General Science Questions (MCQs) for Competitive Examinations

Notes:
According to de Broglie, every object in motion has a wave character. As per de Broglie’s relation, mass and wavelength are inversely proportional to each other.

Notes:
Ecological succession is unidirectional progressive process of development in an ecosystem or biome. Grass ecosystems are an early stage of succession in regions where the mature ecosystems are forests. However, grass ecosystems are climax ecosystems in grassland regions, where there is not enough rainfall to support a forest. Due to limiting factors such as water scarcity and forest fire, a grassland ecosystem changes to a desert ecosystem. The ecological succession of grassland is desert.

Notes:
When a plant is placed under the fan, the speed of air is increased which leads to high rate of transpiration through the stomata. The increase in the rate of transpiration increases the water absorption also. As by keeping the plants under the fan, the transpiration process is boosted. Therefore, more amount of water and other minerals are absorbed by the plant roots from the soil.

Notes:
Swedish naturalist Carlous Linnaeus established the binomial system of naming living organisms, setting a format and a structured process for classifying the interrelationships between plants (among which he included all fungi), and between animals. The binomial system that Linnaeus devised enables an author to refer to a species confident that it will mean the same thing to informed readers anywhere else in the world.

Notes:
Crown gall is a disease caused by the bacterium Agrobacterium tumefaciens (synonym Rhizobium radiobacter), which enters the plant through wounds in roots or stems and stimulates the plant tissues to grow in a disorganized way, producing swollen galls. As the disease progresses, plants lose vigour and may eventually die. In science of Biotechnology, it is considered as natural engineer.

Notes:
Bharat Biotech, a vaccine company, in December 2017, received Pre-Qualification tag from the World Health Organisation (WHO) for Typbar TCV or Typhoid Conjugate Vaccine. The WHO tag would allow the firm to access global public vaccination programmes. Typbar TCV is the first typhoid vaccine, clinically proven to be administered to children from six months of age to adults and confers long term protection against typhoid fever.

Notes:
Plants and photosynthetic organisms utilize this solar energy in fixing large amounts of CO2 while amounts consumed by human beings are relatively small representing only 10% of the energy converted during photosynthesis. The process of photosynthesis in plants involves a series of steps and reactions that use solar energy, water, and carbon dioxide to produce organic compounds and oxygen.

Notes:
Yeasts, moulds (molds), and mushrooms are examples of fungi. Mushrooms are another group of fungi, which are mainly Basidiomycetes and partially Ascomycetes, both of which share a same feature — having a macroscopic “Fruiting-body, a Mushroom”. Yeasts are eukaryotic, single-celled micro organisms classified as members of the fungus kingdom.

Notes:
When a DNA solution is heated enough, the double-stranded DNA unwinds, and the Hydrogen bonds that hold the two strands together weaken and finally break. The process of breaking a double-stranded DNA into single strands is known as DNA denaturation, or DNA melting. The hyper-chromicity of DNA occurs when the DNA duplex is denatured.

Notes:
Palynology is the scientific discipline concerned with the study of plant pollen, spores, and certain microscopic planktonic organisms, by this way diatom, in both living and fossil form. It is associated with the plant sciences as well as with the geologic sciences, notably those aspects dealing with stratigraphy, historical geology, study of organic microfossils (palynomorphs) extracted from ancient coals, paleontology and archaeology.