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Ask QuestionPosted by Rajnandani Chouhan 6 years ago
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Yogita Ingle 6 years ago
Vegetative propagation is the process of formation of new plants from detached vegetative parts or propagules such as roots, stem, leaves, etc.of the parent plant. The new plants produced by vegetative propagation are genetically identical to the parent plants.
Abhinav ? 6 years ago
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Raunak Chauhan 6 years ago
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Krishna Sharma 6 years ago
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Krishna Sharma 6 years ago
Yashwant Jain 6 years ago
Posted by Horizon Singh 6 years ago
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Meghna Thapar 5 years, 10 months ago
Darwin's theory of evolution is known as 'The Theory of Natural Selection'. It can be described as follows:
(i) Within any population there is natural variation. Some individuals have more favourable variations than others.
(ii) Even though all species produce a large number of offspring's, populations remain fairly constant naturally.
(iii) This is due to the struggle between members of the same species and different species for food, space and mate.
(iv) The struggle for survival within populations eliminates the unfit individuals. The fit individuals possessing favourable variations survive and reproduce. This is called natural selection.
(v) The individuals having favourable variations pass on these variations to their progeny from generation to generation.
(vi) These variations when accumulated over a long period of time, lead to the origin of a new species.
Posted by Adarsh Tiwari 6 years ago
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Raunak Chauhan 6 years ago
Posted by Asutosh Pati 6 years ago
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Yogita Ingle 6 years ago
In atmosphere, some OXYGEN (O2) absorbed energy from ultraviolet (UV) ray and split to for single oxygen atoms. This oxygen combined with remaining oxygen and form ozone (O3) molecule.
Diksha ? 6 years ago
Posted by Anshu Gangwani 6 years ago
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Sambhav Maheshwari 6 years ago
Yogita Ingle 6 years ago
(i) Human kidney performs the process of excretion by removing metabolic wastes from the blood.
(ii) It performs the function of osmoregulation by maintaining normal levels of water and mineral ions in the body fluids.
Posted by Sunita Mishra 6 years ago
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Yogita Ingle 6 years ago
Diamond has three dimensional network of strong covalent bonds. It is very difficult to break extended covalent bonding and therefore, diamond is the hardest substance on earth. On the other hand, graphite has layer structure and the layers are held together by weak Vander Waals forces. Therefore, graphite cleaves easily between the layers and, therefore, it is very soft and slippery.
Nannu Singhal 6 years ago
Posted by Aditya G Pai 6 years ago
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Yogita Ingle 6 years ago
It can be prevented by packaging them in air tight containers or packages.
Antioxidants are added to prevent rancidity of foods containing fats and oils. They prevent oxidation of fats and oils.
Posted by ? ... 6 years ago
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Yogita Ingle 6 years ago
Most of the earth's crust, or outer layer, is made up of eight elements. Oxygen tops the list in terms of abundance, with the planet's shell being composed of almost 47% of this nonmetallic chemical element. Silicon posts a second-place ranking at nearly 28% by weight. Add these two elements together, and you get silicates.
Posted by Piyush Dixit 6 years ago
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Miss Zainab 6 years ago
Posted by Siddharth Naresh 6 years ago
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Posted by Diya Jain 6 years ago
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Kusha Lamba 6 years ago
Yogita Ingle 6 years ago
The Allotropes are different forms of an element having different physical properties but the same chemical properties.For example ,the Allotropes of Carbon-that is Graphite and Diamond are allotropes of Carbon.
Posted by Rahul Sharma 6 years ago
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Sambhav Maheshwari 6 years ago
Miss Zainab 6 years ago
Posted by Anusheya Kamatkar 6 years ago
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Yogita Ingle 6 years ago
Acids and bases are most important types of chemical compounds in the field of chemistry.
There are many scientific definitions of these two types of chemical compounds.
Among those definitions,the Arrhenius's definition is very popular.
According to the theory of Arrhenius;
Definition of acid and base are;
1)Acid: A chemical compound which releases H+ ions in it's aqueous solution.
2)Base: A chemical compound which releases OH- ions in it's aqueous solution.
Posted by Archana Sharma 6 years ago
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Parul Ailawadi 6 years ago
Posted by Anmol Malik 6 years ago
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Yogita Ingle 6 years ago
In thermal power plants, steam at high pressure and high temperature is used to rotate large turbines. These turbines are connected to the generator which generates electricity. The steam later passed through condenser to cool it down and turn it into water. This water will again be used for producing steam
Rishiga Pradeesh 6 years ago
Posted by Rishi Gupta 6 years ago
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Meghna Thapar 5 years, 10 months ago
The amount of current in a series circuit is the same through any component in the circuit.
This is because there is only one path for current flow in a series circuit. Because electric charge flows through conductors like marbles in a tube, the rate of flow (marble speed) at any point in the circuit (tube) at any specific point in time must be equal.
Posted by Madhu Sharma 6 years ago
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Yogita Ingle 6 years ago
Carbon occurs in nature in free state as well as in combined state.
- Free state: Diamond , Graphite , Coal
- Combined state :
Gaseous state: 1) In the atmosphere, 2) As a natural gas and petroleum gas
Liquid state: 1) Natural waters - Soluble carbonates and bicarbonates
Solid state: 1) In wood (cellulose) - Mineral deposits of metallic carbonates
Posted by Farzana Resh 6 years ago
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Yogita Ingle 6 years ago
Natural selection is the process whereby organisms better adapted to their environment tend to survive and produce more offspring, whereas other less favourable traits tend to become eliminated. Genetic driftrefers to random changes in gene frequencies that usually occurs in a small population and results from chance processes alone.
Example - A population of red beetles live in an area. Suppose a colour variation arises during reproduction, giving rise to one green coloured beetle instead of red. This beetle passes the colour on to its progeny, so that all its progeny beetles are green. Crows cannot see green-coloured beetles on the green leaves of the bushes, and therefore cannot eat them. So the progeny of green beetles is not eaten, while the progeny of red beetles continues to be eaten. This gives rise to more green beetles than red ones in the beetle population. Here the green coloured variation became common because it gave a survival advantage. In other words, it was naturally selected by the crows. Increase in number of crows results in more red beetles being eaten and subsequent increase in proportion of green beetles in the population. Thus, natural selection is directing evolution in the beetle population. It results in adaptations in the beetle population to fit their environment better.
Suppose another colour variation arises during reproduction in this beetle population, which is blue in colour instead of red. The progeny beetles of this beetle are also blue. Crows can see blue-coloured beetles in the green leaves of the bushes as well as the red one, and therefore can eat them. Initially in the population, as it expands, there are a few blue beetles, but most are red. But at this point, an elephant comes by, and stamps on the bushes where the beetles live, thereby killing most of the beetles. By chance, the few beetles that have survived are mostly blue. The beetle population slowly expands again, but now, the beetles in the population are mostly blue. So here the colour change gave no survival advantage. Instead, it was simply a matter of accidental survival of beetles of one colour that changed the common characteristic of the resultant population. The elephant would not have caused such major change in the beetle population if the beetle population had been very large. So, accidents in small populations can change the frequency of some genes in a population, even if they give no survival advantage. This is the concept of genetic drift, which provides diversity without any adaptations.
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Meghna Thapar 5 years, 10 months ago
Iron is needed to make haemoglobin present in red blood cells. It is found in spinach, green leafy vegetables, apple, egg, cereals, pulses and groundnut.
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