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Definition: The term “biodiversity” has been derived from ‘bio’ and ‘diversity ’. “Diversity” means variety within a species and among species.  Biodiversity is a measure of the variety of organisms present in  different ecosystems. The diversity of plants’ (flora) and animals’ (fauna) in a region depends on climate, altitude, soils and the presence of other species. Biodiversity is not distributed evenly on Earth. Importance of biodiversity Biodiversity provides food for humans.  Drugs are derived, directly or indirectly, from biological sources.   Industrial materials e.g. building materials, fibres, dyes, resins, gums, adhesives, rubber and oil are derived directly from plants. Biodiversity plays important role in making and maintaining ecosystems.  It plays a part in regulating the chemistry of our atmosphere and water supply. Biodiversity is directly involved in recycling nutrients and providing fertile soils. Classification - Aims And Principles bio...

“A species is a group of organisms which can interbreed freely among them and produce fertile offspring, but are reproductively isolated from all other such groups in nature.”  In the definition of species we must emphasize “in nature” because two organisms related to two different but closely related species can cross-breed under artificial conditions. Carolus Linnaeus divided nature into three kingdom s: mineral, vegetable and animal .  Linnaeus used five ranks in classification: class, order, genus, species, and variety .  Linnaeus is best known for his introduction of the method still used to formulate the scientific name of every species i.e. binominal nomenclature . Oldest system  classifies all organisms into two kingdoms i.e. Plantae ( organisms that can prepare food from simple inorganic materials and thus can store energy, are autotroph) and Animalia( organisms that cannot synthesize their food and depend on autotrophs or others are heterotrophs ...

The Shapes of Molecules (VSEPR Theory)  The shapes of molecules are  predicted and rationalize by  Va l ence  Sh ell Electron Pair Repulsion (VSEPR) theory .  The theory is based on minimizing the electrostatic repulsion between electron pairs, as first proposed by Sidgwick and Powell in 1940,   then generalized by Gillespie and Nyholm in 1957. Determine the number of lone pairs on the central atom in the molecule, and add the number of bonded atoms (a.k.a. bonding domains) the  steric number  defines the electronic shape of the molecule by minimizing repulsion. For example a steric number of three gives a trigonal planar electronic shape. The angles between electron domains are determined primarily by the electronic geometry (e.g., 109.5° for a steric number of 4, which implies that the electronic shape is a tetrahedron) These angles are adjusted by the hierarchy of repulsions: (lone pair - lone pair) > (lone pair - bond) > (bond - bond)

Here you go students an easy way to memories parts of your brain ,its basic structure . The  CNS   ( central nervous system ) is comprises of the brain and the spinal cord. The  PNS   ( peripheral nervous system ) comprises of  the spinal nerves that branch from the spinal cord and cranial nerves that branch from the brain. The brain have three parts  cerebrum :  composed of right and left hemispheres. It performs functions like interpreting touch, vision and hearing, as well as speech, reasoning, emotions, learning, and fine control of movement. cerebellum :  function is to coordinate muscle movements, maintain posture, &balance. brainstem  : connecting the cerebrum and cerebellum to the spinal cord. It performs many automatic functions such as breathing, heart rate, body temperature, wake and sleep cycles, digestion, sneezing, coughing, vomiting, and swallowing. The cerebrum is divided into four lobes:  frontal ,  parietal ,...

 INTRODUCTION TO BIOINFORMATICS Over the past few decades rapid developments in genomics and other molecular research technologies and, advancement in information technologies have combined to produce a tremendous amount of information related to molecular biology.  Bioinformatics is an evolving, interdisciplinary field of biology. Bioinformatics is the somewhat new and rather unfortunate term that is commonly employed for referring to the use of computers in biological research.  Bioinformatics is the application of mathematics/statistics and computer to the field of molecular biology. It is the name given to these mathematical and computing approaches used to glean understanding of biological processes.  The term bioinformatics was coined by Ben Hesper and Paulien Hogeweg in 1978 for the study of informatic methods in biological systems. Its primary use since the late 1980s has been in genetics & genomics, mainly in large-scale DNA sequencing area of genomics....

Study Of Malaria - An Example Of Biological Method    malaria is a common disease in many countries including Pakistan.   history  :In ancient times (more than 2000 years ago), physicians were familiar with malaria. They described it as a disease of chills and fevers with recurring attacks. They also observed that the disease was more common among people living in low, marshy areas. It was thought that the stagnant water of marshes poisoned the air and as a result of breathing in this “bad air”, people got malaria. This belief led to the name of this disease. The Italian words “mala” means bad and “aria” means air. For further clarification of the observation, some volunteers drank stagnant water from the marshes. They did not develop malaria. In the 17th century when the New World (America) was discovered, many plants from America were sent back to Europe to be used as medicines. The bark of a tree known as quina-quina was very suitable for curing fevers. It...

          Science is the systemized knowledge derived from observations and experiments.  These  experiments are carried out to determine the principles about how nature operates. Scientists like chemists, biologists and physicists use the same scientific method to make and test new theories. In this chapter, we will study the steps of biological method. We will study malaria as an example to understand the steps in detail. 2.1 Biological Method Questions about living things have provided problems that man has investigated to aid his own survival and to satisfy his desire to know. The scientific method in which biological problems are solved, is termed as biological method . It comprises the steps a biologist adopts in order to solve a biological problem. Biological method has played an important part in scientific research for almost 500 years. From Galileo’s experiment (in the 1590s) to current research, the biological method has contributed to...

  Chapter 1|Biology 9th Class for FBISE &RBISE The detail topic by topic explanation of chapter 1 with PowerPoint slide notes for students of grade 9. CHAPTER – 1 Introduction to Biology Science: Our universe operates under certain principles. For understanding of these principles, the experiments are done and observations are made; on the basis of which logical conclusions are drawn. Such a study is called “Science”. In brief science is the knowledge based on experiments and observations. Biology: The Scientific study of living organisms is called Biology. The word biology is derived from two Greek words “bios” meaning life and “logos” meaning thought, discourse, reasoning or study. It means that all aspects of life and every type of living organism are discussed in biology. Branches of Biology: Biology is divided into following branches: Morphology: The study of form and structure of living organisms is called morphology. It can be further divided into following two part...