Question 1

Which of the following can make you ill if you come in contact with an infected person?

Accepted Answer

Through sneezing, the water droplets carrying the microbes enter into the healthy person. All the others are non communicable diseases.Hence the correct option is C.

Question 2

Classify the following diseases as infectious or non-infectious.(i)AIDS (ii) Tuberculosis (iii) Cholera (iv)High blood pressure (v) Heart disease (vi) Pneumonia (vii) Cancer

Accepted Answer

(i) Infectious (ii) Infectious (iii) Infectious (iv) Non-infectious (v) Non-infectious (vi) Infectious (vii) Non-infectious

Question 3

Differentiate between infectious and non-infectious diseases.

Accepted Answer

Infectious diseasesNon-infectious diseases These occur due to external (extrinsic) factors.These generally occur due to internal (intrinsic) factors.These are cause by the attack of pathogens (viruses, bacteria, fungi, protozoans, worms)These are caused by factors other than living pathogens. Infection is transmitted through direct contact (physical contact, sexual contact) or through medium (air, water, food, insects etc.)Infection is not transmitted through direct contact or through medium except in medium hereditary diseases where it occurs from parent offspring.

Question 4

List the harmful effects caused by alcohol/drug abuse.

Accepted Answer

Alcohol and Drug Abuse can cause various harmful effects not only on the individual but also on the family as well as on society.On Individual Level:1. It effects nervous system because of which the person losses judgment, will-power etc.2. It causes liver cirrhosis, peptic ulcer, gastric carcinoma.3. Reckless behavior, isolation, depression, weight loss etc.4. Drug abuse can also cause dis-functioning of organs like kidney, liver etc.On Family Level: A person addicted to alcohol and drugs shows various issues which lead to frustration, quarrels etc in the family.At Society Level: Deteriorating social network and the person loses interest in social and other activities. A person can cause other problems like violence, damage to properties because of mood swings.

Question 5

Explain life cycle of Plasmodium with diagram.

Accepted Answer

Plasmodium completes its life cycle in two hosts, therefore, it is called digenetic endoparasite.Man is its primary host in which it completes its asexual cycle. Female Anopheles mosquito is its vector or secondary host in which it completes its sexual cycle.Sporozoites are present in the salivary glands of female Anopheles mosquito.They enter the human blood and reach the liver cells.In liver cells, the sporozoites undergo asexual multiple fission and form new cells called merozoites.Liver cells burst out to release the merozoites.These merozoites enter the RBCs and start the erythrocytic phase.Merozoites pass through trophozoite stage and signet ring trophozoite stage.Signet ring trophozoite ingests proteins of the cytoplasm of RBCs.It forms food vacuoles inside which it secretes digestive enzymes.These enzymes proteolysed blood haemoglobin and break it into protein globin and haematin pigment.Globin protein gets digested by the trophozoite.Unused haematin forms malarial pigment called haemozoin.Trophozoite increases in size and becomes rounded called schizont.Schizont undergoes multiple fission and forms many daughter nuclei.Haemozoin granules accumulate in the cytoplasm of RBCs.RBCs burst to release merozoites and the haemozoin granules.The release of haemozoin granules causes malarial fever.Merozoites lose the ability to reproduce and thus form gametes.These gametes enter the female Anopheles mosquito.Male and female gametes undergo fertilization to form immobile zygotes Later zygotes become worm-like and motile called ookinete which pierces peritrophic membrane and reach the outer layer of the stomach.The ookinete becomes rounded and encloses itself in a cyst and is called oocyst.Oocyst takes nutrients from the wall of the stomach and increases in size.Oocyst undergoes mitotic division and forms many micro daughter nuclei.In the cytoplasm, large irregular non-contractile vacuoles are formed.Daughter nuclei arrange around the surface of the vacuoles and get enclosed by cytoplasm.Inside oocyst, many lobes of cytoplasm are formed with the nucleus at its centre.Each lobe converts into the spindle-shaped structure and hangs down in the oocyst.Oocyst bursts and sporozoites become free in the haemocoel.Sporozoites swim in the haemolymph and reach salivary glands of the mosquito.

Question 6

AIDS cannot be transmitted by

Accepted Answer

AIDS is a viral disease transmitted through certain body fluids such as semen, saliva, blood, the breast milk of an AIDS-infected person by sexual contact, breastfeeding from an HIV-infected mother can transmit AIDS to the baby and by blood transfusion. During a hug, nobody fluid is entered into the body from one person to another. Thus, the correct answer is option B.

Question 7

Which one of the following sets includes the bacterial diseases?

Accepted Answer

Cholera is a bacteria infection caused by eating food or drinking water contaminated with Vibrio cholerae. Typhoid fever is caused by Salmonella typhi bacteria. Mumps is a viral disease caused by the mumps virus. Tetanus is bacteria infection caused by Clostridium tetani. Tuberculosis is caused by bacterium Mycobacterium tuberculosis. Measles is caused by virus paramyxovirus. Malaria is a disease caused by Plasmodium parasite. Poliomyelitis is infectious disease caused by the poliovirus. Diphtheria is an infection caused by the Corynebacterium diphtheriae bacterium. Leprosy is caused by bacteria Mycobacterium leprae. Plague is a bacterial infection caused by bacterial strain Yersinia pestis. Thus, the correct answer is 'Diphtheria, Leprosy, Plague.'

Question 8

Write the full form of AIDS. List four modes of transmission of the virus of this disease

Accepted Answer

AIDS or Acquired Immuno Deficiency Syndrome, is a disorder caused by Human Immunodeficiency Virus (HIV).AIDS can be transmitted through the following modes:1. Through unprotected sexual act: It is the most common mode of HIV transmission from an infected partner to a healthy partner.2. Through blood transfusion: Blood donated from an infected person can affect a healthy person and cause AIDS due to transmission of HIV virus. 3. Through the use of used syringes and other products: Using contaminated razors, needles, dental instruments, injections and other blood products can result in transmission of HIV virus.4. From mother to baby: Pregnant women transfer HIV to her baby through placenta or through breast feeding after birth.

Question 9

Name a disease which are caused by virus, bacteria and protozoa . Any two

Accepted Answer

Agents Virus Bacteria Protozoa Diseases caused1. HIV/AIDS, 2.common cold 1. Tuberculosis2. Typhoid 1. Malaria2. Dysentery.

Question 10

Contamination of water with sewage is indicated by cysts of

Accepted Answer

Several outbreaks worldwide caused by the presence of E. histolytica have been reported associated with sewage contamination.Entamoeba histolytica is an invasive, pathogenic protozoan, causing amoebiasis, and an important cause of diarrhoea in developing countries. The life cycle of the parasite is represented by two forms: the cyst and the trophozoite. The cyst is the infective and non-motile form of the parasite.  It is excreted in the faeces and can survive for weeks in the environment.The organism can be prevalent in cold regions as well as tropical and subtropical regions that have contaminated water. In fact, E. histolytica is an important cause of morbidity and/or mortality wherever sewage facilities are inadequate. As is the case for other intestinal protozoan pathogens, wastewater treatment techniques are reported not to be very efficient for E. histolytica elimination possibly because of their resistance to disinfectants and the small size of the cysts. So the answer is 'Entamoeba'.