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Ask QuestionPosted by Monika Sahu 5 years, 2 months ago
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A K47 5 years, 2 months ago
Posted by Vandana 🇮🇳 5 years, 2 months ago
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Gaurav Seth 5 years, 2 months ago
(i) Forelimb of human and bird are homologous organs. They have same structural design and developmental origin but they have different functions and appearance. Homologous organs help us to understand that the organism has evolved from a common ancestor. The more common characteristics the two species have, the more closely they are related.
(ii) Analogous organs are those organs design and developmental origin but have similar appearance and perform similar functions.
Example: The wings of birds and bats look similar but have different design in their structure. They have a common function of flying but their origins are not common. So, birds and bats are not closely related.
(iii) Fossils and their study is useful in knowing about the species which are no longer alive. They provide evidence and missing links between two classes. They are helpful in forming a sequence of organisms in the pathway of evolution. Thus, fossils have an importance in deciding evolutionary relationship. Archaeopteryx is a fossil bird. It had feathers, fused bones and beak which are exclusively bird structures. It also had some features which are found in reptiles, e.g. teeth in jaw, claws on free fingers and a long tail. This fossil provides a clue that birds have evolved from reptiles.
Posted by Aditya Shukla 5 years, 2 months ago
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Maniya Jain 5 years, 2 months ago
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Simran Shira 5 years, 2 months ago
Posted by Rajat Mahananda 5 years, 2 months ago
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Yogita Ingle 5 years, 2 months ago
Importance of soil for plant growth:
(a) Soil provides the base on which a plant can grow.
(b) Soil serves as reservoir of water for plants.
(c) Soil serves as reservoir of different minerals which are essential for growth of plants.
(d) Soil contains micro-organisms that can convert various substances into nutrients.
Posted by Karan Gupta 5 years, 2 months ago
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Maniya Jain 5 years, 2 months ago
Posted by Raphael Roy 5 years, 2 months ago
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Maniya Jain 5 years, 2 months ago
Meghna Thapar 5 years, 2 months ago
Advantages Of Sexual Reproduction Over Asexual Reproduction
- There is diversity in the genetic makeup of the individuals produced by sexual reproduction.
- Since both the parents are involved, the newly formed individuals have the attributes of both.
- Variations are more successful in sexual mode than in asexual one.
- The species produced by sexual reproduction survive more than those produced by asexual reproduction. This is because genetic variations help them to adapt to different environments.
Posted by Manswi Mishra 5 years, 2 months ago
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Maniya Jain 5 years, 2 months ago
Gaurav Seth 5 years, 2 months ago
The light ray will bend towards the normal because air is a rarer medium and water is a denser medium. Since light is travelling from rarer to a denser medium, So, it will bend towards the normal. The ray diagram to show the refraction of light from air to water is as follows:
Posted by Sakshi Kanwar 5 years, 2 months ago
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-_Màximūs_- .. 5 years, 2 months ago
Akanksha Giri 5 years, 2 months ago
Maniya Jain 5 years, 2 months ago
Yogita Ingle 5 years, 2 months ago
It should be cleaned before burning due to the following reasons:
- Magnesium very reactive element which rapidly reacts with oxygen in the air to form a white layer of magnesium oxide and this layer will not burn.
- To remove the Magnesium oxide layer from the ribbon which may prevent or slow down the burning of magnesium ribbon.
- Unwanted impurities deposited on the magnesium ribbon can be removed and only pure magnesium can be used for the reaction.
Md Faisal 5 years, 2 months ago
Posted by Aayush Raj 5 years, 2 months ago
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Gaurav Seth 5 years, 2 months ago
The common name of CaCl2 is calcium chloride.
It is one of the types of salts used on roads during winter to melt ice.
It is called De-icing salt.
It has a dust suppression property.
The second largest application of calcium chloride exploits hygroscopic properties and the tackiness of its hydrates.
It is A a concentrated solution that keeps a liquid layer on the surface of dirt roads, . which It helps in suppresses suppressing the formation of dust.
Posted by Lakhan Jee Madhav 5 years, 2 months ago
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Posted by Tejasvini S 5 years, 2 months ago
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Posted by Abhishek Kumar Choudhary 5 years, 2 months ago
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Sakshi Kanwar 5 years, 2 months ago
Posted by Monishka Mali 5 years, 2 months ago
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Yogita Ingle 5 years, 2 months ago
- Social problems
- Economic problems
- Environmental problems.
Solution to these problems would be adequate rehabilitation, compensation to the displaced persons and afforestation.
Posted by Sushant Sharma 5 years, 2 months ago
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Posted by Tanisha . 5 years, 2 months ago
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Posted by Shivdeep Singh 5 years, 2 months ago
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Srikarthik Josyula 5 years, 2 months ago
Parul . 5 years, 2 months ago
Gaurav Seth 5 years, 2 months ago
A simple Electric Motor :
An electric motor converts electrical energy into mechanical energy.
Principle: It works on the principle of the magnetic effect of the current. when a current-carrying conductor is placed in the magnetic field, it experiences a force and starts moving.
Working :
An electric motor, as shown is, consists of a rectangular coil ABCD of insulated copper wire. The coil is placed between the two poles of a magnetic field such that the arm AB and CD are perpendicular to the direction of the magnetic field. The ends of the coil are connected to the two halves P and Q of a split ring. The inner sides of these halves are insulated and attached to an axle. The external conducting edges of P and Q touch two conducting stationary brushes X and Y, respectively.
Current in the coil ABCD enters from the source battery through conducting brush X and flows back to the battery through brush Y. Notice that the current in arm AB of the coil flows from A to B. In arm CD it flows from C to D, that is, opposite to the direction of current through arm AB. On applying Fleming’s left-hand rule for the direction of the force on a current-carrying conductor in a magnetic field (see Fig. 13.13). We find that the force acting on arm AB pushes it downwards while the force acting on arm CD pushes it upwards. Thus the coil and the axle O mounted free to turn about an axis, rotate anti-clockwise. At half rotation, Q makes contact with the brush X and P with brush Y. Therefore the current in the coil gets reversed and flows along the path DCBA. A device that reverses the direction of flow of current through a circuit is called a commutator. In electric motors, the split ring acts as a commutator. The reversal of current also reverses the direction of force acting on the two arms AB and CD. Thus the arm AB of the coil that was earlier pushed down is now pushed up and the arm CD previously pushed up is now pushed down. Therefore the coil and the axle rotate half a turn more in the same direction. The reversing of the current is repeated at each half rotation, giving rise to a continuous rotation of the coil and to the axle.
The split ring helps in reversing the direction of current in the armature so that it rotates continuously in one direction.
Posted by Armaan Singh 5 years, 2 months ago
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Maniya Jain 5 years, 2 months ago
Tejasvini S 5 years, 2 months ago
Gaurav Seth 5 years, 2 months ago
The amount of urine is regulated by reabsorption of water through blood capillaries. The reabsorption takes place through tubules of nephrons which is a functional unit of kidney. Amount of urine depends on concentration of water converted into urine and amount of water into body thus maintains the neutral concentration of cell volume all over body.
Posted by Sahil Mourya 5 years, 2 months ago
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Gaurav Seth 5 years, 2 months ago
- Mendel conducted the experiments using <i>Pisum sativum </i>or pea plant.
- He selected homozygous tall (TT) and dwarf (tt) pea plants.
- He crossed the tall pea plant with the dwarf pea plant.
- It was observed that the F1 generation are all tall plants.
- Thus, it was concluded that the gene causing tallness is dominant while the gene causing dwarfness is recessive.
- The trait expressing itself in the hybrid is the dominant one.
- This experiment proves Mendel’s first law of inheritance.
- It states that when a pair of contrasting factors is brought in a hybrid, one factor inhibits the appearance of the other, one which inhibits is the dominant one and which is inhibited is recessive.
Posted by Sahil Yadav 5 years, 2 months ago
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Gaurav Seth 5 years, 2 months ago
Download CBSE class 10th revision notes for Chapter 2 Acids Bases and Salts in PDF format for free. Download revision notes for Acids Bases and Salts class 10 Notes and score high in exams. These are the Acids Bases and Salts class 10 Notes prepared by team of expert teachers. The revision notes help you revise the whole chapter in minutes. Revising notes in exam days is on of the best tips recommended by teachers during exam days.
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<a href="https://mycbseguide.com/blog/acids-bases-salts-class-10-notes-science/" ping="/url?sa=t&source=web&rct=j&url=https://mycbseguide.com/blog/acids-bases-salts-class-10-notes-science/&ved=2ahUKEwiE2M7JmrjsAhVOyjgGHe1dAGcQFjAAegQIBhAC" rel="noopener" target="_blank">Acids Bases and Salts class 10 Notes Science - myCBSEguide</a>
Posted by Sharandeep Singh Virk 5 years, 2 months ago
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Posted by Srimukil Arasi 5 years, 2 months ago
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Gaurav Seth 5 years, 2 months ago
Bile Juice
Bile is a digestive juice that is secreted by the liver and stored in the gallbladder. It has two important functions : assists with fat digestion and absorption in the gut and is a means for the body to excrete waste products from the blood.
Posted by Virender Singh 5 years, 2 months ago
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Yogita Ingle 5 years, 2 months ago
Uses of Washing Soda
- Washing soda is used for removing burnt-on grease from kitchen utensils.
- It is prominently used in soap, glass and paper industries.
- It also helps in the removal of permanent hardness of the water.
- It acts as a raw material in the manufacturing of various sodium compounds, for example, borax.
Uses of Baking Soda
- It is used in making soft and fluffy bread and cakes due to the production of carbon dioxide when it is heated or mixed in water.
NaHCO3 + H+ → CO2 + H2O + sodium salt of acid
- It is used for making soda-acid fire extinguisher.
- It is used as an ingredient in the manufacturing of antacids.
Posted by Mr. Intresting 5 years, 2 months ago
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Posted by Kritika Pathak 5 years, 2 months ago
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Pratyush Mallik 5 years, 2 months ago
Posted by Dipsikha Choudhary 5 years, 2 months ago
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Posted by Rahul Chowdhury 5 years, 2 months ago
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Sabari Krishna 5 years, 2 months ago
Rîtíkã Çhäûhāñ 5 years, 2 months ago
Gaurav Seth 5 years, 2 months ago
This is one of the chemical tests for carbon dioxide. That is called as lime water test. When lime (CaO) reacts with water it forms slaked lime . When the carbon dioxide is passing through the slaked lime solution, it turns milky when the calcium carbonate and calcium bicarbonate is formed.
The chemical reaction can be expressed as:
When calcium hydroxide is treated with carbon dioxide, the calcium carbonate and water is formed, then carbon dioxide is released.
Posted by Shivdeep Singh 5 years, 2 months ago
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Rîtíkã Çhäûhāñ 5 years, 2 months ago
Gaurav Seth 5 years, 2 months ago
ACQUIRED TRAIT: INHERITED TRAIT
1.Traits which are developed by the practice 1.the trait are obtain from the parents
2.they make changes in non reproductive cell 2.they make changes in reproductive cells
3.the do not get passed on to next genration 3.they can pass down to next generation
4.this do not bring any alteration in the gene 4.this bring alteration in the gene
5.EXAMPLE:tail of a rat,lion,etc 5.EXAMPLE:hair colour ,skin colour ,etc
Posted by Kanchana Ganga 5 years, 2 months ago
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Parul . 5 years, 2 months ago
Yogita Ingle 5 years, 2 months ago
pH is important in everyday life:
1. Existence of living beings
Organisms require a specific pH for their ideal growth and development. In the human body, all the physiological reactions take place in the pH of 7-7.8. The existence of aquatic plants, animals and microbes is at risk when acid rains mix with natural water bodies.
2. Digestion of food
The pH is important at different levels in the digestive system of the human body for the proper digestion of food. In the stomach, hydrochloric acid is secreted as food enters the stomach. It turns the pH of the stomach between 1 and 3. This pH is important for the activation of the enzyme pepsin, which helps in the digestion of protein in food.
3. Importance in soil
The pH of soil is a critical factor in the growth of crops and other plants. pH 6.5 to 7.3 is ideal for the growth of shrubs and crops. If the pH of soil is less than 6.5, lime is added to it to neutralise its acidity. Similarly, if the pH of soil is more than 7.3, gypsum is added to neutralise its basicity.
4. Stopping tooth decay
Teeth decay when the pH of the mouth falls below 5.5. Bacteria present in food and the mouth breakdown food particles left in the mouth and form acids. This results in lowering the pH of the mouth. Tooth powder and tooth paste which are used for cleaning of teeth are basic in nature. They neutralise the acid produced in the mouth and protect the teeth from decay.
5. Remedy for acidic effect of honeybee bite
When a honeybee bites, it inserts an acidic substance Melittin in our body. To get relief from it, an aqueous solution of a basic substance such as baking soda is applied around the place of bite. It helps to neutralise the acidic poison.
Posted by Harshraj Prajapat 5 years, 2 months ago
- 4 answers
Yogita Ingle 5 years, 2 months ago
Hydrochloric acid: It is the digestive fluid formed by the stomach during the process of digestion.
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Neha Great 5 years, 1 month ago
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