General Science Questions (MCQs) for Competitive Examinations

Notes:
Dolly was the world’s first cloned sheep. It was born on 5 July 1996. It was a female domestic sheep, and the first mammal cloned from an adult somatic cell, using the process of nuclear transfer. Dolly was cloned by Ian Wilmut, Keith Campbell and colleagues at the Roslin Institute, part of the University of Edinburgh, Scotland.

Notes:
Most of the transpiration occurs through foliar surface or surface of the leaves. It is known as foliar transpiration. Foliar transpiration accounts for over 90% of the total transpiration. The rest is mostly lenticular that occurs through holes in bark called lenticels.

Notes:
Liver is the largest gland in human body. It is also the largest (internal) organ in our body and can weigh up to 1.5-1.6 kg for a human adult. The large size of the liver is matched by its functional complexity and involvement in a diverse array of regulatory mechanisms. It plays a major role in regulation of glycogen storage, decomposition of red blood cells, plasma protein synthesis, hormone production, and detoxification.

Notes:
Produced in salivary glands, saliva is 98% water, but it contains many important substances, including electrolytes, mucus, antibacterial compounds and various enzymes. The digestive functions of saliva include moistening food, and helping to create a food bolus, so that it can be swallowed easily. Saliva contains the enzyme amylase that breaks some starch down into maltose and dextrin. Thus, digestion of food occurs within the mouth, even before food reaches the stomach.

Notes:
The abundant enzyme in the living world is Rubisco. It is a key regulator of non-steady state of photosynthesis. Ribulose-1,5-bisphosphate carboxylase oxygenase, most commonly known by the shorter name RuBisCO, is an enzyme that catalyses the first major step of carbon fixation, a process by which atmospheric carbon dioxide and water are converted to energy-rich molecules such as glucose, using sunlight.

Notes:
Frame shift mutations are associated with Thalassemia. They involve a deletion or insertion of one or two base pairs within a coding sequence of a gene. As the coding message is read in triplets codons and deletions, the reading frame of mRNA is altered resulting in a nonsense sequence of amino acids.

Notes:
All viruses contain the following two components: a nucleic acid genome (DNA or RNA) and a protein capsid that covers the genome. Together this is called the nucleocapsid. The proteinous coat surrounds and protects the genetic material.

Notes:
Soaps are cleaning agents that are usually made by reacting alkali with naturally occurring fat or fatty acids. The common alkalis (base) used in soap making are sodium hydroxide (NaOH), also called caustic soda; and potassium hydroxide also called caustic potash.

Notes:
Calcium hypochlorite, an inorganic compound with formula Ca(ClO)2, is commonly known as bleaching powder. It is commonly used to sanitize public swimming pools and disinfect drinking water. Calcium hypochlorite is produced industrially by treating lime (Ca(OH)2) with chlorine gas.

• 2Cl2 + 2Ca (OH)2 —> Ca(OCl)2 + CaCl2 + 2H2O

Notes:
Esters are sweet-smelling substances.

• It is used to make perfumes.
• Ammonia had unpleasant smell.
• Methanol has pungent odor.
• Ethanol had a sweet smell.