General Science Questions (MCQs) for Competitive Examinations

Notes:
As per the Mohs scale of mineral hardness, the soft metals are: Lead, gold, silver, tin, zinc, aluminium, thorium, copper, brass and bronze. Diamond is one of the hardest known metals on earth.

Notes:
Plasma is considered a distinct “fourth state of matter. A plasma is a hot ionized gas consisting of approximately equal numbers of positively charged ions and negatively charged electrons. The characteristics of plasmas are significantly different from those of ordinary neutral gases.

Notes:
Fermentation is an anaerobic chemical process that breaks down glucose molecules. In baking, yeast consumes sugar and converts it into carbon dioxide and alcohol, making the dough rise. This gas gets trapped in the strands of gluten, resulting in air pockets that cause the dough to rise and form the characteristic spongy texture of bread and cakes. Further, the creation of lactic and acetic acids during fermentation augments this dough handling process, improves flavor, enhances the texture, and extends the shelf-life of the baked products.

Notes:
Insulin is central to regulating carbohydrate and fat metabolism in the body. It stops the use of fat as an energy source by inhibiting the release of glucagon. It removes excess glucose from the blood, which otherwise would be toxic. Insulin helps blood sugar enter the body’s cells so it can be used for energy. Insulin also signals the liver to store blood sugar for later use. Blood sugar enters cells, and levels in the bloodstream decrease, signaling insulin to decrease too.

Notes:
Most cases of filariasis are caused by the parasite known as Wuchereria bancrofti. A wide range of mosquitoes can transmit this parasite, depending on the geographic area. In Africa, the most common vector is Anopheles while in the Americas, it is Culex quinquefasciatus. Aedes and Mansonia transmits transmit the infection in the Pacific and in Asia. Thus, Culex, Aedes and Anopheles mosquitoes serve as vector for W. bancrofti in transmission of the disease. Aedes mosquito causes dengue fever. Anopheles mosquito causes malaria. Culex mosquito causes filaria. A wide range of mosquitoes can transmit the parasite, depending on the geographic area. In Africa, the most common vector is Anopheles and in the Americas, it is Culex quinquefasciatus. [This question was wrongly framed in exam as “filaria is caused by__:”. GKtoday has edited it to make it correct.]

Notes:
Typhoid is a common worldwide bacterial disease transmitted by the ingestion of food or water contaminated with the feces of an infected person, which contain the bacterium Salmonella enterica subsp. enterica, serovar Typhi.

Notes:
According to 11th Fiver Year Plan, the Second Green Revolution aims to meet the problems of small and marginal farmers for providing income security to a large section of rural households and treating them as partners of development instead of a mere beneficiary of some government schemes or programme.

Notes:
Trochodendron is a genus of flowering plants with one living species. It is vesselless angiosperm. Fewer than 200 species of angiosperms have the primitive feature of vesselless wood. With two exceptions— Trochodendron and Tetracentron; all vesselless angiosperms occur in the Magnolidae.

Notes:
Bacteriophage refers to any of a group of viruses that infect bacteria. Bacteriophages were discovered independently by Frederick W. Twort in Great Britain (1915) and Felix d’Herelle in France (1917). D’Herelle coined the term Bacteriophage, meaning “bacteria eater”.

Notes:
The urinary bladder is a hollow muscular organ that collects and stores urine from the kidneys before disposal by urination. In humans, the bladder is a hollow muscular organ situated at the base of the pelvis. Urine enters the bladder via the ureters and exits via the urethra.