accompanied by several biological and behavioural changes. It is a vulnerable phase of mental and psychological development of an individual in which an individual may get addicted to alcohol/drugs very easily.
(b) In this age, the first use of drugs or alcohol may be out of curiosity or experimentation, which later on turns to addiction.
(c) Adolescents usually take drugs due to social pressure, need of adventure, excitement, to avoid stress, depression and frustration.
(ii) Addiction It is a psychological attachment to certain effects such as euphoria and temporary feeling of well-being associated with drugs and alcohol.
It makes the person to take up drugs on regular basis, even when they are not needed or even when their use becomes self-destructive.
Dependence It is the tendency of the body to show unpleasant and characteristic withdrawal syndrome, if the dose of alcohol or drug is discontinued abruptly. Dependency pushes the person away from social norms and leads to social adjustment problems.

Case based Questions

Question. The parasite in above diagram reproduces in human host by which method? (Image 21)
Answer : The parasite reproduces in human host by asexualmethod.

Question. The sexual stages of parasite are referred to as?
Answer : The sexual stages of parasite are gametocyte.

Question. Where does the fertilisation and development of parasite take place in mosquito body?
Answer : In mosquito’s body, fertilisation and development of parasite take place in stomach.

Question. What are sporozoites?
Answer : The mature infective stage of mosquito is called sporozoite.

Question. What is the cause of cycles of fever during malaria?
Answer : At regular intervals, the parasite reproduces and causes bursting of RBCs. This releases haemozoin and causes periodic cycles of fever.

Direction Read the following passage and ans the questions that follows.
The principle of immunisation or vaccination is based on the property of memory of the immune system. In vaccination, a preparation of antigenic proteins of pathogen or inactivated/ weakened pathogen (vaccine) are introduced into the body.
The antibodies would neutralise the pathogenic agents during the infection. The vaccine also generates memory B and T-cells that recognise the pathogen quickly on subsequent exposure and overwhelm the invaders with a massive production of antibodies.

Question. Hepatitis-B vaccine is produced from which microbes?
Answer : Hepatitis-B vaccine is produced from transgenic yeast by recombinant DNA technology. It is the first commercially available human vaccine that is produced by the genetic engineering technology.

Question. In which type of immunity, a quick immune response is needed as in tetanus infection, preformed antibodies or antitoxin is injected into the patient body?
Answer : Passive immunity refers to when antibodies are directly injected into the body to generate quick immune response.
Thus, if a person is infected with some deadly microbes to which quick immune response is required as in tetanus, we directly inject the preformed antibodies or antitoxin into the body of the infected person. This is passive immunisation.

Question. Antivenom injection contains preformed antibodies while polio drops that are administered into the body contain which forms of pathogens?
Answer : Oral polio vaccine contains five polio strains in attenuated forms (pathogens).

Question. Use of vaccines and immunisation programmes have controlled which of the infectious diseases?
Answer : Vaccines and immunisation programmes were successful for tetanus, diphtheria, pneumonia, etc., are infectious diseases.

Direction Read the following passage and ans the questions that follows.
Once Gita asked Sarita about her adrenaline and steroid medication. Sarita told Gita that she is allergic to pollens and mites. Sarita also mentioned that she became allergic due to the protected environment provided to her in early life. Upon further conversation, Gita discussed that she is suffering from an autoimmune disease.

Question. Name the antibody which is produced in response to allergens.
Answer : IgE antibody is released in allergic reactions.

Question. Mention few symptoms of allergic reactions.
Answer : Watery eyes, running nose, wheezing, sneezing, etc., are some symptoms of allergy.

Question. How adrenaline and steroids would help Gita to relieve allergy?
Answer : Adrenaline and steroids help to suppress histamine and serotonin from the mast cells upon the entry of allergens in body. Thus, the allergic symptoms are either suppressed or
reduced.

Question. What is an autoimmune disease?
Answer : Autoimmune diseases are those in which the body begin to attack self-cells.

Question. Give two examples of autoimmune diseases.
Answer : Examples of autoimmune diseases are rheumatoid arthritis and type I diabetes.

The outline structure of a drug is given below.   (Image 22)

Question. Which group of drugs does this represent?
Answer : The given structure represents cannabinoids group of drugs.

Question. What are the modes of consumption of these drugs?
Answer : Mode of consumption of these drugs is inhalation or oral ingestion.

Question. Name the organ of the body which is affected by consumption of these drugs.
Answer : Organ affected by consumption of these drugs is heart. It affects the cardiovascular system.

Short Answer Type Questions

Question. Differentiate between active immunity and passive immunity.
Answer : Differences between active immunity and passive immunity are as follows (image) 15

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. Why is mother’s milk considered the most appropriate food for a newborn infant?
Or
Why is colostrum a boon to the newborn baby?
Answer : Mother’s milk is considered most appropriate or a boon for a newborn infant as it provides immunity in the initial period of baby’s life. The yellowish fluid colostrum secreted by mother during the initial days of lactation has abundant antibodies (IgA) to protect the infant.

Question. Answer the following.
(i) Highlight the role of thymus as a lymphoid organ.
(ii) Give the name of the cells that are released from the above mentioned gland. Mention how they help in immunity?
Answer : (i) Thymus is a primary lymphoid organ. It is lobe-shaped and is known to be the site for the growth and differentiation of antigen sensitive T-lymphocytes.
(ii) Thymus releases T-lymphocytes, which are involved in cell-mediated immunity and also help B-lymphocytes to produce antibodies.

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 basic principle of immunisation is based on the property of memory of the immune system. In vaccination, an antigen or antigenic protein or pathogen which is in inactive form is introduced in the body which induces very mild immune response. The vaccine thus, generates antibodies that neutralise pathogen during actual infection. It also generates memory B and T-cells that recognise the pathogen on subsequent exposure and elicit a massive immune response. Yeast cells help in production of hepatitis-B vaccine.