Daily NEET MCQ- July 23, 2022 - NEET MCQ

Hydraulic washing is usually used for concentration of ores when the particles of the ore have a higher mass compared to the earthy or rocky gangue particles. The process is carried out in specially designed tables called Wilfley tables.

Concentration by hydraulic washing requires the ore particles to have a higher mass compared to its gangue particles. Hydraulic washing can be used for oxide ores of iron and tin such as haematite and tinstone and also for native ores of silver and gold. Pyrolusite is concentrated by magnetic separation.

Electromagnetic separation is used to concentrate an ore when either the particles of the ore or the impurities present in it are magnetic in nature. Chromite, magnetite and pyrolusite have magnetic nature and are separated from their non-magnetic gangue particles using this method. Zinc blende is concentrated using electrostatic separation or froth floatation.

The organism carrying another organism to the host is called a vector. A vector itself does not cause disease but transfers the pathogen to host. Some major vectors are plasmids, cosmids, viral vectors, and artificial chromosomes.

A female anopheles mosquito is a vector that transmits the malaria-causing protozoan called Plasmodium. Anopheles gambiae is one of the best-known vectors that transmit Plasmodium falciparum.

Sacculina is a genus of barnacles that resides inside the gut of a crab. It is a parasite that shows adverse effects on crabs such as it hinders the normal metabolism of crab and also reduces its reproduction capacity.

A relationship in which one parasite feeds on another parasite which in turn feed on its host is called epi-parasite. These are also known as secondary or hyper parasites. An example is a bacterium in an insect’s gut that feeds on cattle.

A protozoan living in the digestive tract of a flea living on a dog is an example of Hyper-parasitism. It is also known as secondary or epi-parasite. It is a relationship in which one parasite feeds on another parasite which in turn feeds on its host.

Thomson proposed a model of the atom, in which electrons are embedded to make it as the stable electrostatic arrangement and such that positive charge is equally distributed around a sphere. Mass is assumed to be equally distributed. So. it has different names like plum pudding, watermelon and raisin pudding model.

Henri Becquerel discovered that elements emit radiation and termed this phenomenon as radioactivity. Later Curie on research found out about α-rays, β-rays and γ-rays. Later Rutherford concluded that α particles are helium nuclei.