General Science Questions (MCQs) for Competitive Examinations

Notes:
Swim bladder is also known as air bladder for fishes. It is a buoyancy organ possessed by most bony fishes. The swim bladder is located in the body cavity and is derived from an out-pocketing of the digestive tube. It contains gas (usually oxygen) and functions as a hydrostatic, or ballast, organ, enabling the fish to maintain its depth without floating upward or sinking. It also serves as a resonating chamber to produce or receive sound.

Notes:
To prepare the cotton fabric for dyeing, printing and finishing process, scouring and bleaching is the fundamental step. After scouring and bleaching, cotton is 99% cellulose. Cellulose is a macromolecule- a polymer made up of a long chain of glucose molecules linked by C-1 to C-4 oxygen bridges with elimination of water (glycoside bonds).

Notes:
The monosaccharides responsible for sweet taste in fruits is Fructose. Fructose is a natural form of sugar, which is why fruits with large amounts of fructose taste sweet. Fructose is an element that causes fruits to sweet in taste is a type of sugar which already present in the human body with glucose.

Notes:
The process of photosynthesis occurs when green plants use the energy of light to convert carbon dioxide (CO2) and water (H2O) into carbohydrates. Light energy is absorbed by chlorophyll, a photosynthetic pigment of the plant, while air containing carbon dioxide and oxygen enters the plant through the leaf stomata.

Notes:
Anaemia is a condition that develops when blood lacks enough healthy red blood cells or haemoglobin. The three main types of Anaemia are due to blood loss, decreased red blood cell production, and increased red blood cell breakdown. Causes of decreased production include iron deficiency, a lack of vitamin B12, thalassemia, and a number of neoplasms of the bone marrow.

Notes:
A fern is any one of a group of about 20,000 species of plants classified in the phylum or division Pteridophyta, also known as Filicophyta. Fern ally is a general term covering a somewhat diverse group of vascular plants that are not flowering plants (angiosperms) and not true ferns. Like ferns, these plants reproduce by shedding spores to initiate an alternation of generations. Both Ferns and fern allies belong to Pteridophytes.

Notes:
Most of Earth’s oxygen comes from tiny ocean plants – called phytoplankton – that live near the water’s surface and drift with the currents. Like all plants, they photosynthesize – that is, they use sunlight and carbon dioxide to make food. Scientists believe that phytoplankton contribute between 50 to 85 percent of the oxygen in Earth’s atmosphere (National Geographic).

Notes:
Plants that flower and fruit only once and then die are termed monocarpic or semelparous such as bamboo. The term was first used by Alphonse de Candolle. Other terms with the same meaning are hapaxanth and semelparous. The antonym is polycarpic, a plant that flowers and sets seeds many times during its lifetime; the antonym of semelparous is iteroparous. 

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 benthic zone is the ecological region at the lowest level of a body of water such as an ocean or a lake, including the sediment surface and some subsurface layers. It is found in salt water ecosystem. The benthic region of the ocean begins at the shore line and extends downward along the surface of the continental shelf out to sea.