General Science Questions (MCQs) for Competitive Examinations

Notes:
Rings of cartilage are present in the throat, specifically in the trachea or windpipe, to ensure that the air passage does not collapse. These semi-circular rings provide the necessary structural support to keep the airway open regardless of pressure changes that occur during breathing. This is very important for maintaining a clear, open path for air to flow into our lungs for respiration.

Notes:
Jhum is a traditional form of shifting cultivation that is common in the North-East of India. Also known as slash and burn agriculture, it is practiced by the tribal groups in Arunachal Pradesh, Meghalaya, Mizoram and Nagaland and the hilly areas of Assam. Jhum involves clearing a piece of land by setting fire or clear felling and using the area for growing crops.

Notes:
Female gametes are also called eggs or ova. They are created during the cellular reproduction process known as meiosis. The resulting gamete cell is a haploid cell. When the two haploid cells, the egg and sperm, fuse together during fertilization, the result is a diploid cell called a zygote.

Notes:
The transition from dormancy to germination in seeds is a key physiological process during the lifecycle of plants. Abscisic acid (ABA) is the sole plant hormone known to maintain seed dormancy. It acts through a gene expression network involving the transcription factor Abscisic Acid Insensitive 3 (ABI3).

Notes:
Skeletal muscle is a form of striated muscle which is under the voluntary control of the somatic nervous system. Most skeletal muscles are attached to bones by bundles of collagen fibres known as tendons. It is one of three major muscle types, the others being cardiac muscle and smooth muscle.

Notes:
The pulmonary veins are a set of veins that deliver clean oxygenated blood from the lungs to the heart. It brings oxygen-rich blood to the left atrium. Systemic veins deliver deoxygenated blood to the heart.

Notes:
The largest invertebrate is Mollusc. With over 80,000 species, molluscs form the second largest phylum of animals on Earth and range from tiny snails to giant squid and octopuses.

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In plants, secondary growth is the result of the activity of the two lateral or secondary meristems, the cork cambium and vascular cambium. Secondary growth increases the girth of the plant root or stem, rather than its length. In contrast, primary meristems, found at the apex of the stem, is responsible for the primary growth (lengthening) of the plant.

Notes:
Night blindness, also called nyctalopia, is failure of the eye to adapt promptly from light to darkness that is characterized by a reduced ability to see in dim light or at night. It occurs as a symptom of numerous congenital and inherited retinal diseases or as a result of vitamin A deficiency.

Notes:
Herpetology is the branch of zoology concerned with the study of amphibians (including frogs, toads, salamanders, newts, and caecilians (gymnophiona)) and reptiles (including snakes, lizards, amphisbaena, turtles, terrapins, tortoises, crocodilians, and the tuataras). It is the study of ectothermic (coldblooded) tetrapods.