1. Chapter 1 Exploring Life
introduction to Biology
Chapter 1: Exploring Life Dr. Nezar Redwan

2. المصطلـــــــــــــــــــــــــــــــــح تعريف المصطلــــــــــح
Introduction: Getting Acquainted with Biology مدخل : التعريف بعلم الحياة
المصطلـــــــــــــــــــــــــــــــــح
تعريف المصطلــــــــــح
Biology Is The Science Of Life In All Its Living Forms, Plants, Animals And Microorganisms Including Man
علم الحياة هو علم دراسة ظاهرة الحياة ممثلة في النبات والحيوان والكائنات الدقيقة وكذا الإنسان
Biology Is The Scientific Study Of Life
علم الأحياء هو الدراسة العلمية للحياة
The Term “Biology” Derived From Bios = Life And Logos = Science Logos
مصطلح “Biology” مشتق من كلمتين يونانيتين : Bios يعني حياة و Logos يعني علـــم
Living Organisms
الكائنات الحية
Adaptation
التكيف وهي التهيؤ والاستعداد الفطري للكائن الحي للعيش تحت ظروف بيئته التي يوجد فيها
Evolution
التطور هو عملية التغير المفطور عليها الكائن التي يكيف بها حياته ويحورها
Organization
التعضية صفة أخرى هامة للكائنات الحية بها تحدد موضوعات الدراسة في علم الأحياء
Hierarchy Of Life
التنظيم الهرمي للحياة
Emergent Properties
صفات جديدة تعرف بالصفات الناشئة
Biosphere
الغلاف الجوي – كل البيئات (الأنظمة البيئية) الداعمة للحياة على الأرض
Chapter 1: Exploring Life Dr. Nezar Redwan

3. العشيرة – كل أفراد النوع الواحد يتزاوجون فيما بينهم فقط في منطقة معينة
Ecosystem
النظام البيئي – كل الجماعات من الكائنات المختلفة التي تعيش في منطقة معينة
Community
الجماعة – كل الكائنات المختلفة (العشائر المختلفة) التي تعيش في نظام بيئي معين
Population
العشيرة – كل أفراد النوع الواحد يتزاوجون فيما بينهم فقط في منطقة معينة
Organ Systems
الأجهزة العضوية – لها وظائف محددة وتتألف من أعضاء
Organs
الأعضاء – تؤدي وظائف محددة للكائن
Tissues
الأنسجة – مكونة من مجموعة من الخلايا المتشابهة
Molecules
جزيئات – تجمع من الذرات
Organelles
عضيات – تراكيب غشائية ذات وظائف محددة
Cells
خلايا – كيانات حية تفترق بغشاء عن بيئتها
Living And Nonliving Components
المكونات الحية والغير الحية
Photosynthetic Organisms
الكائنات القادرة على البناء الضوئي
Producers Are Called And Provide Food
المُنتجات توفر الغذاء
Consumers
بالمُستهلكات
كائنات تتغذى على النباتات ( أو على حيوانات تتغذى على النباتات )
The Nonliving Components
المكونات غير الحية عبارة عن مواد غذائية كيميائية ضرورية للحياة
Chapter 1: Exploring Life Dr. Nezar Redwan

4. إعادة تدوير الكيماويات Necessary For Life
Recycle Chemicals
إعادة تدوير الكيماويات
Necessary For Life
Move Energy Through The Ecosystem
تحريك الطاقة خلال النظام البيئي
Prokaryotic Cells
خلايا أولية النواة
Genetic Material Is Not Surrounded By A Nuclear Membrane
المادة الوراثية غير محاطة بغلاف نووي
Simple And Small
صغيرة وبسيطة
Bacteria Are Prokaryotic
البكتيريا أولية النواة
Eukaryotic Cells
خلايا حقيقية النواة
Possess Organelles Separated By Membranes
تمتلك عضيات محاطة بأغشية تفصلها عن السيتوبلازم
Plants, Animals, And Fungi Are Eukaryotic
النباتات والحيوانات والفطريات حقيقية النواة
Nucleus
نواة
Contains DNA Surrounded By Nuclear Membrane
تحتوي على دنا محاط بغلاف نووي
Membrane
غشاء
DNA Is The Genetic (Hereditary) Material Of All Cells
الدنا هو المادة الوراثية لكل الخلايا
A Gene Is A Discrete Unit Of DNA
الجين عبارة عن وحدة مميزة من الدنا
Chapter 1: Exploring Life Dr. Nezar Redwan

5. النظام – التعضي المعقد للكائنات الحية Regulation
Order
النظام – التعضي المعقد للكائنات الحية
Regulation
التنظيم – المقدرة على المحافظة على بيئة داخلية متناسقة مع الحياة
Growth And Development
النمو والتطور الجنيني
Energy Processing
معالجة الطاقة – إكتساب الطاقة وتحويلها لصورة نافعة للكائن بممارسة الأيض
Response To The Environment
الاستجابة للبيئة – قدرة الاستجابة للمؤثرات البيئي
Reproduction
التكاثر – المقدرة على إكثار النوع
Evolutionary Adaptation
التكيف التطوري – اكتساب الصفات الأكثر تناسباً للكائن مع بيئته
Domains
عوالـــم
The Three Domains (Groups) Of Life
هناك ثلاث عوالم ( مجاميع ) حيوية
Bacteria - Prokaryotic, And Most Are Unicellular And Microscopic
البكتيريا – أولية النواة ، وعادة ما تكون وحيدة الخلية و مجهرية
Archaea - Like Bacteria, Are Prokaryotic, And Most Are Unicellular And Microscopic
البدائيات – أولية النواة ، وعادة ما تكون وحيدة الخلية و مجهرية شأنها شأن البكتيريا
Eukarya - Are Eukaryotic And Contain A Nucleus And Organelles
حقيقيات النواة – خلايا حقيقية النواة أي لها نواة و عضيات
Chapter 1: Exploring Life Dr. Nezar Redwan

6. العلم الاستقرائي – يستخدم مشاهدات وقياسات متنوعة لوصف العلم
THE PROCESS OF SCIENCE
الطريقة العلمية
Discovery Science
العلم الاستقرائي – يستخدم مشاهدات وقياسات متنوعة لوصف العلم
Hypothesis- Based Science
العلم الافتراضي (الإستنتاجي – الإستدلالي) – يستخدم البيانات الذي يوفرها العلم الاستقرائي وذلك لوضع تفسيرات علمية (إنه العلم التجريبي)
A Hypothesis
الفرضية هي تفسير مقترح لمجموعة من المشاهدات وبمعنى آخر هي الإجابة التخمينية للأسئلة التي تثيرها المشاهدة
A Theory
النظرية هي إستنتاج علمي مبني على التجربة مؤيد بعدد كبير ومتزايد من الأدلة المدعومة بالتجارب
Chapter 1: Exploring Life Dr. Nezar Redwan

7. Topics Discussed in this chapter
The Characteristics of Life
Biological Organization
The 3 domains of life
Steps in the Scientific Method
Chapter 1: Exploring Life Dr. Nezar Redwan

8. What is Biology? Biology is the study of all living things
Living things are called organisms
Organisms include bacteria, protists, fungi, plants, & animals
Chapter 1: Exploring Life Dr. Nezar Redwan

9. The term “Biology” derived from bios = life and logos = science
is the scientific study of life in all its living forms, plants, animals and microorganisms including man
The term “Biology” derived from
bios = life
and
logos = science
Click to add notes
Chapter 1: Exploring Life Dr. Nezar Redwan

10. All Living Things Share Common Characteristics known as: The Characteristics of Life
Chapter 1: Exploring Life Dr. Nezar Redwan

11. The Characteristics of Life
Order(organization) :
Living organisms are organized in several levels of increasing complexity best described as a :
Hierarchy of life levels.
Atoms Molecules Organelles
Cells – life starts here
Tissues Organs System
Organism Population Community
Ecosystem Biosphere
Chapter 1: Exploring Life Dr. Nezar Redwan

12. Life’s hierarchy of organization
Biosphere
Ecosystem
جميع العشائر المختلفة المتفاعلة مع ما يحيط
بها من ماء وهواء وتربة ومناخ في منطقة
معينة مثل ساحل فلوريدا Florida coast
Community, All organisms on
the Florida coast ال
Population, Group
of brown pelicans
Organism
Brown pelican
Spinal cord
Organ system
Nervous system
Nerve
Brain ا
Figure 1.1 Life’s hierarchy of organization.
Organ ا
Brain
Tissue
Nervous tissue
Cell
Nerve cell
Nucleus ا
Atom
ذرة
Organelle
Nucleusن
Molecule
DNA

13. Organism
Population
Organ system
Organ
Community
Tissue
Bone cells
Cell
Nucleus
Organelle
Ecosystem
Macromolecule
Biosphere
Molecule
Oxygen atom
Hydrogen atoms
Water

14. Hierarchy of life levels.
Atom
Molecules - clusters of atoms
Organelles - membrane-bound structures with different jobs inside Cells
Cells - life starts here. The simplest entity that has all the properties of life
Tissues - made of groups of similar cells that carries out a particular function in an organism
Organs - A structure consisting of two or more tissues that performs specialized functions within an organism
Organ systems - have specific functions; are composed of organs that carries out a particular function in an organism
A study of reductionism could be introduced at this point. Reductionism is the reduction of complex systems, such as an animal, to simpler components that are easier to study.
Student Misconceptions and Concerns
1. Many students enter our courses with a limited appreciation of the diversity of life. Ask any group of freshmen at the start of the semester to write down the first type of animal that comes to mind, and the most frequent response is a mammal. As the diversity of life is explored, the common heritage of biological organization can be less, and not more, apparent. The diverse forms, habits, and ecological interactions overwhelm our senses with striking distinctions. Emphasizing the diversity as well as the unifying aspects of life is necessary for a greater understanding of the rich evolutionary history of life on Earth.
2. We live in a world that is largely understood by what we can distinguish and identify with our naked senses. However, the diversity of life and the levels of biological organization extend well below the physical scale of our lives. For many students, appreciating the diversity of the microscopic world is abstract, nearly on par with an understanding of the workings of atoms and molecules. The ability to examine the microscopic details of the world of our students (the surface of potato chips, the structure of table salt and sugar, the details of a blade of grass) can be an important sensory extension that prepares the mind for greater comprehension of these minute biological details.
Teaching Tips
1. Consider asking students to bring to class a page or two of some article about biology that appeared in the media in the last month. Alternatively, you could have each student a Web address of a recent biology-related news event to you. You might even have them relevant articles to you for each of the main topics you address throughout the semester.
2. The scientific organization Sigma Xi offers a free summary of the major science news articles appearing each weekday in major U.S. news media. The first paragraph or so of each article is included in the with a hyperlink to the rest of the article. The diverse topics are an excellent way to learn of general scientific announcements and reports. Typically, 5–10 articles are cited in each . To sign up for this free service, go to
3. For a chance to add a little math to the biological levels of organization, consider calculating the general scale differences between each level of biological organization. For example, are cells generally 5, 10, 50, or 100 times larger than organelles? Are organelles generally 5, 10, 50, or 100 times larger than macromolecules? For some levels of organization, such as ecosystems, communities, and populations, size/scale differences are perhaps less relevant and more problematic to consider. However, at the smaller levels, the sense of scale might enhance an appreciation for levels of biological organization.
4. The U.S. Census Bureau maintains updated population clocks that estimate the U.S. and world populations on its website at If students have an accurate general idea of the population of the United States, statistics about the number of people affected with a disease or disaster become more significant. For example, the current population of the United States is approximately 305 million (2009). It is currently estimated that about one million people in the United States are infected with HIV. The number of people infected with HIV is impressive and concerning, but not perhaps as meaningful as realizing that the number of people infected represents one out of every 305 people in the United States. Although the infected people are not evenly distributed among geographic and ethnic groups, if you apply this generality to the enrollments in your classes, the students might better appreciate the tremendous impact of the infection.
Chapter 1: Exploring Life Dr. Nezar Redwan

15. Life’s hierarchy of organization
Organism:
Population:
All the individuals of a species only interbreed with each other within a specific area
Community:
The array of organisms (different populations) living in a particular ecosystem
Ecosystem:
All the organisms (communities) living in a particular area
Biosphere :
All the environments (ecosystems) on Earth that support life
Student Misconceptions and Concerns
1. Many students enter our courses with a limited appreciation of the diversity of life. Ask any group of freshmen at the start of the semester to write down the first type of animal that comes to mind, and the most frequent response is a mammal. As the diversity of life is explored, the common heritage of biological organization can be less, and not more, apparent. The diverse forms, habits, and ecological interactions overwhelm our senses with striking distinctions. Emphasizing the diversity as well as the unifying aspects of life is necessary for a greater understanding of the rich evolutionary history of life on Earth.
2. We live in a world that is largely understood by what we can distinguish and identify with our naked senses. However, the diversity of life and the levels of biological organization extend well below the physical scale of our lives. For many students, appreciating the diversity of the microscopic world is abstract, nearly on par with an understanding of the workings of atoms and molecules. The ability to examine the microscopic details of the world of our students (the surface of potato chips, the structure of table salt and sugar, the details of a blade of grass) can be an important sensory extension that prepares the mind for greater comprehension of these minute biological details.
Teaching Tips
1. Consider asking students to bring to class a page or two of some article about biology that appeared in the media in the last month. Alternatively, you could have each student a Web address of a recent biology-related news event to you. You might even have them relevant articles to you for each of the main topics you address throughout the semester.
2. The scientific organization Sigma Xi offers a free summary of the major science news articles appearing each weekday in major U.S. news media. The first paragraph or so of each article is included in the with a hyperlink to the rest of the article. The diverse topics are an excellent way to learn of general scientific announcements and reports. Typically, 5–10 articles are cited in each . To sign up for this free service, go to
3. For a chance to add a little math to the biological levels of organization, consider calculating the general scale differences between each level of biological organization. For example, are cells generally 5, 10, 50, or 100 times larger than organelles? Are organelles generally 5, 10, 50, or 100 times larger than macromolecules? For some levels of organization, such as ecosystems, communities, and populations, size/scale differences are perhaps less relevant and more problematic to consider. However, at the smaller levels, the sense of scale might enhance an appreciation for levels of biological organization.
4. The U.S. Census Bureau maintains updated population clocks that estimate the U.S. and world populations on its website at If students have an accurate general idea of the population of the United States, statistics about the number of people affected with a disease or disaster become more significant. For example, the current population of the United States is approximately 305 million (2009). It is currently estimated that about one million people in the United States are infected with HIV. The number of people infected with HIV is impressive and concerning, but not perhaps as meaningful as realizing that the number of people infected represents one out of every 305 people in the United States. Although the infected people are not evenly distributed among geographic and ethnic groups, if you apply this generality to the enrollments in your classes, the students might better appreciate the tremendous impact of the infection.
Chapter 1: Exploring Life Dr. Nezar Redwan

16. The Characteristics of Life
Metabolism:
Sum of all the chemical reactions in an organism. Organized synthesis and break down of molecules; can produce energy to power life processes.
Energy processing:
Acquiring energy and transforming it to a form useful for the organism through metabolism
Motility:
Organisms can move themselves or their parts.
Responsiveness:
An ability to respond to environmental stimuli .
Chapter 1: Exploring Life Dr. Nezar Redwan

17. The Characteristics of Life
6. Regulation: An ability to maintain an internal environment consistent with life (Homeostasis) Within The Ranges Required For Life. Stable internal conditions of pH, temperature, water balance, etc 7.Development: Develop from simple to more complex organism. 8. Reproduction: The ability to perpetuate the species, genes are passed from parent to offspring; genes control an organism’s phenotype
Chapter 1: Exploring Life Dr. Nezar Redwan

18. The Characteristics of Life
9. Evolution: Evolution is the process of change that transforms life. Populations change over time as they adapt to their environment. 10. Adaptations: The innate fitness of an organism for its environmental condition. the environment selects organisms with traits/ that are best suited for an organisms environment (natural selection). The leopard is an excellent example of an organism adapted to its environment. Adaptations are the result of evolution
Chapter 1: Exploring Life Dr. Nezar Redwan

19. (7) Evolutionary adaptation
(3) Growth and
development
(4) Energy processing
(2) Regulation
Order
(5) Response to the
environment
(6) Reproduction
(7) Evolutionary adaptation ا
Figure 1.4B Some important properties of life.
Some important properties of life
Chapter 1: Exploring Life Dr. Nezar Redwan

20. Some important properties of life
The environment outside
an organism (a living thing)
frequently changes,
but mechanisms regulate
the organism’s internal
environment, keeping
it within limits that
sustain life
Figure 1.4B Some important properties of life.
(2) Regulation
For example, a jackrabbit can adjust its body temperature by regulating The amount of blood flowing through its ears. When the rabbit’s body temperature rises, more blood flows through the vessel in its ears, allowing excess heat to be released to the air.

21. Some important properties of life
Information carried by genes
the units of inheritance that
transmit information from parents
To offspring – controls the pattern
of growth and development in all
organisms, including the
Nile crocodile
Figure 1.4B Some important properties of life.
(3) Growth and development
Chapter 1: Exploring Life Dr. Nezar Redwan

22. Some important properties of life
Organisms take in energy
and transform it in
performing all of life’s
activities
Fro example, when this
bear eats the fish, it will
use the chemical energy
stored in the fish
to power its own activities
and chemical reactions
(metabolism)
Figure 1.4B Some important properties of life.
(4) Energy processing
Metabolism
Chapter 1: Exploring Life Dr. Nezar Redwan

23. Some important properties of life
All organisms respond
to environmental stimuli
Fro example, a Venus flytrap
closes its trap in response
to the environmental stimulus
of an insect landing on it
Figure 1.4B Some important properties of life.
(5) Response to the environment
Chapter 1: Exploring Life Dr. Nezar Redwan

24. Some important properties of life
Organisms reproduce their
own kind, by producing
offsprings.
This emperor
Penguins is protecting its baby.
By reproduction survival of
the specie, not extinction,
is achieved
Figure 1.4B Some important properties of life.
(6) Reproduction
Chapter 1: Exploring Life Dr. Nezar Redwan

25. Some important properties of life
Reproduction underlies the
capacity of populations to
change (evolve) over time
Fro example, the appearance
of the pygmy seahorses
has evolved in the way
that camouflage the animal
in its environment
Figure 1.4B Some important properties of life.
(7) Evolutionary adaptation
Chapter 1: Exploring Life Dr. Nezar Redwan

26. Life requires interactions between living and nonliving components
1.2 Living organisms interact with their environments, exchanging matter and energy
Life requires interactions between living and nonliving components
Photosynthetic organisms provide food and are called producers
Others eat plants (or animals that profit from plants) and are called consumers
Decomposers: Recycle all organic materials(Dead plants and animals)
The nonliving components are chemical nutrients required for life
The nonliving components are recycled and used over and over again. Carbon dioxide, oxygen, water, and various minerals are examples of components cycled within an ecosystem.
Student Misconceptions and Concerns
1. Many students enter our courses with a limited appreciation of the diversity of life. Ask any group of freshmen at the start of the semester to write down the first type of animal that comes to mind, and the most frequent response is a mammal. As the diversity of life is explored, the common heritage of biological organization can be less, and not more, apparent. The diverse forms, habits, and ecological interactions overwhelm our senses with striking distinctions. Emphasizing the diversity as well as the unifying aspects of life is necessary for a greater understanding of the rich evolutionary history of life on Earth.
2. We live in a world that is largely understood by what we can distinguish and identify with our naked senses. However, the diversity of life and the levels of biological organization extend well below the physical scale of our lives. For many students, appreciating the diversity of the microscopic world is abstract, nearly on par with an understanding of the workings of atoms and molecules. The ability to examine the microscopic details of the world of our students (the surface of potato chips, the structure of table salt and sugar, the details of a blade of grass) can be an important sensory extension that prepares the mind for greater comprehension of these minute biological details.
Teaching Tips
1. Consider asking students to bring to class a page or two of some article about biology that appeared in the media in the last month. Alternatively, you could have each student a Web address of a recent biology-related news event to you. You might even have them relevant articles to you for each of the main topics you address throughout the semester.
2. The scientific organization Sigma Xi offers a free summary of the major science news articles appearing each weekday in major U.S. news media. The first paragraph or so of each article is included in the with a hyperlink to the rest of the article. The diverse topics are an excellent way to learn of general scientific announcements and reports. Typically, 5–10 articles are cited in each . To sign up for this free service, go to
3. Help the class think through the diverse interactions between an organism and its environment. In class, select an organism and have the class develop a list of environmental components that interact with the organism. Items in this list will likely fall into living and nonliving categories.
Chapter 1: Exploring Life Dr. Nezar Redwan

27. To be successful, an ecosystem must accomplish two things
1.2 Living organisms interact with their environments, exchanging matter and energy
To be successful, an ecosystem must accomplish two things
Recycle chemicals necessary for life
Move energy through the ecosystem
Energy enters as light and exits as heat
The importance of plants and other photosynthetic organisms to ecosystem dynamics cannot be overstated.
Student Misconceptions and Concerns
1. Many students enter our courses with a limited appreciation of the diversity of life. Ask any group of freshmen at the start of the semester to write down the first type of animal that comes to mind, and the most frequent response is a mammal. As the diversity of life is explored, the common heritage of biological organization can be less, and not more, apparent. The diverse forms, habits, and ecological interactions overwhelm our senses with striking distinctions. Emphasizing the diversity as well as the unifying aspects of life is necessary for a greater understanding of the rich evolutionary history of life on Earth.
2. We live in a world that is largely understood by what we can distinguish and identify with our naked senses. However, the diversity of life and the levels of biological organization extend well below the physical scale of our lives. For many students, appreciating the diversity of the microscopic world is abstract, nearly on par with an understanding of the workings of atoms and molecules. The ability to examine the microscopic details of the world of our students (the surface of potato chips, the structure of table salt and sugar, the details of a blade of grass) can be an important sensory extension that prepares the mind for greater comprehension of these minute biological details.
Teaching Tips
1. Consider asking students to bring to class a page or two of some article about biology that appeared in the media in the last month. Alternatively, you could have each student a Web address of a recent biology-related news event to you. You might even have them relevant articles to you for each of the main topics you address throughout the semester.
2. The scientific organization Sigma Xi offers a free summary of the major science news articles appearing each weekday in major U.S. news media. The first paragraph or so of each article is included in the with a hyperlink to the rest of the article. The diverse topics are an excellent way to learn of general scientific announcements and reports. Typically, 5–10 articles are cited in each . To sign up for this free service, go to
3. Help the class think through the diverse interactions between an organism and its environment. In class, select an organism and have the class develop a list of environmental components that interact with the organism. Items in this list will likely fall into living and nonliving categories.
Chapter 1: Exploring Life Dr. Nezar Redwan

28. The cycling of nutrients
Sunlightأ
Ecosystem
Producers
(such as plants)
Cycling of
chemical
Nutrients
Heat
Chemical energy
Consumers
(such as animals) )
Figure 1.2 The cycling of nutrients and flow of energy in an ecosystem.
Heat
The cycling of nutrients
and flow of energy
in an ecosystem
Decomposers

29. THE PROCESS OF SCIENCE Scientific Method
Chapter 1: Exploring Life Dr. Nezar Redwan

30. Steps in the Scientific Method
Observation
Hypothesis
Experiment
Data Collection
Conclusion
Retest
Chapter 1: Exploring Life Dr. Nezar Redwan

31. 1.7 Scientists use two main approaches to learn about nature
Two approaches are used to understand natural causes for natural phenomena
Discovery based science:
is results that have been found from actually having carried out the experiment or investigation.
uses verifiable observations and measurements to describe science.
Hypothesis- based science:
is an educated guess by a scientist of what will happen during an experiment or investigation.
uses the data from discovery science to explain science.This requires proposing and testing of hypotheses.
Inquiry is at the heart of science, and scientists conduct research on a variety of specific questions. Inquisition drives science.
Student Misconceptions and Concerns
1. The authors’ distinction between natural and supernatural explanations is essential to understanding the power and limits of scientific explanations. This distinction is important when distinguishing between science and supernatural explanations for the origin of life and the generation of biodiversity.
2. Contrasting the concept of faith with the tentative nature of science can help to define and distinguish science from other ways of knowing. Students sometimes enter science classes expecting absolutes of facts and rigid dogma. Instead, scientific knowledge reflects degrees of confidence closely correlated to the strength of evidence.
3. The common use of the terms law and theory often blur the stricter definitions of these terms in science. In general, laws describe and theories explain. Both are typically well-established concepts in science. A free online publication by the National Academy of Sciences helps to define these and related terms more carefully. See Chapter 1 of Teaching About Evolution and the Nature of Science at
Teaching Tips
1. Have your students explain why a coordinated conspiracy promoting a specific idea in science is unlikely to succeed. Have your students describe aspects of science that would check fraudulent or erroneous claims and/or political efforts.
Chapter 1: Exploring Life Dr. Nezar Redwan

32. 1.7 Scientists use two main approaches to learn about nature
There is a difference between a theory and a hypothesis
A hypothesis is a proposed explanation for a set of observations
A theory is supported by a large and usually growing body of evidence
Most nonscientists think of a theory as being nothing more than a “hunch.” Actually, a theory is accepted by most scientists as being factual. For example, the theory of relativity and the theory of evolution are supported by a significant amount of factual data.
Student Misconceptions and Concerns
1. The authors’ distinction between natural and supernatural explanations is essential to understanding the power and limits of scientific explanations. This distinction is important when distinguishing between science and supernatural explanations for the origin of life and the generation of biodiversity.
2. Contrasting the concept of faith with the tentative nature of science can help to define and distinguish science from other ways of knowing. Students sometimes enter science classes expecting absolutes of facts and rigid dogma. Instead, scientific knowledge reflects degrees of confidence closely correlated to the strength of evidence.
3. The common use of the terms law and theory often blur the stricter definitions of these terms in science. In general, laws describe and theories explain. Both are typically well-established concepts in science. A free online publication by the National Academy of Sciences helps to define these and related terms more carefully. See Chapter 1 of Teaching About Evolution and the Nature of Science at
Teaching Tips
1. Have your students explain why a coordinated conspiracy promoting a specific idea in science is unlikely to succeed. Have your students describe aspects of science that would check fraudulent or erroneous claims and/or political efforts.
Chapter 1: Exploring Life Dr. Nezar Redwan

33. 1.8 With hypothesis-based science, we pose and test hypotheses
Dead batteries
Observations
Question ر
Hypothesis #2:
Burned-out bulb
يعمل
Test prediction ا
Test falsifies hypothesis
Test does not falsify hypothesis
Prediction:
Replacing batteries
will fix problem ت
We solve everyday problems by using hypotheses
An example would be the reasoning we use to answer the question, “Why doesn’t the flashlight work?”
Using deductive reasoning we realize that the problem is either the:
(1) bulb or (2) batteries.
The hypothesis must be testable
The hypothesis must be falsifiable
A hypothesis must be testable—find ways to check the validity of the idea. A hypothesis must also be falsifiable—find ways to reveal whether such an idea is actually not true.
Teaching Tips
1. Consider using a laboratory exercise to have your students plan and perhaps conduct investigations using discovery science and/or investigations using a hypothesis-driven approach. Emphasize the processes and not the significance of the questions. Students can conduct descriptive surveys of student behavior (use of pens or pencils for taking notes, use of backpacks) or test hypotheses using controlled trials. Students will need some supervision and advice while planning and conducting their experiments.
2. Consider presenting your class with descriptions of several scientific investigations that you have written or found described in the media. Edit or include numerous examples of improper methodology (small sample size, several variables existing between the control and experimental groups, failure to specifically test the hypothesis, etc.). Let small groups or individuals analyze the experiments in class to identify the flaws. This critical analysis allows students the opportunity to suggest the characteristics of good investigations in class.
3. Have your students explain why a coordinated conspiracy promoting a specific idea in science is unlikely to succeed. Have your students describe aspects of science that would check fraudulent or erroneous claims and/or political efforts.

34. The Process of Science Deductive reasoning:
Draws specific conclusions based on information (facts)
Inductive reasoning:
Draws general conclusions based on specific (observations)
Chapter 1: Exploring Life Dr. Nezar Redwan

35. Steps in the Scientific Method
Observation
Question or problem
Hypotheses
Testable predictions
Experiments
Analyze data
Conclusions
Chapter 1: Exploring Life Dr. Nezar Redwan

36. hypothesis-based science
An example of
hypothesis-based science
Hypothesis #1:
Dead batteries
Observations
Question ر
Hypothesis #2:
Burned-out bulb
يعمل
Test prediction ا
Test falsifies hypothesis
Test does not falsify hypothesis
Prediction:
Replacing batteries
will fix problem ت
Figure 1.8A An example of hypothesis-based science.

37. A tentative explanation for observations Consistent with facts
The Hypothesis
A tentative explanation for observations
Consistent with facts
Can be tested
Tests can be repeated by others
Can be rejected
Chapter 1: Exploring Life Dr. Nezar Redwan

38. Testing Predictions by Experiment
Deductive product of a hypothesis
Control group
Closely matches experimental group
Experimental group
Differs from control group in 1 variable
Chapter 1: Exploring Life Dr. Nezar Redwan

39. 1.8 With hypothesis-based science, we pose and test hypotheses
Another hypothesis:
Mimicry helps protect nonpoisonous king snakes from predators where poisonous coral snakes also live
The hypothesis predicts that predators learn to avoid the warning coloration of coral snakes
Teaching Tips
1. Consider using a laboratory exercise to have your students plan and perhaps conduct investigations using discovery science and/or investigations using a hypothesis-driven approach. Emphasize the processes and not the significance of the questions. Students can conduct descriptive surveys of student behavior (use of pens or pencils for taking notes, use of backpacks) or test hypotheses using controlled trials. Students will need some supervision and advice while planning and conducting their experiments.
2. Consider presenting your class with descriptions of several scientific investigations that you have written or found described in the media. Edit or include numerous examples of improper methodology (small sample size, several variables existing between the control and experimental groups, failure to specifically test the hypothesis, etc.). Let small groups or individuals analyze the experiments in class to identify the flaws. This critical analysis allows students the opportunity to suggest the characteristics of good investigations in class.
3. Have your students explain why a coordinated conspiracy promoting a specific idea in science is unlikely to succeed. Have your students describe aspects of science that would check fraudulent or erroneous claims and/or political efforts.
Chapter 1: Exploring Life Dr. Nezar Redwan

40. 1.8 With hypothesis-based science, we pose and test hypotheses
Experimentation supports the prediction of the mimicry hypothesis:
Nonpoisonous snakes that mimic coloration of coral snakes are attacked less frequently
The experiment has a control group using brown artificial snakes for comparison
The experimental group is artificial snakes with the red, black, and yellow ring pattern of king snakes
The control group is the part of scientific inquiry that acts as a basis of comparison. The experimental group adds variables that will prove or disprove the hypothesis.
Teaching Tips
1. Consider using a laboratory exercise to have your students plan and perhaps conduct investigations using discovery science and/or investigations using a hypothesis-driven approach. Emphasize the processes and not the significance of the questions. Students can conduct descriptive surveys of student behavior (use of pens or pencils for taking notes, use of backpacks) or test hypotheses using controlled trials. Students will need some supervision and advice while planning and conducting their experiments.
2. Consider presenting your class with descriptions of several scientific investigations that you have written or found described in the media. Edit or include numerous examples of improper methodology (small sample size, several variables existing between the control and experimental groups, failure to specifically test the hypothesis, etc.). Let small groups or individuals analyze the experiments in class to identify the flaws. This critical analysis allows students the opportunity to suggest the characteristics of good investigations in class.
3. Have your students explain why a coordinated conspiracy promoting a specific idea in science is unlikely to succeed. Have your students describe aspects of science that would check fraudulent or erroneous claims and/or political efforts.
Chapter 1: Exploring Life Dr. Nezar Redwan

41. Eastern coral snake (poisonous)
Figure 1.8B Eastern coral snake (poisonous).
Eastern coral snake (poisonous)
Chapter 1: Exploring Life Dr. Nezar Redwan

42. Scarlet king snake (nonpoisonous)
Figure 1.8C Scarlet king snake (nonpoisonous).
Scarlet king snake (nonpoisonous)
Chapter 1: Exploring Life Dr. Nezar Redwan

43. Artificial king snake that was not attacked (left); artificial brown snake that was attacked by a bear (right)
Figure 1.8D Artificial king snake that was not attacked (left); artificial brown snake that was attacked by a bear (right).
Artificial king snake that was not attacked
Artificial brown snake that was attacked by a bear
Chapter 1: Exploring Life Dr. Nezar Redwan

44. You should now be able to
1. Describe life’s hierarchy of organization
2. Describe living organisms’ interactions with their environments
3. Describe the structural and functional aspects of cells
4. Explain how the theory of evolution accounts for the unity and diversity of life
5. Distinguish between discovery science and hypothesis-based science
6. Describe ways in which biology, technology, and society are connected
Chapter 1: Exploring Life Dr. Nezar Redwan

45. Training Questions (Choose the right answer)
Structure fits …………. at all levels of organization in the organism is a basic concept of biology
a) Species b) Adaptation c) Function
d) Strength e) Response
Which of the following is composed of a sequence of nucleotides?
a) DNA b) Starch c) Protein
d) RNA e) A and D are correct choices.
A (an)__________ is a group of organisms consisting of only one species that live in the same place at the same time and producing its own offspring.
a) Organism b) Population c) Ecosystem
Biosphere e) Community
The middle tier of life hierarchy is characterized by the _______ which is a living thing.
a) Organ b) Organism c) Species
d) Population e) Ecosystem
Living organisms have many __________ that distinguish them from nonliving:
a) Names b) Attributes c) Colors
d) Characters (Traits) e) B And D Are Correct Choices