BIOLOGY CH24 Environmental Science — Science STD 9 — Question

Ultrasonic sounds cannot be heard by the Human beings.

The unit of amount of substance is candela

The symbol for the units derived from the names of scientists are written in capital letter

Clean and Fresh water is essential for every human activity.

Epithelial layer does not allow regulation of materials between the body and the external environment.

State whether true or false. If false, correct the statement.

Trachea are the respiratory organ of Annelida.

• True

• False

State whether true or false. If false, correct the statement.

The motion of a city bus in a heavy traffic road is an example for uniform motion.

• True

• False

If the volume of object is above the water surface, then the object is less densed.

Radioisotopes can be easily detected and estimated quantitatively.

Sublimation is conversion of solid into liquid.