General Science Questions (MCQs) for Competitive Examinations

Notes:
Blood pressure is usually expressed in terms of the systolic (maximum) pressure over diastolic (minimum) pressure and is measured in millimetres of mercury (mm Hg). It is one of the vital signs along with respiratory rate, heart rate, oxygen saturation, and body temperature. Normal resting blood pressure in an adult is approximately 120/80 mm Hg.

Notes:
Myxine is a species of jawless fish (Agnatha). It is known as Hag fish in Europe. These are generally classified with the lampreys into the superclass Agnatha (jawless vertebrates) within the subphylum Vertebrata. All other living fishes (shark, rays, chimeras and bony fishes) possess true jaws derived from gill arches and are placed in the superclass Gnathostomata.

Notes:
Casein-Lactose protein-sugar pair is present in milk. Normal bovine milk contains 30-35 grams of protein per litre of which about 80 percent is arranged in casein micelles. Casein is present in milk, but it’s not a milk sugar like lactose. Instead, casein is one of the proteins found in milk. Unlike lactose, which causes an intolerance, these proteins in milk are what’s responsible for a milk allergy, according to Food Allergy and Research Education.

Notes:
The National Viral Hepatitis Control Program aims to combat hepatitis and achieve country wide elimination of Hepatitis C by 2030. Launched on 28 July, 2018, it also aims to achieve significant reduction in the infected population, morbidity and mortality associated with Hepatitis B and C viz. Cirrhosis and Hepato-cellular carcinoma (liver cancer).

Notes:
Bats are mammals of the order Chiroptera. With their forelimbs adapted as wings, they are the only mammals capable of true and sustained flight. Bats are more maneuverable than most birds, flying with their very long spread-out digits covered with a thin membrane or patagium. 

Notes:
Chlorophyll, a photo-receptive pigment, allows plants to absorb sunlight. Chlorophyll is a chlorine pigment, which is structurally similar to and produced through the same metabolic pathway as other porphyrin pigments such as heme. At the center of the chlorine ring is a magnesium ion. The molecular formula of C55H70O6N4 Mg. Hence, chlorophyll as a pigment lacks calcium.

Notes:
Lysosomes are membrane-enclosed organelles that are known as suicidal bags of the cell. They contain digestive enzymes, and break down food, cellular debris and foreign invaders like bacteria. In the event that the cell is injured beyond repair, or becomes old, the lysosome digests the cell, hence the name ‘suicide bag of the cell’.

Notes:
Pleiotropy describes the genetic effect of a single gene on multiple phenotypic traits. The underlying mechanism is that the gene codes for a product that is, for example, used by various cells, or has a signaling function on various targets. A classic example of pleiotropy is phenylketonuria, a human disease that affects multiple systems but is caused by one gene defect.

Notes:
Frogs that spend the coldest times of the year inside of the mud or within rotten heaps of leaves during hibernation receive their necessary oxygen through their skin. This is referred to as cutaneous gas exchange. They use their skin to soak in the oxygen their bodies require. Outside of hibernation period, frogs usually respire using their lungs.

Notes:
In the collateral type of vascular bundle, xylem and phloem are arranged side by side on the same radius. This may be either open or closed. Usually xylem is seen towards the inner side and phloem towards outer side. The collateral vascular bundle is also known as conjoint.