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Ask QuestionPosted by Pankaj R_S 3 years, 9 months ago
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Ashish Kumar Jha 3 years, 9 months ago
Posted by Tamanna Singh 3 years, 9 months ago
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Yogita Ingle 3 years, 9 months ago
Plasma membrane is a thin membrane that surrounds every living cell, separating it from the external environment around it. The plasma membrane consists of water-soluble substances like nucleic acids, proteins, carbohydrates. Typically, the plasma membrane defines the boundary of a cell. Apart from protecting the constituents of the cell, substances are exchanged through the surface of the plasma membrane.
The plasma membrane is composed of lipids and proteins that contribute to the functioning of the membrane. Even though the plasma membrane is the only barrier between internal components of the cell and the extracellular environment in some species. In some organisms, have an extra-barrier, apart from plasma membrane called the cell wall. Functions of plasma membrane include protection, selective permeability, cell signaling, endocytosis and exocytosis.
Posted by Sara Tonger 3 years, 9 months ago
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Posted by Pranjal Sharma 3 years, 9 months ago
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Yogita Ingle 3 years, 9 months ago
Mixtures which have uniform composition throughout are called Homogeneous Mixture. For example – mixture of salt and water, mixture of sugar and water, air, lemonade, soda water, etc.
Mixtures which do not have uniform composition throughout are called Heterogeneous Mixture. For example – mixture of soil and sand, mixture of sulphur and iron fillings, mixture of oil and water etc. The boundaries of constituent particles of a homogeneous mixture can be identified easily; as a homogeneous mixture has two or more distinct phases.
An alloy is a material composed of two or more metals or a metal and non metal. It may be a solid solution of the elements of single phase or a mixture of two or more metallic phases. Solid alloys give a single solid phase microstructure. Alloys are used where their properties are superior to those of pure component elements. Examples are steel,solder,brass,amalgam etc.
Posted by Pranjal Sharma 3 years, 9 months ago
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Pranjal Sharma 3 years, 9 months ago
Gaurav Seth 3 years, 9 months ago
ANSWER Na
Group one alkali metals are soft metals. Since, Na is an alkali metal so it is soft metal. Non-Metals are generally Soft
They can be easily cut with knife.
For Ex: Sulphur ,Phosphorus.
Posted by Pranjal Sharma 3 years, 9 months ago
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Gaurav Seth 3 years, 9 months ago
reduce the force exerted by the ball
He does this to increase the change in momentum time of the ball. This helps him to save himself from getting hurt by the ball.
While catching a fast moving cricket ball, a fielder in the ground gradually pulls his hand backward because by doing this, he increases the time in which the velocity of ball will become zero. Thus, the rate of change of momentum will be large and less force will be exerted by the ball on the hand of the fielder. Hence, he will not get injured by the ball.
Posted by World Wide Handsome💜 3 years, 9 months ago
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Ashmita Das 3 years, 9 months ago
Gaurav Seth 3 years, 9 months ago
Static. no work
Work is done when a force is applied on a body such that it causes displacement of the body in the direction of the force.
1. Man sitting on a bench is remaining static. Hence, no work is done.
2. The person standing with a basket of fruit on the head is also remaining stationary, no displacement is involved. Hence, no work is done.
3. Climbing a tree, the person is doing displacement against gravitational force. Hence, work is done.
4. Pushing a wheelbarrow requires some force and because of the force applied it moves. Hence, work is done.
Posted by Rengavadivelammal .C 3 years, 9 months ago
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World Wide Handsome💜 3 years, 9 months ago
Meghna Thapar 3 years, 9 months ago
According to WHO “Health is a state of complete physical, mental and social well-being and not merely the absence of disease or infirmity”. While the disease is the condition of abnormal dysfunction of the mental-physical states thus leading to illness. The length of time after treatment during which no disease is found. Can be reported for an individual patient or for a study population.
Posted by Tanuja Rana 3 years, 9 months ago
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Meghna Thapar 3 years, 9 months ago
A mixture of two miscible liquids having a difference in their boiling points more than 25 °C can be separated by the method of simple distillation.
The mixture of kerosene and petrol which are miscible with each other can be separated by distillation.
The mixture in a distillation flask and fit it with a thermometer. On heating the mixture slowly, we will observe that petrol vaporises first as it has a lower boiling point. It condenses in the condenser and is collected from the condenser outlet. Kerosene is left behind in the distillation flask.
Posted by Utkarsh Kesri 3 years, 9 months ago
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Gaurav Seth 3 years, 9 months ago
The total number of electrons present in oxygen is 8.
The distribution of electrons in oxygen atom is given by:
First orbit or K shell =2(2n2=2×11=2)
Second orbit or L shell =6(8−2=6)
Posted by Tamanna Pant 3 years, 9 months ago
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Yogita Ingle 3 years, 9 months ago
The cellular components are called cell organelles. These cell organelles include both membrane and non-membrane bound organelles, present within the cells and are distinct in their structures and functions. They coordinate and function efficiently for the normal functioning of the cell. A few of them function by providing shape and support, whereas some are involved in the locomotion and reproduction of a cell.
Posted by Satyam Kumar 3 years, 9 months ago
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Yogita Ingle 3 years, 9 months ago
Let R be the radius of semi-circular path as shown in figure.
Displacement in semi circular path = 2R
distance covered in semi circular path = πR
ratio of distance covered to displacement = π/2
Posted by Satyam Kumar 3 years, 9 months ago
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Sia ? 3 years, 5 months ago
speed of thief = 12 + 60 km/hr = 72 km/hr
speed of police = 80 km/hr
speed of thief w.r.t police = 72-80 km/hr = -8km/hr
Posted by Mukul Kalal 3 years, 9 months ago
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Nitin Tripathi 3 years, 9 months ago
Suraj Yadav 3 years, 9 months ago
World Wide Handsome💜 3 years, 9 months ago
Yogita Ingle 3 years, 9 months ago
A vaccine is an antigenic substance that develops immunity against a disease which can be delivered through needle injections or by mouth or by aerosol.
Vaccination is the injection of a dead or weakened organism that forms immunity against that organism in the body.
Posted by Madankumar Deshpande 3 years, 9 months ago
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Khushi Vats 3 years, 9 months ago
Gaurav Seth 3 years, 9 months ago
Explanation:
- The sum of the atomic mass of all atoms in the formula of the compound is called as formula unit mass.
- In the following atoms are present:
- Sodium (Na)
- Hydrogen (H)
- Carbon (C)
- Oxygen (O)
- The number of atoms present in the compound are as follows:
- Sodium (Na) - 1
- Hydrogen (H) - 1
- Carbon (C) - 1
- Oxygen (O) - 3
- Atomic mass of atoms present in the compound are as follows:
- Sodium (Na) - 1 (23)
- Hydrogen (H) - 1 (1)
- Carbon (C) - 1 (12)
- Oxygen (O) - 3(16) = 48
- The formula unit mass of = 23+1+12+48 = 84u
Yogita Ingle 3 years, 9 months ago
Formula unit mass of NaHCO3= Mass of Na+ Mass of H+ Mass of C+ Mass of O
=23 u+1 u+12 u+48 u
=84 u
Posted by Jatin Nehra 3 years, 9 months ago
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Yogita Ingle 3 years, 9 months ago
Heating the solution to dryness will not remove soluble impurities and crystals of very poor quality are obtained.
Posted by Jatin Nehra 3 years, 9 months ago
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Khushi Vats 3 years, 9 months ago
Gaurav Seth 3 years, 9 months ago
The S.I. unit of force is
<article id="post-1195251">The S.I. unit of force is Newton.
F = ma
1 Newton = 1 kg x 1 m/s2
</article>Posted by Hemanth Krishna 3 years, 9 months ago
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Gaurav Seth 3 years, 9 months ago
Monocotyledon | Dicotyledon |
The monocot embryos have a single cotyledon | The dicot embryos have a pair of cotyledons |
They have a fibrous root system | They have a tap root system |
Leaves in monocots have parallel venation | Leaves in dicots have reticulate or net venation |
In monocot flowers, the count of parts of the flower is a multiple of three or equal to three | The count of parts in a dicot flower is a multiple of four or five or equal to four or five |
The roots and stems of Monocotyledons does not possess a cambium and cannot increase in diameter | The roots and stems of Dicotyledons possess a cambium and have the ability to increase in diameter. |
A few examples of monocotyledons are garlic, onions, wheat, corn and grass | A few examples of dicots are beans, cauliflower, apples and pear |
Posted by Khiyati Dhillon 3 years, 9 months ago
- 2 answers
Nischay Kumar 3 years, 9 months ago
Gaurav Seth 3 years, 9 months ago
Work
When a force acts on an object and the object actually moves in the direction of force, then the work is said to be done by the force.
Work done by the force is equal to the product of the force and the displacement of the object in the direction of force.
If under a constant force F the object displaced through a distance s, then work done by the force
W = F * s = F s cos θ
where a is the smaller angle between F and s.
Work is a scalar quantity, Its S1 unit is joule and CGS unit is erg.
∴ 1 joule = 107 erg
Its dimensional formula is [ML2T-2].
Posted by David Kumbang 3 years, 9 months ago
- 2 answers
Gaurav Seth 3 years, 9 months ago
According to Archimedes principle, the weight of water displaced is equal to the weight of immersed part.For a solid floating in a liquid, its weight acting vertically down at its centre of gravity is equal to the weight of the liquid displaced by the immersed part of the solid acting vertically up at its centre of buoyancy. In the floating condition, the apparent weight and the apparent density of the solid are zero and the body is said to be weightless.
Yogita Ingle 3 years, 9 months ago
According to Archimedes principle, the weight of water displaced is equal to the weight of immersed part.For a solid floating in a liquid, its weight acting vertically down at its centre of gravity is equal to the weight of the liquid displaced by the immersed part of the solid acting vertically up at its centre of buoyancy. In the floating condition, the apparent weight and the apparent density of the solid are zero and the body is said to be weightless.
Posted by Tisha Patel 3 years, 9 months ago
- 1 answers
Yogita Ingle 3 years, 9 months ago
A force of 5 N gives a mass m1 an acceleration of 8ms−2 and a mass m2 an acceleration of 24 ms−2. What acceleration would it give if both the masses are tied together?
when a force of 5N gives an acceleration of 8ms-² to a body
then its mass = 5/8 kg = 0.62kg
so, m₁ = 0.6kg
when a force of 5N gives an acceleration of 20ms⁻² to a body
then its mass = 5/24 kg = 0.20kg
so, m₂ = 0.20kg
when the two bodies r tied total mass of the system bcomes = 0.82kg
so acceleration of the system will b = force/mass = 5/0.82 = 609 ms⁻²
Posted by Padmapriya M Shenoy 3 years, 9 months ago
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Khushi Vats 3 years, 9 months ago
Posted by Ritik Dahiya 3 years, 9 months ago
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Gaurav Seth 3 years, 9 months ago
Acute Diseases | Chronic Diseases |
These diseases occur suddenly. | They occur over a prolonged period. |
They last for a shorter period. | They last longer, even for a lifetime. |
They do not cause damage to the body. | They damage the body of the patient. |
They are not fatal. | Chronic diseases are fatal. |
Eg., common cold, jaundice, typhoid, malaria | Eg., HIV, Elephantiasis, Cancer, Tuberculosis |
Posted by Smitha Shaju 3 years, 9 months ago
- 1 answers
Gaurav Seth 3 years, 9 months ago
Sleeping sicknessd
Sleeping sickness is an infection caused by tiny parasites carried by certain flies. It results in swelling of the brain.
<section>Causes
Sleeping sickness is caused by two types of parasites Trypanosoma brucei rhodesiense and Trypanosomoa brucei gambiense. T b rhodesiense causes the more severe form of the illness.
</section>Posted by Satyam Singh Rajput 3 years, 9 months ago
- 3 answers
Khushi Vats 3 years, 9 months ago
Aiims Delhi Bhai Bhai 720 3 years, 9 months ago
Posted by Bhagwan Singh Rawat 3 years, 9 months ago
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Gaurav Seth 3 years, 9 months ago
As the disease affects the body, the functioning of body organs can be a concern, and medication needs which can cause side effects including allergies. There are certain diseases that can not be treated so the prevention is better than cure.
- When someone is ill, person body functions get weakened and can never fully recover.
- It takes time to cure a disease and the person is likely to be in bedridden for some time, even though adequate care is provided to him.
- The person with an infectious disease will serve as the medium for further spreading the infection to others.
Posted by Muralidharan Deepa 3 years, 9 months ago
- 2 answers
Khushi Vats 3 years, 9 months ago
Gaurav Seth 3 years, 9 months ago
Lysosomes
They are simple tiny spherical sac like structures evenly distributed in the cytoplasm.
Each lysosome is a small vesicle surrounded by a single membrane and contains enzymes.These enzymes are capable of distributing or breaking down all organic material.They are made of RER.
Posted by Bhoomika Chauhan 3 years, 9 months ago
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Gaurav Seth 3 years, 9 months ago
Answer.
a) Salivary glands secrete saliva along with enzymes.Ptyalin is the strach hydrolysing enzyme secreted by salivary glands in human beings. It is also called as salivary amylase. Ptyalin secreted in the mouth brings about digestion of starch in the mouth itself. It hydrolyses starch into disaccharaides like maltose and isomaltose and other small dextrins called as limit dextrins. Ptyalin hydrolyses at about 30 percent of the starch in the mout itself.
b) Gastric glands secrete HCL, pepsinogen, mucous.Gastric juice is a secretion of gastric glands located in the lining of the stomach. It is mainly made up of electrolytes, mucus, enzymes, hydrochloric acid, intrinsic factor etc. HCl secreted by parietal cells provides acidic medium for many enzymes to get activated. Neck cells secrete mucus which lubricated the passage of the food. Chief cells secrete pepsinogen which helps in the digestion of proteins after getting activated into pepsin by HCl. Enzymes of the gastric juice bring about digestion of different components of the food. Gastric lipase helps in emulsification of lipids in the stomach. Partially digested food in the stomach is called as chyme and this passes on into small intestine
c) Intestinal glands are present in the inner lining of small intestine. These secrete various enzymes which aid in the process of digestion of all the components of food. Maltase, sucrase and lactase bring about digestion of carbohydrates. Peptidases help in digestion of proteins. Enterokinase helps in the activation of other enzymes
d) Liver is the largest gland in our body. The liver secretes a yellowish green watery fluid called bile. It is temporarily stored in a sac called the gall bladder. Bile provides an alkaline environment for many enzymes to get active. It also reduces the acidity of chyme. Bile plays an important role in the digestion of fats. Bile is sent into duodenum through a narrow tube-like structure called the bile duct. Bile breaks the larger fat molecules into tiny droplets, thereby increasing their surface area, which helps in the digestion of fats easily.
e) Pancreas is the mixed gland. It acts as both endocrine and exocrine gland. The pancreas secretes the pancreatic juice that helps to digest carbohydrates, proteins and fats. The pancreatic juice converts carbohydrates into simple sugars and glucose, proteins into amino acids, and the lipids into fatty acids and glycerol. Trypsin and chymotrypsin help in the digestion of proteins.
Posted by Jd Sharma 3 years, 7 months ago
- 1 answers
Yogita Ingle 3 years, 9 months ago
- The muscular tissues are connected to the same nerve bundles.
- The nerve impulse from the brain tells the muscles to contract.
- Each muscle cell contains the proteins actin and myosin. These proteins slide past one another when the signal is received for contraction.
- A single cell contracts up to 70% in length. The entire muscle shortens during contraction.
- Muscular tissues help in the movement of bones, squeeze different organs, or compress chambers.
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Gaurav Seth 3 years, 9 months ago
In 1911, Rutherford performed the gold foil experiment. He bombarded a stream of a-particles on a gold foil, a thin sheet which was 0.00006 cm thick in an evacuated chamber. An a-particle is a positively charged helium ion (He +).
Most of the a-particles passed straight through the foil without any deflection. This concluded that most of the space inside of an atom is empty.
(ii) A few particles were deflected through small angle and few through larger angles. This happened due to positive charge on particles and core (nucleus) of the atom. The heavy positively charged 'core' was named as nucleus.
(ii) The number of particles which bounced back was very small. This concluded that the volume of the nucleus is very small in comparison to the total volume of the atom. On the basis of gold foil experiment, Rutherford concluded that an atom consists of nucleus which has positive charge and it is surrounded with electrons which are moving around the nucleus. The number of electrons and protons are equal and the entire mass of the atom is concentrated at its nucleus. Drawbacks in the Rutherford's model
(i) According to classical electro-magnetic theory, a moving charged particle, such as an electron under the influence of attractive force loses energy continuously in the form of radiations. As a result of this, electron should lose energy and therefore, should move in even smaller orbits ultimately falling into the nucleus. But the collapse does not occur. There is no explanation for this behavior.
(ii) Rutherford did not specify the number of orbits and the number of electrons in each orbit.
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