General Science Questions (MCQs) for Competitive Examinations

Notes:
Factor IX, also known as Christmas factor, is one of the serine proteases of the coagulation system; it belongs to peptidase family S1. Deficiency of this protein causes Haemophilia B. It was discovered in 1952 after a young boy named Stephen Christmas was found to be lacking this exact factor, leading to haemophilia.

Notes:
Carbon monoxide (CO) is considered a pollutant since it is toxic to haemoglobic animals (including humans) when encountered in concentrations above about 35 ppm. It combines with haemoglobin to produce carboxy-haemoglobin, which usurps the space in haemoglobin that normally carries oxygen, but is ineffective for delivering oxygen to bodily tissues. HGB with 250 times attinity to carbon monoxides as compared to oxygen is toxic. A level of 50% carboxy-haemoglobin may result in seizure, coma, and fatality.

Notes:
Bariatric surgical procedures cause weight loss by restricting the amount of food the stomach can hold, causing malabsorption of nutrients, or by a combination of both gastric restriction and malabsorption. The most common bariatric surgery procedures are gastric bypass, sleeve gastrectomy, adjustable gastric band, and biliopancreatic diversion with duodenal switch. Gastric bypass and other weight-loss surgeries make changes to digestive system.

Notes:
The pituitary gland is a tiny organ, the size of a pea, found at the base of the brain. As the “master gland” of the body, it produces many hormones that travel throughout the body, directing certain processes or stimulating other glands to produce other hormones.

Notes:
There are two regions of endoplasmic reticulum that differ in both structure and function. One region is called rough ER because it has ribosomes attached to the cytoplasmic side of the membrane. The other region is called smooth ER because it lacks attached ribosomes.

Notes:
Interbreeding destroys the genetic integrity of a species, causing it to become progressively infertile or extinct, evolutionary changes in anatomy and biology developed to prevent interbreeding between species. The specific term is Reproductive Isolation, which acts to prevent some, any, or all stages of reproduction from occurring. Reproductive Isolation is very important in keeping animal species separated.

Notes:
Pasteurisation is a process of heating milk for 30 minutes at 62° C and cooling rapidly to kill harmful bacteria and prevent their further proliferaction. Because of the nature of the heat treatment it sometimes referred to as the ‘High Temperature Short Time’ (HTST) process. Once the milk has been heated, it is then cooled very quickly to less than 3°C.

Notes:
Antibiotics are medicines used to treat a wide variety of infections or diseases caused by bacteria, such as respiratory tract infections (eg, pneumonia and whooping cough), urinary tract infections, skin infections and infected wounds. Antibiotics work by blocking vital processes in bacteria, killing the bacteria or stopping them from multiplying.

Notes:
Vitamins A, D, E, and K are the fat-soluble vitamins. Unlike water-soluble vitamins, these vitamins dissolve in fat and are stored in body tissues. Too much vitamin A, D, or K (Hypervitaminosis) can lead to increased levels that are unhealthy and can cause health consequences. For example, too much vitamin A can lead to birth defects.

Notes:
Robert Harding Whittaker was a distinguished American plant ecologist who was the first to pro pose the five-kingdom taxonomic classification of the world’s biota into the Animalia, Plantae, Fungi, Protista, and Monera in 1969. He also proposed the Whittaker Biome Classification, which categorized biome-types upon two abiotic factors: temperature and precipitation.