Q1. Which one is the most important human activity leading to extinction of wildlife?
(a) Alteration and destruction of the natural habitats.
(b) Hunting for commercially valuable wildlife products.
(c) Pollution of air and water.
(d) Introduction of alien species.
Biology - Human Health and Diseases
Following are the diseases that can affect the circulatory system:
⑴ Hypertension:
It is the most common disease affecting the heart and blood vessels. A blood pressure of 120/80 mmHg is considered normal. But the increase in blood pressure beyond 140 mmHg (systolic) and 90 mmHg (diastolic) is called high blood pressure (hypertension). A diet full of oily food is known to increase cholesterol levels, causing thickening of the arteries which results in high blood pressure. Tobacco smoking increases the heart rate, contracts blood vessels and raises blood pressure. High blood pressure can harm the heart, brain, kidneys and eyes.
Q1: Which of the following statements is wrong for viroids?
(a) They cause infections.
(b) Their RNA is of high molecular weight.
(c) They lack a protein coat.
(d) They are smaller than viruses.
Topics Covered: Work, Power and Energy
Q1: A bullet is fired from a rifle, If the rifle recoils freely, then the kinetic energy of the rifle will be:
(a) same as that of bullet
(b) more than that of bullet
(c) less than that of bullet
(d) none of these
Q2: A body of mass 2 kg, initially at rest, is acted upon simultaneously by two forces, one of 4N and the other of 3N, acting at right angles to each other. The work done by the body after the 20s is
(a) 500 J
(b) 1250 J
(c) 2500 J
(d) 5000 J
Salts/Compounds Colour
1. Potassium dichromate, K₂Cr₂O₇ Orange
2. Potassium permanganate, KMnO₄ Violet
3. Ferric tetra-oxide, Fe₃O₄ Black
4. Ferrous sulphate, FeSO₄.7H₂O Green
5. Ferric sulphate, Fe₂(SO₄)₃ Yellow
6. Ferric hydroxide, Fe(OH)₂ Green
(General Science)
2. Which Vitamin is known as the anti-infetive vitamin
3. Which Vitamin is used for ELISA test (AIDS)?
4. Which Vitamin contains Cobalt?
Structure of Atom
1. Discovery of Electron — Discharge Tube Experiment:
In 1879, William Crooks studied the conduction of electricity through gases at low pressure. He performed the experiment in a discharge tube which is a cylindrical hard glass tube about 60 cm. in length.
Mass of electron = 9.109534 x 10⁻³¹ kg
Charge on a electron = (-) 1.602 x 10⁻¹⁹ C
2. Properties of Cathode Rays
(i) Cathode rays travel in straight line.
(ii) Cathode rays start from cathode and move towards the anode.
For Class 11/Class 12 Physics - NEET - JEE
Physics deals with the study of the basic laws of nature and their manifestation in different phenomena. The basic laws of physics are universal and are applied in widely different contexts and conditions. Physics is a basic discipline in the category of natural sciences which also includes other disciplines like Chemistry and Biology. The word physics comes from a Greek word meaning nature.
Here is a partial list of Physicists and their contributions in various fields of physics.
1. Swedish botanist Carolus Linnaeus established binomial nomenclature.
2. Caper Bauhin expressed proposed binomial nomenclature for the first time
3. In binomial nomenclature, the first word is a generic name having first letter capital and second word is a specific epithet having first letter. e.g. Homo sapiens, Mangifera indica
4. After end of biological name, the name of author is written in abbreviated form who gave the name to that organism.
5. Both the words of a biological name when handwritten are separately underlined and when printed are typed in italics to indicate their Latin origin and also give respect to the name.
CBSE Class 11 Biology - The Living World
Q1: Do five kingdom classification include viruses, viroids and lichens?
Answer: Five kingdom system of classification do not includes Virus, Viroids and Lichens.
Q2: What is a virus? What is its structure?
Answer: Viruses are non-cellular organisms having inert crystalline structure outside the living. A virus is a small particle consisting of a nucleic acid core surrounded by a protein coat; in order to reproduce, a virus must infect a living cell.
Topics Covered: Laws of Motion, Circular Motion
