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Chapter 1 evolution, themes of biology, & scientific inquiry What is life? 5 unifying themes in Biology 1. Organization 2. Information 3. Energy and Matter 4. Interactions 5. Evolution  We recognize life by what living things do...

Chapter 1 evolution, themes of biology, & scientific inquiry What is life? 5 unifying themes in Biology 1. Organization 2. Information 3. Energy and Matter 4. Interactions 5. Evolution  We recognize life by what living things do 93% https://www.researchgate.net/publication/328111571_Association_between_dietary_calcium_and_dietary_Vitamin_ D_deficiency_body_composition_and_bone_mass_in_healthy_adults  How do mice illustrate the unifying themes of biology? Evolution Inland Beach mouse mouse Organization Information Gene for brown fur Organ (heart) Tissue Gene for white fur Cell Molecule Flow of energy Interactions Energy & Cycling of matter matter Figure 1.1b © 2021 Pearson Education, Inc. What is life? 5 unifying themes in Biology 1. Organization 2. Information 3. Energy and Matter 4. Interactions 5. Evolution  1. Organization 1. Biosphere The Biosphere 2. Ecosystems 3. Communities 4. Populations 5. Organism 6. Organs 7. Tissues 8. Cells 9. Organelles 10. Molecules © 2021 Pearson Education, Inc. Molecules Figure 01.03a Exploring levels of biological organization The Biosphere All life on Earth, and all the places life exists on Earth. (anywhere from the sediment below the ocean floor to the atmosphere kilometers above the surface) Figure 01.03b Ecosystems All components in a particular environment (ex. meadow, forest, grassland, desert, coral reef, etc.) – Includes the living things and the nonliving things that they interact with (soil, water, atmospheric gases, light). Figure 01.03c Communities The variety organisms inhabiting a particular ecosystem. (Ex. plants, animals, fungi, bacteria, etc.) Figure 01.03d Populations All the individual organisms of the same species that are living within a specific area. Individuals in the same population can interbreed. (Ex. Lupines) Figure 01.03e Organisms An individual living thing. Each individual plant, animal, fungus, and bacterium is an organism. Figure 01.03f Organs A body part that has a specific function. (Ex. Organs in a plant include leaves, stems, and roots.) Organs are made up of tissues. Figure 01.03g Tissues 50 µm Tissues are groups of cells that work together to perform a specialized function. (Ex. The tissue on the left side functions to convert light energy into chemical energy, in a process called photosynthesis.) Figure 01.03h Cell 10 µm Cells Some organisms have 1 cell that performs all it’s functions. Some organisms have many cells. Multicellular organisms have specialized cells Cells are made that perform specialized functions. up of organelles (Ex. A function of this leaf cell is photosynthesis) Figure 01.03i Chloroplast 1 µm Organelles A functional component of cells. (Ex. A chloroplast is an organelle found in leaf cells. They function to produce energy from photosynthesis) Figure 01.03j Atoms Chlorophyll molecule Molecules A chemical structure consisting of 2+ atoms. (Ex. Chloroplast organelles contain chlorophyll molecules.) Figure 1.3 Questions? © 2021 Pearson Education, Inc. What is life? 5 unifying themes in Biology 1. Organization 2. Information 3. Energy and Matter 4. Interactions 5. Evolution  2. Information Genetic information is contained in molecules of DNA (deoxyribonucleic acid) A double helix consisting of 2 strands One of the building blocks of those strands are nucleotides. Information is encoded in the sequence of nucleotides 4 nucleotides in DNA: A, T, C, G © 2021 Pearson Education, Inc.  2. Information Nearly every cell in our bodies contain DNA. What are cells made up of? Hint: Think of the levels of organization we just covered. DNA is found in an organelle called the nucleus © 2021 Pearson Education, Inc. Figure 1.6 Nuclei containing DNA Genes are the units of inheritance Sperm cell Egg cell © 2021 Pearson Education, Inc. Figure 1.6 All the genetic information Nuclei containing DNA an organism inherits is referred to as it’s genome 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 © 2021 Pearson Education, Inc.  2. Information A single molecule of DNA contains many genes. Genes are segments of DNA that encode for something. Usually a molecule like a protein. Gene expression: when a gene is used to make a protein (or another cellular product). © 2021 Pearson Education, Inc. DNA is like an instruction manual for making cell products (like proteins) The sequence of nucleotides is important. If the sequence changes, the instructions change, and could impact the product! Stop & Think How many copies of this specific hemoglobin gene do humans have? Stop & Think What level of organization is hemoglobin? What is the specialized function of hemoglobin? What is the specialized cell that contains hemoglobin? What is life? 5 unifying themes in Biology 1. Organization 2. Information 3. Energy and Matter 4. Interactions 5. Evolution  3. Energy & Matter ENERGY FLOW What is the name of this process? Light Plants energy convert Heat is lost comes sunlight to from the from the chemical ecosystem. sun. energy. Organisms use chemical energy to do work. Figure 01.09 © 2021 Pearson Education, Inc. 3. Energy & Matter ENERGY FLOW Energy flow starts from the sun in the form of light Producers (plants and some other organisms that do photosynthesis) convert light energy from the sun into chemical energy. – Sugars are an example of chemical energy. Consumers are organisms that feed on other organisms or their remains – When consumers feed on producers, that producer’s chemical energy is passed to the consumer. – Other consumers can eat that consumer, and collect chemical energy from their body. When an organism uses chemical energy to perform work (like contracting muscles or growing new cells) some of that energy is lost to the environment as heat.  3. Energy & Matter ENERGY FLOW Chemicals pass to organisms that eat the plants. Decomposers Plants take up return chemicals from chemicals to the soil and air. the soil. Chemicals Figure 01.09 © 2021 Pearson Education, Inc.  Questions? 3. Energy & Matter ENERGY FLOW Chemicals pass to organisms that eat the plants. Light Plants energy convert Heat is lost comes sunlight to from the from the chemical ecosystem. sun. energy. Organisms use chemical energy to do work. Decomposers Plants take up return chemicals from chemicals to the soil and air. the soil. Chemicals Figure 01.09 © 2021 Pearson Education, Inc. What is life? 5 unifying themes in Biology 1. Organization 2. Information 3. Energy and Matter 4. Interactions 5. Evolution  Stop & Think 4. Interactions What are the levels of biological hierarchy? Interactions can occur at any level in the biological hierarchy. We’ll discuss 2 categories of interactions: External interactions: between an organism & it’s surroundings Internal interactions: inside an organism  External Interactions An Organism’s Interactions with Other Organisms & the Physical Environment Interactions Interaction with the with other physical organisms environment © 2021 Pearson Education, Inc. Internal Interactions Interactions Within Organisms When some sort of stimulus is detected inside an organism, it triggers a response within that organism. There organism uses feedback to regulated it’s response. There are 2 types of feedback regulation: 1. Negative Feedback: The response will decrease the stimulus. 2. Positive feedback: The response will increase the stimulus. Stop & Think If your core body temperature is too high, would you want to fix this situation with positive feedback or negative feedback?  Stop & Think If your blood doesn’t have enough water in it, would you want to fix this situation with positive feedback or negative feedback? If you are pregnant and going into labor, your uterus will detect the pressure the baby is putting on the cervix. Would you want positive or negative feedback? What is life? 5 unifying themes in Biology 1. Organization 2. Information 3. Energy and Matter 4. Interactions 5. Evolution  5. Evolution Evolution: organisms are modified descendants of common ancestors Species A common Species B ancestor Species C Species D Species E Species F © 2021 Pearson Education, Inc.  5. Evolution Evolution: organisms are modified descendants of common ancestors Natural selection drives evolution. Nature “selects” certain traits to survive and others to die out. © 2021 Pearson Education, Inc.  5. Evolution Evolution: organisms are modified descendants of common ancestors Natural selection drives evolution. Nature “selects” certain traits to survive and others to die out. Evolution explains how we have such a wide diversity of traits between species. © 2021 Pearson Education, Inc. 5. Evolution Evolution alsos explains how different species can have common traits that they inherited from a common ancestor. A striking unity underlies the diversity of life; for example, DNA is the universal genetic language common to all organisms Unity is evident in the similar skeletons of different animals What is life? 5 unifying themes in Biology 1. Organization 2. Information 3. Energy and Matter 4. Interactions 5. Evolution Questions? What is life? Some Properties of Life: Order Evolutionary Adaptation Regulation Energy processing Growth and development Response to environment Reproduction © 2017 Pearson Education, Inc. What is life? 5 unifying themes in Biology 1. Organization 2. Information 3. Energy and Matter 4. Interactions 5. Evolution Classification of Life Classification of Life Taxonomy: the science of classifying organisms Domain Kingdom Phylum Class Order Family Genus All living things can be classified in one of 3 Species domains  Classification of Life: Domains These domains consist of single-celled prokaryotic organisms. Prokaryotic cells do not have membrane-enclosed organelles, like a nucleus  Classification of Life: Domains This domain consists of eukaryotic organisms. It includes both single-celled organisms and multicellular organisms. Eukaryotic cells DO have membrane-enclosed organelles, like a nucleus  Questions? Figure 1.13 Scientific Inquiry Scientific Method Set of steps to arrive at scientific results Make observations Ask questions Form a hypothesis (a proposed explanation) – Can be tested with an experiment – Can be proven false Conduct an experiment to test your hypothesis Analyze Results Figure 01.22 Observation: Desk lamp doesn’t work. Question: Why doesn’t the desk lamp work? Hypothesis #1: Hypothesis #2: Bulb is burnt out. Bulb is improperly screwed in. Prediction: Replacing Prediction: Reinstalling bulb will fix problem. bulb will fix problem. Test of prediction: Test of prediction: Replace bulb. Reinstall bulb. Result: Result: Lamp works. Desk lamp doesn’t work. Hypothesis is supported. Hypothesis is not supported. Experimental Design Good experiments test only 1 variable – Variables = any factor that can change Experimental Design Controlled experiments compare an experimental group to a control group If you want to test the effects of 7-up on plant growth, what would be the experimental group? What would be the control group? What is the variable that is being tested? How do we control for other variables? Experimental Design Good experiments test only 1 variable – Variables = any factor that can change The variable that the scientists want to test is called the independent variable. The result the scientist wants to measure is called the dependent variable. If you want to test the effects of 7-up on plant growth, what is the independent variable? What is the dependent variable? Chapter 1 5 Themes of Life Classification of Life Scientific Inquiry