General Science Questions (MCQs) for Competitive Examinations

Notes:
Endocrine glands secrete their products, hormones, directly into the blood rather than through a duct. The main endocrine glands include the pituitary gland, pancreas, ovaries, testes, thyroid gland, and adrenal glands. The thyroid gland in neck is vertebrate anatomy, is one of the largest endocrine glands. The thyroid gland controls how quickly the body uses energy, makes proteins, and controls how sensitive the body is to other hormones.

Notes:
The cerebrum in fore brain is the seat of intelligence and provides us with the ability to read, write and speak; make calculations and compose music; remember the past and plan for the future; and create works. However, hypothalamus acts as centre for the emotional reactions regulating feeling of thirst, hunger, sexual desire, etc.

Notes:
In botany, heliophytes refer to plants that thrive in bright sunlight; while those growing best in shade are known as sciophytes. Heliophytes are capable of a more efficient use of high light intensities than sciophytes. Examples of heliophytes are sugar cane, sunflower and maize.

Notes:
Curcumin is the principal curcuminoid of the popular Indian spice turmeric, a member of the ginger family. The curcuminoids are natural phenols that are responsible for the yellow color of turmeric.

Notes:
A brick building is made up of many bricks, which are its basic units of structure. Cells are like the bricks of a building—they are the building blocks of life. All living things are made up of one or many cells. Most living things are made up of many cells (multicellular) that collectively make up the organism.

Notes:
Nematocyst, minute, elongated, or spherical capsule produced exclusively by members of the phylum Cnidaria (e.g., jellyfish, corals, sea anemones). Several such capsules occur on the body surface. Also called cnidocyte or cnidoblast, these are specialized cells found in the tentacles of jellyfish capable of projecting a thread-like structure as a form of self-defence or to capture prey.

Notes:
Valency of an element is a measure of its combining power with other atoms when it forms chemical compounds or molecules. It is the number of electrons present in outermost orbit of that element and refers to the tendency to attain octet configuration. Atoms would react to attain an octet configuration, that is, stable configuration, by gaining, losing or sharing electrons.

Notes:
In silvery paints, the main constituent is aluminium powder because of lustrous similarily wiht silver.

Notes:
A reactive metal is one that readily reacts with other elements to give up its electrons. The order of intensity of reactivity is known as reactivity series. Potassium is at the top of the series and hence most reactive. Reactivity of some metals are given in descending order:

• K > Na > Ca > Mg > Al > Zn > Fe > Pb > Cu

Notes:
Liquefied petroleum gas (LPG) is mostly propane (C3H8), mostly butane (C4H10) and, most commonly, mixes including both propane and butane. In the northern hemisphere winter, the mixes contain more propane, while in summer, they contain more butane.