Hard and Heavy Water, Climate and Weather, Cardiac and Skeletal Muscles

Doorsteptutor material for IAS is prepared by world's top subject experts: Get detailed illustrated notes covering entire syllabus: point-by-point for high retention.

Download PDF of This Page (Size: 109K)

Hard Water

  • Hard water is that type of water which does not form lather easily.

  • Its formula is .

  • Hard water is not used in nuclear power plants.

Heavy Water

  • Heavy water is deuterium oxide in which hydrogen of water is replaced by its heavier isotope, Deuterium.

  • The formula of heavy water is .

  • Heavy water is used in nuclear power plants.

Climate & Weather


Climate is the normal weather conditions for an area during a season or a year. ii) Climate of an area is described by means of an average means of an average of the statistics of the various weather factors over a period of time, normally 30-years.


  • Weather is the condition of the atmosphere at any one place and time.

  • Weather is described by air, temperature and humidity, wind speed and direction, cloud amount and precipitation, sunshine and visibility.

Cardiac & Skeletal Muscles

Cardiac Muscles

  • Cardiac muscles are present in the heart only.

  • They have centrally placed nuclei.

  • They never fatigue.

  • They are composed of long fibers.

  • They are under involuntary control.

Skeletal Muscles

  • Skeletal muscles are present in the skeleton of the body.

  • Nuclei are not centrally placed in skeletal muscle.

  • They can fatigue.

  • They are not composed of long fibers.

  • They are under voluntary control.

Haze & Smog


  • The dust particle smoke etc. that may be visible in atmosphere close to the earth’s surface is known as Haze.

  • It does not affect natural visibility.

  • It does not occur particularly near coastal areas.


  • It is a mixture of solid and liquid fog as well as particles of smoke. It is formed when humidity is high.

  • Smog reduces visibility.

  • It occurs near coastal areas.

Enzyme & Hormone


  • These are organic catalysts produced in the protoplasm of all living cells.

  • These are mostly protein in nature.

  • They control all biochemical reactions of the cell.

  • These are present in all cells and show their activity there.


  • These are organic substances produced in places away from their functional sites.

  • These are mostly acids.

  • They promote and inhibit growth, flowering, sex expression, etc.

  • These are mobile. They are produced at one site and show their activities at other sites.

Igneous & Sedimentary Rocks

Igneous Rocks

  • Igneous rocks are formed when magma (or molten rocks) has cooled down and solidified.

  • Igneous rocks are commonly found inside the Earth’s crust or mantle,

  • Igneous rocks can be an important source of minerals,

  • Examples of Igneous rocks include granite and basalt.

Sedimentary Rocks

  • Sedimentary rocks are formed by the accumulation of other eroded substances, ii) Sedimentary rocks are usually found in water bodies (sea, oceans etc.).

  • Sedimentary rocks, or their bedding structure, are mostly used in civil engineering; for the construction of housing, roads, tunnels, canals etc. iv) Examples of Sedimentary rocks include shale, limestone and sandstone.

  • OR What is the difference between Igneous Rocks and Sedimentary Rocks? - Igneous rocks are formed from molten liquid minerals called magma, while sedimentary rocks are formed from lithification (cementing, compacting and hardening) of existing rocks.

  • Igneous rocks are non-porous for water, while sedimentary rocks are porous to the water. That is water cannot penetrate through igneous rocks but can through sedimentary rocks.

  • Igneous rocks are having fossils very rarely, while sedimentary rocks are rich in fossils.

  • Igneous rocks are harder than sedimentary rocks.

  • Tendency to react with acids is higher to sedimentary rocks when compared to igneous rocks.

  • Igneous rocks may be light or dark colored, while sedimentary rocks have great color variety.

Producers & Consumers


Producers are organisms that make their own food through photosynthesis or other reactions and are a food source for other organisms (ex. plants, extremophile benthos communities).


Consumers are organisms that ingest other organisms, like plants, in order to gain energy (ex. herbivores, carnivores, omnivores, and derivers).

Developed by: