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Ask QuestionPosted by Shwet Kumar Mishra 5 years, 11 months ago
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Shreya ... 5 years, 11 months ago
Posted by Jayesh Tiwari 5 years, 11 months ago
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Yogita Ingle 5 years, 11 months ago
The functional group ketone is said to have one carbonyl group lies between two carbon atoms.
Hence the first member of the functional group ketone must have three carbon atoms.
Therefore the first member of the ketone is propanone.
Posted by Jayesh Tiwari 5 years, 11 months ago
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Jayesh Tiwari 5 years, 11 months ago
Posted by Abhi Mittal 5 years, 11 months ago
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Meghna Thapar 5 years, 10 months ago
Evidences of evolution:
Some of the important sources which provide evidences for evolution are:
(a) Analogous Organs: Organs which performs similar function but are different in structure and origin.
Example - wings of a bird and wings of an insect.
The presence of analogous organs indicates that even the organisms having organs with different structures can adapt to perform similar functions for their survival under hostile environmental conditions. Thus, the presence of analogous organs in different animals provide evidence for evolution by telling us that though they are not derived from common ancestors, they can still evolve to perform similar functions to survive, flourish and keep on evolving in the prevailing environment.
(b) Homologous Organ: Organs which have different functions but similar structure and origin.
Example - fore arm of frog, lizard, bird and human.
The presence of homologous organs in different animals provides evidence for evolution by telling us that they are derived from the same ancestor who had the 'basic design' of the organ on which all the homologous organs are based.
(c) Fossils: The remains of dead animals or plants that lived in the remote past are known as fossils. The fossils provide evidence of evolution. For example, a fossil bird called Archaeopteryx looks like a bird but it has many features which are found in reptiles. This is because Archaeopteryx has feathered wings like those of birds but teeth and tail like those of reptiles. Therefore, Archaeopteryx is a connecting link between the reptiles and birds and suggests that birds have evolved from reptiles. Thus, fossils provide evidence that the present plants and animals have originated from the previously existing ones through the process of continuous evolution.
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Meghna Thapar 5 years, 10 months ago
On reaching puberty, one egg is produced every month by one of the ovaries in the females. The egg is carried from the ovary to the womb through a thin oviduct or fallopian tube. The two oviducts unite into an elastic bag-like structure known as the uterus. The uterus opens into the ****** through the cervix. The sperms of the male enter through the vaginal passage during sexual intercourse. They travel upwards and reach the oviduct where they may encounter the egg. The fertilised egg, the zygote, gets implanted in the lining of the uterus, and starts dividing.
Posted by Hargun Singh 5 years, 11 months ago
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Shreya Sood 5 years, 11 months ago
Dr. Shreyas Samarth 5 years, 11 months ago
Yogita Ingle 5 years, 11 months ago
When adolescence reaches to maturity at sexual level then this period is known as puberty.
Basically it is an age where a person went through both physical and chemical changes in the body.
For example, in girls during puberty there occurs physical changes like starting of mensuration cycle, development of breasts, development of feminine voice, growth of hairs at pubic area and underarms etc.
Shirin .Pvt 5 years, 11 months ago
Posted by Vishal Kumar 5 years, 11 months ago
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Hargun Singh 5 years, 11 months ago
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Posted by Anusree Sandhya 5 years, 11 months ago
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Smart World 5 years, 11 months ago
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Shreya Sood 5 years, 11 months ago
Smart World 5 years, 11 months ago
Arman Saifi 5 years, 11 months ago
Yogita Ingle 5 years, 11 months ago
An eye defect in which a person can able to see distant objects while can't able to see near by objects is known as hypermetropia.
This is also known as long slightedness.
Reasons:
1) Elongation of lens,
2) lens becomes less converging.
It can be corrected by using convex lens to make eye len's more converging.
Jayavel Ramalingam 5 years, 11 months ago
Posted by Surendar Kumar 5 years, 11 months ago
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Yogita Ingle 5 years, 11 months ago
Colostrum is known to contain immune cells (as lymphocytes) and many antibodies such as IgA, IgG, and IgM.
Posted by Surendar Kumar 5 years, 11 months ago
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Yogita Ingle 5 years, 11 months ago
Colostrum is a thin, yellowish, opalescent fluid released after birth from the mother’s breast for 2 to 3 days. It is also called foremilk.
Posted by Lalit Pargai 5 years, 11 months ago
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Yogita Ingle 5 years, 11 months ago
Lead Nitrate crystals when heated in a dry test tube it gets decomposed and forms Lead Oxide as product and Nitrogen dioxide and Oxygen gases as by-products.
This Nitrogen dioxide {tex}NO_2{/tex} is a brown coloured gas will be evolved from the reaction after it gets processed.
The composition of the Lead Nitrate is {tex}Pb(NO_3)_2{/tex}.
The reaction is:
{tex}2Pb(NO_3)_2 \rightarrow 2PbO + 4NO_2 + O_2{/tex} (in presence of heat).
Posted by Lavish Kumar 5 years, 11 months ago
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Dr. Shreyas Samarth 5 years, 11 months ago
Posted by ___ Alone _____ 5 years, 11 months ago
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Hargun Singh 5 years, 11 months ago
Shirin .Pvt 5 years, 11 months ago
Yogita Ingle 5 years, 11 months ago
Gregor Mendel chose pea plant because the garden pea is an ideal subject in the study of genetics for the following reasons:
(i)They grow quickly.
(ii)They have a short life-cycle.
(iii)They are easily self- and cross-pollinated and produces many offspring in one cross.
(iv)They have easily observed characteristics.
Posted by Anand Singh 5 years, 11 months ago
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Meghna Thapar 5 years, 10 months ago
Extraction of Metals:
Different methods are used for extracting metals belonging to category of highly reactive metals, moderately reactive metals and less reactive metals. This is because the extraction of a metal from its concentrated ore is essentially a process of reduction of the metal compound present in the ore. For example: Manganese metal is obtained by the reduction of its oxide with aluminium powder and not carbon. This is because carbon is less reactive than manganese. Carbon, which is a non-metal, is more reactive than zinc and it can be placed just above Zn in the reactivity series. Hence, carbon can reduce the oxides of zinc and all other metals below zinc to form metals. The reactivity of elements differs for different metals.
Extraction of Less Reactive Metals:
The less reactive metals are extracted by the reduction of their oxides by heat alone.
Example: Mercury (II) sulphide ore is roasted in air when mercury (II) oxide is formed. When this mercury (II) oxide is heated to about 300° C, it decomposes to form mercury metal.
Extraction of Moderately Reactive Metals:
The moderately reactive metals in the middle of the reactivity series are extracted by the reduction of their oxides with carbon, aluminium, sodium or calcium.
It is easier to obtain metals from their oxides (by reduction) than from carbonates or sulphides. So, before reduction can be done, the ore is converted into a metal oxide. The concentrated ores can be converted into metal oxides by the process of calcination or roasting.
Calcination is the process in which a carbonate ore is heated strongly in the absence of air to convert it into a metal oxide.
For example: When zinc carbonate is heated strongly in the absence of air, it decomposes to form zinc oxide and carbon dioxide.
Extracting Metals towards the Top of the Activity Series:
Metals high up in the reactivity series are very reactive. These metals have a strong affinity for oxygen. So, oxides of sodium, magnesium, calcium and aluminium cannot be reduced by carbon.
These metals are obtained by electrolytic reduction.
Posted by Rishant Rai 5 years, 11 months ago
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Meghna Thapar 5 years, 10 months ago
A switch is meant for the 'on-off' of the device. It is always connected to live wire so that the appliance could be connected to high potential point through the live wire. The neutral wire doesn't have any voltage until it is connected to the live wire. So, it is always better to cut off the supply which is given from the live wire.
Posted by Srishti Singh 5 years, 11 months ago
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Meghna Thapar 5 years, 10 months ago
When a ray of light passes through a prism, it bends towards the base of prism. The angle between incident ray and emergent ray is called angle of deviation.
Posted by Raginee Tiwari 5 years, 11 months ago
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Posted by Jhalak Saluja 5 years, 11 months ago
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Yogita Ingle 5 years, 11 months ago
- Each month egg is released by either of the ovary .
- The uterus walls becomes thick and spongy so as to receive the egg and nourish it.
- The walls surrounds with extensive network of blood.
- If The ovum fuses with sperm it leads to pregnancy otherwise if it does not fuses it breaks and come out with blood and mucus which is known as menstuation.
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Shwet Kumar Mishra 5 years, 11 months ago
1Thank You