General Science Questions (MCQs) for Competitive Examinations

Notes:
In most fish, the heart consists of four parts, including two chambers and an entrance and exit. The first part is the sinus venosus, a thin-walled sac that accumulates blood from the fish’s veins before permitting it to flow to the second part, the atrium. The atrium is a large muscular chamber, present as a one-way passage, that sends blood to the third part, the ventricles. The ventricle is a thick-walled, muscular chamber that pumps the blood, first to the fourth part, bulbus arteriosus. The bulbus arteriosus is a large tube, and then out of the heart, which attaches to the aorta, through which blood flows to the gills for oxygenation.

Notes:
The Passenger Pigeon or Wild Pigeon is an extinct North American bird. The species lived in enormous migratory flocks until the early 20th century, when continued hunting and habitat destruction led to its demise.

Notes:
Different fluids in the human body generally have a delicate range of acid-alkaline balance they maintain for optimal functioning. Human blood has a normal pH of about 7.41. The pH of urine has a wider range. Normal ranges for urine pH are from 4.5 to 8 and saliva has pH range of 6-8 to 7-0.

Notes:
A tannin is an astringent, bitter plant polyphenolic compound that binds to and precipitates proteins and various other organic compounds including amino acids and alkaloids. It refers to the use of wood tannins from oak in tanning animal hides into leather.

Notes:
Hydrogen peroxide (H2O2) is a water molecule with an extra oxygen atom hence, also called oxygenated water. It is very unstable and breaks down readily into water and a single oxygen molecule. So in nutshell, when Hydrogen peroxide readily loses active oxygen, Water is formed.
2H2O2 —> 2H2O + O2

Notes:
The scientific name of peacock is Pavo Cristatus. It is also known as the Indian blue peafowl, common peafowl, blue peafowl, and blue Indian peafowl. It is a large and brightly coloured bird, is a species of peafowl native to the Indian subcontinent, but introduced in many other parts of the world.

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All verteberates have notochord, body cavity and gills in their embryonic stage or adult stage but not have haemocoel. It’s presence is well marked in the members of phylum in Arthopoda.

Notes:
Metamorphosis is a process by which animals undergo extreme, rapid physical changes some time after birth. Commonly known examples of metamorphosis include the process undergone by most insects, and the transformation of tadpoles into frogs. Hormones called molting and juvenile hormones, which are not species specific, apparently regulate the changes.

Notes:
Adamsia (Sea anemone), Pennatula (Sea-pen) are examples of Anthozoa Class under Coelenterata Phylum. The organism under this phylum are mostly marine, solitary or colonial, sessile, or free-swimming and radially symmetrical animals. Other examples of Anthozoa class are Meandrina (brain-coral), Fungia, Gorgonia (sea fan or horny coral), etc.

Notes:
The bark of cinchona tree yields quinine, a white crystalline alkaloid having antipyretic (fever-reducing), anti-malarial, analgesic (painkilling), and anti-inflammatory properties. Quinine was the first effective Western treatment for malaria caused by Plasmodium falciparum.