1. Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings PowerPoint ® Lecture Presentations for Biology Eighth Edition Neil Campbell and Jane Reece Lectures by Chris Romero, updated by Erin Barley with contributions from Joan Sharp Chapter 1 Exploring life

2. Overview: Introduction Biology is the science of life (Bio = life & ology = science) Biologists ask questions such as: – How a single cell develops into an organism – How the human mind works – How living things interact in communities – How changes on Earth occur (organisms living on Earth are modified) = Evolution Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

3. A simple, one-sentence definition of life is “Life is recognized by what living things do” 7 properties common to all living organisms: Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

4. Some important properties of life بعض صفات الحياة الهامة (3) Growth and development (4) Energy processing (2) Regulation (1)Order (5) Response to the environment (6) Reproduction (7) Adaptation

5. New properties emerge at each level in the biological hierarchy The study of life can be divided into different levels of biological organization

6. المحيط الحيوي كل الأنظمة البيئية على الكرة الأرضية ذرة النظام البيئي جميع العشائر المختلفة المتفاعلة مع ما يحيط بها من ماء وهواء وتربة ومناخ في منطقة معينة جزيئ الخلية الجماعة: كل الكائنات المكونة للعشائر المختلفة في منطقة معينة العشيرة: مجموعة من الكائنات الحية من نفس النوع تتزاوج فيما بينها نسيج الجهاز العضوي الجهاز التنفسى الكائن Levels of biological organization

7. The organism (an individual living thing) compose of يتكون الكائن )وهو الفرد الحى) من: : –Organ systems : –Organs : provide specific functions for the organism –Tissues - made of groups of similar cells –Cells Copyright © 2009 Pearson Education, Inc.

8. The cell is the lowest level of organization that can perform all activities required for life All cells: – Are enclosed by a membrane – Use DNA as their genetic information – The ability of cells to divide is the basis of: reproduction, growth, and repair of multicellular organisms Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

9. There are two basic types of cells 1)Prokaryotic cell 2)Eukaryotic cells

10.  Prokaryotes أولية النواة Single-celled No cell nucleus The genetic material in prokaryotes is not membrane- bound Examples include bacteria and archaea  Eukaryotes حقيقية النواة Have "true" nuclei containing their DNA May be unicellular, as in amoebae May be multicellular, as in plants and animals 10

11. By comparison: A eukaryotic cell has: membrane-enclosed organelles, the largest of which is usually the nucleus. A prokaryotic cell is simpler and usually smaller, and does not contain a nucleus or other membrane-enclosed organelles Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

12. DNAدنا (no nuclear envelop) (لايوجد غلاف نووي) Prokaryotic cell خلية أولية النواة Membraneغشاء Eukaryotic cell خلية حقيقة النواة Nucleusنواة (contains DNA surrounded by nuclear membrane) (تحتوي على دنا محاط بغلاف نووي) Organellesعضيات Contrasting the size and complexity of prokaryotic and eukaryotic cells تباين الحجم والتعقيد بين الخلايا أولية النواة وحقيقة النواة

13. Such diversity of life can be arranged into three domains يمكن ترتيب التنوع الحيوي في ثلاثة عوالم The 3 Domains (Groups) of life are : هناك ثلاث عوالم ( مجاميع ) حيوية : –Domain (Group) Bacteria –Domain (Group) Bacteria - prokaryotic, and most are unicellular and microscopic البكتيريا – البكتيريا – أولية النواة ، وعادة ما تكون وحيدة الخلية و مجهرية –Domain (Group) Archaea –Domain (Group) Archaea - like bacteria - are prokaryotic, and most are unicellular and microscopic – البدائيات – البدائيات – أولية النواة ، وعادة ما تكون وحيدة الخلية و مجهرية شأنها شأن البكتيريا –Domain (Group) Eukarya –Domain (Group) Eukarya - are eukaryotic and contain a nucleus and organelles – حقيقيات النواة – حقيقيات النواة – خلايا حقيقية النواة أي لها نواة و عضيات

14. Domain Eukaryaعالم حقيقيات النواة Kingdom Animalia المملكة الحيوانية Kingdom Fungi مملكة الفطريات Archaea (multiple kingdoms) الأركيا ( ممالك متعددة ) Domain Archaea عالم البدائيات Domain Bacteria عالم البكتيريا Bacteria (multiple kingdoms) البكتيريا ( ممالك متعددة ) Protists (multiple kingdoms) الأوليات ( ممالك متعددة ) Kingdom Plantae المملكة النباتية

15. Organisms interact with their environments, exchanging matter and energy Every organism interacts with its environment, including other organisms – For example, a tree takes up water and minerals from the soil and carbon dioxide from the air; the tree releases oxygen to the air and roots help form soil Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

16. Ecosystem Dynamics The dynamics of an ecosystem include two major processes: – The flow of energy from sunlight to producers to consumers – Cycling of nutrients, in which materials acquired by plants eventually return to the soil Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

17. Living organisms interact with their environments Life requires interactions between living and non-living components producers –Photosynthetic organisms provide food and are called producers consumers –Others eat plants (or animals that profit from plants) and are called consumers Copyright © 2009 Pearson Education, Inc.

18. Ecosystemنظام بيئي Producers (such as plants) منتجات (مثل النباتات) Sunlightأشعة الشمس Cycling of chemical Nutrients دورة المواد الغذائية الكيميائية Chemical energy طاقة كيميائية Consumers (such as animals) مستهلكات (مثل الحيوانات) Heatحرارة The cycling of nutrients and flow of energy in an ecosystem دورة المواد الغذائية وسريان الطاقة في نظام بيئي

19. Energy Conversion Energy can be stored in different forms, for example, light, chemical, kinetic, or thermal The energy exchange between an organism and its environment Energy flows through an ecosystem, usually entering as light and exiting as heat Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

20. EVOLUTION, THE CORE THEME OF BIOLOGY Copyright © 2009 Pearson Education, Inc.

21. The continuity of life is based on heritable information in the form of DNA Chromosomes contain most of a cell’s genetic material in the form of DNA (deoxyribonucleic acid). Each chromosome has one long DNA molecule with hundreds or thousands of genes Make the structures and complex chemicals necessary for life PROTEINS DNA is transcribed into RNA then translated into a protein Genes are the units of inheritance that transmit information from parents to offspring

22. DNA Structure and Function DNA in every body cell is exactly alike DNA is inherited by offspring from their parents DNA controls the development of organisms Genes control protein production indirectly An organism’s genome is its entire set of genetic instructions

23. Each DNA molecule is made up of two long chains arranged in a double helix Each link of a chain is one of ( 4 ) kinds of chemical building blocks called nucleotides Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

24. DNA: The genetic material

25. Nuclei containing DNA Sperm cell Egg cell Fertilized egg with DNA from both parents Embryo’s cells with copies of inherited DNA Offspring with traits inherited from both parents Inherited DNA directs development of an organism

26. Diversity of Life Approximately 1.8 million species have been identified and named to date, and thousands more are identified each year Estimates of the total number of species that actually exist range from 10 million to over 100 million Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

27. Grouping Species: The Basic Idea Taxonomy is the branch of biology that names and classifies species into groups of increasing breadth Domains, followed by kingdoms, are the broadest units of classification Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

28. SpeciesGenusFamilyOrderClassPhylumKingdomDomain Animalia Eukarya Classifying life

29. Charles Darwin and the Theory of Natural Selection Charles Darwin published on the Origin of Species by Means of Natural Selection in 1859 Darwin made (2)main points: – Species showed evidence of “descent with modification” from common ancestors – Natural selection is the mechanism behind “descent with modification” Darwin’s theory explained the duality of unity and diversity

31. – Individuals in a population have traits that vary – Many of these traits are heritable (pass from parents to sons) – Competition is necessary – Species generally suit their environment Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Darwin observed that:

32. – Individuals that are best suited to their environment are more likely to survive and reproduce – Over time, more individuals in a population will have the advantageous traits In other words, the natural environment “selects” for beneficial traits Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Darwin concluded that:

33. Population with varied inherited traits. Elimination of individuals with certain traits. Reproduction of survivors. Increasing frequency of traits that enhance survival and reproductive success. 43 21

34. Scientists use two main approaches to learn about nature –Discovery science - uses verifiable observations and measurements to describe science –Hypothesis- based science - uses the data from discovery science to explain science

35. Discovery Science Discovery science : This approach is based on observation and the analysis of data. Data are recorded observations or items of information, fall into two categories – Qualitative, or descriptions rather than measurements – Quantitative, or recorded measurements, which are sometimes organized into tables and graphs

36. Hypothesis-Based Science Observations can lead us to ask questions and propose hypothetical explanations called hypotheses Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

37. The Role of Hypotheses in Inquiry A hypothesis is a tentative answer to a well- framed question A scientific hypothesis leads to predictions that can be tested by observation or experimentation Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

38. For example, – Observation: Your flashlight doesn’t work – Question: Why doesn’t your flashlight work? – Hypothesis 1: The batteries are dead – Hypothesis 2: The bulb is burnt out Both these hypotheses are testable Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

39. Hypothesis #1: Dead batteries الفرضية الاولى : البطارية لا تغمل Observations المشاهدة Question الاستفسار Hypothesis #2: Burned-out bulb الفرضية الثانية : المصباح لا يعمل Test prediction اختبار التكهن Test prediction اختبار التكهن Test falsifies hypothesis الاختبار يكذب الافتراض Test does not falsify hypothesis الاختبار لا يكذب الافتراض Prediction: Replacing batteries will fix problem تكهن : هل تغيير البطارية سيحل المشكلة Prediction: Replacing batteries will fix problem تكهن : هل تغيير المصباح سيحل المشكلة الاستنتاج = النظرية الكشاف الضوئي لا يعمل لماذا لا يعمل الكشاف الضوئي؟ ا لإجابة التخمينية التكهن التجربة

40. Deduction: The “If…Then” Logic of Hypothesis Based Science Deductive reasoning uses general premises to make specific predictions For example, if organisms are made of cells (premise 1), and humans are organisms (premise 2), then humans are composed of cells (deductive prediction) Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

41. A Closer Look at Hypotheses in Scientific Inquiry A hypothesis must be testable and falsifiable Hypothesis-based science often makes use of two or more alternative hypotheses Failure to falsify a hypothesis does not prove that hypothesis – For example, you replace your flashlight bulb, and it now works; this supports the hypothesis that your bulb was burnt out, but does not prove it (perhaps the first bulb was inserted incorrectly) Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

42. Theories in Science In the context of science, a theory is: – Broader in scope than a hypothesis – General, and can lead to new testable hypotheses – Supported by a large body of evidence in comparison to a hypothesis Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings