Questions

All living cells arise from pre-existing cells is one component of the cell theory.

The Cell Theory is one of the basic principles of biology.

The Cell Theory states:

1. All living organisms are composed of cells. They may be unicellular or multicellular.

2. The cell is the basic unit of life.

3. Cells arise from pre-existing cells.

During daylight hours, plants capture carbon dioxide from the atmosphere and use it to make carbohydrates which is stored as starch in the plant. Animals feed on the plants and extract the carbohydrates through their digestive system. The carbohydrates, namely glucose, are used by the animals for production of ATP through cellular respiration.

Cellar respiration in the animals produces carbon dioxide as a waste product. The carbon dioxide is released into the atmosphere, from where it is again captured by plants and the cycle is repeated.

Hence, option B) Plant ----> Animal ----> Atmosphere is the path possible in carbon cycle.

Air Pressure can be defined as the pressure of air in the earth's atmosphere. It reaches a maximum of about 100,000 Pa near sea level and decreases as altitude increases.

The barometer is an instrument which is used for measuring Air pressure.

Physics instruments and their uses:

Barkometer  - - - Tanning liquors used in tanning leather

Bolometer  - - - Electromagnetic radiation

Spectrometer - - -  Properties of light.

The blood of some invertebrate animals like the earthworm is red due to haemoglobin pigment, but the pigment is dissolved in the plasma. In vertebrates the same pigment is found in the red corpuscles and not in the plasma.