Biology Textbook for Class 9 - Sindh Textbook Board PDF

THE TEXTBOOK OF BIOLOGY 9 For Class Sindh Textbook Board, Jamshoro  THE TEXTBOOK OF BIOLOGY For Class 9 Sindh Textbook Board, Jamshoro  All rights are reserved with the SINDH TEXTBOOK, BOARD, JAMSHORO. Prepared by Association For Academic Quality (AFAQ) for Sin...

THE TEXTBOOK OF BIOLOGY 9 For Class Sindh Textbook Board, Jamshoro  THE TEXTBOOK OF BIOLOGY For Class 9 Sindh Textbook Board, Jamshoro  All rights are reserved with the SINDH TEXTBOOK, BOARD, JAMSHORO. Prepared by Association For Academic Quality (AFAQ) for Sindh Text Book Board Reviewed by Directorate of Curriculum Assessment and Research Sindh, Jamshoro Prescribed by the Board of Intermediate and Secondary Education Hyderabad, Sukkur, Larkana, Mirpurkhas and Karachi for Secondary School Examination. Approved by the Education and Literacy Department, Government of Sindh. No.SO(G-III) SELD/3-910/2019 Dated 21-10-2019 for the province of Sindh Patron in Chief Agha Sohail Ahmed Chairman, Sindh Textbook Board. Managing Director Project Director Shahid Warsi Khwaja Asif Mushtaq Association for Academic Quality (AFAQ) Association for Academic Quality (AFAQ) Project Manager Patron in Chief Rafi Mustafa Agha Sohail Ahmed Association for Academic Quality (AFAQ) Association for Academic Quality (AFAQ) AUTHORS REVIEWERS Prof. Dr. Nasir uddin Sheikh Prof. Dr. Basir Ahmed Arain Prof. Muhammad Saleem Mughal Prof. Dr. Nasir uddin Sheikh Prof. Dr. Altaf Ahmed Simar Prof. Muhammad Saleem Mughal Prof. Dr. Zahid Ahmed Shaikh Mr. Piaro Khan Saharan Ms. Samreen Arain Mr. Muhammad Qasim Qureshi Mr. Daryush Kafi Sayed Saleh Muhammad Shah EDITORS Technical Assistance Prof. Dr. Nasir uddin Sheikh Mr. Nazir Ahmed Shaikh Prof. Muhammad Saleem Mughal Mr. M. Arslan Shafaat Gaddi Composing Designing & Illustration Association For Academic Quality (AFAQ) Printed at:  CONTENTS CHAPTER CHAPTER NAME PAGE NO. CHAPTER 1 INTRODUCTION TO BIOLOGY 1 CHAPTER 2 SOLVING A BIOLOGICAL PROBLEM 18 CHAPTER 3 BIODIVERS1TY 29 CHAPTER 4 CELLS AND TISSUES 51 CHAPTER 5 CELL CYCLE 92 CHAPTER 6 ENZYMES 107 CHAPTER 7 BIOENERGETICS 118 CHAPTER 8 NUTRITION 138 CHAPTER 9 TRANSPORT 174  PREFACE The century we have stepped in, is the century of Biology. The modern disciplines Biology are strongly influencing not only all the branches of science but each and every aspect human life. To keep the students. abreast with the recent knowledge, it is a must that the curricula, at all the levels, be updated regularly by introducing the rapid and multidirectional development taking place in all the branches of Biology. The recent book of Biology for class IX has been written in this preview and in accordance with the revised curriculum prepared by Ministry of Education, Govt of Pakistan, Islamabad reviewed by independent team of Bureau of Curriculum, Jamshoro sindh. Keeping in view of the importance of Biology, the topics have been revised and re-written according to the need of the time. Since long Biology was teaching only in IX class, the text book was consits of 19 chapters which was unable to complete in working hours. it has been decided now the Biology syllabus will be divided into portions, one should teach in 9th class and other will teach 10th class. So this book is consist of 9 chapters which have been thoroughly revised and re-written to meet the requirement of the curriculum. Special emphasis has also been paid to the applied aspect including the biological problems of daily life. Attention has also been focused on the causes and preventive measures of the common disorders of the human body. Being agriculture country, the agriculture aspects and problems of country are also discussed. Among the new editions are the introductory paragraphs, information boxes, summaries and a variety of extensive exercises which I think will not only develop the interest but also add a lot to the ut ility of the book. The Sind Textbook Board has taken great pains and incurred expenditure in publishing this book inspite to its limitations. A textbook is indeed not the last word and there is always room for improvement. While the authors have tried their level best to make the most suitable presentation, both in terms of concept and treatment, there may still have some deficiencies and omissions. Learned teachers and worthy students are, therefore, requested to be kind enough to point out the short comings of the text or diagrams and to communicate their suggestions and objections for the improvement of the next edition of this book. In the end, I am thankful to our learned authors, editors and specialist of Board for their relentless service rendered for the cause of education. Chairman Sindh Textbook Board  Chapter 1 Major Concept In this Unit you will learn: Ø Introduction of Biology Ÿ Definition of Biology Ÿ Divisions and Branches of Biology Ÿ Relation of Biology with other sciences Ÿ Quran Instructs to reveal the study of life Ø The Levels of Organization  2 INTRODUCTION TO BIOLOGY INTRODUCTION Biology is a branch of natural sciences which deals with the study of living beings. It provides the knowledge about living organisms which differ from each other in shape, size, composition etc. The word biology comes from Greek language “Bios” meaning “live” and “Logos” meaning “thought or reasoning”. Thus biology meaning study of life. What is life? Life cannot be defined properly, but on the basis of life processes, it can be identified through following functions of living organisms. Digestion Respiration Metabolism Movement Growth Development Excretion Irritability Reproduction 1.1 Divisions and branches of Biology 1. Division of Biology: There are three major divisions of biology: (i) Zoology: The word Zoology is derived from Greek language, “Zoon” meaning animals and Logos meaning “study or knowledge”. It deals with the study of animals. (ii) Botany: The word Botany is taken from Greek language, “Butane” meaning plants and Logus meaning “study or knowledge”. It deals with the study of plants. (iii) Microbiology: It deals with the study of microscopic organisms such as Bacteria etc, which can be seen only with the help of microscope. BIOLOGY 3 2. Branches of Biology: Modern biology deals with the structure, function and many other descriptions of living things. Advance research during the 20th Century has led to the division of biology into specialized branches. Some important branches are defined below: (i) Morphology (Gr. morph; form, logos; discourse): The study of external form and structure of organisms. (ii) Anatomy (Gr. ana; part/up, tome; cutting): The study of internal parts of body of living organisms by cutting them open. (iii) Cell biology (L. cells, compartment, Gk. Bios= life; logos; discourse): The study of cell and its organelle. (iv) Histology (Gr. histos: tissue; logos, discourse): The study of structure of tissues of plant and animals. (v) Physiology (Gr. physis; nature, logos, discourse): The study about functions of living organisms. (vi) Taxonomy (Gr. taxis, arrangement, nomos: name): The study of the rules, principles, grouping and naming the living organisms. (vii) Genetics (Gr. genesis; descent, origin): The study of heredity, that is transferring of characters from parents to offspring. (viii) Developmental biology (Gr. embryon; embryo, logos, discourse): The study of formation and development of embryo. (ix) Environmental biology: The study of relationship between living organisms and non-living factors of environment and their effects on each other. (x) Paleontology (Gr. palaios; ancient, ontos; being, logos: discourse): The study of remote past organic life, with the help of fossils. (xi) Biotechnology: The study about techniques for manipulination of gene to bring the changes in structure and location of genes to achieve desireable characters is called biotechnology. (xii) Socio-biology (L. sociare; to associate,): The study of social behavior of living organisms. i.e interaction between themselves. (xiii) Parasitology (Gr. para; up): The study of parasites.  4 INTRODUCTION TO BIOLOGY (xiv) Pharmacology (Gr. pharmakon, drug;). The study about action of drugs. (xv) Molecular biology: The study of organic molecules which constitute cell and its organelles. 1.1.1 Relationship of biology with other sciences: Biology is a multidimensional subject and linked with other sciences. For example, the movement of animals follows the laws of motion in physics. Biology is considered as interdisciplinary science, which is related with other sciences. Some of these are mentioned below: Biophysics: It is a branch of physics, in which laws and techniques of physics are applied to explain the processes of life. The radiophysics branch where radioactive isotopes are used to trace the translocation of different materials within the organisms. Radio-labeling and carbon-dating also show some uses of radioactive isotopes in determining the age of fossils, uses of sound waves as ultrasound and laser technology show relation of physics with biology. Biomathematics/Biometry: The branch of mathematics which collects data of living organisms. It plays very important role in research. Biochemistry: It is branch of biology which deals with the study of molecules which form living organisms or cell and requires authentic knowledge about biology and chemistry to explain the synthesis of biomolecules and function of different molecules in the body of an organism. Biogeography: It deals with the distribution of different living organisms in different geographical regions of the world. Many living organisms are restricted to particular geographical regions due to environmental conditions. BIOLOGY 5 Bio-economics: This deals with the economically important organisms involved in production, e.g meat production, etc. are calculated for cost value and profit value. 1.1.2 Careers in biology: The career of student is subject to obtain a degree. The students, who have chosen the biology, they can plan to adopt some as a career in following fields: Medicine and Surgery: Medicine deals with diagnosis and treatment of diseases and surgery deals with repair, replacement or removal the affected organ. Agriculture: This deals with production of varieties of crops, fruit, vegetables, dairy products, etc. Pakistan being an agricultural country, it can play very important role. Horticulture: This is also part of agriculture, in which work is carried out for the development of new varieties of plants and their products. Forestry: Forests are the source of biodiversity of plants and animals of many kinds which live there. It is important in development of new forests as well as preservation of existing ones. Farming: In this profession, the development of different kinds of farms takes place, such as fish farm, cattle farm, poultry farm, etc. New technologies are used for the production of animals as source of meat and milk, leather, wool, etc. Animal husbandry: This profession is part of agriculture science. It deals with the care and breeding of animals which are beneficial for man.  6 INTRODUCTION TO BIOLOGY Fisheries: This profession deals with the increased quantity and quality of fish production. Fish is one of the best source of protein. Biotechnology: This is very important and sensitive profession. It deals with manipulation of gene to produce valuable chemical products, such as insulin, growth hormones, interferon, etc from bacteria as well as others. 1.1.3 Quran and Biology: The Almighty Allah has conveyed a great knowledge about the origin and characteristics of animals and plants through our Holy Book, the Quran. A few of Ayah are quoted as under: Allay Says; “We made every living thing from water”. (Surah: Ambia, Verse: 30) “And Allah has created every animal from water of them there are some that creep on their bellies, some that walk on two legs; and some that walk on four. Allah creates what He will Lo! Allah is able to do all things.” (Surah Al-Nur, Ayah-45) Here water is symbolized with the protoplasm as the basis of life and the vital power of protoplasm seems to depend on the constant presence of water. BIOLOGY 7 “And in the earth are neighboring tracks, vineyards and ploughed lands, and date-palms, like and unlike which are watered with one water. And we have made some of them to excel others in fruit. Lo! Here in verily are portents for people who have sense.” (Surah: Al-Ra'd, Ayah: 4) Here Allah has revealed some facts about plant growth and development. 1.1.4 Contribution of Muslim Scientists: The Muslim scientists have played great role in the development of biological science. They began experiments and observations from the first Century of Hijra. Following are some details about the important Muslim scientists, who made significant contribution towards the development of biology. 1. Jabir Bin Hayan (722-817 A.D): He was born in Iran. He worked in the field of chemistry but he also wrote a number of books on plants and animals. “Al-Nabatiat” and “Al- Haywan” are his two famous books on plants and animals, respectively. 2. Abdul Malik Asmai (741-828 A.D): He was great zoologist and wrote many books on animals like “Al- Kheil” on horse, “Al-Ibil” on camels, “Al-Shat” on sheep, “Al-Wahoosh” on wild animals and “Khalqul Insan” on the different parts of human body and their functions. 3. Bu Ali Sina (980-1037 A.D): He was greatest of all the Muslim scientists and considered as the founder of medicine. He is called as Avicenna in the west. He identified many diseases like tuberculosis, meningitis and other such inflammations. He also worked in the field of mathematics, astronomy, physics, paleontology and music. He wrote book like “Al-Qanoon” and “Fil Tib Al-Shafa”.  8 INTRODUCTION TO BIOLOGY 1.2 THE LEVEL OF ORGANIZATION Atom Oxygen (O) The levels of organization in living world are based on chemical foundation. All the living Molecule organisms are made up of cells and the Dioxide (O2) protoplasm of cell is the physical as well as Macromolecule chemical basis of life. These levels are as Phospholipid follows: Cell 1. Atomic level of organization: Clara Cell All the matter is made up of elements, Tissue which is composed of atom (a: not, form: cut). Epithelial Each atom is made up of sub-atomic particles, tissue such as electrons, protons and neutrons. Organ In nature, there are more than 100 kinds of Lung elements and among these 16 elements are Organ System called as bio-elements, which are vital for life. Respiratory Only six elements such as C, H, O, N, S and P System are called basic elements of life. Organism 2. Molecular level of organization: Panthera leo (Lion) Molecules are formed by the binding of Population atoms. These organic molecules of cells are Pride of called as bio-molecules. These are constructed Lions in great variety and complexity. They are Community classified as micro-molecules and macro- molecules. Lions and Zebras Glucose, amino acid and fatty acids are Ecosystem micro-molecules, where as carbohydrates, Lions, Zebras, proteins and lipids are macro-molecules. The and the Environment units of micro-molecules combine together to Biosphere form macro-molecules. Life on Earth Fig: 1.1 Levels of organization BIOLOGY 9 3. Cellular level of organization: The biomolecules when work together in the form of suspension, It is called Protoplasm. Protoplasm is the combination of organic and specific inorganic substances. When protoplasm work in the form of a unit, this is called Cell. Cell is the basic unit of living organisms. When similar type of cells organize together in a group, called tissues. The different types of tissues arranged in a particular manner to work together are called Organs. Organs of different types work in a co-ordinated manner to perform a function is called Organ-system. When different organ-system function in co-ordination in as a unit, they form a body or Multicellular Organism. 4. Taxonomic level: There is another level of organization which is related with living organisms. The Species is the smallest unit of taxonomic level of organization, which includes morphologically similar living organisms which inter-breed and produce fertile offspring. 5. Population level: All the members of a species, living in specific habitat are called Population. A group of parrots living on tree, is called parrot population. 6. Community level: The members of different species living in specific habitat are called as Community. A group of different kind of birds, living on tree, is called as bird community. 7. Ecological system: Communities always depends upon their non-living environment in a reciprocal interaction for their survival. For example oxygen for respiration is obtained from environment and in turn given out CO2. This interaction is called Ecosystem or Ecological system. 8. Biosphere level: The part of earth where life exists is called biosphere. It consists of different kinds of eco systems.  10 INTRODUCTION TO BIOLOGY 1.2.1 Unicellular Organizations: All single cell organisms carry out all activities of life. They digest the food, respire, excrete, move etc on the cellular base by simple methods. Bacteria, Amoeba, Paramecium and Euglena are common examples of unicellular organisms. 1.2.2 Colonial Organization: Many unicellular organisms live together by forming colonies but do not have any division of labor among them. In colonial type of cellular organization, each unicellular organism lives its own life, they are not dependent on each other and never form any multicellular structure. Volvox is a green alga (as shown in figure 1.4), is an example of colonial form of organization. 1.2.3 Multicellular Organization: The organism formed by many cells is called as multicellular organism. Frog and mustard plant are examples of multicellular organization. Flower Mustard plant: Brassica campestris is commonly Flower bud known as mustard plant and locally it is Fruit called “Sarsoon”. It is multicellular and cultivated in winter season. The leaves of this plant are used as vegetable while seeds are used for oil extraction. The Old leaf Young length of this plant is 1 to 1.5 meter. This leaf plant has two parts, the vegetative part, which consists of root, stem and leaves and reproductive part which consists of flowers. Each flower is yellowish in color and produce seeds. Stem Root Fig: 1.2 Brassica campestris BIOLOGY 11 Frog: Rana tigrina is the scientific name of spotted frog found commonly in our region. It is multicellular animal. It lives in both water as well as on land. Its body is divided into head and trunk. There is no neck. Its body is made of organ system with different organs. Fig: 1.3 Frog All organs are made of different tissues such as epithelial, glandular, muscular, nervous etc. Frog lives near ditches, pools, ponds, stagnant stream and slow moving rivers. It feeds on small insects. Activity: Identification of organs and organ-system in dissected frog: Material Required: Preserved frog dissecting tray dissection box pins Procedure: Place the preserved frog on a dissecting tray on its back, as all vertebrates are dissected ventrally, pin down the fore limbs and hind limbs. Take scissor to cut the abdomen ventrally, from cloaca to the mouth. Again cut down the skin of limbs from each side and pin down. Expose the visceral organs clearly and make observation with the help of diagram. Locate the organs and identify them as below: Table showing different organs with the relative organ system. Organs Organ System Mouth, buccal cavity, Pharynx, Esophagus, stomach, small intestine, large intestine, cloaca, liver, gall Digestive system bladder,pancreas. Heart, atria ventricle, Aortae, Vena cavae Circulatory system Lungs, trachea, nostrils Respiratory system Kidneys, Ureter, Urinary Bladder Excretory system Testes, vasa efferentia, Ovaries, Oviduct, Ovisac Reproductive system Brain, Spinal Cord, Nerves Nervous system  12 INTRODUCTION TO BIOLOGY Draw the labelled diagram of dissected frog. Fig: 1.4 Dissected frog Amoeba: Amoeba is a unicellular organism found in the mud of shallow pond, pools and at any stagnant water. Its size is about 0.25mm. Amoeba has a irregular shape. It has a cell membrane which helps in movement of molecules and protects cytoplasm. The outer part of cytoplasm is clear and transparent, called ectoplasm (gel) and inner part is called endoplasm (sol). The cytoplasm contains nucleus, food vacuoles, mitochondria etc. Amoeba moves by false foot, called pseudopodia. Fig: 1.5 Amoeba BIOLOGY 13 Volvox: Volvox is a polyphyletic (many ancestors) genus of chlorophyte green algae in the family Volvocaceae. It forms spherical colonies of upto 50,000 cells. They live in a variety of fresh water habitats and were first reported by Antonie Van Leeuwen Hoek in 1700. Flagella Contractile vacuole Eye spot Nucleus Chloroplast Non reproductive cell Gelatinous cell wall Fig: 1.6 Volvox colony Volvox once called algae that live together in a colony. Each Volvox cell has two flagella. The flagella beat together to roll the body in water. Volvox cells have chlorophyll and make their own food by photosynthesis. These photosynthesis organisms are an important part of many aquatic eco system. Volvox are not harmful to humans because they do not produce any toxic substance.  14 INTRODUCTION TO BIOLOGY Summary Ÿ Biology deals with the study of living beings. Ÿ Life can be identified on the basis of certain processes. Ÿ Biology can be divided in three major divisions. Ÿ Biology is linked with other sciences such as Physics, Chemistry, Mathematics, etc. Ÿ Economically, Biology is very important for food, medicines, forestry and farming etc. Ÿ The Almighty Allah has conveyed a great knowledge about origin and characteristics of living beings in the Holy Quran. Ÿ Muslim Scientists have played great role in the development of biological science. Ÿ Various levels of organization have been identified in the living world. Ÿ Protoplasm is the chemical basis of life. Ÿ Smallest unit of protoplasm is cell. Ÿ Organisms could be unicellular or multicellular. Ÿ Brassica campastris is commonly known as Mustard (Sarsoon) plant. Ÿ Rana tigrina is biological name of frog. Ÿ Amoeba is unicellular organism. Ÿ Volox belong polyphylectic group of algae. It lives in colonial form. BIOLOGY 15 Review Questions 1. Encircle the correct answer: (i) A localized group of organisms that belong to the same species is called a: (a) Biosphere (b) Community (c) Ecosystem (d) Population (ii) Increased quantity and quality of fish production: (a) Fisheries (b) Farming (c) Animal husbandry (d) Forestry (iii) Study of remote past organic life, with the help of fossils. (a) Entomology (b) Paleontology (c) Taxonomy (d) Histology (iv) Laws and techniques of physics are applied to explain the living processes of life. (a) Biometry (b) Biostatistics (c) Biophysics (d) Bio-economics (v) Choose the incorrect statement: (a) Six elements such as C, H, O, N, S and P are called basic elements of life. (b) Foundation of life based on chemicals. (c) Members of different species form population. (d) Part of earth where life exists is called biosphere (vi) Science of diagnosis and treatment of diseases. (a) Agriculture (b) Medicine (c) Surgery (d) Both B and C  INTRODUCTION TO BIOLOGY 16 (vii) Similar cells combine together to form: a) Organs (b) System (c) Tissue (d) Body (viii) Scientific name of frog is: (a) Palaeon (b) Rana tigrina (c) Periplaneta (d) Pheretima (ix) Select the correct sequence of biological organization (a) Atom → Cell → Tissue → Molecule → Organ (b) Atom → Tissue → Cell → Molecule → Organ (c) Atom → Molecule → Cell → Tissue → Organ (d) Atom → Cell → Molecule →Tissue → Organ (x) Volvox is a polyphyletic genus of (a) Green algae (b) Red algae (c) Brown algae (d) None of these 2. Fill in the blanks (i) Techniques for manipulation of gene to achieve desirable characters are called____________. (ii) Distribution of different living organisms in different regions of the world____________. (iii) Part of agriculture for the development of new varieties of plant, and their fruit is ____________. (iv) Bio elements considered as vital for life are __________ in members. (v) Members of different species living in specific habitat are called __________. (vi) The Muslim scientists who identified many diseases like tuberculosis, meningitis and other such inflammations was _______. (vii) Part of earth where life exists is called______. BIOLOGY 17 INTRODUCTION TO BIOLOGY 17 (viii) Foundation of life based on ________. (ix) Fish is one of the best source of_________. (x) Radio labeling and carbon dating also show some uses of radioactive isotopes in determining the ________ of fossils. 3. Define the following terms (i) Anatomy (ii) Histology (iii) Immunology (iv) Pharmacology (v) Entomology (vi) Biometry (vii) Biogeography (viii) Surgery (ix) Animal husbandry (x) Bioelements 4. Distinguish between the following in tabulated form (i) Colonial organization and multicellular organization (ii) Agriculture and horticulture 5. Write short answers of following questions. (i) Why subject biology is named as multidimensional subject? (ii) How farming profession helps mankind? (iii) Why species is called as smallest taxonomic level? (iv) How population is different from community? (v) How new varieties of plant are produced? (vi) Draw a labeled diagram of frog’s digestive system. 6. Write detailed answers of the following questions. (i) Describe the role of Muslim scientists in the field of biology. (ii) Describe the relationships of biology to other sciences. (iii) Describe the level of organization.  Chapter 2 Major Concept In this Unit you will learn: Ø Biological Method Ÿ Scientific problem, Hypotheses, Deductions and Experiments Ÿ Theory, Law and Principle Ÿ Data organization and Data analysis Ÿ Mathematics as an integral part of the Scientific Process  19 BIOLOGY Science is the systematic study of nature and how it affects us and the environment. It is a body of knowledge that is constantly changing through the use of better and more accurate tools for investigation. At the core of biology and other sciences lies a problem-solving approach called the scientific method. The scientific method is a series of steps followed by scientific investigators to answer specific questions about the natural world. 2.1 BIOLOGICAL METHOD As you know that biology is the branch of science concerned with the study of living things, or organisms. The system of advancing knowledge by formulating a question, collecting data about it through observation and experiment, and testing a hypothetical answer about living things is called biological method. Biological Problem Related observations and previous knowledge Hypothesis New Inductive To explain Deductive Reasoning Hypothesis Reasoning Experiment Data collection and Data analysis If data supports If data does not hypothesis supports hypothesis Theory Figure 2.1 The steps involved in a biological method SOLVING A BIOLOGICAL PROBLEM 20 2.1.1 Biological problem, Hypothesis, Deduction and Experiments: Biological problem is a set of questions to be solved, about the natural world. These problems can be environmental, ecological, health related, etc. No matter what types of problems are being studied, scientists use the same problem-solving method to find answers that are logical and supported by evidence. Here we take an example of malaria (the greatest killer disease of man for centuries). You are familiar with the disease of malaria which spread through a female Anopheles mosquito. Previously the cause of malaria was unknown. It was thought that the malaria is caused by “bad air” (Latin word: 'mala' means bad, and 'aria' means air). This problem is solved when a Scientist identified the reason of malaria. Observation: The first step is to identify the reason of the problem followed by the formulation of a question about what has been observed. The solution of biological problem starts with observation. Your observation can be on anything from plant movement to animal behavior. An observation is a statement of knowledge gained through the senses (qualitative) or through the use of scientific equipment (quantitative). Quantitative Data refers to measurable Qualitative Data refers to observations observations. Tools for quantitative data using five senses: include: Sight Hearing 5 Senses Taste Touch Smell Figure 2.2 The qualitative and quantitative observation About 280 million people suffer from malaria in over 100 countries, and more than 2 million die every year from the disease.  21 BIOLOGY In 1880, a French physician, Laveran, studied the blood sample of malaria patient under microscope and observed tiny creatures in it and named as Plasmodium. So the observation was made that Plasmodium is present in the blood of malaria patients. Figure 2.3 Plasmodium in blood sample Hypothesis: Hypothesis is a key component of the scientific process. It is defined as “the intelligent guess made by a scientist in the form of statement”. It is important to note that a hypothesis must be testable. That means, you should be able to test your hypothesis through experimentation. Your hypothesis must either be supported or falsified by your experiment. For Example: In malaria case, an intelligent guess is made after observation that Plasmodium is the cause of malaria. But it is only a guess which can be presented as a hypothesis. Reasoning: Biologists collect information about the problem and formulate the hypothesis by using a reasoning process i.e. 'inductive reasoning and deductive reasoning'. 4 Mosquito 5 stages tes me Ga Human blood cell cycle 3 Human Ookinete blood cell Oocy st 6 H livuma 2 staer n Sporozoites ge Human 1 liver cell Figure 2.4 A female Figure 2.5 The Malarial Anopheles mosquito Parasites (Plasmodium) SOLVING A BIOLOGICAL PROBLEM 22 Ÿ Inductive reasoning moves from specific to general e.g. Shark is a fish. All fishes have scales therefore sharks also have scales. Ÿ Deductive reasoning moves from general to specific. It is based on “if- then” statement. Deductive reasoning can be tested and verified by experiments. In malaria case, the following deduction is made: “If Plasmodium is the cause of malaria, then all the malaria patient should have Plasmodium in their blood” as shown in figure 2.3. Experiment: Once a problem has been observed and a hypothesis is suggested, the next step in the scientic method is to design an experiment based on reasoning. Experiment is a practical performance of a scientist to identify the real cause of a problem based on inductive and or deductive reasoning. A key assumption is that the experiment will be repeated many times by other scientists. Scientist performs two types of test i.e. control group and experimental group. To find out the cause of malaria, blood samples of 100 malaria patients (experimental group) and the blood samples of 100 healthy persons (control group) were examined under microscope. Figure 2.6 Hypothesis, an intelligent guess which leads the scientist to perform Experiment.  23 BIOLOGY Result The results are where you report what happened in the experiment. That includes detailing all observations and data made during your experiment. Result veries the hypothesis. In the case of malaria, it was found that all the malaria patients (experimental group) had Plasmodium in their blood whereas the blood samples of healthy persons (control group) were free from Plasmodium. Conclusion: The nal step of the scientic method is developing conclusion. This is where all the results from the experiment are analyzed and a determination is reached about the hypothesis. If your hypothesis was supported, its great. If not, repeat the experiment or think of other ways to improve your procedure. Example: Conclusion is made that “Plasmodium is the cause of malaria”. 2.1.2 Theory, Law and Principle: Theory: Scientists use the word “theory” in a very different way than non- scientists. When many people say “I have a theory“, they really mean “I have a guess”. Scientic theories, on the other hand, are well-tested and highly reliable scientic explanations of natural phenomena. They unify many repeated observations and data collected from lots of experiments. For example Theory of Evolution. Law and principle: A scientic law is a uniform or constant fact of nature, it is virtually an irrefutable theory. Biology is short in laws due to puzzling nature of life. 2.1.3 Data organization and Data analysis: For data organization you will prepare a table or graph of the data. Don’t throw out data points you think are bad or that don't support your predictions. Some of the most incredible discoveries in science were made because the data looked wrong! Once you have recorded the data, you may need to perform a mathematical analysis to support or refuse your hypothesis. SOLVING A BIOLOGICAL PROBLEM 24 Number of Malaria Patients Jan 2017 A bar chart showing the trend of malaria cases reported in Sindh 2016-17 Others 3% Scabies 7% Dysentery 8% Acute Respiratory Diarrhoea Infection 15% (ARI) 51% Malaria 16% A Pie Chart showing Infectious diseases in Pakistan (2006) In data analysis, the statistical methods (ratio and proportion) are applied. Ratio is a comparison of two values expressed as a quotient (1st/2nd). Example: A flower has 4 sepals and 12 petals. The ratio of sepals to petals is 4:12. This ratio can also be expressed as an equivalent fraction 1:3. A Proportion is an equation stating that two ratios are equal. Example: 4:12::1:3.  25 BIOLOGY 2.1.4 Mathematics as an integral part of the scientific process: Imagine that you are a biologist studying the insect population. You go into the field and count the population sample in a specific region, then compare your sample with other regions to get population estimated. At every step of this process, you depend upon mathematics to measure, predict, and understand natural phenomena. Mathematical biology is a field of research that examines mathematical representations of biological systems. One key role of mathematics in biology is the creation of mathematical models. There are equations or formulas that can predict or describe natural occurrences, such as organism behavior patterns, population changes over time, structure of protein, height of living organisms, population of an endangered species, bacterial growth and so on. Finally we can say that mathematics plays a critical role in better understanding the natural world. Summary Ÿ Science is the systematic study of nature and how it affects us and the environment. Ÿ The biological method is the stepwise process in which a scientist finds out the reason of any biological problem about living things. Ÿ An observation is a statement of knowledge gained through the senses (qualitative) or through the use of scientific equipment (quantitative). Ÿ Your question should tell what it is that you are trying to discover or accomplish in your experiment. Ÿ A hypothesis is an idea that is suggested as an explanation for a natural event, particular experience, or specific condition that can be tested through definable experimentation. Ÿ The deductive reasoning involves the use of “if-then” logic. It moves from general to specific. Ÿ Result includes detailing all observations and data made during your experiment. SOLVING A BIOLOGICAL PROBLEM 26 Ÿ Conclusion is where all the results from the experiment are analyzed and a determination is reached about the hypothesis. Ÿ Theories are the well-tested and highly reliable scientific explanations of natural phenomena. Ÿ A scientific law is a uniform or constant fact of nature. Ÿ Mathematical biology is a field of research that examines mathematical representations of biological systems. Review Questions 1. Encircle the correct answer: (i) Select the correct sequence of biological method. (a) Law → Theory → Reasoning → Hypothesis (b) Hypothesis → Theory → Law → Reasoning (c) Hypothesis → Reasoning → Theory → Law (d) Law → Hypothesis → Reasoning → Theory (ii) Select the odd one (a) Theory (b) Law (c) Hypothesis (d) Ratio (iii) Field of research that examines mathematical representations of biological system called. (a) Ratio (b) Mathematical biology (c) Proportion (d) Law (iv) Biological method involves all of the following except. (a) Data collection (b) Observation (c) Experiment (d) Proportion  27 BIOLOGY (v) Scientific reasoning moves from specific to general. (a) Inductive (b) Deductive (c) Observation (d) Both a and b (vi) Quantitative observation is the use of (a) Senses (b) Equipment (c) Guess (d) Ratio (vii) Equation stating that two ratios are equal (a) Ratio (b) Proportion (c) Guess (d) Senses (viii) The comparison of two values is called (a) Ratio (b) Proportion (c) Graph (d) Table (ix) What is a hypothesis? (a) The same thing as an unproven theory. (b) A tentative explanation that can be tested and is falsified. (c) A verifiable observation. (d) A fact based on quantitative data that is falsified. (x) In data organization, which method is mostly useful? (a) Table (b) Graph (c) Ratio (d) Both a and b 2. Fill in the blanks: (i) Problem solving approach of biology and other sciences called__________. (ii) Solution of biological problem starts with___________. (iii) The key component of the scientific process is ___________. (iv) Scientific reasoning based on “if-then” statement called ____________. SOLVING A BIOLOGICAL PROBLEM 28 (v) Final step of the scientific method is developing _____________. (vi) The uniform or constant fact of nature, virtually an irrefutable theory is ____________. (vii) Once you have the data, you may need to perform _____________ analysis. (viii) The equation stating that two ratios are equal is called ___________. (ix) Ratio is comparison of ________ values. (x) The cause of malaria is ____________. 3. Define the following terms: (i) Ratio (ii) Biological method (iii) Graph (iv) Hypothesis (v) Law (vi) Inductive reasoning (vii) Conclusion (viii) Proportion (ix) Observation (x) Mathematical models 4. Distinguish between the following in tabulated form: (i) Theory and Law (ii) Inductive reasoning and deductive reasoning 5. Write short answers of following questions: (i) Theory is highly reliable scientific explanations, why? (ii) Why biological sciences need mathematical models? (iii) Draw a chart showing steps involved in biological methods. (iv) Why table or graph is necessary for data organization? (v) Why experiment is necessary for theory?  Chapter 3 Major Concept In this Unit you will learn: Ø Definition and Introduction of Biodiversity Ø Aims and Principles of Classification Ø History of Classification Systems Ÿ Two-Kingdom Classification System Ÿ Three-Kingdom Classification System Ÿ Four-Kingdom Classification System Ÿ Five-Kingdom Classification System Ø The Five Kingdoms Ø Binomial Nomenclature Ø Conservation of Biodiversity BIODIVERSITY 30 Nature has made the man with intelligence and he is always concerned with his aims to be achieved. He designs the things for this purpose into sequence. Similarly biologists mapped the whole diversity of organisms exist on earth, into simple groups. To understand about the characteristics of specific organisms individually, is simply called classification. Classification is actually based on the similar and dissimilar characteristics what organisms shared with each other and by this biologists can easily study and identify the organisms. 3.1 DEFINITION AND INTRODUCTION OF BIODIVERSITY Biodiversity is the combination of two words; Bio (life), diversity (variation) thus it is defined as; “The biodiversity or biological diversity is the degree of variation within or among the species exist on different regions of the earth”. It is comprised of different organisms such as bacteria, protozoans, algae , fungi , animals and plants. 3.1.1 Importance of Biodiversity: Biodiversity provides many beneficial products which includes fiber, oil, dyes, rubber, water, timber, paper and food. It also stabilizes the ecosystem by recycling the nutrients, reduces the amount of pollution by means of forest. Biodiversity also plays an important role in drug discovery and medicinal resources. Medicines from nature account for usage by 80% of the world's population. It also beautifies the nature with lots of tress and animals found in different regions which enhances the tourism. Pictorial view of major biodiversity on earth: Angiosperm plant Gymnosperm Plant 31 BIOLOGY Hornworts Liverworts Mosses Figure: 3.1(a) variety of plants on earth. Polar bear Desert hopping mouse Blue Bird Cobra Figure 3.1.(b) variety of Can you identify other different animals on earth life on earth? BIODIVERSITY 32 3.2 AIMS AND PRINCIPLES OF CLASSIFICATION A system of classification is necessary because of the abundance of the variety of life on earth. There are currently around 1.5 million species that have been described and have been given scientific names. In future, more can be identified if they are found. To study such a diverse pack of organisms exist on earth, biologists classified the organisms into groups and sub groups. This grouping of organisms is called biological classification. 3.2.1 Principles of Classification: Some organisms share similar fundamental characteristics or functions. It is further explained by means of Morphology (external features of an organism) in which we study the organisms on the basis of their Homologous (similar in structure and have different functions) and Analogous (different in structure and have same functions). As shown in fig 3.2 a and b. Alligator Bat Human Wings of Butterfly Wings of Bat Human Cat Whale Bat Figure 3.2 (a) Analogous structure Figure 3.2 (b) Homologous structure Have you seen the arm of a man and wing of a bird? Which type of structure is this? Sometimes it is impossible to classify organisms using morphological characters, therefore scientists use other characteristics to classify organisms which include; Cytology and genetics in which organisms are classified on the basis of cellular study, genetic constitution and their development pattern. Biochemistry is also employed in which the chemical substances of the organisms are compared.  33 BIOLOGY Taxonomic Hierarchy The groups into which organisms are classified are known as taxonomic categories or taxa (singular taxon). The taxa are arranged in ascending order and form a ladder, called taxonomic hierarchy. All organisms are classified into five kingdoms, so the kingdom is the highest taxon of classification. On the basis of similarities, each kingdom is further divided into smaller taxa in the following ways: Do you know? The Kingdom one who studies taxonomy is called Phylum taxonomist. Class Order Teacher will give the definition of Family these units in Genus brief. Species Units of classification: The smallest and basic unit of classification is species. Taxonomic studies consider a group of individual organisms with the fundamental similarities as a species. Thus all the members of the particular species share the similar characteristics and can naturally interbreed to produce a fertile offspring. Closely related species are grouped together into genera (singular-genus). Similar genera are grouped together into families, families into orders, orders into classes, classes into phyla or division and phyla or division into kingdoms. Simple Classication of two Organisms Taxa Human Pea Kingdom Animalia Plantae Phylum Chordate Magnoliophyta Class Mammalia Magnoliopside Order Primates Fabales Family Moninidae Fabaceae Genus Homo Pisum Species Sapiens Sativum Scientic name Homo sapiens Pisum sativum BIODIVERSITY 34 3.2.2 Aims of Classification: Biologists classified the organisms in order to make them study easily, so the science of classification is called Taxonomy. (Tazm=group, Nomy=naming) The main aims of this branch are; Ÿ To determine similarities and dissimilarities among organisms so that they can be studied easily. Ÿ To find the evolutionary relationship among organisms. Use internet to search out THREE different species belongs to same Genus. 3.3 HISTORY OF CLASSIFICATION The system that we still use today for giving scientific names to plants and animals has many founders, from the Greek philosopher Aristotle to the Swedish physician and botanist Carolus Linnaeus. Taxonomy's first father was the philosopher Aristotle (384-322 BC), sometimes called the "father of science." It was Aristotle who first introduced the two key concepts of taxonomy as we practice it today: classification of organisms by type and binomial definition. Aristotle was the first to attempt to classify all the kinds of animals in his book on Animals (Historia Animalium in Latin). He grouped the types of creatures according to their similarities: animals with blood and animals without blood, animals that live on water and animals that live on land. Aristotle Abu usman Umer Aljahiz Abu Usman Umer Aljahiz was the first eminent Arab zoologist of the Muslim world.  35 BIOLOGY He used to slaughter animals for studying the internal organs of their bodies. He also opened the abdomen of pregnant animals to find out the number of embryos and the location of each one of them in the body. His Encyclopedic work in seven big volumes Kitab al-Haywan (Book of Animals) is the most famous work on zoology, in which he has described in detail, the kinds of animals, their behavioral characteristics and their diseases and treatment. Carolus Linnaeus is considered as the father of Taxonomy. 3.3.1 Two Kingdom classification: Previously the organisms were classified into two groups; all the organisms possess cell wall were placed in plant kingdom and all the organisms do not possess cell wall were placed in animal kingdom. THE LIVING BEING Plant Animal Kingdom Kingdom absent locomotion present slow response to fast external stimuli Plants do not eat mode of nutrition eat Animals absent conductile and present contractile system present cell wall absent Bacteria, Algae, Invertebrates Fungi, Bryophytes, (including protozoa), Pteridophytes, Gymno- Vertebrate Sperms, and angiosperms Two kingdom classification 3.3.2 Three Kingdom classification Ernst Hackle in 1866, introduced a new Kingdom named as Protista to accommodate the organisms exhibiting characters either common to both plants and animals, or unique to their own such as Euglena, Bacteria were also placed under this kingdom. In 1937, Édouard Chatton clearied the concept of procariotique and Eucariotique to describe the cellular characteristics of organisms. BIODIVERSITY 36 In 1930s, electron microscopy revealed, two distinct patterns among single celled organisms: Kingdom Protista Lower protists Higher protists prokaryotic unicellular eukaryotic unicellular Bacteria and Cyanobacteria or multicellular organisms such as fungi algae 3.3.3 Four kingdom classification: except blue green algae After the clear concept for kingdom Protista, Copeland (1959) came forward with a four kingdom system to classify the living beings. He designed a new kingdom named as Monera to place all the lower protists which include prokaryotic unicellular organisms and remaining single celled eukaryotic organisms were included in Protista. THE LIVING BEING Kingdom Kingdom Kingdom Kingdom Monera Protista Metaphyta Metazoa Lower protists Higher protists Plants Animals (Prokaryotic protists) (Eukaryotic protists) (Eukaryotic) (Eukaryotic) Becteria and Blue Algae and Bryophytes, Invertabrates and Green algae Fungi pteridophyte, Vertebrates Gymnosperms and Angiosperms Four Kingdom classification 3.3.4 Five Kingdom Classification: Robert Whittaker in 1969 classified the organisms into Five kingdoms which clearly categorized fungi into a separate kingdom.This system of classification was based on; Ÿ Cellular structure and body organization; unicellular Prokaryote, Unicellular and multicellular eukaryotes. Ÿ Mode of nutrition; autotrophs (plants), Ingestive heterotrophs (animals) and absorptive heterotrophs (fungi). Draw a linkage chart to show the establishment of Five Kingdom System that includes Two to Five Kingdom classification. 37 BIOLOGY 3.4 THE FIVE KINGDOMS THE LIVING BEING Photosynthesis Kingdom Bacteria and and Absorption Monera Cyanobacteria Absorption, Kingdom Microalgae Photosynthesis, Protista (phytoplanktonic Ingestion forms), Protozoa, Slime moulds tion ing est orp photosynthesis ion abs Kingdom Kingdom Kingdom Fungi Plantae Animalia Microfungi Macroalgae, Bryophytes, Invertebrates Macrofungi Pteridophytes, Gymnosperms, Vertebrates slime and water Angiosperms mould Five Kingdom classification (i) Kingdom Monera: It includes all the prokaryotes i-e Bacteria and cyanobacteria. Chromosomal DNA Heterocyst Akinetes Flagellum Vegetative cell Capsule Cell wall Ribosomes Pilus Cytoplasmic Plasmid inclusion DNA Structure of bacteria and function Figure 3.3 Bacteria and cyanobacteria BIODIVERSITY 38 (ii) Kingdom Protista: It is the place for all the eukaryotic unicellular organisms, except yeast which some of them have the features of both plant and animal like. Most protists are aquatic. It includes protozoa and unicellular algae. Paramecium Algae Figure 3.4 protozoa and algae (iii) Kingdom Fungi: It includes all the multicellular eukaryotic fungi. They are Achlorophyllous, absorptive heterotrophs. They have cell wall made up of mainly chitin. They have a body called Mycelium which is made up of a thread like structure called hyphae. Mushroom Mucor Figure 3.5 Examples of fungi  39 BIOLOGY (iv) Kingdom plantae: It includes all the multicellular, eukaryotic, photosynthetic organisms. They have cell wall mainly made up of cellulose. It includes multicellular Algae, bryophytes, pteridophytes, gymnosperm and angiosperms. Thallus Undulate margin Holdfast Ulva lactuca Bryophytes Figure 3.6 Plants type (v) Kingdom Animalia: All animals are multicellular, eukaryotic which are ingestive heterotrophs without cell wall. It includes all vertebrates and invertebrates except protozoa. Star fish Kangaroo Figure 3.7 Animals type BIODIVERSITY 40 Table: Comparative characteristics of Five kingdom life. Five Kingdoms Characters Monera Protista Fungi Plantae Animalia Cell type Prokaryotic Eukaryotic Eukaryotic Eukaryotic Eukaryotic (Polysaccharide Present in Present (without Present + amino acid) some (cellulose) Absent Cell wall cellulose) or cellulose Nuclear Absent Present Present Present Present membrane Body Cellular without Tissue/organ/ bonded Cellular Multicellular/ Tissue/ organisation organelles loose tissue organ organ system Autotrophic Autotrophic Heterotrophic Autotrophic Heterotrophic (chemosynthetic (Photosyn (Saprophytic/ (Photosyn (Holozoic/ mode of photosynthetic) thetic) and Parasitic) thetic) saprophytic nutrition and Hetero- Hetero- etc.) trophic (sapro- trophic phyte/parasite) Structure of Virus: Virus is non cellular obligate endoparasite (lives inside host cell). It does not have cellular organization but do have nuclear material either DNA or RNA. It has protein coat called capsid that encloses the nucleic acid. It reproduces only inside the host cell. Due to its non-cellular nature it cannot be placed in any of the five kingdoms. It causes number of diseases in plant like tobacco Mosaic Disease etc and animals like, cold, flue, dengue, polio, hepatitis, AIDS etc. Prions and viroids are also non-cellular particles so cannot be placed in five kingdom classification system 3.5 BINOMIAL NOMENCLATURE Carolus Linnaeus Swedish naturalist and explorer who was the first to frame principles for defining natural genera and species of organisms and to create a uniform system for naming them. The advantages of scientific over common names are that they are accepted by speakers of all languages, that each name applies only to one species, and that each species has only one name. As common names cause many problems to identify the organisms as different regions have different languages for the same thing for example; common name of onion in Urdu is 'Piyaz' but in other regions it is also known as 'ganda' or 'basal' etc but in scientific language it is known as Allium cepa.  41 BIOLOGY This avoids the confusion that often arises from the use of a common name to designate different things in different places or from the existence of several common names for a single species. Table: Biological name of some common plants and animals. COMMONE NAME BIOLOGICAL NAME PLANTS 1. Onion plant Allium cepa 2. Mango plant Mangifera indica L. 3. Neem plant Azadirachta indica ANIMALS 1. Frog Rana tigrina 2. Cat Felis catus 3. Housefly Musca domestica Through a system of nomenclature in which each species of animal, plant or others receives a name of two terms of which the first identifies the genus to which it belongs and the second the species itself or its specific names. Principles for binomial nomenclature: Some of the rules which are universally adopted for writing scientific name of a species are: Ÿ Scientific name of any organisms should be italicized when printed, such as Homo sapiens and when handwritten these are underlined. Ÿ The first word of the name is generic always started with capital letter, while second term is species which is never capitalized. Ÿ When the scientific name is written first time, it is written full but when it is repeated several times, it is abbreviated. For example; The scientific name of the red rose is Rosa indica, it is abbreviated as R.indica. Ÿ Sometimes the author name appears after species name which means the species was described by Him. For example; (mango plant) Mangifera indica L. It means Mangifera indica was first described by Linnaeus. Use internet to search a scientific name of potato, matar, china rose and Dog. 3.6 CONSERVATION OF BIODIVERSITY Pakistan is one of few countries in the world to have every kind of geological structure. The geography of Pakistan is a blend of landscapes. BIODIVERSITY 42 You'll find plains, deserts, forests, hills, and plateaus. There are coastal areas along the Arabian Sea and mountains of the Karakoram Range in the north part of Pakistan. Figure 3.8 Beautiful views of Pakistan This diversity contains diversified habitats and landscapes that support a rich biodiversity of both fauna and flora (animals and plants respectively). Arid and semi-arid regions covering almost 80% of the total land area of the country possess significant portion of country's biodiversity. During the last two-three decades, a number of animal and plant species have become threatened or endangered mainly due to over- exploitation and loss of natural habitat. Factors like deforestation, overgrazing, soil erosion, salinity and water logging are posing major threats to the remaining biodiversity of the country. The continuing loss of forest habitat, with its associated fauna and flora, will have serious implications for the nation's other natural and agricultural ecosystems. To overcome all these problems biodiversity should be paid attention in order to save the organisms from being endangered. “Conservation simply is the way of caring, saving the species, inhabit on earth from dangers”. 3.6.1 Reasons to conserve Biodiversity Biologists warned that global ecosystem would be collapsed if biodiversity continues to be reduced at the same rate. Therefore, it is mandatory to conserve life on earth in order to make nature stable.  43 BIOLOGY Some of the key points are highlighted below: Ÿ Human should conserve biodiversity because of its benefit for example services and biological resources which are essential to live our life on earth. Ÿ Biodiversity boosts ecosystem productivity where each species can easily survive in their habitat, if the one will not conserve biodiversity, so food chain and ecosystem will be imbalanced. Ÿ With more plants, trees and animals, the soil improved and became stronger - less prone to erosion, drought and flooding. Graph: Reporting the data to show the biodiversity at risk. Mammals Birds Reptiles Amphibians Fishes Insects Mollusks Plants 0% 5% 10% 15% 20% 25% 30% Critically endangered Endangered Vulnerable 3.6.2 Problems associated to conserve biodiversity in Pakistan: The article from 2009“Biodiversity in Pakistan Key issues”, identied some of the primary challenges to implement Biodiversity Action Plan (BAP) are: Ÿ Lack of awareness of environmental issues on the part of decision- makers and civil society. Ÿ Weak governance (slow decision-making processes, inability to conceptualize policy, and lack of distinction between public and private interests). BIODIVERSITY 44 Ÿ Weak capacity of government departments (lack of individual capacity and incentives for performance). Ÿ Lack of funding. 3.6.3 Problems associated to conserve biodiversity due to human intervention: The International Union for Conservation of Nature (IUCN) reported that 75 percent of genetic diversity of agricultural crops has been lost, 75 percent of the world's fisheries are over exploited, and one-third of coral reefs are threatened with extinction. Man is the factor, which is directly involved in the destruction of biodiversity. The table below show some of the human intervention in the loss of biodiversity. Table: Impact of human activities on Biodiversity. Human activities Urbanization or Deforestation Pollution Over-hunting Industrialization Overpopulation Soil erosion Global Direct killing leads to the need Plant life Warming of of buildings. destroy wild animals Low rainfall Climate change Biodiversity is effected Causes of Animal Extinction (Pie Chart) Habitat Destruction Hunting & Other Types of intentional Killing Other Causes Introduction to Invasive Species  45 BIOLOGY Climate changes are not the only pressure on our environments. Habitat loss and degradation, pollution, overexploitation, and invasive species also play significant roles in biodiversity decline. These pressures are because of human invading activity. 3.6.4 Deforestation-causes and its effect on Biodiversity Forests cover 31% of the land area on our planet. They produce vital oxygen and provide homes for people and wildlife. Many of the world's most threatened and endangered animals live in forests, and billions of people rely on its benefits. Forests offer food, fresh air, clothing, medicine and shelter. Forests play a critical role in reducing climate change because they act as a carbon sink soaking up carbon dioxide that would otherwise be free in the atmosphere and contribute to ongoing changes in climate patterns. But man is destroying this natural beauty by cutting them down for his sake and comfort. “The cutting down of trees for the conversion of forest into non forest land is known as Deforestation”. Figure 3.9 Deforestation Causes of Deforestation: Deforestation is done deliberately due to the Mining, paper making, urbanization, timber, for making roads and Agriculture Expansion & Livestock breeding. Effects of Deforestation: Deforestation result with the great loss in Biodiversity such as; increase in the concentration of green house gases (carbon dioxide, BIODIVERSITY 46 Methane, water vapopur, Nitrous oxide etc.) which leads to Global warming, temperature will be high that causes glaciers melting which is the reason of raising sea level and causes flood. It is also the reason of habitat loss of wild life. Soil erosion, low rainfall due to no transpiration are also the result of Deforestation. 3.6.5 Endangered and extinct species Due to human activities such as entertainment or food, animals are becoming endangered (at risk of extinction in future) or some have gone extinct (surety of not finding the last individual of that species in ecosystem). Some of the endangered species are mentioned below: Long Billed Green Sea Snow Vulture Turtle leopard Marco polo European Otter Baluchistan Forest sheep Dormouse Sindh Ibex Indus river dolphin Asian black bear (Markhor) Figure 3.10 Endangered species of Pakistan 47 BIOLOGY Summary Ÿ Biodiversity or biological diversity is the degree of variation with or among species exist on different regions of the earth. Ÿ Biodiversity provides many beneficial products including fibre, oil, dyes, ruber, water, timber, paper and food. Ÿ Classification of organisms takes place on the basis of mological character or cytological character or genetical character. Ÿ Morphological classification occur on homologous (Similar in structure) or an analogous characters (different in structure but similar in function). Ÿ The groups of classified organism called taxon(Pl: taxa). Ÿ The smallest and basic unit of classification is species. It is a group of organism which are similar in structure, can interbreed to provide fertile and visible off spring. Ÿ The arrangement of taxa in ascending order to form a ladder called Taxanomic hierarchy. Ÿ The science of classification is called Taxanomy. Ÿ The father of Taxanomy is Carolus Linnaeus. Ÿ Carolus Linnaeus gave the concept of binomial Nomenclature. Ÿ In the beginning living organism were classified into two kingdom plant and animal kingdom. Ÿ Ernst Hackle in 1866 introduced thee kingdom system. Ÿ Copeland in 1959 classified living organism in four kingdoms. Ÿ Robert Whittaker classified organism in 5 kingdoms, Monera, Protista, fungi, plantae and animalia. Ÿ Lack of awareness of environmental issues, weak governance, etc are the main problems associate to conserve biodiversity. BIODIVERSITY 48 Review Questions 1. Encircle the correct answer: (i) Which of the following is the correct way of writing a scientific name of an organism? (a) Houbara bustard (b) E.coli (c) Alium Cepa (d) canis lupis (ii) Select the mismatched (a) Plantae → Pteridophyta (b) Fungi → Mucor (c) Protista → Paramecium (d) Animalia → Amoeba (iii) Identify the correct sequence of classifying an organism. (a) Species → Genus → Kingdom → Phylum → Class → Order → Family (b) Kingdom → Phylum → Class → Order → Family → Genus → Species (c) Kingdom → Phylum → Class → Family → Order → Genus → Species (d) Species → Genus → Class → Phylum → Order → Kingdom → Family (iv) All are involve in classification except (a) Analogous (b) Homologous (c) Cytology (d) Genetics (v) In the taxonomic hierarchy choose the term which encompasses all other in the list (I) Genus (II) Species (III) Order (IV) Class (a) I and II (b) II (c) II and III (d) IV (vi) In four kingdom classification, kingdom Metaphyta includes all of the following except. (a) Algae (b) Angiosperm (c) Gymnosperm (d) Bryophyta  49 BIOLOGY (vii) In five kingdom system virus placed in (a) Monera (b) Protista (c) Plantae (d) None of these (viii)Biological name of cat (a) Felis catus (b) Azadirachta indica (c) Alium Cepa (d) Canis lupis (ix) Members of which kingdom have cell wall and are all heterotrophic (a) Monera (b) Protista (c) Plantae (d) Fungi (x) Biodiversity is effected with (I) Pollution (II) Deforestation (III) Over hunting (a) I only (b) II only (c) I and II (d) I, II and III 2. Fill in the blanks: (i) Degree of variation within or among the species exists on different regions of the earth called ______________. (ii) _________ Species are given scientic names. (iii) __________ Structures have different functions (physiology) but having similar internal architecture. (iv) Science of classication is called ________. (v) Most protists are _________. (vi) ___________ are achlorophyllous and absorptive living organism. (vii) ___________ is non-cellular obligate parasite. (viii) Scientic name of any organism should be __________ when printed. (ix) Cutting down of trees called _____________. (x) Animals which are at the risk of extinction in future called ___________. 3. Define the following terms: (i) Analogous (ii) Classification (iii) Species (iv) Family (v) Metazoa (vi) Mycelium (vii) Hyphae (viii) Genus (ix) Endangered species (x) Kingdom BIODIVERSITY 50 4. Distinguish between the following in tabulated form: (i) Plant kingdom and Animal kingdom (ii) Monera and protista (iii) Fungi and Plantae 5. Write short answers of following questions: (i) Why scientific naming is necessary? (ii) How living organisms are classified into two kingdom classification? (iii) Why virus is not placed in any kingdom? (iv) Draw chart showing three kingdom classification. (v) Why amoeba is not placed in animal kingdom? (vi) Why cyanobacteria are placed in monera? 6. Write detailed answers of the following questions: (i) Describe in detail five kingdom classification. (ii) What is taxonomic hierarchy? Explain aims of classification. (iii) Describe effect of deforestation on biodiversity.  Chapter 4 Major Concept In this Unit you will learn: Ø Microscope and Emergence of Cell Theory Ÿ Light microscope and electron microscope Ø Cellular Structures and Functions Ÿ Difference in prokaryotic and eukaryotic cells Ÿ Relationships between cells function and structure Ø Cell size and shape as they relate to surface area to volume ratio Ø Active and Passive Transport of Matter Ÿ Diffusion Facilitated diffusion Ÿ Osmosis Filtration Ÿ Active transport Endocytosis Ÿ Exocytosis Ø Tissues Ÿ Animal tissues Plant tissues smooth muscle tissue Stomach Loose connective tissue Nervous tissue Blood Columnar epithelium  52 CELLS AND TISSUES You could find cells just as intricately patterned and beautifully formed in any plant you looked at-from the rose in your backyard, to the grass growing up through the sidewalk, to the carrots you ate for a snack. Let's not limit it to plants, either: exquisite layers of cells can be found in your skin, in an insect's wing, and in just about any other living tissue you choose to look at. We, and the world around us, are made of cells. We just need some microscopy to appreciate it. 4.1 MICROSCOPE AND EMERGENCE OF CELL THEORY Zacharias Janssen is generally believed to be the first investigator to invent the compound microscope in the 1590. It was simply a tube with lenses at each end and its magnification ranged from 3X to 9X. Zacharias Janssen Van Leeuwenhoek's microscope (1580-1638) Robert Hooke had improved his version of the compound microscope to observe organisms. Microscopes are instruments designed to produce magnified visual or photographic images of objects too small to be seen with the naked eye. There are two parameters especially important in microscopy; magnification and resolution. Magnification: The enlargement of an image is called magnification. By combining a number of lenses in the correct manner, a microscope can be produced that will yield very high magnification values. Resolution: The resolution of a microscope is defined as the smallest distance between two points on a specimen that can still be distinguished as two separate objects. It helps to measure clarity of object. BIOLOGY 53 Both magnification and resolution are very important if you want a clear picture of something less than 0.1. For example, if a microscope has high magnification but low resolution, all you'll get is a bigger version of a blurry image. 4.1.1 Light microscope and electron microscope: There are two microscopes are used in microscopy i.e. light microscope (LM) and electron microscope (EM). (a) Light microscope: In a light microscope, visible light passes through the specimen (the biological sample you are looking at). A photograph of an image taken through a microscope is called micrograph. Logan’s Simple Microscope (circa 1871) Figure 4.1 Light microscopes from simple to complex The magnification of a light microscope is formed by using a mixture of the powers of the eye piece and the objective lens. In order to ascertain the total magnication when viewing an image with a compound light micrscope, take the power of the objective lenses, which is at 4x, 10x, 40x and multiply it by the power of the eye piece which is typically 10x. Therefore, a 10x eyepiece used with a 10x objective lens will produce a magnication of 100x. This means that the object can be magnied, 40x, 100x or 400x.  54 CELLS AND TISSUES Figure 4.2 Light microscopic micrograph of onion cells and Amoebae (b) Electron microscope: Electron microscopes differ from light microscopes, that they produce an image of a specimen by using a beam of electrons rather than a beam of light. Electrons have a much shorter wavelength than visible light, and this allows electron microscopes to produce higher-resolution images than standard light microscopes. Electron microscopes can be used to examine not just whole cells, but also the subcellular structures and compartments within them. A live cell cannot be imaged by electron microscope. Figure 4.3 Electronic microscope (TEM) Figure 4.4 Salmonella bacteria under light micrograph (left) and through electron microscope (right). BIOLOGY 55 Electron microscope has a resolution as small as 0.2 nanometer (nm) and magnification upto 250,000 times. There are two major types of electron microscopes. 1. Scanning electron microscopy (SEM) 2. Transmission electron microscopy (TEM) In scanning electron microscopy, a beam of electrons moves back and forth across the surface of a cell or tissue, creating a detailed image of the 3D surface. In transmission electron microscopy, in contrast, the sample is cut into extremely thin slices before imaging, and the electron beam passes through the slice rather than skimming over its surface. TEM is often used to obtain detailed images of the internal structures of cells. Figure 4.5 SEM (left) and micrograph of Amphipod (right) 4.2 HISTORY OF THE DEVELOPMENT OF CELL THEORY Ancient Greeks were the first to make comprehensive attempts to organize the data of the natural world. Aristotle presented an organized observation to support the idea that all animals and plants are somehow related. Later this idea gave rise to questions like 'is there a fundamental unit of structure shared by all organisms?” But before microscope was first used in 17th century, no one knew that living organisms do share a fundamental unit i.e. cell. 56 CELLS AND TISSUES 1665 Cell was rst observed by Robert Hooke, an English scientist, discovered a honeycomb-like structure in a cork slice using a primitive compound microscope. He only saw cell walls as this was dead tissue. He coined the term "cell" for these individual compartments he saw. 1670 First living cells were seen by Anton van Leeuwenhoek, a Dutch biologist, from pond water with a microscope. 1683 Miniature animals: Anton van Leeuwenhoek made several more discoveries on a microscopic level, eventually publishing a letter to the Royal Society in which he included detailed drawings of what he saw. Among these was the rst protozoa and bacteria discovered. 1833 The center of the cell was seen by Robert Brown, an English botanist, discovered the nucleus in plant cells. 1839 Cell theory: Theodor Schwann, a German botanist reached the conclusion that not only plants, but animal tissue as well is composed of cells. 1839 This ended debates that plants and animals were fundamentally different in structure. He also pulled together and organized previous statement on cells into one theory, which states: 1- Cells are organisms and all organisms consist of one or more cells. 2 - The cell is the basic structure unit for all organisms. 1840 Where does life come from Albrecht von Roelliker discovered that sperm and eggs are also cells. 1845 Carl Heinrich Braun reworked the cell theory, calling cells the basic unit of life. 1855 3rd part to the cell theory added by Rudolf Virchow, a German physiologist/physician/pathologist. Added that cell is not Denovo structure. This translates mean that all cells develop only from existing cells. 1862 Louis Pasteur was a French biologist; microbiologist and chemist provided the experimental proof of this idea. BIOLOGY 57 Figure 4.6 Robert Hooke, an English scientist, discovered a honeycomb-like structure in a cork slice using a primitive compound microscope. 4.2.1 Cell theory: One of the most important concepts in biology is that a cell is a basic structural and functional unit of living organism. This is known as a cell theory and was proposed jointly by two scientists in 1839. A Belgian Botanist called Schleiden and the German zoologist called Schwan. In 1855 Rudolf Virchow, a German physicians proposed an important extension of cell theory-that all living cells arise from pre-existing. The postulates of cell theory are: 1. All Living organisms are made of one or more cells. 2. The cell is the fundamental unit of structure and function in all living organisms. 3. The new cell is derived from pre-existing cells dividing into two by cell division. 4. The cell contains the hereditary material which is passed from generation to generation. 58 CELLS AND TISSUES Mathias Jakob Theodor Schwann Rudolf Virchow Schleiden Major contributors in the development of cell theory Sub-cellular or Acellular Particles: According to the first principle of the cell theory all organisms are composed of one or more cells. Viruses, prions and viroids are not composed of cells rather they are sub- cellular or acellular particles but do not run any metabolic activity inside them. As they show some characteristics of living organisms i.e. they can increase in number and can transmit their characteristics to the next generations. Cell: Cells are the basic units of organisms and all tissues and organs are composed of cells. There are different types of cells. Cells can either be prokaryotic or eukaryotic. Eukaryotic cells have a proper nucleus and membrane bound organelles. Plant and animal cells are eukaryotes. Plant cells are generally a cubical shape while animal cells are usually spherical. Plant cells and animal cells have evolved different organelles to perform specic functions. The activity of an organism depends on the total activity of independent cells. Energy flow occurs in cells through the breakdown of carbohydrates by respiration. Cells contain the information necessary for the creation of new cells. This information is known as 'hereditary information' and is contained within DNA. The contents of cells from similar species are basically the same. BIOLOGY 59 DNA (the hereditary information of cells) is passed from 'parent' cells to 'daughter' cells during cell division. Cells are the smallest form of life; the functional and structural units of all living things. Your body contains several billion cells, organized into over 200 major types, with hundreds of cell-specic functions. Some functions performed by cells are so vital to the existence of life that all cells perform them (e.g. cellular respiration). Others are highly specialized (e.g. photosynthesis). 4.2.2 Comparison between Prokaryotes and Eukaryotes: Organisms whose cells have a membrane bounded nucleus are called eukaryotes (from the Greek words ‘Eu’ means well or truly and ‘karyon’ means kernel or nucleus. Organisms whose cells do not have a membrane bounded nucleus are called prokaryotes ( ‘pro’ means before). Cytoplasm Ribosomes DNA Bacterial flagellum Pili Capsule Cell wall Plasma membrane Figure 4.7 The structure of Bacterial Cell 60 CELLS AND TISSUES Compare between prokaryotes and eukaryotes: Cellular Structures Prokaryotic cell Eukaryotic cell Example; Bacteria and Cyanobacteria Animals and plants Nucleus Without membrane Membrane bounded Number of One but not true