General Science GK

Rickets affects bones and malaria affects blood cells which may in turn damage spleen or liver.

Blood platelets (thrombocytes) are cell fragments that are essential for blood clotting. They clump together at the site of injury and release clotting factors. RBCs carry oxygen, WBCs fight infection, and lymph is part of the lymphatic system - none directly cause clotting.

85 dB is typically cited as the maximum safe exposure limit for occupational hearing safety (about 8 hours exposure). Beyond this level, prolonged exposure can cause permanent hearing damage. The pain threshold is much higher (~120 dB), but 85 dB is the safety cutoff.

A chronometer is a precise timekeeping instrument, essentially a highly accurate clock. It specifically measures time. The other options are incorrect: sound waves are measured by oscillosodes or frequency meters, water waves by wave height/length analyzers, and color contrast by photometry tools.

A heart attack (myocardial infarction) occurs when blood flow to the heart muscle is blocked, usually by a blood clot in a coronary artery. This lack of blood supply causes heart muscle cells to die. It's not caused by bacteria, and the heart doesn't completely stop beating (that's cardiac arrest).

Short-sightedness (myopia) occurs when the eyeball is elongated (too long) or the cornea is too curved. This causes light to focus in front of the retina instead of on it. The iris controls pupil size, muscles control lens shape, and the retina is the light-sensing layer - none are the primary cause of myopia.

Active transport is the movement of molecules across a cell membrane against their concentration gradient (from low to high concentration). This requires energy (ATP). Osmis and diffusion are passive processes (with the gradient), and passive transport also moves down the gradient.

Blood type O negative is the universal donor because it lacks A, B, and Rh antigens on red blood cells. This means it won't trigger an immune response in recipients with any blood type. Type A, B, and AB all have antigens that would react with incompatible recipients.

The most common type of color blindness is red-green color blindness (protanopia/deuteranopia). People with this condition cannot distinguish between red and green wavelengths. The other color pairs listed are not typically confused in common color blindness conditions.

Blood consists of RBCs, WBCs, platelets, and plasma. 'Plasanta' is not a real blood component - it appears to be a typo, likely intended to be 'placenta' (which is an organ during pregnancy, not in blood) or it's a nonsense word. Either way, it's correctly identified as not being present in blood.

Antacids are medications that neutralize stomach acid. They are used to treat conditions caused by excess stomach acid, including indigestion, heartburn, and stomach aches. They do not treat headaches (pain relievers), asthma (bronchodilators), or hormone deficiency (hormone replacement).

The adult human skeleton consists of 206 bones, which provide structure, protection for organs, and leverage for muscles. This number is reached after bones fuse during growth from approximately 270 at birth.

Alzheimer's disease primarily affects neurons (nerve cells) in the brain, leading to progressive memory loss and cognitive decline due to plaque and tangle formation. While brain cells are affected, 'nerve cells' is the more precise medical term for neurons.

A theodolite is a precision optical instrument used by surveyors to measure angles in both horizontal and vertical planes. It is essential for construction, mapping, and land surveying work.

Normal human body temperature is 37°C, which equals 310 K on the Kelvin scale. To convert Celsius to Kelvin, add 273.15: 37 + 273.15 = 310.15 K, rounded to 310 K.

Alcohol thermometers are used to measure very low temperatures because alcohol has a lower freezing point (-114°C) compared to mercury (-39°C). This makes alcohol thermometers suitable for measuring temperatures in cold environments.

The correct matching is: Electric force - Newton (force unit), Electric charge - Coulomb (charge unit), Electric Potential - Volt (potential unit), Electric capacity - Farad (capacitance unit). This gives II-A, IV-B, I-C, III-D.

Vitamin D is essential for proper bone and teeth formation because it helps the body absorb calcium and phosphorus from food. Without adequate Vitamin D, bones can become soft and weak (rickets in children, osteomalacia in adults).

The liver is the primary organ affected by alcohol consumption because it metabolizes alcohol. Chronic alcohol consumption can lead to fatty liver, alcoholic hepatitis, and cirrhosis. While alcohol affects multiple organs, the liver bears the primary impact.

The correct matching is: Anemometer - fluid velocity (measures wind/air speed), Tachometer - rotation speed (measures rotational speed), Pyrometer - high temperatures (measures very high temperatures), Dynamometer - machine power (measures force/torque/power). This gives IV-A, III-B, I-C, II-D.

A hydrometer is an instrument used to measure the specific gravity (relative density) of liquids. It floats at different levels depending on the liquid's density and is commonly used to check battery electrolyte, alcohol content, or urine specific gravity.

The correct matching is: BCG Vaccine - Tuberculosis (III-A), BPL Vaccine - Rabies (IV-B), Chloroquin - Malaria (I-C), Penicillin - Sore throat (II-D, though penicillin treats bacterial infections broadly). This gives III-A, IV-B, I-C, II-D.

If father has blood group A (genotype could be AA or AO) and mother has blood group O (genotype OO), their children can inherit either A or O alleles from the father and O from the mother. Possible genotypes are AO (blood group A) or OO (blood group O). Therefore, the son could have blood group O or A, but not B or AB.

A. Typhoid -             I. Bacteria
B. Malaria -              III. Protozoa
C. AIDS -                  II. Virus 
D. Ringworm -        V. Fungi

The deficiency of vitamin E causes sterility.