Questions

The objects through which light cannot pass are called as Opaque objects. Some objects allow some light to pass through them and are called as Translucent objects. The objects which allow all the light to pass through them are called as Transparent objects.

Here in the given options Book is an example of opaque object as it does not allow light to pass through it. Water is transparent object and notebook paper and sun glasses are examples of translucent objects.

Asterias has bilateral symmetry only at larval stagebut fivefold symmetry (pentamerism, a special type of radial symmetry) as adults.

Nereis do not possess any symmetry elements in their body organisation.

A spreadsheet is an interactive computer application for organization, analysis and storage of data in tabular form. This software allows users to store data in rows and columns.