Welcome to Biology… Everyone is a Biologist !

What is Biology? Bio = life ology = the study of Biology = the study of life

Three Objectives over the next three days: 1. What are the characteristics of life? 2. What is classification and why do we need it? 3. How do we study the natural world?

1. What are the Characteristics of Life? There are 7 characteristics that scientists use to classify something as “ALIVE”

The 7 characteristics of Life 1.Organization 2.Metabolism 3. Homeostasis 4. Reproduction 5. Growth and Development 6. Response to Stimuli 7. Change Through Time

1. Organization Living things are composed of cells Cells carry out the basic activities of life Cells are bounded by a membrane that separate it from the surrounding environment

Cells Cells are split into two major groups 1. Prokaryotes: older and simpler cells, usually single celled organisms Pro = before Kary = nucleus 2. Eukaryotes: newer and more complex cells, can be both single celled or multi cellular organisms Eu = true Kary = nucleus

Levels of organization Atom Molecule Organelle Cell Tissue Organ Organ system Multicellular organism

Levels of organization (cont)

2. Metabolism Metabolism – reactions that happen in your body to create ENERGY Why do organisms need energy? How do organisms obtain energy?

Metabolism (cont)

3. Homeostasis Homeostasis - the ability of an organism to maintain its internal environment despite conditions in the external environment. Example: human body temperature if body temperature rises, you sweat. if body temperature lowers, you shiver.

4. Reproduction Asexual reproduction - involves a single parent; offspring are genetically identical to the parent. Sexual reproduction - involves 2 parents; offspring are genetically diverse. Is it essential for an individual to reproduce?

5. Growth and development Living things grow and change over time Example: human and chicken embryos look very similar but develop into very different organisms

6. Response to stimuli Irritability - immediate response to a stimulus.

Response to stimuli (cont) Adaptation - an inherited behavior or characteristic that enables an organism to survive & reproduce. Over time, adaptations are modified by natural selection.

7. Change through time Life is always changing….. On the level of DNA…… Change = Evolution Evolution is the backbone of biology.

Change through time cont. Example: the flu virus mutated (changed) last year to create the H1N1 (swine) flu. Of course, we don’t consider viruses living organisms, but they do change over time

What are the Characteristics of Life? A Short Quiz: 1. What are the characteristics of life? 2. What is homeostasis? What is an example of homeostasis? 3. Is a computer living? Why or why not? 4. Why is energy required by living things?

What is classification and why do we need it? Biodiversity refers to the many different types of organisms on earth. How many different kinds of living organisms do you think there are on planet earth?

What is this animal called?

Possible names… Dog Siberian Husky Ayee (Somali) Pero (Spanish) Chien (French) What do you call this animal? Scientists call it Canis familiaris

Question to think about… Why do you think scientists worldwide need to use the same name for a particular organism? –Scientists have discovered over 2.5 million different kinds of organisms –There may be over 20 million “undiscovered” –A way to keep track of all organisms –So they know they are talking about the same organism

Carolus Linnaeus Carolus Linnaeus is the person responsible for developing a naming system called binomial nomenclature Binomial nomenclature gives all organisms a two- part name Genus name followed by species name Example – Homo sapien –What organism does that name belong?

A few more examples Ursus maritimus –Polar bear Carcharodon carcharias –Great white shark

Taxonomy Taxonomy is the science of naming organisms and assigning them to groups based on shared characteristics. Kingdoms are the largest group Each group gets smaller until you end up with a specific species (Domain) Kingdom Phylum Class Order Family Genus Species

How can you remember this order? KingdomKing PhylumPhillip ClassCame OrderOver FamilyFor GenusGood SpeciesSpaghetti –or whatever you can think of…

Example (Domain – Eukarya) Kingdom – Animalia Phylum – Chordata Class – Mammalia Order – Carnivora Family – Ursidae Genus – Ursus Species – arctos Scientific name – Ursus arctos Common name – grizzly bear or brown bear

Human classification DomainEukarya Kingdom Animalia Phylum Chordata ClassMammalia Order Primates Family Hominidae GenusHomo Speciessapien Scientific name: Homo sapien Common name: Humans

How do scientists decide how to group organisms? Taxonomists try to group organisms in ways that show their evolutionary relationships. They do this by studying homologous (similar) features in embryos and adult organisms.

Which two of these organisms are more closely related?

Dolphin and Human! Even though the dolphin and shark both live in the water; the dolphin and the human have more similarities and are therefore more closely related. All three belong to the Kingdom Animalia, and the Phylum Chordate (having a backbone), but dolphins and humans are in the Class Mammalia, while sharks belong to a different Class.

History of classification 2,400 years ago- Aristotle classified all organisms into two groups (plants or animals) What is wrong with the assumption that an organism is either a plant or an animal? Today most scientists use a six kingdom classification system What do you think the six kingdoms are???

Kingdom Bacteria TyGIF.

Kingdom Archaea Type:JPG

Kingdom Protista Type:JPG.

Kingdom Plantae Type:JPG

Kingdom Fungi Type:JPG

Kingdom Animalia Type:JPG

What is classification and why do we need it? A Short Quiz: 1. What is the order of classification from smallest to largest? 2. Which has more critters: an order or a genus? 3. What is taxonomy? 4. The scientific name includes the _____ and _____ name.

How do we study the Natural World? The Scientific Method!! Scientists use a systematic approach to gain understanding of the natural world.

1. Ask Questions (Observation) The scientific method starts when you ask a question about something that you observe: How, What, When, Who, Which, Why, or Where? In order for the scientific method to answer the question it must be about something that you can measure, preferably with a number.

Example “How many students came to school today?” can be answered by performing an experiment “Why did you come to school today?” cannot be answered by performing an experiment Using the information I just gave you write a question to be answered by the scientific method on a separate sheet of paper with a partner.

2. Do Background Research Rather than starting from scratch in putting together a plan for answering your question, you want to be a savvy scientist using library and Internet research to help you find the best way to do things and insure that you don't repeat mistakes from the past. Source validity – see language arts handout!

3. Construct Hypothesis A hypothesis is an educated guess about how things work: "If _____[I do this] _____, then _____[this]_____ will happen." You must state your hypothesis in a way that you can easily measure, and of course, your hypothesis should be constructed in a way to help you answer your original question.

Example: I observe that there are not many bees visiting my yard this summer (but I like bees and want them there). So I ask, “How can I attract more bees to my yard next summer?” I research bees and find out native flowers, especially native bee balm, attracts them to certain areas. Based on my research I propose a hypothesis; If I plant native bee balm in my yard then more bees will visit my yard. Your turn! Write a hypothesis to the question that you asked earlier.

4. Test with an Experiment Your experiment tests whether your hypothesis is true or false. It is important for your experiment to be a fair test. You conduct a fair test by making sure that you change only one factor at a time while keeping all other conditions the same. You should also repeat your experiments several times to make sure that the first results weren't just an accident.

Controlled Experiment Consists of one control group – the group with no change Also consists of one variable group – the group where one condition is changed Both groups are treated exactly the same except for the one variable being tested

Example: In my yard I set up two areas; a control area and a variable area. The control area will be just grass The variable area will be grass with the addition of native bee balm (which I am testing to see if it attracts bees) Both areas will be exactly the same (light, temperature, rainfall, etc.) except for the bee balm Now you! Write a simple experiment for your hypothesis

Two types of variables… Independent variable – the manipulated variable (or what we change) –Example: planting bee balm Dependent variable – the responding variable (or what happens) –Example: more bees come to my yard

5. Collect Data Two kinds of data are collected: –Quantitative – refers to numbers (Plant with added fertilizer grew 5 inched taller than plants without). Quantitative data is always expressed through charts and graphs –Qualitative – refers to observations that you make (Plants with added fertilizer are greener)

6. Analyze Data and Draw Conclusions Once your experiment is complete, you analyze your data to see if your hypothesis is true or false. Scientists often find that their hypothesis was false, and in such cases they will construct a new hypothesis starting the entire process of the scientific method over again. Even if they find that their hypothesis was true, they may want to test it again in a new way.

7. Reporting Results In this class you will always report your lab results! Results (also called the Conclusion in a lab write-up) include: –You will explain and interpret the results of your lab being very careful to explain any errors or problems you encountered. –The most important part of communicating results is that you demonstrate that you understand the point of the lab and can interpret what you have done in the lab.

Reporting Results cont –Draw conclusions from the results and answer the question, “So what?” What does this lab mean? What did you learn? –It is important that you make recommendations for improving the lab –Never, ever tell me how you feel about the lab, I don’t care if you had fun or not, I want to know what you learned. –Professional scientists do almost exactly the same thing by publishing their final report in a scientific journal or by presenting their results on a poster at a scientific meeting.

Issues Some scientists (and students) stop after they make a hypothesis and use their common sense instead of following the scientific method. Quantitative errors Numbers prove new ideas but scientist doesn’t see it Numbers do not prove new ideas but scientist thinks it does Bias! Some scientists want a certain outcome or result Scientists working for large oil companies will claim that burning fossil fuels does not contribute to increased carbon levels.

What is difference between hypothesis, theory & law? Hypothesis - “an educated guess”; a tentative explanation of phenomena. Theory - a widely accepted explanation of natural phenomena; has stood up to thorough & continual testing. Law - a statement of what always occurs under certain conditions.

How do we study the Natural World? A Short Quiz: 1. What is the first step in the scientific method? 2. In the scientific method, questions and/or observations lead to__________? 3. In the scientific method, an educated guess or possible explanation is called a ________?

Chapter 1 What is Life? How do we study the Natural World?