Chapter 1: The Study of Life Section 1.1: The Study of Life Section 1.2: Unifying Themes of Biology Section 1.3: Scientific Thinking and Processes

I. What is Biology? Biology: The study of all living and once living things If you break it down: Bio = means Life logy = means the study of Biologist: A person who studies living and once living things

Earth is home to an incredible diversity of life Biosphere - Bio = Life - sphere = circle Biosphere = Earth It is where all living things and all the places they are found. Includes environments (ecosystems) such as deserts, grasslands, forests, saltwater and freshwater, etc.

- diversity = variety/differences Biodiversity Video Biodiversity - Bio = “life” - diversity = variety/differences Biodiversity = all the variety of life across the biosphere. Why is biodiversity greater closer to the equator? Species – is a particular type of living organism that can reproduce by interbreeding among themselves to produce fertile offspring. Approximately 10,000 species discovered a year. Approximately 50,000 species become extinct every year.

Characteristics of Life - Video What does it mean to be living? - To be considered LIVING, ALL Characteristics of Life must be met. - Organism – is any individual living thing. 1. All living organisms are made of CELLS The cell is the basic unit (building blocks) of structure and function in all living things (life) Some organisms are unicellular - one-celled (all bacteria) Some are multicellular - made of many cells Intro to cells video

2. Need for Energy: Living organisms need a source of chemical energy. Characteristics of Life 2. Need for Energy: Living organisms need a source of chemical energy. - Three ways an organism obtains food Consumers – (Animals) that rely on other organisms for food. Producers – (plants) make or produce their own food through photosynthesis. Decomposers – (bacteria, fungi) Break down items by releasing digestive enzymes onto it. * Energy is important for metabolism! Metabolism – all the chemical processes in the the body that build up or break down materials.

Characteristics of Life 3. Living organisms RESPOND TO THE ENVIRONMENT Organisms must react to a stimulus (stimuli) in their environment in order to survive. A stimulus causes a reaction. Physical – light, temperature and touch. Reaction video

Characteristics of Life 4. Reproduction and Development - Reproduction - A process of creating offspring (new individuals of same species). *Includes the passing of genetic material, DNA, from parent to offspring. *DNA = Deoxyribonucleic Acid *This is Important for the survival of a species. *There are 2 types of reproduction.

TWO TYPES of REPRODUCTION A. Sexual Reproduction Formation of a new organism by the union of 2 reproductive cells (sperm and egg) The offspring will be genetically different from the parents. B. Asexual Reproduction video Formation of a new organism from only 1 cell Offspring will be genetically identical to the parent cell. Example: a bacterial cell dividing into two identical cells.

Characteristics of Life - Development Organisms grow in size (length and width) using materials and energy from the environment As a living organism grows; body structures develop and change. Examples: Adolescents change into adults (puberty) Maggot develops into a fly Caterpillar develops into a butterfly Tadpole develops into a frog

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II. Unifying Themes of Biology 1. All levels of life have systems of related parts. - System – is an organized group of related parts that interact to form a whole. - Examples: - Ecosystem Eco = environment System = related parts - Ecosystem – all the living and nonliving parts interacting with one another. - Ecosystem video

Unifying Themes of Biology 2. Structure and Function are related. - What something does (function) in an organism is directly related to its shape or form (structure). - List five cell examples below: Structure Function

Unifying Themes of Biology 3.Maintaining Homeostasis in order to survive in diverse environments. - Homeostasis - Homeo = constant/remains the same - stasis = stable - Homeostasis – maintaining a constant internal condition with changing environmental conditions. - Examples - Body temperature and outside temperature - Shiver when cold - Sweat when hot - thirsty when you need water. - Blood sugar (glucose/insulin) Video (girl) Homeostasis reaction video

Unifying Themes of Biology 4. Evolution explains the unity and diversity of life - Unity – how things are the same - Diversity – how they are different - Two organisms can be very different like a human and bacteria but can share similar cell characteristics. - Evolution – a change over a long period of time. - One way evolution occurs is through adaptations. - Adaptation - a trait that makes a living organism better able to survive. Evolution Video

1.3 Scientific method A series of steps used to solve a problem Make an observation - Use your senses to record data and study the world. - Observations can recorded as data. 1. Qualitative data - include descriptions such as sights, sounds, touch, taste and smells. 2. Quantitative data – can be measured or counted such as mass, volume, temperature.

Scientific method A series of steps used to solve a problem 2. Form a hypothesis- Based on your observations and data research, what do you think will happen? Or what could be a possible explanation? - A hypothesis is a proposed answer for a scientific question that can be tested. - Always written as an “if” “then” “because” sentence. - If I place ice in boiling water then the ice will melt because heat causes the molecules to move faster. - When data does not support a hypothesis, it is rejected.

Scientific method Conduct a controlled experiment - Testing the hypothesis using a step-by-step procedure. - A controlled experiments tests 1 variable at a time. 1. An independent variable - a condition that is changed or manipulated by a scientist. - What you are testing. 2. A dependent variable – what you are observing and measuring during the experiment. - Everything in a controlled experiment remains constant (the same) except for one thing that you change. Scientific method

Scientific method 3. Controlled experiment continued - A controlled experiment needs to have 2 groups. 1. The experimental group – receives the independent variable. 2. The control group – is used for comparison to the experimental group.

Scientific method 4. Analyze the Data – Interpret the recorded results of the experiment in order to make a conclusion. 5. Draw a conclusion – Evaluate the results. - A conclusion should address the following: Was the hypothesis correct? How does the data support your conclusion? Were there errors that might have changed the results? How might those errors be avoided next time?

SCIENTIFIC METHOD CONTINUED - Experiments should be repeated many times to check the results for consistency. If the results are not the same then a new hypothesis needs to be made. A hypothesis can become a theory if it is tested over and over again and is supported with a wide range of evidence. A theory can be used to predict the outcome of other events. Theories are not proven to be true. Theories can change based on new evidence. Are supported by a wide range of evidence.

SCIENTIFIC METHOD CONTINUED