Unit 1- lecture notes 24-25.pdf

Unit 1: Diversity of Life Chapters 1, 4, 15, 16, 18, 19 Lecture 1.1 Characteristics of Life BIOLOGY= The study of life/living things Organism- A living thing Biotic- anything that is alive Abiotic- things that were never living eubacteria archaeabacteria What characteristics does a living...

Unit 1: Diversity of Life Chapters 1, 4, 15, 16, 18, 19 Lecture 1.1 Characteristics of Life BIOLOGY= The study of life/living things Organism- A living thing Biotic- anything that is alive Abiotic- things that were never living eubacteria archaeabacteria What characteristics does a living organism have? 8 Characteristics of Life *to be considered living (biotic) the specimen MUST have all 8 characteristics of life!  8 Characteristics of Life 1. Made of Cells – Complex and organized cell = basic unit of life cell types: prokaryotic or eukaryotic  8 Characteristics of Life 2. Respond to Stimuli – both external and internal Some more responses to stimuli  8 Characteristics of Life 3. Maintain Homeostasis -stable internal conditions Ex. Thermoregulation- temperature (humans 98.6 °F) Other Examples: pH level Blood glucose Osmoregulation (Water level)  8 Characteristics of Life 4. Acquire Energy 1. Autotrophic: make their own food – Via sun - photosynthesis – Via chemicals - chemosynthesis Energy (from sun or chemicals like hydrogen sulfide) is used to link inorganic Carbon into organic molecules used by organisms. 2. Heterotrophic: gets carbon and energy from its food sources  8 Characteristics of Life Metabolism- the sum of all chemical reactions that occur within a single cell or w/in a multicellular organism – Cellular Respiration C6H12O6 + 6O2 🡪 6CO2 + 6H2O + ATP – Photosynthesis Sunlight + 6H2O + 6CO2 🡪 C6H12O6 + 6O2  8 Characteristics of Life 5. Grow and Develop - there is a limit to cell size - cell division makes more cells - not bigger - COMPLEX  8 Characteristics of Life 6. Reproduce themselves 1. Asexual- A single parent organism produces its own offspring 2. Sexual- genetic material from 2 parents is combined to form offspring  Pro ☺ Con ☹ Examples Asexual Costs very little: Very low genetic - Bacteria: binary fission, Energy, resources, diversity for the the parent body divides time group = bad for - Hydra: budding, a new survival and smaller individual forms species evolution as an attachment to the parent, then drops off Sexual Provides a lot of Costs a lot - Humans: fertilization of genetic diversity (the egg & sperm offspring is a unique - Plants: pollination mix of mom and dad)  8 Characteristics of Life 7. Contain DNA -inherited molecule, is the instructions for life  8 Characteristics of Life 8. Have the capacity to Evolve Our Taxonomic Family Hominidae Is it always clear whether something is biotic or abiotic? Viruses??? -Not made of cells- no ribosomes, no cytoplasm -No source of energy -Cannot reproduce unless they use a host cell So viruses do not follow ALL characteristics of life = NOT LIVING Lecture 1.2 Hierarchy of Life Hierarchy of Life Simplest to most complex. Example: Subatomic particles make up an atom Atoms bonded together make a molecule Molecules come together to make cell parts Cell parts make up a cell…..  1. Subatomic Particles The particles that make up an atom protons (+) neutrons (0) electrons (-)  2. Atom An element ex. carbon, nitrogen, oxygen  3. Molecule Atoms bonded together ex. water glucose DNA  4. Organelle A structure within a cell that performs a specific function (like a small organ!) ex. mitochondria nucleus  5. Cell Smallest unit of life! ex. paramecium nerve cell (neuron) muscle cell blood cell bacteria  Cell Specialization Cells come in many different structures that correspond with their functions Nerve cell- very long and branched structure for ex. communication & signaling Blood cells- round to float through blood stream, ex. Phagocyte white blood cells have a lot of lysosomes to destroy bacteria & viruses Muscle cells- have extra mitochondria to make a lot of ATP to power movement  6. Tissue A group of cells that perform a specific function ex. nervous tissue, muscle tissue  7. Organ A structure usually composed of several tissue types that form a functional unit ex. brain liver eye  8. Organ System Two or more organs working together in the execution of a specific bodily function ex. nervous system digestive system  9. Multicellular Organisms A living thing composed of many cells, many organ systems working together ex. mushroom tulip octopus tiger  10. Population Members of one species inhabiting the same area ex. herd of deer, pride of lions, pack of wolves  11. Community 2 or more populations of different species living and interacting in the same area – All biotic in an assigned area ex. In this picture: snakes, deer, hawk, grass, trees, shelf fungi, woodpecker, rabbit etc  12. Ecosystem A community together with its nonliving surroundings: biotic & abiotic ex. forest pond  13. Biosphere All of Earth’s ecosystems combined, they areas that are inhabited by life Major ecosystems are called biomes ex. rainforest, tundra, desert Our biome: Deciduous Forest Lecture 1.3 Taxonomy  Taxonomy the system scientists use to classify organisms and to assign each with a scientific name We classify organisms by putting them into groups called taxons A good classification system: 1. Reveals evolutionary trends 2. Show relationships 3. Allows change to the taxon of an organism based on new information  Taxons General 🡪 Specific Domain: encompasses the most! There are 3 domains: Bacteria, Archaea, Eukarya Kingdom There are 6 kingdoms: Eubacteria, Archaebacteria, Protista, Fungi, Plantae, Animalia Phylum Class Order Family Genus Species: encompasses just one type of organism Mnemonic: Dear King Philip came over for great spaghetti What animal is this?  DOMAIN- Eukarya Protist- amoeba Fungi- Portobello Plant- fern Animal- insect arctos  Binomial Nomenclature (2-word scientific name) Developed by Carolus Linnaeus Written in Latin 2 words: Genus species – ex. Homo sapien, E. coli H. sapien Scientific names must be italicized or underlined Genus is capitalized species lowercase Ursus arctos Common Name: Leopard Scientific name: Panthera pardus Panthera onca Panthera uncia Panthera leo Panthera pardus Panthera tigris Cheetah?? Acinonyx jubatus Cute of the Day  Humans’ Taxonomic Rank Domain _______________ Kingdom _______________ Phylum _______________ Class _______________ Order _______________ Family _______________ Genus _______________ Species _______________  Human Taxonomy Domain…Eukarya Kingdom…Animalia Phylum…Chordata (having a spinal cord) Class…Mammalia (hair & mammary glands) Order…Primates (grasping fingers) Family…Hominidae (walk upright) Genus…Homo (walk straight upright) Species…sapien (high forehead, thin skull bones) Scientific name: Homo sapien  Lecture 1.4 Abiogenesis & Endosymbiosis  Origins of Life Abiogenesis- theory of how life on Earth arose from nonliving matter. – Dawn of time supported theory – No oxygen on early Earth = anaerobic – Protocell created  Origins of Life Abiogenesis- theory of how life on Earth arose from nonliving matter. – Dawn of time supported theory – No oxygen on early Earth = anaerobic  Geological Timeline 4.6 billion years ago Earth formed 3.5 bya oldest cell fossils (prokaryotic) 2 bya first eukaryotic cells 1.5 bya first multicellular organisms 0.5 bya life moves to land Darwin knew evolution needed a very long time to create the diversity of life we have today Life arose from non-life via abiogenesis 1. Random inorganic molecules react to produce complex organic molecules 2. Organic molecules accumulate & combine to make the first cell (protocell) *No life to digest them ☺ *No oxygen to react & break them down ☺ inorganic🡪 organic🡪 biotic  Inorganic- simple molecules that do NOT contain Carbon AND Hydrogen at least – Early gases: H H O NH CO 2 2 3 2 Organic- complex molecules that do consist of Carbon AND Hydrogen at least – Glucose C H O 6 12 6 – Amino acids- combo C, H, O, & N – become foundation of early cell parts Abiogenesis= first cells  Progression of Life on Earth -Life first evolved in water! – 1st life= anaerobic heterotrophic prokaryotes that ate organic molecules – 2nd group of living things were autotrophic prokaryotes (2.5 bya) Chemosynthesis then PHOTOSYNTHESIS!!! Can use sun energy to make organic food molecules They didn’t have to compete for food ☺ = many survived Photosynthesis releases Oxygen!!! Allows for: 1. Development of aerobic cellular respiration - much more efficient metabolism= more complex organisms possible 2. Ozone layer formation (O3) - protects organisms from harmful sun radiation 3. Abiogenesis no longer possible!! - oxygen is too reactive to allow abiotic to biotic evolution  rd 3 group= Prokaryotes that do aerobic cellular respiration!  Prokaryotic Cells NO NUCLEUS or membrane-bound organelles – DNA is 1 circular chromosome – Some have extra piece of DNA known as a plasmid – smaller than euk’s and ALWAYS unicellular – Cell wall made of peptidoglycan carbohydrate & protein  Domain: Bacteria Kingdom: Eubacteria - some are disease causing Escherichia coli Streptococcus bacteria (heterotrophic) Cyanobacteria (autotrophic) Domain: Archaea Kingdom: Archaebacteria - some are extremophiles Thermophile (temp) Ex. Thermophilus aquaticus lives in hot springs (boiling) Halophile (salt), live in the Dead Sea - gave rise to Eukarya!!!  Domain: Eukarya – evolved from Domain Archaea (proks) by endosymbiosis – all have eukaryotic cells “True Nucleus” – membrane-bound organelles (nucleus, mitochondria, ER, golgi…) – Unicellular (yeast & many protists) and multicellular  Endosymbiotic Theory Theory of how prokaryotes gave rise to eukaryotes Literally means “living together inside” – Symbiosis: close interaction of 2 organisms By Lynn Margulis in 1970 1. Mitochondria and Chloroplasts used to exist on their own as prokaryotic bacteria 2. A prokaryote living inside another prokaryote lead to the evolution of eukaryotes -both cells benefited= mutualism Endosymbiosis Diagram Endosymbiosis Diagram  Evidence for Endosymbiosis 1. Both mitochondria and chloroplast have their own DNA – diff DNA from in the nucleus 2. Mito. and chloro. have their own ribosomes 3. Mito. and chloro. have double membranes 4. Mito & chloro replicate themselves by a process similar to binary fission (prokaryotic asexual reproduction)  st Prokaryotic 🡪 1 Eukaryotic Cells Kingdoms w/in Eukarya 1. Protista 2. Fungi 3. Plantae 4. Animalia  Lecture 1.5 Major Evolutionary Milestones  Geological Timeline 4.6 billion years ago Earth formed 3.5 bya oldest cell fossils (prokaryotic) 2 bya first eukaryotic cells 1.5 bya first multicellular organisms 0.5 bya life moves to land Darwin knew evolution needed a very long time to create the diversity of life we have today 5 6 3 2 4 1  Protista Eukaryotic (from endosymbiosis) Most diverse of all the kingdoms! Unicellular, colonial, multicellular Autotrophic, heterotrophic, mixotrophic Sexual or Asexual reproduction Led to evolution of plants, animals, and fungi, which are multicellular 3 Common Unicellular Protists: 1. Amoeba- pseudopods, heterotrophic 2. Euglena- flagella, mixotrophic 3. Paramecium- cilia, heterotrophic 3 Common Unicellular Protists: 1. Amoeba- pseudopods, heterotrophic 2. Euglena- flagella, mixotrophic 3. Paramecium- cilia, heterotrophic  Amoeba Euglena Paramecium Paramecium → under scope  Paramecium- using contractile vacuole Euglena using Flagella  Amoeba using Pseudopods to Move Amoeba using Pseudopods to Eat Colonial- the step before multicellular Example colonial protist- Volvox “Globe Algae” Common Multicellular Protist: Algae (many types)- kelp, seaweed, lake algae Red Alga Green Alga Kelp Forest Protista gave rise to Fungi, Plantae, & Animalia Fungus-Like Protists Animal-Like Protists Plant-Like Protists – Arose by endosymbiosis of cyanobacteria  Evolution of Multicellular Organisms Unicellular 🡪 Colonial Living 🡪 Multicellular - First was a colonial algae 🡪 multicellular algae - Soft bodies aquatic animal 🡪 sea sponge Major Evolution in Relation to Oxygen Cell Size  Cell Function Limits Cell Size Metabolic requirements set a limit to the size of a single cell - All cells are very small » Most between 1-100 micrometers – As a cell increases in size, its volume increases faster than its surface area (SA) If the cell is too big ☹ = inefficient – The surface area will not be big enough to diffuse molecules across to sustain the volume of the cell – Molecules cannot move within the cell quick enough  Cube Cell Surface area to volume calculations: S.A. = side x side x 6 Volume = side x side x side SA : V ratio = SA divided by V the smaller the cell.. bigger its ratio is and the more efficient the cell A smaller cell has more connections to outside and less demands of volume  Cube Cell Example SA = s x s x 6 SA = s x s x 6 V=sxsxs V=sxsxs SA:V= SA:V=  Cube Cell Example more efficient cell bc larger SA to V ratio! =2x2x6 =5x5x6 = 24 = 150 =2x2x2 =5x5x5 =8 = 125 24 : 8 150 : 125 = 3.0 : 1 = 1.2 : 1 Smaller objects have a larger ratio of SA to volume ☺ good for cells Multicellular Organism- A cluster of small cells of the same total volume maintains a larger surface area  Fungi mushrooms, molds, and yeasts Multicellular – Exception: Yeast single-celled Heterotrophic (absorption) – decomposers Cell walls- made of chitin Sexual reproduction  Ophiocordyceps unilateralis (cordyceps) article- https://theconversation.com/zombie-ants-meet-the-parasitic-fungi-that-take-c ontrol-of-living-insects-118489  Plantae moss, ferns, cone-bearing, flowering Autotrophic and multicellular Cell walls- made of cellulose Sexual reproduction Land Plant Evolution & Planet Carnivorous Plants Animalia sponges, coral, worms, insects, fish, birds, reptiles, mammals All heterotrophic and multicellular No cell walls Sexual repro Motile Rapid response to stimuli Figure 18.4 No true 9 Major Animal Phyla tissues Porifera Radial sponges symmetry Cnidarians Ancestral colonial Platyhelminthes flatworms Protostomes protist Eumetazoans Nematoda roundworms True Annelida tissues segmented worms Bilaterians Arthropoda Bilateral Deuterostomes symmetry Mollusca Echinodermata X do not Chordata memorize Major Evolution in Relation to Oxygen  Life invades the Land (.5 billion years ago) Less predators New and empty niches (habitat & role) First land dwellers: -Plants -Arthropod animals (ex. insect) Our Phylum- Chordata All embryos (babies) have: 1. notochord- supportive rod - early chordates keep notochord as adults & are known as INVERTEBRATE CHORDATES - VERTEBRATES- notochord becomes spine bones 2. dorsal nerve cord -VERTEBRATES- becomes spinal cord 3. pharyngeal slits 4. post-anal tail Our Phylum- Chordata All embryos have: 1. notochord- supportive rod - early chordates keep notochord as adults & are known as INVERTEBRATE CHORDATES - VERTEBRATES- notochord becomes spine bones 2. dorsal nerve cord -VERTEBRATES- becomes spinal cord 3. pharyngeal slits 4. post-anal tail Classes of the Chordata Phylum Evolution Cladogram Chordata Phylum Evolution Cladogram Movement to LAND!!!  a m fr om C la do g r v i t y You r ee A c t i ne t i c T r P h y l o ge  Chordates Fish Cartilaginous v. Bony  Chordates Special group of Bony Fish: Lobe-Finned Fish Have rod-shaped bones in their fins – could use their lobed fins to “walk” under water!!! ex. Coelacanth ex. Lunged fish  Chordates Tetrapod: four-limbed animal - including all amphibians, reptiles/birds, and mammals (extant and extinct) - evolved from a lobe-finned fish ancestor! Tiktaalik Figure 19.1 Chordates Tunicates Chordates Ancestral Lancelets chordate Hagfishes Craniates Brain Lampreys Vertebrates Head Sharks, Jawed vertebrates rays Vertebral column Ray-finned Jaws fishes Lobe-fins Lungs or lung derivatives Amphibians Tetrapods Lobed fins Reptiles Amniotes Legs X do not Amniotic egg Milk Mammals memorize  Chordates Amphibians Salamanders, frogs, toads, and caecilians Still have ties to water – eggs are jelly-like (like fish) – baby lives in water until metamorphosis - breathe through their moist skin frog sound video  Chordates Reptiles Lizards, snakes, turtles, crocs, dinosaurs – 1st fully terrestrial evolution of the amniotic egg! – Ectothermic- use behavior and environment for thermoregulation NOT “cold-blooded” ex. a lizard needs to maintain a body temp of 88F – If too cold- bask on warm rocks If too hot- seek shade, take a swim ☺  Chordates AMNIOTIC EGG (don’t need to know parts an with X) X X X  Chordates AMNIOTIC EGG - Allowed tetrapods to break ties with water and be fully terrestrial!!! - Embryo develops in an aquatic environment protected by a hard, waterproof shell so it avoids desiccation (drying out) X X X  Chordates Birds Reptile lineage that adapted scales into feathers for flight Unlike other reptiles, birds are endothermic Can generate heat by their metabolism to maintain homeostasis  Chordates Mammals Hair Mammary glands Endothermic 3 major taxa - monotremes - marsupials - eutherians  Chordates 1. Monotreme- egg laying mammal Spiny anteater, duck-billed platypus  Chordates 2. Marsupial- pouch mammal Brief gestation followed by birth of tiny embryo into pouch for further development More Marsupials!  Chordates 3. Eutherians- placental mammals Complete develop of young in mother’s uterus attached to placenta (exchanges nutrients btwn mom & offspring) Still amniotic! – babies devo in fluid surrounded by amniotic sac  Chordates AMNIOTIC Womb X  Chordates AMNIOTIC Womb - Amniotic egg evolves to be internal to the body - Embryo develops in an aquatic environment & parent body provides nutrients during development X  X X X X The following slides are extra videos I have selected for you related to unit 1 content You are welcome to look for your own youtube videos at anytime throughout the unit! For accurate science and a good level of detail I recommend: Crash Course, Amoeba Sisters, & Khan Academy Extra Video Overview! Crash Course- Origin of Life Extra Video Overview! Amoeba Sisters- Prokaryotic v. Eukaryotic Cells Extra Video Overview! The 3 Domains of Life Extra Video Overview! Amoeba Sisters- Classification Extra Video Overview! Amoeba Sisters- Prokaryotic Eubacteria Examples Extra Video Overview! Amoeba Sisters- Prokaryotic Eubacteria Examples Extra Video Overview! Khan Academy- Cell Size