Explanation

Eugenics is the practice or advocacy of improving the human species by selectively mating people with specific desirable hereditary traits

Explanation

A bell works with the principle of working of electromagnetism.

Explanation

A rectifier is an electrical device that converts alternating current (AC),

which periodically reverses direction, to direct current (DC), which flows in only one direction.

Explanation

Measured on an individual level, social stability refers to the range of life structure and reliable routine that is protective against further situational hazards and helps maintain connections with social resources and societal expectations

Explanation

Coagulation and filtration is one of the most common water treatment techniques used by larger water systems, used for removing particulates and turbidity from surface water.

Explanation

scotograph is an instrument for writing in the dark, or by the blind. 

Explanation

Bees are by far the most effective pollinators because they feed only on flowers.

Flowers attract and reward bees for their pollination service.

Explanation

A beta particle, also called beta ray or beta radiation (symbol β), is a high-energy, high-speed electrons emitted by the radioactive decay of an atomic nucleus during the process of beta decay.

Explanation

The medulla oblongata is a cone-shaped neuronal mass in the brain located in the brain stem, directly below the pons and anterior to the cerebellum.

Explanation

Aquatic animals may breathe air or extract oxygen that dissolved in water through specialized organs called gills, or directly through the skin.