General Science Questions (MCQs) for Competitive Examinations

Notes:
The foramen magnum (“great hole”) is a large opening in the occipital bone of the cranium. It is one of the circular apertures in the base of the skull (the foramina), through which the spinal cord (an extension of the medulla oblongata) enters and exits the skull vault.

Notes:
The liver produces urea and other waste materials and then it pours it all in the right ventricle of the heart for oxygenation. The heart then distributes the blood to various parts of the body. So the impure blood brought by the Hepatic Vein and other blood vessels gets distributed through the aorta. This clearly indicates that hepatic vein from kidneys carries the largest amount of urea, while the renal vein from kidneys carries the least.

Notes:
The term xerophyte refers to a plant species that has evolved over time to adapt to dry and arid regions like deserts. Xerophytes have adapted to be able to keep extremely large amounts of water for a long period of time. Without this capability, the plant would die, as the desert region itself does not provide enough water to sustain life. They have thick cuticle, sunken stomata and leaves modified in form of spines such as in opuntia.

Notes:
In general, liver is a good source of vitamin A, iron, zinc, copper and manganese, and a very good source of protein. There are twenty grams of protein in a single slice of liver.

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:
Test tube baby is born from in vitro fertilization. In vitro fertilization (IVF) is a process by which an egg is fertilized by sperm outside the body: in vitro. When a woman’s natural cycle is monitored to collect a naturally selected ovum (egg) for fertilization, it is known as natural cycle IVF. The fertilized egg (zygote) is then transferred to the patient’s uterus with the intention of establishing a successful pregnancy.

Notes:
In the nucleus of each cell, the DNA molecule is packaged into thread-like structures called chromosomes. Each chromosome is made up of DNA tightly coiled many times around proteins called histones that support its structure.

Notes:
Gustation is usually called the sense of taste. Taste is the sensation produced when a substance in the mouth reacts chemically with taste receptor cells located on taste buds in the oral cavity, mostly on the tongue. Taste cells are gathered together in taste buds on the tongue, and taste buds are hidden in bumps on the tongue called papillae.

Notes:
All crustaceans have a body covered with a protective shell composed of a horny substance called chitin. The outer skeleton is not continuous but made up of divided sections called somites. It limits the growth of an organism therefore need to be shed from time to time.

Notes:
The pituitary gland also considered as the master gland secretes FSH which further stimulate the secretion of male sex hormone testosterone and in female ovary induces the secretion of oestrogen and progesterone. It also secrete hormones such as lutenizing hormones to ovulation , oxytocin for child birth and prolacting for breast development and milk secretion from mother.