CET Biology 15

BCG (Bacillus Calmette-Guerin) is a vaccine primarily used to prevent tuberculosis. It is derived from an attenuated strain of Mycobacterium bovis.

Allografting involves the transplantation of tissue between two genetically non-identical members of the same species. Autografting is from the same individual, and heterografting is between different species.

Jaipur foot, a prosthetic for below-knee amputees, is made of both vulcanized rubber and aluminium. The rubber provides flexibility and comfort, while aluminum provides structural support. This combination makes it durable, lightweight, and affordable.

PET (Positron Emission Tomography) imaging is a nuclear medicine technique that uses radiotracers to measure metabolic processes and blood flow, including cerebral blood volume.

'Brown sugar' is a street name for heroin, particularly in South Asia. It refers to less refined heroin that appears brownish. LSD is a synthetic hallucinogen, hashish comes from cannabis, and barbiturates are sedatives - none of which are called 'brown sugar'.

Atherosclerosis is the thickening and hardening of arteries due to cholesterol and plaque buildup. Rheumatic heart is caused by streptococcal infection, blood pressure is a measurement, and cardiac arrest is sudden heart stoppage - none describe the gradual thickening process from cholesterol.

Amniocentesis is a medical procedure used for prenatal diagnosis. It involves extracting amniotic fluid to analyze the fetal cells for chromosomal abnormalities.

The sinoatrial (SA) node acts as the natural pacemaker of the heart, initiating the electrical impulse. An artificial pacemaker is implanted to replace this function when the SA node fails.

India was the first country in the world to launch a national family planning program in 1952 to control population growth.

THC (tetrahydrocannabinol) is the primary psychoactive compound found in the Cannabis sativa plant.

IUCD stands for Intrauterine Contraceptive Device. Copper-T is a well-known example of an IUCD used to prevent pregnancy.

Developing countries typically exhibit high fertility rates, declining mortality rates due to improved healthcare, rapid population growth, and a large proportion of young people.

Endemic hunger and chronic undernourishment are widespread issues in South Asia, parts of Africa, and Latin America due to socioeconomic factors and food insecurity.

According to the 2001 Census of India, the decadal growth rate for the period 1991-2001 was approximately 21.54%.

Oral contraceptive pills typically contain synthetic versions of estrogen and progesterone, which work together to inhibit ovulation.

Environmental resistance refers to the sum of all factors (like food scarcity, predation, disease) that limit the growth of a population and prevent it from reaching its biotic potential.

When a population exceeds the carrying capacity of its environment, the resources become depleted, often leading to a population crash.

Study of trends in human population growth and prediction of future development is called demography.

The Hepatitis-B vaccine is considered a second-generation vaccine because it is produced using recombinant DNA technology, specifically by expressing the viral surface antigen in yeast.

ELISA is a screening test for HIV. Western blot is the standard confirmatory test used to verify positive ELISA results.

Medical ultrasound imaging uses frequencies in the megahertz range, typically 1-15 MHz. Higher frequencies provide better resolution but less tissue penetration. Options A and B have incorrect units and are too low, while D is too high for diagnostic imaging.

Vaccines function by introducing a harmless form of a pathogen (or its proteins) to the immune system, allowing it to develop memory and immunity without causing the disease.

Myasthenia gravis is an autoimmune disorder where antibodies attack acetylcholine receptors at the neuromuscular junction, causing muscle weakness. The antibody targets acetylcholine receptors (the question says 'acetylcholine' as the self protein target, which is imprecise but clearly intends this meaning). Options A, B, and D are unrelated hormones or substances not involved in this condition.

Anti-AIDS drugs, such as reverse transcriptase inhibitors, work by interfering with the viral enzyme reverse transcriptase, which is essential for the HIV virus to replicate its genetic material.

Amphetamine is correctly classified as a stimulant - it increases central nervous system activity. Option B is incorrect because LSD (lysergic acid diethylamide) is a hallucinogen/psychotropic, not a narcotic. Option C is incorrect because heroin is an opioid/narcotic, not a psychotropic. Option D is incorrect because benzodiazepines are anti-anxiety drugs, not painkillers.

The AIDS virus has been known by several names during its discovery, including HIV (Human Immunodeficiency Virus), HTLV-III (Human T-cell Lymphotropic Virus type III), and LAV (Lymphadenopathy-Associated Virus).

Hybridoma technology is the standard method for producing monoclonal antibodies by fusing B-lymphocytes with myeloma cells. This creates immortalized cell lines that secrete specific antibodies.

IgA immunoglobulin is present in colostrum/mother’s milk. Colostrum contains antibodies to protect the newborn against disease. In general, protein concentration in colostrum is substantially higher than in milk.

The spleen acts as a filter for the blood, where it identifies and removes old or damaged red blood cells. It also serves as a reservoir for blood and plays a role in the immune system.

PET scans use radiotracers, which are isotopes of elements like carbon, nitrogen, or oxygen that are naturally found in the body. These tracers allow for the visualization of metabolic processes in living tissue.

The secondary lymphoid system comprises of spleen, lymphocytes, tonsils and mucosal lymph tissue. 

Antitoxins and toxoids are specifically used to provide immunity or neutralize toxins associated with bacterial diseases like diphtheria. Smallpox and chickenpox are viral and typically managed via vaccines, not antitoxins.

 T-lymphocytes are principal cells in lymph node’s cortical centre.

Immunoglobulins are proteins that belong to the globulin class of serum proteins. They are named for their structural classification as globular proteins involved in immune responses.

SQUID sensors are extremely sensitive magnetometers used to measure the incredibly weak magnetic fields generated by neuronal activity in the brain, a technique known as magnetoencephalography.