RRB General Science Model Question With Answer
- Which of the following is the most acceptable theory for movement of water through plants?
(a) Cohesion theory
(b) Passive transport
(c) Root pressure
Translation of food in flowering plants occurs in the form of
pH of saliva is
(a) 6.5 (b) 8
(c) 7 (d) 9.5
As blood becomes fully O2 saturated, haemoglobin is combining with____ molecule(s) of oxygen.
Coronary artery disease (CAD) is often referred to as
(a) Heart failure
(b) Cardiac arrest
The part of an eye which acts like diaphragm of a photographic camera, is
The most common carrier of communicable diseases is
(b) unwanted herbs
(d) fungal pests
Red data book contains list of
(a) endangered species of plants and animals
(b) extinct animals and plants
(c) exotic plants and birds
(d) rare species of plants and animals
The period during which foetus remains within mother’s womb
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1. (a) Cohesion of water and transpiration pull theory is the most widely accepted theory put forth by Dixon and Jolly in 1894, and further supported by Renner (1911, 1915), Curtisand Clark (1951), Bouner and Golston (1952), Kramerand Kozlowskl (1960). It is also known as Dixons cohesion theory, or Cohesion tension theory.
3. (a) pH of saliva is 6.5.
4. (c) Haemoglobin has 4 subunits, each of which binds to 1 molecule of O2 for a total of 4 molecules of O2 bound to 1 haemoglobin molecules.
5. (c) Coronary Artery Disease (CAD) or Atherosclerosis is a disorder in which the deposition of calcium, fat, cholesterol and fibrous tissue occurs in coronary arteries which makes the lumen of arteries narrower and thereby affect the blood supply.
7. (c) All communicable diseases are caused by micro-organisms. They spread through contact, air, water, food or insects (flies and mosquitoes). Insects are called the carriers of diseases.
8. (b) Weeds are plants, other than the crop plants, growing alongwith the crop. Weeds grow vigorously and draw more nutrition from the soil than the crop plants. This makes the soil poor in minerals and deprives the crop of its minerals needs.
9. (a) A list of threatened species of plants and animals in different parts of the world has been prepared and issued by World Conservation Union (WCU) assigning responsibility of protecting these species to the respective Governments.