Test: Human Health & Disease - 1 - Grade 12 MCQ

Plasmodium completes their life cycle in two hosts, female anopheles and human beings. The motile zygote of plasmodium occurs in gut of female anopheles, which get transferred to human being during mosquito bite.

Topic in NCERT: Fertilization and development take place in the mosquito's gut.

Line in NCERT: "Fertilization and development take place in the mosquito's gut."

• Typhoid fever in the human being is caused by Salmonella typhi.
• The pathogen enters the small intestine through food and contaminated water and migrates to other organs through blood

This illustration depicts a photomicrograph of Salmonella typhi bacteria:

Topic in NCERT: Pathogenic organisms are discussed here alongwith the diseases caused

Line in NCERT: "Salmonella typhi is a pathogenic bacterium which causes typhoid fever in human beings."

Alzheimer disease is a neurological disorder in which the death of brain cells causes memory loss and cognitive decline. It is caused in human due to deficiency of acetylcholine.

The gut microbiota can influence the central nervous system through the synthesis of ACh and other neuroactive molecules:

The release of toxic haemozoin by the ruptured RBCs during malarial infection accounts for the recurrence of high fever and chill every 3-4 days.

• Entamoeba histolytica causes Amoebic Dysentery or Amoebiasis in the large intestine of humans.
• Its symptoms include constipation, abdominal pain, cramps and stools with excess mucus and blood clots.

Topic in NCERT: Entamoeba histolytica in the large intestine

Line in NCERT: "Entamoeba histolytica is a protozoan parasite in the large intestine of human which causes amoebiasis (amoebic dysentery)."

• Goitre is the enlargement of the thyroid gland which occurs due to deficiency of iodine in the body. Iodine is needed for the synthesis of thyroid hormone. When the iodine levels are low, the thyroid gland becomes hyperactive and enlarged to compensate for the deficiency of thyroid hormone in the body. The enlarged thyroid gland is visible as a swelling in the throat known as goitre.
• Grave's disease or exophthalmic goitre occurs due to over secretion of thyroid hormone as the thyroid gland becomes hyperactive. In exophthalmic goitre, protrusion of eyeballs occurs due to the deposition of excess fat behind the eyes. 
• The thyroid gland may also become hyperactive due to hypersecretion of TSH (Thyroid-stimulating hormone) from the anterior pituitary and this can occur due to pituitary adenoma (benign tumours of the pituitary gland).

Excessive intake of exogenous thyroxine can't cause goitre.

The first antibiotic was discovered by Alexander Fleming from the fungus Penicilliumnotatum in 1928.

Antibodies in our body are present in the blood in form of glycoproteins. They produce antigens in response to foreign particles to provide immunity against the pathogen.

Topic in NCERT: Antibodies in the body

Line in NCERT: "The B-lymphocytes produce an army of proteins in response to pathogens into our blood to fight with them. These proteins are called antibodies."

Memory cells are formed in lymphocytes of WBC. Immunization against the particular disease based on the function of memory cell induced due to mild, heat killed pathogen administrated during immunization.

Topic in NCERT: Lymphoid organs

Line in NCERT: "Lymphoid organs: These are the organs where origin and/or maturation and proliferation of lymphocytes occur."

• Physiological barriers to the entry of microorganisms into the human body are tears in the eyes, saliva in the mouth and HCl in the stomach.
• The enzymes lysozymes are found in tears and saliva and inhibit the synthesis of peptidoglycan present in the cell wall of microorganisms especially eubacteria.
• Disease-causing microorganism enters through different routes into the body. The physiological barrier prevents their entry. Tears act as a physiological barrier for entry of pathogen.

Topic in NCERT: Innate immunity

Line in NCERT: "Skin on our body is the main barrier which prevents entry of the micro-organisms."

Skin and respiratory allergy problems arise in hilly areas due to allergen present in these areas. Allergen induce inflammatory reaction in the body.

Topic in NCERT: Allergies

Line in NCERT: "Many children in metro cities of India suffer from allergies and asthma due to sensitivity to the environment."

AIDS is caused by Human immunodeficiency virus of member of group of virus called retrovirus. It is a type of RNA virus that inserts a copy of its genome into the DNA of a host cell that it invades, thus changing the genome of that cell.

Topic in NCERT: Retrovirus

Line in NCERT: "AIDS is caused by the Human Immuno deficiency Virus (HIV), a member of a group of viruses called retrovirus."

AIDS day is celebrated on December 1 all over the world. Its aim is to create awareness about this dreaded disease.

A tumor enclosed within a capsule is called benign tumor. Benign tumors normally remain confined to their original location and do not spread to other parts of the body and cause little damage.

Topic in NCERT: Tumors: benign and malignant

Line in NCERT: "Tumors are of two types: benign and malignant. Benign tumors normally remain confined to their original location and do not spread to other parts of the body and cause little damage."

AIDS can be transmitted from infected person to healthy person through blood transfusion. The most common way of transmission of AIDS is during sexual intercourse with multiple partners without protection.

Topic in NCERT: Transmission of HIV infection

Line in NCERT: "Transmission of HIV-infection generally occurs by (a) sexual contact with infected person, (b) by transfusion of contaminated blood and blood products, (c) by sharing infected needles as in the case of intravenous drug abusers and (d) from infected mother to her child through placenta."

Malignant tumours of the skin or mucous membrane are called carcinoma. The physical, chemical or biological agents that convert a normal cell into the cancerous cell are called carcinogens.

Topic in NCERT: Malignant tumors

Line in NCERT: "Cancer cells appear to have lost this property. As a result of this, cancerous cells just continue to divide giving rise to masses of cells called tumors."

Cancer cells divide rapidly and hence they are said to be more active with a less prominent nucleus and low-density cytoplasm.

Hence, they get destroyed easily by laser treatment. Moreover, the form lumb in a certain place which can be easily distinguished by the doctors.

Topic in NCERT: Cancer cell characteristics

Line in NCERT: "These cells grow very rapidly, invading and damaging the surrounding normal tissues."

Opioids are the drugs which bind to specific opioid receptors present in our central nervous system and gastrointestinal tract.

Topic in NCERT: Opioids

Line in NCERT: "Opioids are the drugs, which bind to specific opioid receptors present in our central nervous system and gastrointestinal tract."

Lysergic acid diethylamide is one of the most potent mood changing chemicals manufactured from lysergic acid, which is found in ergot fungus that grow on rye and other grains.

Cirrhosis of liver is caused by the chronic intake of alcohol. Regular consumption of alcohol damages the liver cells. Cirrhosis of liver is a serious condition when normal liver tissue is replaced by scar tissue.

Topic in NCERT: Drugs and alcohol abuse

Line in NCERT: "The chronic use of drugs and alcohol damages nervous system and liver (cirrhosis)."

Heroine or smack is chemically diacetylmorphine which is a white, odourless, bitter crystalline compound.

Topic in NCERT: Heroin composition

Line in NCERT: "Heroin (Figure 7.7), commonly called smack is chemically diacetylmorphine which is a white, odourless, bitter crystalline compound."

Marijuana, hashish, charas, and ganja contain chemicals called cannabinoids. They are generally, taken as inhalation or oral ingestion to effects cardiovascular system of the body.

Topic in NCERT: cannabinoids

Line in NCERT: "Cannabinoids are obtained from the inflorescences of the plant Cannabis sativa."

Amphetamines is kind of drug which is used as stimulant. It is a strong CNS stimulant that is used in the treatment of ADHD. Lysergic acid dimethyl amide is not a narcotic and heroin is not a psychotropic agent.

NCERT Topic: Drugs and alcohol abuse

NCERT Line: "Drugs like barbiturates, amphetamines, benzodiazepines, and other similar drugs, that are normally used as medicines to help patients cope with mental illnesses like depression and insomnia, are often abused."

A. Invasiveness of a pathogen is its ability to gain entry into a host and grow.

B. Toxigenicity is the power of a pathogen to form toxins capable of damaging host cells.

C. Virulence is the ability of a pathogen to produce disease.

D. Co-operation is a property not exhibited by a pathogen.

Hence, the correct answer is option D: Co-operation

Degenerative diseases are those diseases which are caused by ageing resulting in malfunctioning or decreased deficiency.
Example: Hypertension, Atherosclerosis, Alzheimer’s disease etc.