Kitab Nagri

Harmful Effects of Bacteria   i) Bacteria cause damage of food, clothes and other things in decaying process.   ii) Denitrifying bacteria damage the soil fertility.   iii) Bacteria cause many diseases in plants.   iv) Bacteria cause many diseases in cattle e.g. TB and anthrax.   v) Bacteria cause many diseased in man e.g.…

Advantages of Bacteria   i) Bacteria help to decompose the dead remains of organisms.   ii) Bacteria can add nitrogenous compounds in soil. In this way they improve the fertility of soil.   iii) Some bacteria are used in manufacturing butter, cheese and yogurt.   iv) Some bacteria are used in fibers, leather, coffee and…

Bacteria and their Classification   Discovery:   Leeuwenhoek discovered bacteria in 1697 for the first time.   Size and Shape:   Their size range is from lum to 1oum in length and 0.2um to lum in width. On the basis of shape bacteria has four types:   i) Rounded Cocci   ii) Rod like Bacilli…

Viruses & its Types in Biology   Virus is Latin word which means poison.   Discovery:   Viruses were discovered by lwanowsky in 1892 from infected leaves of tobacco.   Living or Non-living:   They have characteristics of living and non-living things. When they enter in the body of living organisms they reproduce like living…

Microorganisms in Biology   Some organisms are so small that they cannot be seen with naked eye. They can only be seen by electron microscope. Therefore they are called microorganisms Micro means small and organism means living things e.g. virus, bacteria.   In the settings, before starting a workout, you need to set the workout…

Definition of Species in Biology   A species can be defined as a group of organisms that can breed with one another in nature and produce fertile offspring.   At school, the load is growing, and even more unassimilated sections need to be tightened up in those subjects that will have to be passed in…

Basic Unit of Classification   The basic unit of classification is species.   Now, overloading with classes (or information boom) leads to the fact that the teenager sometimes just turns off. He does not hear the speech addressed to him, does not react to it. Those. a protective reflex is triggered, because in his head…

What is Analogy   The organs that are similar in function but different in basic structure are called homologous organs.   Stress-free exam It’s no secret that 9th graders (and not only students) live in terrible stress all year round. After all, for them the exam is the first serious test in life. Fear in…

What is Homology   The similarity in structure of organs of organisms because of common ancestoral origin is called homology.     Example:   Arm of a monkey, flipper of a whale and wing of a bat are homologous organs.   Here he will be taught to cope with his psychological state with the help…

Darwin’s theory of Common Descent   According to Darwin’s Theory of Common Descent, the organisms having common ancestory in the near pass would resemble one another very closely, while those having more distant common ancestory would show more differences.   And, in addition, in just 12 sessions, young people will master special exercises for their…