01Big Ideas in Bio

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2009-2010 “Big Ideas” in Biology AP Bio 2009-10

How do you define “life”? : 

How do you define “life”? Not as simple as it seems Defies a one-sentence definition

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Order Evolutionary adaptation Response to the environment Reproduction Growth and development Energy processing Regulation Fig. 1-3

Why study “big ideas” of Biology? : 

Why study “big ideas” of Biology? Biology is an ever expanding body of knowledge WAY too much to memorize!! need to generalize to understand create a framework upon which to organize new knowledge “big ideas” (themes) are the key to understanding and connecting biological concepts

The “Big Ideas” : 

The “Big Ideas” Scientific Method Evolution Organization Matter & Energy transfer Relationship of structure to function The Cell Continuity of Life- DNA Regulation & Feedback

Big Idea 1: Scientific Method : 

Big Idea 1: Scientific Method Science is a process of INQUIRY

Science as a process of inquiry : 

Science as a process of inquiry Built on repeatable observations & testable, falsifiable hypotheses

Science, technology & society : 

Science, technology & society Science & technology must function within the rules of society ethics

Big Idea 2: Evolution : 

Big Idea 2: Evolution Evolution makes sense of everything we know about living organisms Organisms living on Earth are modified descendents of common ancestors

Natural selection : 

Natural selection Evolutionary change is a product of the process of natural selection Organisms don’t adapt; Organisms have adaptations.

"Nothing in biology makes sense except in the light of evolution." : 

"Nothing in biology makes sense except in the light of evolution." -- Theodosius DobzhanskyMarch 1973 Geneticist, Columbia University (1900-1975)

Evolution explains unity & diversity : 

Evolution explains unity & diversity Unity what do organisms have in common & why do similarities exist? common biochemistry & physiology evolutionary relationships connected through common ancestor Diversity but why are there differences? natural selection adaptations allow different individuals to survive in different environments

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Fig. 1-22 COMMON ANCESTOR Warbler finches Insect-eaters Seed-eater Bud-eater Insect-eaters Tree finches Green warbler finch Certhidea olivacea Gray warbler finch Certhidea fusca Sharp-beaked ground finch Geospiza difficilis Vegetarian finch Platyspiza crassirostris Mangrove finch Cactospiza heliobates Woodpecker finch Cactospiza pallida Medium tree finch Camarhynchus pauper Large tree finch Camarhynchus psittacula Small tree finch Camarhynchus parvulus Large cactus ground finch Geospiza conirostris Cactus ground finch Geospiza scandens Small ground finch Geospiza fuliginosa Medium ground finch Geospiza fortis Large ground finch Geospiza magnirostris Ground finches Seed-eaters Cactus-flower-eaters The organisms that show the most recent divergence are the most closely related Watch orientation of tree!

Organization : 

Organization Making sense out of the diversity Hierarchical scheme Eastern gray squirrel Sciurus carolinensis

Three Domains of Life : 

Three Domains of Life Bacteria, Archaea, Eukarya Eukarya Bacteria Archaea

Big Idea 3: Organization/Emergent Properties : 

Big Idea 3: Organization/Emergent Properties New properties emerge at each level in the biological hierarchy Life can be studied at different levels from molecules to the entire living planet The study of life can be divided into different levels of biological organization

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Fig. 1-4 The biosphere Communities Populations Organisms Ecosystems Organs and organ systems Cells Cell Organelles Atoms Molecules Tissues 10 µm 1 µm 50 µm

Emergent Properties : 

Emergent Properties Emergent properties result from the arrangement and interaction of parts within a system Emergent properties characterize nonbiological entities as well For example, a functioning bicycle emerges only when all of the necessary parts connect in the correct way

Systems Biology : 

Systems Biology A system is a combination of components that function together Systems biology constructs models for the dynamic behavior of whole biological systems The systems approach poses questions such as: How does a drug for blood pressure affect other organs? How does increasing CO2 alter the biosphere?

Big Idea 4: Matter & Energy Transfer : 

Big Idea 4: Matter & Energy Transfer Organisms interact with their environments, exchanging matter and energy Every organism interacts with its environment, including nonliving factors and other organisms Both organisms and their environments are affected by the interactions between them For example, a tree takes up water and minerals from the soil and carbon dioxide from the air; the tree releases oxygen to the air and roots help form soil

Energy transfer : 

Energy transfer Life is an open system need input of energy energy flows through energy comes in,energy goes out need a constant input need input of materials nutrients are recycled around & around ENTROPY RULES! DECOMPOSERS RULE, too! nutrients

Ecosystem Dynamics : 

Ecosystem Dynamics The dynamics of an ecosystem include two major processes: Cycling of nutrients, in which materials acquired by plants eventually return to the soil The flow of energy from sunlight to producers to consumers Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

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Fig. 1-5 Sunlight Ecosystem Heat Heat Cycling of chemical nutrients Producers (plants and other photosynthetic organisms) Chemical energy Consumers (such as animals)

Energy utilization : 

Energy utilization You think they’re eating…They’re harvestingenergy!

Energy Conversion : 

Energy Conversion Work requires a source of energy Energy can be stored in different forms, for example, light, chemical, kinetic, or thermal The energy exchange between an organism and its environment often involves energy transformations Energy flows through an ecosystem, usually entering as light and exiting as heat

Big Idea 5: Structure is Related to Function : 

Big Idea 5: Structure is Related to Function Structure and function of living organisms are closely related For example, a leaf is thin and flat, maximizing the capture of light by chloroplasts

Form follows function : 

Form follows function The alignment of structure & function is seen at all levels of biology organism cell organelle organ

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(a) Wings (c) Neurons (b) Bones Infoldings of membrane Mitochondrion (d) Mitochondria 0.5 µm 100 µm Fig. 1-6

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Fig. 1-6a (a) Wings

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Fig. 1-6b (b) Bones

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Fig. 1-6c (c) Neurons 100 µm

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Fig. 1-6d Infoldings of membrane Mitochondrion (d) Mitochondria 0.5 µm

Big Idea 6: Cells are an organism’s basic units of structure and function : 

Big Idea 6: Cells are an organism’s basic units of structure and function The cell is the lowest level of organization that can perform all activities required for life All cells: Are enclosed by a membrane Use DNA as their genetic information The ability of cells to divide is the basis of all reproduction, growth, and repair of multicellular organisms

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A eukaryotic cell has membrane-enclosed organelles, the largest of which is usually the nucleus By comparison, a prokaryotic cell is simpler and usually smaller, and does not contain a nucleus or other membrane-enclosed organelles Bacteria and Archaea are prokaryotic; plants, animals, fungi, and all other forms of life are eukaryotic

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1 µm Organelles Nucleus (contains DNA) Cytoplasm Membrane DNA (no nucleus) Membrane Eukaryotic cell Prokaryotic cell Fig. 1-8

Big Idea 7: Continuity & change : 

Big Idea 7: Continuity & change Continuity of life is based on heritable information in the form of DNA DNA – the genetic material – carries biological information from one generation to the next You can make more,a lot like you! T R A I T

DNA Structure and Function : 

DNA Structure and Function Each chromosome has one long DNA molecule with hundreds or thousands of genes DNA is inherited by offspring from their parents DNA controls the development and maintenance of organisms

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Fig. 1-10 Nucleus DNA Cell Nucleotide (a) DNA double helix (b) Single strand of DNA

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Nuclei containing DNA 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 Fig. 1-9

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Genes control protein production indirectly DNA is transcribed into RNA then translated into a protein An organism’s genome is its entire set of genetic instructions

Big Idea 8 : 

Big Idea 8 Feedback mechanisms allow biological processes to self-regulate Negative feedback means that as more of a product accumulates, the process that creates it slows and less of the product is produced Positive feedback means that as more of a product accumulates, the process that creates it speeds up and more of the product is produced

Regulation : 

Regulation Organisms need to maintain a “steady state” in the face of changing conditions maintain homeostasis achieve this through feedback monitor the body like a thermostat turn on when it’s needed, off when its not

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Fig. 1-13 Negative feedback  Excess D blocks a step D D D A B C Enzyme 1 Enzyme 2 Enzyme 3 D (a) Negative feedback W Enzyme 4 X Positive feedback Enzyme 5 Y + Enzyme 6 Excess Z stimulates a step Z Z Z Z (b) Positive feedback

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Fig. 1-13a Excess D blocks a step (a) Negative feedback Negative feedback D D D D C B A Enzyme 1 Enzyme 2 Enzyme 3 –

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Fig. 1-13b Excess Z stimulates a step (b) Positive feedback Z Positive feedback Enzyme 4 Enzyme 5 Enzyme 6 Z Z Z Y X W +

You should now be able to: : 

You should now be able to: Briefly describe the unifying themes that characterize the biological sciences Distinguish among the three domains of life, and the eukaryotic kingdoms Distinguish between the following pairs of terms: discovery science and hypothesis-based science, quantitative and qualitative data, inductive and deductive reasoning, science and technology Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

Any Questions?? : 

2009-2010 Any Questions??