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Mutation is a sudden heritable change in the DNA sequence that results in the change of genotype.

Translation is the process in which sequence of codons of m-RNA is decoded and accordingly amino acids are added in specific sequence to form a polypeptide on ribosomes.

Part A is the anti-codon. 

Part B is the amino acid. 

Part C is the larger subunit of ribosome.

Satellite Launch Vehicle.

Polar Satellite Launch Vehicle.

Geosynchronous Satellite Launch Vehicle.

Indian Space Research Organisation.

The milky way.

Correct answer is (a) ISRO

Indian National Committee for Space Research (INCOSPAR).

There are about 1 billion solar systems in the Milky Way galaxy. Many of them have some earth-like planets. These planets may have suitable environment to sustain life. Hence, these planets hold the possibility of life.

About one billion years.

Gaia Hypothesis.

(c) Aryabhata

USSR took the initiative and sent the first man-made satellite Sputnik – 1 in October 1957 into space. Sputnik -1 orbited around the earth while maintaining a distance between 939-215 km from the earth. The radio transmitters on Sputnik -1 sent data about higher level of atmosphere, in the form of beeps. It was burnt into pieces while entering the earth. USSR went further ahead and took the lead in sending the first animal, first man (Yuri Gagarin), exhibiting first spacewalk, landing an unmanned spaceship on a celestial body, and installing the space station named Salute-1.

India is among the top countries in the field of space research. India has developed state of the art rocket launchers and satellites. India has developed the capability to make SLV, PSLV and GSLV; the vehicles for satellite launches. India has been doing this at a fraction of cost at which developed nations are able to do. Hence, satellite launch from India is highlv cost effective. This has attracted many nations to India and has enabled ISRO to earn huge amount of foreign exchange.

India has sent many satellites into space. These satellites are being utilized for collecting data so that weather forecast can be accurately done. Moreover, Indian satellites are also helping in transmitting signals for radio, television, mobile telephones, internet, etc. This is helping in proper functioning of business and commerce.

International Space Station.

(c) Neil Armstrong

Many private agencies have also started taking interest in space. Their main objective is to explore space tourism to earn money. Google has announced the Lunar Ex Award to encourage such efforts. Team Indus is working hard to land a robot on the moon, to win the prize from Google. A company; called Moon Express has obtained permission from NASA to ferry people from earth to moon. It can be possible that some people may be fortunate enough to enjoy a journey to the moon in 2017. The co-founder of this company, Navin Jain says that space exploration would benefit industries, like diamond, energy, mining, etc. Fuel stations shall be established on the moon to facilitate travel to the deeper space.

The space research in India started in 1948 in the form of Physics Research Institute, Ahmedabad. The effort got a boost when the government of India established Indian National Committee for Space Research (INCOSPAR) in 1962 under the leadership of Dr. Vikram Sarabhai. This committee established Thumba Rocket Launching Station and started space research on upper levels of atmosphere. Indian Committee for Space Research was renamed a Indian Space Research Organisation (ISRO) in 1969. ISRO has been at the forefront of developments in space technology since its day of inception.

(b) One billion

(b) International Space Station

(a) Yuri Gagarin

(a) Radio remote sensor

I got up at 5:00 AM Greenwich Mean Time (GMT). It was time to finish the early morning chores. I strapped myself to the toilet seat. After that I sucked some toothpaste from the tube and brushed my teeth. This was followed by a 30 minute jogging on treadmill. Breakfast was served in plastic tubes with colour-codes on them. The breakfast was nutritious but tasted awful. After that, it was time to move to another chamber which had state of the art laboratory. Along with my fellow astronauts, I conducted an experiment about plant’s growth in zero gravity. During the break, I took photos of earth which was passing by at frequent intervals. During night, India was looking like a jewel fitted with glittering stones. After a hard schedule of about eight hours, it was time to take rest.

Following is the significance of artificial satellites:

• Valuable data is obtained about atmosphere and troposphere.
• Signals for television and radio are transmitted by artificial satellites.
• Modern telecommunication system is fully dependent on artificial satellites.
• Internet could be developed because of these satellites.
• Better forecast of weather is now possible.

After Darwin’s Theory of Evolution it became clear that the earth was formed like a hot sphere which cooled down in due course of time and an environment was created on it. Elements in the atmosphere combined to make simple compounds and eventually to complex compounds. These compounds also had some fundamental molecules for life, e.g. water, amino acid and nucleic acid. Condensation of these molecules instantaneously created the first life form.

(d) Pioneer 10

Latest scientific researches show that there are one billion earth-like world and many of them are rocky like earth. There are about 100 billion galaxies in the known universe. The senior scientist from NASA, Allen Stephen says that we have solid proof to tell that we shall be able to find extra terrestrial life in the coming decade. People from the scientific community also believe that the extra-terrestrial life is abundant in number. It keeps on coming continuously on earth in the form of microorganisms. Scientists also believe that the first life form was not created on earth rather came from somewhere else. Another group of scientists thinks that there is possibility of life outside the earth but that may not be as developed as on earth. They believe that only having a rocky planet with water is not enough to sustain life.

I think that alien life can be in different stages of development. At some planet, the alien life may be highly advanced. At others, it can be in the form of microorganisms only.

(c) On earth-like planet

• I will myself go up to her and befriend her. I will also help her in whatever way I can. I will not worry if others isolate me for helping her as I can understand that she needs support.
• I will try to talk to others at a later point in time to change their view towards her.

(i) Pritha got isolated with her peers because of her economic background. She also faced bullying as her affluent classmates made fun of her dressing sense. She felt humiliated and unaccepted. It affected her mental well-being. She probably felt that she could not discuss those issues at her home and felt helpless.

(ii) It was a very difficult and disturbing phase in her life. But she could have talked to her teachers and parents and sought their guidance. She could have also shared everything with her friends outside college.

(iii) I would have talked to my parents and discussed everything openly. My parents would have surely guided me on how to deal with peers coming from different backgrounds and provided me their thoughts and ideas. I would also have concentrated more on my studies.

(iv) Yes, Pritha should have spoken and informed her parents of what was going on in her college life, instead of lying about going to college. Lying was only multiplying her troubles. They could have given her support and also maybe talked to her teachers and managed to get the situation under control.

➢ Diffusion in gases is very fast. This is because the particles in gases move very quickly in all directions.

Examples – 1:

➢ The smell of food being cooked in the kitchen reaches us even from a considerable distance.

➢ The smell of hot sizzling food reaches us even when we are at a considerable distance but to get the smell of cold food, we have to go close to it.

➢ This is due to the fact that the rate of diffusion of hot gases (released by the hot sizzling food) is much faster than the rate of cold gases released by the cold food.

Example –2:

➢ When someone opens a bottle of perfume in one corner of a room, its smell spreads in the whole room quickly.

➢ When the bottle of perfume is opened, then the liquid perfume quickly changes into vapour (or gas).

➢ The perfume vapours move very rapidly in all directions in air, mix with the air particles and hence spread with air in the whole room.

Example – 3:

➢ The leakage of cooking gas (LPG) in our homes is detected due to the diffusion of a strong smelling substance (ethyl mercaptan) present in the cooking gas, into air.

Plaster of Paris, [CaSO₄. ½ H₂O]

Calcium sulphate with half a molecule of water per molecule of the salt (hemi-hydrate) is called plaster of paris (plaster of paris).

Water of Crystallization

When crystals of certain salts are formed, they do so with a definite number of molecules of water, chemically combined in a definite proportion. Water of crystallization is the number of water molecules, chemically combined in a definite molecular proportion, with the salt in its crystalline state. This water is responsible for the geometric shape and color of the crystals.

Remember

A substance containing water of crystallization is called a hydrous substance or a hydrate. This water can be expelled, by heating, and then the salt is said to have become anhydrous.

Uses of Plaster of Paris, [CaSO₄. ½ H₂O].

• In surgery for setting broken or fractured bones.

• For making casts for statues, in dentistry, for surgical instruments, and toys etc.

• In making black board chalks, and statues.

• In construction industry.

(d) polygonal in shape

The cells of sclerenchyma and tracheids become dead because they lack protoplasm.

Phloem consists of four types of Cells: 

1. Sieve elements 

2. Companion cells 

3. Phloem parenchyma 

4. Phloem fibres.

(d) Sclerenchyma are actively dividing cells

Isodiametric sclereids, with hard cell wall. It is found in bark, pith cortex, hard endosperm and fleshy portion of some fruits. eg: Pulp of Pyrus.

It is made up of single layer of parenchyma cells which are arranged compactly without intercellular spaces. It is devoid of epidermal pores and cuticle. Root hair is always single celled, it absorbs water and mineral salts from the soil. The another important function of piliferous layer is protection.

In some Xerophytic plants (eg: Cycas, Nerium), stomata is sunken beneath the abaxial leaf surface within stomatal crypts. The sunken stomata reduce water loss by transpiration.

(b) osteosclereids

Some cells of upper epidermis (eg: Grasses) are larger and thin walled. They are called bulliform cells or motor cells. These cells are helpful for the rolling and unrolling of the leaf according to the weather change.

Correct Answer is: (b) grasses

The four types of clouds are : 

(a) Cirrus clouds — These are feathery, fibrous clouds which form at very high levels of 5 to 10 km. They consist of tiny crystals of ice and look like wisps of cotton floating in the sky. 

(b) Cumulus clouds — These are cauliflower-shaped clouds that have great vertical height and a flat base; they cause rainfall with lightning and thunder, and are usually white or grey in colour. 

(c) Stratus clouds — These are sheet-like clouds that spread out 42 Arundeep’s Self-Help to Voyage-7 over the whole sky. They usually form at low levels, less than 2 km. They are uniformly grey and dull. 

(d) Nimbus clouds — These are the real rain clouds – thick, dark and black, and spread out in layers. They cause continuous rain or snow.

Wind is air in motion. A wind vane indicates the direction of the wind and consists of a rotating arm pivoted on a vertical rod. The arrow of the wind vane always points in the direction from which the wind blows and the wind is named accordingly. For example, if the pointer is pointing to the East, the wind is blowing from East to West and, therefore, this wind is called an easterly wind. Wind vanes are usually placed away from obstacles such as high buildings, trees, etc.

Correct answer is

(D) all of these

Correct Answer is: (B) Aquatic animal 

• Fish farming or Pisciculture involves raising fish commercially in tanks or enclosures such as fish ponds, usually for food. 

• It is the principal form of aquaculture, while other methods may fall under mariculture.