Atoms and Molecules — Science STD 9 — Question

Heat generating cells of animals are:

When both crops and livestock are raised on the same farm, it is known as:

1. Mixed farming.
2. Mixed cropping.
3. Intercropping.
4. Crop rotation.

Haversian canals are found in ________?

The number of electrons in the outermost shell in the atom of an inert element is:

The Bohr model of atoms:

In Rutherford's alpha-ray scattering experiment, a screen is used to detect the alpha particles which is coated by:

A disused railway line has a length of 300m. A man puts his ear against one end of the rail and another man hits the other end with a metal hammer. Sound travels at 5000m/ s in steel. The time it takes for the sound to travel along the rail is:

AIDS virus has:

1. Single strand DNA.
2. Double strand DNA.
3. Single strand RNA.
4. Double strand RNA.

Name the cell organelle which is called the Control room of the cell.

Epithelial tissue always has an exposed outer surface and an inner surface anchored to connective tissue by a thin, non- cellular structure called the: