100A – Introductory Biology 1 Lecture: MW 9:50 – 11:05 AM, ASC-B 132 Lab classroom: ASC-B 344 Dr. Patrick Krug pkrug@calstatela.edu Office hours: W, 1-2 PM NOTE: 3- 4 PM, this Wed only LaKretz Hall room 314, 3-2076 Course web page – http:// instructional1.calstatela.edu/pkrug/Bio100A note: NO “www” in front! skeletonized lectures missing some text will be posted before class - download, print out, bring to class for note-taking weekly study guides will be posted, with sample exam questions 100A – Introductory Biology 1 Lecture: MW 9:50 – 11:05 AM, ASC-B 132 Lab classroom: ASC-B 344 Dr. Patrick Krug pkrug@calstatela.edu Office hours: W, 1-2 PM NOTE: 3- 4 PM, this Wed only LaKretz Hall room 314, 3-2076 Retaking class – if satisfied with lab grade from a prior offering, see me about re-taking the lecture portion only as credit-by-exam Adds will be done only if there is space in a given recitation + lab section Recitation + lab sections: TA 02+03 M 11:15 am – 2:45 pm LeBlanc, Mark 05+06 M 3:10 – 6:40 pm Chau, Kevin 08+09 W 11:15 am – 2:45 pm LeBlanc, Mark 11+12 W 3:10 – 6:40 pm Santhanam, Ash 14+15 T 8:30 am – 12:00 pm Barrett, Craig 17+18 T 12:10 – 3:40 pm Meas, Diane 20+21 R 8:30 am – 12:00 pm Johnson, Daisy 23+24 R 12:10 – 3:40 pm Torres, Lisa Structure of 100A Required Textbook: Principles of Biology, Nature Education e-text. Required Purchase access to this class at the CSULA Bookstore - this is an online text that will be used for the entire 100ABC series Required Lab Manual: Gamon JA, Krug P, Salmassi T (2005) Diversity of Life, 2nd edition - available at campus bookstore, or at the Student Bookmart (1725A N. Eastern Ave, Los Angeles, 323-262-5511) Structure of 100A Point assignment: midterm final exam 8 lab quizzes 8 recitation assignments 8 lab activities writing assignment Total 60 120 80 (10 pts each) 40 (5 pts each, all or nothing) 40 (5 pts each, all or nothing) 20_____________ 360 points Note: HALF your grade comes from the lab portion of class! Take lab very seriously. You’re not leaving early. Your TA is your new best friend. “How am I doing?” This class is graded on a curve, which means your grade depends on how you do, relative to everyone else. The mean (= average) score is roughly a low B One standard deviation above the mean is where A’s start One SD below the mean is the C-range You need a C or better to advance to 100B Flashcards The #1 reason students don’t do well in 100A is they get overwhelmed by the vocabulary Required: You must make 10 flashcards per lecture (20 per week) and show them to your lab TA You will not get credit for the recitation activity if you do not show your 20 cards from the previous week Flashcards can be on 3 x 5 index cards, or pieces of paper, but they must have a vocabulary word or phrase on the front and the definition on the back In my lectures, BOLDED terms in colored fonts are terms I expect you to know for exams, so these would be good ones to use and to learn – use the flashcards to study in your spare time “Why didn’t I do better?” To do well in this class, you MUST: - review your vocabulary flashcards every week - attend ALL lectures - spend the full 2 ½ hr in every lab - the lab manual is also your study guide - do not expect to study for an exam in one week - come to office hours regularly, to go over unclear material - ask questions to stay awake and engaged - DO THE STUDY GUIDES and go over your answers with clever classmates, your TA, and me during office hours Academic Honesty ALL students are required to sign a pledge stating that they understand the university academic honesty policy A copy of the full policy is available in the lab to read, and a link to the website is provided on the syllabus You will FAIL the course for a SINGLE instance of plagiarism - written assignment in lab will use proper citations Excessive talking in lectures = I toss you out Consideration of Others Excessive talking in lectures = I toss you out The people around you are paying money to learn, not to be distracted by your conversation God help you if I hear other students shushing you because of your conversations Likewise, stay off the web and use your laptop to take notes in my lectures, nothing else Main themes of 100A (1) Ecology - how organisms interact with their living and non-living (abiotic) environment A) What controls the distribution and abundance of organisms? B) What controls the biodiversity of an area – i.e., how many different species are found there? C) What ecosystem processes keep the species in a community and their physical environment in balance? D) What is the ecological niche of an organism: the living and abiotic resources or requirements used to survive Main themes of 100A (2) Evolution - genetic change in a population over time Understand: A) How organisms that belong to biologically meaningful groups are related by descent from a common ancestor B) The adaptations of an organism that make it suited to its niche are the product of natural selection C) The forces that generated Earth’s biodiversity (the number of different species in a place) D) The form and function of key features in successful groups what is it made of? what does it do? success = many species in that group What’s this “life” stuff, anyway? Reproduction - make more of your own kind Energy transfer, metabolism Membranes, cells Respond to the environment (regulation) Organization - there is an order to living things Information content (DNA, RNA) Common features of all cellular life Information stored in DNA; genes expressed through RNA Same 20 amino acids used to make proteins, which then catalyze chemical reactions in the cell Same genetic code used to direct the synthesis of proteins Membranes separate inside from outside Generation of ATP (stored energy) by electron transport systems, made up of proteins embedded in membranes Levels of Biological Organization molecules - proteins, DNA, sugar, water 100B cells - smallest unit of life (perhaps) tissues - 2 or more cell types, working together (muscles, nerves) organs - 2 or more tissues form a structure performing a function for the organism (leaf, heart) 100C Levels of Biological Organization molecules Organisms cells Communities 100A tissues Ecosystems organs Biosphere Levels of Biological Organization molecules Organisms individual living things cells Communities all species in an area tissues Ecosystems species + abiotic things they interact with, in an area (forests, deserts, coral reefs) organs Biosphere all the ecosystems of the earth, combined into one planet-wide system Earth as a System Aug 1992, NASA a complex system has its own properties that are more than the sum of its parts the earth functions as a system, with different biomes connected through global processes like climate and the carbon cycle Earth has changed over 4.6 billion years Early conditions (first 800 MY): hostile to “life as we know it” bombardment from outer space extremely hot volcanic activity – release of SO2 (acidic) no atmosphere Later conditions early atmosphere: lots of CO2, no O2 (oxygen gas) or O3 (ozone) Our oxygen-rich atmosphere was eventually created by microbes (cyanobacteria) producing O2 as a by-product of photosynthesis -- a fairly recent development in our plant’s hsitory Evidence for early life 3.8 BYA – Evidence from molecular (DNA) studies (early life was hot, lived on chemical energy) – Geological evidence (organic deposits in earliest sedimentary rocks) 3.5 BYA – Possible fossil bacteria with organic inclusions 3.2 BYA – Filamentous microfossils 3.0 – 2.7 BYA – Developed bacterial communities (photosynthesizers that built stromatolites) BYA = billion years ago A “clock” view of life’s history bacteria appear very early on Raven & Johnson 1992 A “clock” view of life’s history bacteria appear very early on life began changing the atmosphere Raven & Johnson 1992 A “clock” view of life’s history bacteria appear very early on cells got more complex (eukaryotes) life began changing the atmosphere Raven & Johnson 1992 A “clock” view of life’s history multi-cellular life appears bacteria appear very early on cells got more complex (eukaryotes) life began changing the atmosphere Raven & Johnson 1992 Stromatolites, modern “rock” formations built as sediment sticks to mats of bacteria (Australia, ~3,000 yr old) Fossil stromatolite, ~ 3.5 billion yr old The age of fossil stromatolites suggest bacteria may have appeared almost as soon as the planet was cool enough to permit life, ~3.9 billion years ago (MY) Evolution of the Earth’s atmosphere % of today’s oxygen 100% 10% 1% 0.1% millions of years ago life created our oxygen-rich atmosphere Graedel & Crutzen 1995 Aug 1992, NASA Earth as a System Biomes are big terrestrial ecosystems, defined by a dominant vegetation type, and distinctive abiotic environmental conditions Examples: - Arctic tundra - tropical rainforest - temperate dry forest 14 terrestrial biomes The biome that develops in an area is mainly determined by (1) average temperature and rainfall, (2) variation in temp, rain These factors regulate how much photosynthesis occurs, and when Global Carbon Cycle Photosynthesis & respiration drive the exchange of carbon (as CO2) between the biosphere & the atmosphere Biological processes are affected by the environment, but also alter the environment. Stan Houston Primary Production All biomes are connected by the global carbon cycle, the uptake and release of CO2 by living things Photosynthesis “fixes” CO2, = removes it from the atmosphere and traps it in solid form (plant + animal bodies oil) Productivity = amount of CO2 fixed as organic (solid) carbon, “producing” energy for an ecosystem by trapping sunlight CO2 is produced by respiration, burning (woods, fossil fuels) Net primary production = how much carbon is fixed and not burned off by respiration ... i.e., stays trapped in plant tissue Seasonal patterns of net primary production Satellites and computer models provide new tools for studying the Earth as a system Global photosynthesis during our summer (top) and winter (bottom) note shift in net primary production with season http://earthobservatory.nasa.gov/Newsroom/NasaNews/2003/2003042214379.html Global Carbon Cycle human activity puts ~8 gigatons of carbon into the atmosphere a year (= 2 trillion pounds) - net 4.5 gigatons fixed by photsynthesis on land & in the ocean - so, we add 3.5 extra gigatons per year to our atmosphere Increasing atmospheric [CO2] and average global temperatures Long predicted that increased CO2 would trap sunlight, leading to greenhouse effect There is scientific consensus that this temperature increase is mainly caused by human activity Campbell & Reece, 2005 Kerr (2005) Science 309: 1807 Take-home messages 1) Living things adapt to their environment -- both the living and non-living parts of their environment 2) Organisms also change their environment - our oxygen-rich atmosphere is entirely a product of life - the increasing CO2 levels in our atmosphere can only be explained as a product of human activity - primary production (photosynthesis by plants, algae and ocean-dwelling bacteria) only removes half what we make 3) If the environment changes faster than living things can adapt... extinctions usually follow; we will come back to this at the end of the course