Questions

An organelle called Eyespot allows some protists to detect light. It allows the cells to sense light direction and intensity and respond to it by swimming either towards the light (positive phototaxis) or away from the light (negative phototaxis).

Eyespot is a photoreceptive organelle found in the flagellate or (motile) cells of green algae and other unicellular photosynthetic organisms such as euglenids.

Eyespot-mediated light perception helps the cells in finding an environment with optimal light conditions for photosynthesis. Eyespots are the simplest and most common "eyes" found in nature, composed of photoreceptors and areas of bright orange-red pigment granules.

The nucleus of hydrogen consists of only a single proton.

Its parts are a single negatively-charged electron that circles a single positively-charged nucleus of the hydrogen atom.

The electron is bound to the nucleus by the Coulomb force.

Volatile memory is computer memory that requires power to maintain the stored information. It is a temporary memeory which cannot contain information permanently.

Example :: RAM or Random Access Memory

To display current date and time in MS Excel, we use Now() method. 

Internet service providers (ISP's) emerged in the late 1980's and early 1990's.

The ARPANET was decommissioned in 1990.

By 1995, the Internet was fully commercialized in the U.S., when the NSFNet was decommissioned, removing the last restrictions on use of the Internet to carry commercial traffic.

Galileo Galilei (1564-1642) was an Italian Astronomer who

1) Discovered 4 satellites of Jupiter

2) Developed Telescope

3) Discovered that the movement of pendulum produces a regular time measurement

He is Physicist, Mathematician, inventor, and philosopher Too.

Passivity of iron is due to formation of an extremely thin and impervious film of ferrosoferric oxide Fe3O4on the surface of iron. Chromic acid, being a powerful oxidising agent (like nitric acid ) renders iron passive.