Public interest litigation is litigation for public interest i.e., it is a case filed in the interest of the public by a representative of the public. PIL was started to protect the fundamental rights of people who are poor, ignorant or in socially/economically disadvantaged position.

The big bang is how astronomers explain the way the universe began. It is the idea that the universe began as just a single point, then expanded and stretched to grow as large as it is right now (and it could still be stretching).

When the universe began, it was just hot, tiny particles mixed with light and energy. It was nothing like what we see now. As everything expanded and took up more space, it cooled down.

The tiny particles grouped together. They formed atoms. Then those atoms grouped together. Over lots of time, atoms came together to form stars and galaxies.

The first stars created bigger atoms and groups of atoms called molecules. That led to more stars being born. At the same time, galaxies were crashing and grouping together. As new stars were being born and dying, then things like asteroids, comets, planets, and black holes formed!

• The cells of plants, fungi and bacteria are surrounded by the cell wall.
• The cell walls of fungi, plants, and bacteria allow them to take up water via osmosis when they are placed in hypotonic media or a medium that is more dilute than their internal environments. 
• The presence of cell walls outside the cell membrane allows these cells to tolerate high internal pressures. 
• Hence, when these cells are placed in hypotonic solutions they swell up but do not burst.

Membrane biogenesis is the synthesis of cell membrane using lipids and proteins. Endoplasmic reticulum is responsible for membrane biogenesis.

Cells are capable of performing multiple functions in an organism. A cell contains specific components which are called Organelles. Each organelle in the cell can perform different functions such as making new cells or clearing the waste of the cell. Thus, organelles allow a cell to perform several kinds of activities in an organism.

Phloem, also called bast, tissues in plants that conduct foods made in the leaves to all other parts of the plant. Phloem is composed of various specialized cells called sieve tubes, companion cells, phloem fibres, and phloem parenchyma cells. Phloem is the vascular tissue responsible for the transport of sugars from source tissues (ex. photosynthetic leaf cells) to sink tissues (ex. non-photosynthetic root cells or developing flowers). Other molecules such as proteins and mRNAs are also transported throughout the plant via phloem. Phloem cells conduct food from leaves to rest of the plant. They are alive at maturity and tend to stain green (with the stain fast green). Phloem cells are usually located outside the xylem. The two most common cells in the phloem are the companion cells and sieve cells.

The moisture present in the atmosphere is called humidity. A dry atmosphere can hold more water molecules than a humid atmosphere. Hence, the rate of evaporation of aqueous solution decreases with the increase of humidity and vice versa.

That’s why increase in humidity in the atmosphere decreases the rate of evaporation of an aqueous solution.

• Characteristics of Particles of Matter:

• Particles of Matter have Space between them:

When we dissolve sugar in a glass of water, the volume of water remains the same and does not increase. This shows that there are spaces between the particles of water into which the particles of sugar fit together.

• Particles of Matter are Continuously Moving:

Particles of matter are continuously moving, that is, they possess kinetic energy. As the temperature rises, particles move faster. So, we can say that with increase in temperature the kinetic energy of the particles also increases. When we light an incense stick in one corner of a room, its fragrance spreads in the whole room quickly.

• Particles of Matter Attract Each Other:

There are some forces of attraction between the particles of matter which bind them together. The force of attraction between the particles of the same substance is known as cohesion. The force of attraction is maximum in the particles of solid matter and minimum in the particles of gaseous matter.

Advantages

1) Life is become easy and comfortable through science and technology.

2) Travelling has become easy and fast in minutes.

3) Communication is become easy, fast and cheaper.

4) Standard of living have increased with the increase in technology.

5) Man have become advanced by using various new technology.

 Disadvantages

1) Man had misused the technology and used in destructive purpose.

2) Man is doing illegal things by using it.

3) New Technology like mobile, I-pods etc are creating bad effect on children.

4) Terrorist are using modern technology for their destructive work.

5) Due to the development of atomic energy and atom bomb create many harmful diseases like skin disease etc.

Gravitational force acts on all objects in proportion to their masses. But a heavy object does not fall faster than a light object. As force is directly proportional to mass, acceleration is constant for a body of any mass. 

The boiling point of a liquid is the temperature at which the vapour pressure of the liquid becomes equal to the atmospheric pressure of the liquid’s environment. At this temperature, the liquid is converted into a vapour.

Distance = 3 m + 4 m =7 m

Displacement = 4 m - 3 m =1 m

Water has an amazing property, like other substances it contracts when cooled but only up to 4 degree Celsius after that, on further cooling it starts expanding. When it reaches the freezing point water expands nearly 9% whereas the cold drink bottles keeps on contracting. Due to lack of space for the expansion in volume ice, the bottle breaks.

The food vacuole or digestive vacuole is a membrane-bound cell organelle (as in an amoeba) associated with a digestive function. They take up the food material by the process of phagocytosis and the ingested food is digested by food vacuole.

Contractile vacuoles: A contractile vacuole has a highly extensible and collapsible membrane. It is also connected to a few feeding canals. The feeding canals obtain water with or without waste products from the surrounding cytoplasm. They take part in osmoregulation and excretion.

Sap vacuoles: They are fluid-filled vacuoles or vesicles which are separated from the cytoplasm by a selectively permeable membrane called tonoplast. It has a number of transport systems for the passage of different substances. A number of small sap vacuoles occur in animal cells and young plant cells.

Vacuoles in both plant and animal cells serve as storage organelles inside the cell. The main difference between plant and animal vacuoles is that plant vacuoles are large in size and are single in number whereas animal vacuoles are small in size and are more in number. ... Animal vacuoles store nutrients, ions, and water. In animal cells, vacuoles perform mostly subordinate roles, assisting in larger processes of exocytosis and endocytosis. Animal vacuoles are smaller than their plant counterparts but also usually greater in number. There are also animal cells that do not have any vacuoles.

• An object is said to be in uniform motion if it travels equal distances in equal intervals of time, howsoever small the intervals may be.
• If a body covers equal distances in equal time intervals, howsoever small the intervals may be, then it is said to have uniform speed (or constant speed).
• A body is said to be moving with uniform velocity (or constant velocity) if it travels along a straight line, covering equal distances in equal intervals of time, howsoever small these intervals may be.

One way would be to add a little more of the solute to the solution. If there is no precipitation, the earlier solution was not saturated. If there is precipitation or the solute added collects at the bottm, the solution was saturated.

If we consider both solution as a salt solution then If to a given solution, more salt is added and it dissolves, then it is unsaturated. If the salt added settles down,  it is saturated.

Grana - A series of stacked thylakoid disks, found in the inner membrane of chloroplasts. Grana are connected by intergranal lamellae.

Grana function in the light reactions of photosynthesis. The grana of chloroplast consists of pigment system made upof chlorophyll-a, chlorophyll-b, carotine and xanthophyll.