General Science Questions (MCQs) for Competitive Examinations

Notes:
The smallest bone in the human body is the stapes. The stapes is one of three small bones in the middle ear that allow mammals to transmit sound waves through their eardrum and hear. The stape bone is also known as the stirrup bone because it is shaped like a stirrup.

Notes:
With its excess secretion, also known as hypersecretion, thyroxine (T4) causes an increased heart rate, high blood pressure, possible palpitations, and could lead to heart failure. It is related to hyperthyroidism.

Notes:
Lysosomes are membrane-enclosed organelles that are known as suicidal bags of the cell. They contain digestive enzymes, and break down food, cellular debris and foreign invaders like bacteria. In the event that the cell is injured beyond repair, or becomes old, the lysosome digests the cell, hence the name ‘suicide bag of the cell’.

Notes:
Plaster of Paris is a plaster made by calcining gypsum.
CaSO4•1/2?H2?O.
It can be used to impregnate gauze bandages to make a sculpting material called modroc. It is used to make classic plaster orthopedic casts to protect limbs with broken bones.

Notes:
Vitamin K refers to a group of fat-soluble vitamins that play a role in blood clotting, bone metabolism, and regulating blood calcium levels. The body needs vitamin K to produce prothrombin, a protein and clotting factor that is important in blood clotting and bone metabolism.

Notes:
Babies breathe much faster than older children and adults. A newborn’s normal breathing rate is about 30-60 times each minute. This may slow to 20 to 40 times per minute when the baby is sleeping. The pattern of breathing in a baby may also be different. A baby may breathe fast several times, then have a brief rest for less than 10 seconds, then breathe again.

Notes:
The loose union of structure of the same whorl is called cohesion, but the intimate histological union is called connation. When anthers are fused with each other, the condition is described as syngenesious e.g., Compositae, Lobeliaceae. This fusion is called cohesion. When there is fusion of stamens with petals, they are described as epipetalous e.g., Gamopetale.

Notes:
The skin is the human body’s largest organ, colonized by a diverse milieu of microorganisms, most of which are harmless or even beneficial to their host. The skin may get infected by Protozoa, Bacteria and Virus.

Notes:
All mammals and birds are warm-blooded while all reptiles, arachnids, insects, amphibians, fish are coldblooded. Therefore, all primates (such as humans, apes, and monkeys), cats (tigers, cheetahs, and domestic cats), rodents (rats, beavers, and chipmunks), marsupials (kangaroo), weasels (badgers and meerkats), monotremes (platypuses), sea mammals (whales, seals, walruses, manatees, and dolphins), dogs, pigs, and elephants are warm-blooded.

Notes:
Those who eat a well-balanced diet and have no metabolic disorders, excess dietary carbohydrates?are converted by the liver into complex chains of glucose called glycogen. Glycogen is stored in liver and muscle cells and is a secondary source of energy to freely circulating blood glucose.