Biol114: Principles of Biology II

Exploring LifeChapter 1, 2

The creation waits in eager expectation for the sons of God to be revealed. Romans 8:19

Biology is the scientific study of lifeBiology not just about memorizing factual details

2After this lecture, you should be able to Describe each themes help to organize biological informationNew properties emergent at each levelOrganisms interact with each other & the environment Life requires energy transfer and transformationStructure and function are correlated at all levelsCells are organisms basic units Continuity of life is based on heritable informationFeedback mechanisms regulate biological systemsEvolution accounts for the unity and diversity of life (etc)Understand the process of hypothesis-based science

1. Emergent Properties:Biologists explore life from the microscopic to the global scale.New properties emerge with each step upward in the hierarchy of biological orderEach level of biological organization has emergent properties The whole is greater than the sum of its partsResult from arrangements and interactions within systemsSystems biology

Study of Biological SystemsReductionism:Reducing complex systems to simpler components that are easier to studyExamples:Studies of DNA structure and the Human GenomeSystems Biology:Seeks to create models of the dynamic behavior of whole biological systemsExample:Map of interactions between proteins in a fruit fly cellRegulatory systems:Many biological processes are self-regulating

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6Examples:Water is made up of hydrogen and oxygen atoms. A mixture of oxygen and hydrogen will not give you the properties of water.Photosynthesis will only take place in an intact chloroplasts. Requires chlorophyll and other chloroplast molecules. Photosynthesis will not take place in a test tube even if chlorophyll and other chloroplasts components are mixed in a test tube.

Both organisms and their environments are affected by the interactions between them

7biosphereecosystemcommunitypopulationorganismorgan systemorgantissuecellorganellemolecular

Biology can be studied at different levels of organization:8Biosphereall of the environments on Earth that support lifeEcosystemall the organisms living + nonliving in a particular area and the physical components with which the organisms interactCommunitythe entire array of organisms living in a particular ecosystemPopulationall the individuals of a species living in a specific areaOrganisman individual living thingOrgan systemseveral organs that cooperate in a specific functionOrgana structure that is composed of tissues and that provides a specific function for the organismTissuesa group of similar cells that perform a specific functionCellsthe fundamental unit of lifeOrganellea membrane-bound structure that performs a specific function in a cellMoleculea cluster of small chemical units called atoms held together by chemical bonds

BiosphereEcosystemCommunityPopulationOrganismOrgan systemOrganTissuesCellsOrganelleMolecule

PhysiologistCell BiologistEcologistMolecularBiologistQuestion:Can you give specific examples at each hierarchy level? Atoms, molecules, organelles, cells, etc.

Arrange the following in the correct the hierarchy of biological organization, from least to most complex. Digestive system, hydrogen, intestinal cell organelle, protein, intestinal cell, intestinal tissue

1.2. hydrogen, protein, intestinal cell organelle, intestinal cell, intestinal tissue, Digestive system

112. Living organisms interact with other organisms and their environmentInteraction is between both living and nonliving components

System:A combination of components that form a more complex organization (e.g. Cells, organisms, and ecosystems)Ex. Ecosystem

Both benefit each other = symbiosisOne benefitWith the expense of the other = parasitismWith no effect on the other = commensalismWith harmful effect on the other = antagonismInteract, but no effect to each other = neutralismHarmful to each other = competition

2. Living organisms interact with other organisms and their environmentGlobal WarmingHumans have modified our environmentHalf the human-generated CO2 stays in atmosphere and contributes to global warmingGlobal warming is a major aspect of global climate changeImportant to understand effects of global climate change on the Earth and its populations

Global Warming Tax For Fuel!!!The global warming fee adds 2.25 percent to the full retail price of gasoline which includes existing taxes and fees in the State of California

153. Structure and function are correlated at all levels of biological organizationComparative study of animals reveals close correlation between structure & functionAnatomy Study structure of organismsPhysiology Study functions performed by organismModel organismsShort generation time

Study of Biological SystemsReductionism:Reducing complex systems to simpler components that are easier to studyExamples:Studies of DNA structure and the Human GenomeSystems Biology:Seeks to create models of the dynamic behavior of whole biological systemsExample:Map of interactions between proteins in a fruit fly cellRegulatory systems:Many biological processes are self-regulating

17Bacteria: Escherichia coli

Plants: Arabadopsis thalianaFungi: Saccharomyces cerevisiae

Nematode:Caenorhabditis elegans

Mouse: Mus musculusAnimalsModel Organisms

Fruit fly: Drosophila melanogaster

184. Life requires energy transfer and transformationOrganisms in an ecosystem will includes producers, consumers, decomposersTwo process related to energy:Recycling of chemical nutrients Flow of energy

Note the flow of energy:

Sunlight-> Producers -> Consumers -> Recycling

5. Cells: Basic units of lifeCell is the lowest level of organization that can perform all activities of lifeThe ability of cells to divide is the basis of all reproduction, growth, and repair of multicellular organisms

Forms of cellsAll cellsAre enclosed by a membraneUse DNA as their genetic informationEukaryotic cell has membrane-enclosed organellesLargest is usually the nucleusProkaryotic cell is simpler, usually smaller, and does not contain membrane-enclosed organelles

We will examine, Cell structure and organellesCell replicationMitosisMeiosis

6. Continuity of life based on heritable informationCells heritable information - DNADirects the cells activitiesDNA is the substance of genesGenes encode information for building proteins

24DNA Structure and FunctionEach chromosome is one long DNA molecule with many genesGenes encode information for building proteinsDNA is inherited by offspring from their parentsDNA controls the development and maintenance of organisms

25Genomics: Large-Scale Analysis of DNA SequencesAn organisms genome is its entire set of genetic instructionsThe human genome has been sequenced using DNA-sequencing machinesGenomics is the study of sets of genes within and between species

267. Feedback Regulation in Biological SystemsRegulatory systems ensure a dynamic balance in living systems Chemical processes catalyzed by enzymesMany biological processes are self-regulating: (product regulates the process)Negative feedbackPositive feedback

Negative feedbackAccumulation of product slows down the process itselfTo achieve homeostasisEx. Sweating to maintain 37oCPositive feedback Product speeds up its own productionEx. Uterus contraction during child birthStudy of Biological SystemsReductionism:Reducing complex systems to simpler components that are easier to studyExamples:Studies of DNA structure and the Human GenomeSystems Biology:Seeks to create models of the dynamic behavior of whole biological systemsExample:Map of interactions between proteins in a fruit fly cellRegulatory systems:Many biological processes are self-regulating

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8. Evolution to accounts for lifes unity and diversity Evolution seeks to give the history of life as an account of a changing Earth that is billions of years oldCharles Darwin published On the Origin of Species by Natural Selection in 1859Darwin made two main points Species show evidence of descent with modification from common ancestorsNatural selection is mechanism for descent with modificationDarwinism became almost synonymous with the concept of evolution

30As a Christian, how does the emphasis of evolution in Biology affect your faith and study of Biology?

The word science comes from the Latin to know. Is science the only way of knowing?

Does the scientific method have epistemological limits (i.e. are there questions beyond the scope of science)?

31Limitations of ScienceLimitations of science are set by its naturalismScience seeks natural causes for natural phenomenaScience cannot support or falsify supernatural explanations, which are outside the bounds of scienceRead:Chapter 3 The Scientific Enterprise in Biology Through the Eyes of Faith (by Richard Wright)What other limitations are pointed out in this chapter?

Process of Science

Biologists use various forms of inquiry to explore life Inquiry is the search for information and explanationTwo main processes of scientific inquiry:Discovery science: describe nature through careful observation and data analysisExamples: understanding cell structure, expanding databases of genomesHypothesis-based science: explain nature by proposing and testing hypothesesHypotheses are hypothetical explanations

Hypothesis: a proposed explanation for an observation that makes testable predictionsWe solve everyday problems by using hypothesesEx. Why doesnt a flashlight work?Using deductive reasoning we realize that the problem is either (1) the bulb or (2) the batteries.Further, a hypothesis must be testableand falsifiable

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36Hypothesis testing in science must have the following features: Appropriate controla control is a parallel experiment that alters one variable under studyReproducibilitythis refers to the confidence we can place in the experimental data: are our results reliable?

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Scarlet king snakeEastern coral snakeCase from the natureObservation: eastern coral snakes are poisonous and marked with a bold colour pattern. Scarlet king snakes are non-poisonous but have markings that mimic coral snakes.

38QuestionDoes the scarlet king snake benefit from its mimicry of the eastern coral snake?

HypothesisThe scarlet king snake avoids predation due to its mimicry of the eastern coral snake.

Predictions In areas with both species, predators will avoid scarlet king snakes; in areas with only scarlet king snakes, their pattern will have no protective effect.

39Experimental group: artificial scarlet king snakesControl group: artificial brown snakesIdeally, the control group should differ from the experimental group by only one variable the variable under study Reproducibility: place hundreds of each kind of snake.

Test: place artificial snakes in the environment and measure predation how frequently the models are attacked:

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Results:

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