Ask questions which are clear, concise and easy to understand.
Ask QuestionPosted by ?? Thakur 06 ???? 5 years, 10 months ago
- 2 answers
Yogita Ingle 5 years, 10 months ago
- Atomic number of an element is numerically equal to the number of electrons round the nucleus.
- The number of electrons in turn is equal to the number of protons in the nucleus.
- Atomic number is a more fundamental property of an element than its atomic mass because when the elements are arranged in the increasing order of their atomic number, most of the defects of Mendeleev's classification get rectified.
Posted by Abhiraj Dhiman 5 years, 10 months ago
- 1 answers
Yogita Ingle 5 years, 10 months ago
Gene
A gene is a section of DNA which is involved in carrying information for a particular trait. They are functional units of heredity and are made of DNA.Genes are responsible for the hereditary and this is the reason why we all have similar characteristics of both the parents like the pigmentation of the eye, hair color, etc. There are about 29 to 30 thousands of genes in every cell of the human body. The term gene was first coined in the year 1909 by a Danish botanist Wilhelm Johannsen.
Chromosomes
Chromosomes are thread-like structures merged together and are made of proteins and a single molecule of deoxyribonucleic acid – DNA. They are mainly found inside the nucleus of both animal and plant cells. They are passed to offspring from their parents, over generations. The term chromosome is derived from the Ancient Greek word meaning coloured body. Every human cell contains 46 or 23 pairs ofchromosomes. These chromosomes play an important role in cell division process and ensure that DNA molecules are copied and distributed evenly.
Posted by Abhishek De 5 years, 10 months ago
- 4 answers
Posted by Mia Rode 5 years, 10 months ago
- 0 answers
Posted by G Kaur 5 years, 10 months ago
- 2 answers
Yogita Ingle 5 years, 10 months ago
Hydrogen Peroxide or H2O2 is a highly reactive compound which gets dissociated in the presence of light to form water and oxygen.
To prevent this dissociation reaction, H2O2 is stored in coloured bottles to prevent light from entering the bottles.
Aditya Pawar 5 years, 10 months ago
Posted by Saurabh Kumar 5 years, 10 months ago
- 1 answers
Meghna Thapar 5 years, 10 months ago
- Reaction of Metals with Water: Metals react with water to produce metal oxides with the release of hydrogen gas. But all metals do not react with water.
Metal + Water → Metal oxide + Hydrogen
Metal oxides that are soluble in water dissolve in it to further form metal hydroxide.
Metal oxide + Water → Metal hydroxide
Metals such as sodium and potassium react vigorously with cold water to lead to evolution of hydrogen, which immediately catches fire producing a large quantity of heat.
2Na + 2H2O → 2NaOH + H2 + Heat
2K + 2H2O → 2KOH + H2 + Heat
Metals such as aluminium, zinc and iron do not react with cold or hot water, but they react with steam to form metal oxides and hydrogen.
2Al + 3H2O → Al2O3 + 3H2 + Heat
3Fe + 4H2O → Fe3O4 + 4H2 + Heat
- Reactions of Metals with Acids: Metals react with acids to form salt and hydrogen gas.
Metal + Dilute acid → Salt + Hydrogen
Metals react with dilute hydrochloric acid to give metal chloride and hydrogen gas. Example - Magnesium reacts violently with dilute hydrochloric acid to form magnesium chloride and hydrogen.
Mg + 2HCl → MgCl2+ H2
Metals react with sulphuric acid to form metal sulphate and hydrogen gas.
Fe + H2SO4 → FeSO4+ H2
Posted by Tanmayee Deshpande 5 years, 10 months ago
- 2 answers
Yogita Ingle 5 years, 10 months ago
Brisk effervescence is defined as the rapid or vigorous evolution of a gas in a chemical reaction. For example, when hydrochloric acid is added to sodium bicarbonate, bubbles of carbon dioxide gas are formed vigorously.
Posted by Nancy Dewangan 5 years, 10 months ago
- 1 answers
Aditya Pawar 5 years, 10 months ago
Posted by Vipin Semwal 5 years, 10 months ago
- 2 answers
Yogita Ingle 5 years, 10 months ago
The sun is located near the horizon of the earth during sunrise and hence light travels a longer distance through the earth's atmosphere. the particles that are suspended in the air scatter the light of shorter wavelength like the blue colour. the light that reaches the earth is of longer wavelength that is red.t has it appears red.
This phenomenon will not be observed by an astronaut because on the moon there is no atmisphere. hence there will not be any scattered light and it will appear dark.
Posted by Vipin Semwal 5 years, 10 months ago
- 2 answers
Varun Saini 5 years, 10 months ago
Yogita Ingle 5 years, 10 months ago
Placenta is a special tissue connection between embryo and uterine wall. It acts as an endocrine gland.
Role of placenta:
- It possesses villi that increase the surface area for absorption of nutrients.
- Facilitates passage of nutrition and oxygen to embryo from mother through blood.
- Waste substances produced by embryo are removed through placenta into mother’s blood.
Posted by Manav Agrawal 5 years, 10 months ago
- 1 answers
Yogita Ingle 5 years, 10 months ago
The front and rear (or back) focal planes are defined as the planes, perpendicular to the optic axis, which pass through the front and rear focal points. An object an infinite distance away from the optical system forms an image at the rear focal plane. For objects a finite distance away, the image is formed at a different location, but rays that leave the object parallel to one another cross at the rear focal plane.
Posted by lumb****@***** 5 years, 10 months ago
- 2 answers
Rajat Dubey 5 years, 10 months ago
Yogita Ingle 5 years, 10 months ago
DNA or Deoxyribonucleotide is the basis of genetic mechanism. Genes are the specific parts of chromosomes or Deoxyribo Nucleic Acid (DNA) segments which determine the hereditary characteristics.
Importance of DNA copying in reproduction:
- DNA copying mechanism is extremely necessary for reproduction as copying of DNA helps in transfer of information or characters from parents to offspring.
- It also generates variations during sexual reproduction. This variation leads to evolution.
- DNA copying is also necessary because DNA (Deoxyribonucleic acid) is the genetic material found in chromosomes, which are present in the nucleus of a cell.
- DNA determines the body design of an individual. It carries the genetic information and key for the production of every type of cell proteins, which control the function of living organisms.
- DNA copying also helps in proper survival of the organism by similar copying and variation during DNA copying leads to evolution.
Posted by Sumit Singh 5 years, 10 months ago
- 2 answers
Yogita Ingle 5 years, 10 months ago
Excretion in plants occurs through various means -
1. Excess water is removed through stomata by transpiration which is the process of removal or evaporation of water.
2. Plants also get rid of oxygen, a by - product in the process of photosynthesis and carbon dioxide which is the by - product formed during respiration. The plants get rid of these by stomata present in their leaves.
3. Some of the wastes stored in the leaves are removed by the detachment of the leaves itself from the tree.
4. Waste are also stored in the cellular vacuoles which do not affect the functioning of cytoplasm because of its outer membrane known as tonoplast.
5. Other waste products are stored in resins and gums, especially in old xylem which stops working thereby.
Posted by Aryan Chahal 5 years, 10 months ago
- 1 answers
Yogita Ingle 5 years, 10 months ago
National Parks are allowed to remain in their pristine form because they contain highest biological diversity, natural habitats for many wild animals, flora and fauna. Their primary use is to conserve biodiversity and protection of many wild and endangered species. National parks are established under International Union for Conservation of Nature (IUCN) as category II protected areas. National parks are essential for maintaining the ecosystem. National parks are having influence on cultural heritage, health, and social prosperity.
Posted by Avika Goel 5 years, 10 months ago
- 4 answers
Posted by Shreya Kothari 5 years, 10 months ago
- 1 answers
Astha Chaudhari 5 years, 10 months ago
Posted by Avika Goel 5 years, 10 months ago
- 2 answers
Nikhil Sharma 5 years, 10 months ago
Diksha ? 5 years, 10 months ago
Posted by Diksha ? 5 years, 10 months ago
- 20 answers
Tanish Chimaniya 5 years, 10 months ago
Broken Buddy 5 years, 10 months ago
Posted by Riddhi Jain 5 years, 10 months ago
- 1 answers
Tanish Chimaniya 5 years, 10 months ago
Posted by Priya Verma 5 years, 10 months ago
- 1 answers
Posted by Puia Khiangte 5 years, 10 months ago
- 2 answers
Nikhil Sharma 5 years, 10 months ago
Neha Kothari 5 years, 10 months ago
Posted by Yash Preet 5 years, 10 months ago
- 1 answers
Posted by Neha Saini 5 years, 10 months ago
- 1 answers
Posted by ?? Thakur 06 ???? 5 years, 10 months ago
- 5 answers
Rani Mishra ??? 5 years, 10 months ago
Dr. Sanskari ?⚕️?⚕️ 5 years, 10 months ago
Posted by Anshika - 5 years, 10 months ago
- 3 answers
Rashmi Sharma 5 years, 10 months ago
?? Thakur 06 ???? 5 years, 10 months ago
Dr. Sanskari ?⚕️?⚕️ 5 years, 10 months ago
Posted by Anshika - 5 years, 10 months ago
- 5 answers
Rashmi Sharma 5 years, 10 months ago
Rashmi Sharma 5 years, 10 months ago
Shreya .... 5 years, 10 months ago
Posted by Sumitcool Coolsharma 5 years, 10 months ago
- 2 answers
Anshika - 5 years, 10 months ago
?? Thakur 06 ???? 5 years, 10 months ago
Posted by Aman Raj 5 years, 10 months ago
- 1 answers
myCBSEguide
Trusted by 1 Crore+ Students
Test Generator
Create papers online. It's FREE.
CUET Mock Tests
75,000+ questions to practice only on myCBSEguide app
Shreya Dubey 5 years, 10 months ago
1Thank You