Bio Exam 3 Study Guide Notes PDF

CONT: Lecture 14: Plants: Structure & Function (36.3-36.4) What are the two types of 1. Xylem - transfers water (primarily) vascular tissue + their a. Cells are not living when mature functions and differences? 2. Phloem - transports organic compounds and certain m...

CONT: Lecture 14: Plants: Structure & Function (36.3-36.4) What are the two types of 1. Xylem - transfers water (primarily) vascular tissue + their a. Cells are not living when mature functions and differences? 2. Phloem - transports organic compounds and certain minerals; sugar products of photosynthesis a. Cells are living when mature b. Have companion cells to help further transport sugar from outside to inside What types of plants produce Herbaceous (non-woody) plants mostly vascular tissues? Where does primary growth Occurs at tips to elongate the plant occur in plants? - Growth at apical meristems (SAMs and RAMs) Which type of growth do Begin with only primary vascular systems (that allow for PG) → start woody plants begin life with? producing secondary growth tissue only when mature How do trees grow? Trees grow from outside out and top up! What is secondary growth secondary growth - increases stem thickness and where does it originate? Occurs in secondary (lateral —> meaning “side”) meristems - vascular cambium and cork cambium What are the secondary Vascular cambium - meristem that produces produces secondary xylem meristems that are involved (“wood”) and secondary phloem (“inner bark”) in secondary growth? - Secondary xylem more interior - Secondary phloem more exterior - Same functions as in primary growth → sec. xylem transports water, cells are not living when mature, sec. phloem carries sugars from photosynthesis and is living when mature Cork cambium - outermost meristem that produces cork cells (bark) - Outer bark accumulates as dead cells - Protective layer What are examples of Rhizomes - modified stems that occur underground and grow horizontally modified stems? - Ex. - potatoes are tips of rhizomes that store carbohydrates Grass Stems grow horizontally as rhizomes (underground) or stolons (above) - Leaves continually grow upward from attachment point to rhizome, an adaptation that helps protect SAMs from grazing and wildfires - Grass elongates from bases → explains why grass needs to be cut! What are the major functions Major functions of root systems: of root system adaptations? - Absorbing water and minerals - Anchoring plant in soil - Storing nutrients, water, and sugar What types of roots do Eudicots have taproots - one prominent primary root that develops when eudicots and monocots have? seed germinates Monocots have fibrous roots - roots with similar length and diameter → usually forms dense shallow root system Lecture 15: What is a Tree? Intro to phylogenetic trees AND Plant evolution and diversity What is a lineage and how is it Lineage - sequence of biological entities (species, populations, genes) that depicted? are connected by a continuous line of descent from an ancestor to a descendent - Depicted using phylogenetic trees (diagrams) What is the taxonomic Taxon - each group at any level (plural, taxa) hierarchy? DKPCOFGS (dear king philip came over for good soup) - Domain, kingdom, phylum, class, order, family, genus, species What are the three domains Bacteria, Archaea, Eukarya of life? - Eukarya - consists of 4 kingdoms (Protista, Fungi, Plantae, Animalia) How/when does taxonomy Change when researchers gather new evidence about change? characteristics/genetics of species - Morphological features, DNA Use binomial nomenclature to name species What are the parts of a Node - branching point on tree phylogenetic tree? Root - most recent common ancestor of all taxa in the tree Branch - lineage of organisms Clade - group of organisms that includes a common ancestor and all of its * should be viewed as a descendents hypothesis that can be tested, - NOT a clade if it leaves out a common ancestor or some descendents later refined, etc. * use marked lines to represent emergence of a specific trait that all species going forward share Cladogenesis -one species diverges into 2 or more species Anagenesis - one species diverges into a separate species Most basal group = root Sister groups: 2 descendents that split from same group Lecture 16: Colonization of land What is the most ancient Chlorophyte green algae group of algae and its - Unicellular and produce mostly asexually characteristics? - Contain chlorophyll pigments like those in plants - Produce starch in plastids (chloroplasts) Types of chlorophyte green algae: - Spirogyra - Chlamydomonas - Volvox (seem to be multicellular but are not) What is the group of algae Simple streptophyte algae that came after chlorophyte - Possess a cellulose-rich cell wall green algae? - Some multicellular group - Sexual reproduction, but LACK distinct sperm and eggs (all gametes are the same) What is the most recent Complex streptophyte algae group of algae? - Have distinctive egg and sperm (also characteristic of modern plants) - Plasmodesmata - gaps in cell walls for communication - Zygotic life cycle (not shared with plants) - More branched + complex forms that more closely resemble plants What is a streptophyte? Land pants (embryophytes) and their close relatives among green algae Kingdom Plantae originated from algae that would be characterized as a streptophyte - Many features in common with land plants (distinctive types of cytokinesis, intercellular connections called plasmodesmata, sexual reproduction) What are the stages of the {finish to study} zygotic life cycle of a complex - See diagram streptophyte? - Diploid stage (2n) is limited to unicellular zygote - Zygote formed by fertilization undergoes immediate meiosis, returning to haploid (n) stage What type of lifecycle do Zygotic life cycle - after fertilization, they make a zygote but not an embryo streptophyte algae have? What’s the difference? - Embryos are multicellular, result from zygote undergoing mitosis (like most plants) - In streptophytes, zygote undergoes meiosis to become spores and never becomes an embryo! What’s a disadvantage of the Max number of spores that can be produced is 4 (much more can be zygotic life cycle? produced with sporophytes) Why would algae undergo a zygotic lifecycle? - Reproduction in aquatic environment = easier, 4 spores more likely to survive What type of life cycle do Sporic life cycle plants undergo and what is Large multicellular individual grows (via mitosis) after fertilization the advantage? Advantage: sporophyte can produce many more spores What are other adaptations of Embryo develops within protective confines of gametophyte tissues → the plant life cycle? matrotrophy - Protection from desiccation (drying) - Nutrients for developing embryo Spores develop within enclosure of tough cell walls → sporangia - Protection from UV, microbial attack - Aids in dispersal What are the differences See worksheet - review to study between embryos, zygotes, sporic/zygotic life cycles, gametophytes/sporophytes? What is the alternation of - One of key traits seen across land plants generations? - Two types of multicellular bodies (gametophyte and sporophyte) that differ in chromosome # (haploid vs diploid) - Alternate during life cycle See worksheet for differences btw. sporophyte and gametophyte What challenges did algae Salinity, temperature, UV exposure, drought, lack of structural support encounter when they began against gravity (water is buoyant), reduced dispersal (spores of algae need moving to land 590-600 water to swim), pathogens million years ago? What structures did land 1. Apical meristem - allows growth to maximize available sunlight + plants evolve to solve these build sturdy body problems? 2. Sporic life cycle a. Produce many spores, then wind dispersal b. Protect embryo by maternal tissues 3. Tough spores (later pollen) protected by sporopollenin 4. Stomata & guard cells 5. Supporting tissue - sclerenchyma a. Sclerenchyma - rigid support b. Collenchyma - more flexible support Tissues provide land plants w increased ability to avoid water loss What are the 9 phyla of living Liverworts plants? Mosses Hornworts Lycophytes Cycads Ginkgos Conifers Flowering plants (angiosperms) Types of bryophytes, simplest of all living plants - Arose before modern groups of vascular plants (internal water and nutrient-conducting vascular tissues that provide structural support) Characteristics of bryophytes Earliest (extant) land plants - Photosynthetic gametophyte - Non-photosynthetic or less photosynthetic sporophyte - Non-vascular plants - Small - Terrestrial but require moist environment - 3 taxa How do bryophytes transfer - Usually very small (short distance for water/nutrients to travel) water if they don’t have xylem - Live in very moist areas or phloem? What are the three taxa of Hornworts - upright, horn-shaped spore capsules (least recent) bryophytes? Liverworts - flat, lobed thallus that often grows close to ground; no distinct stems or leaves  ○ Thallus - flat plane of tissue growing close to the ground (gametophyte) Mosses - visible “stems” + “leaves” (most recent) ○ but not vascularized, so not technically stems and leaves These 3 = simplest of all (surviving) land plants What are the two structures Archegonia - sex organ that produces eggs that produce gametes? Antheridia - sex organ that produces sperm Female and male gametangia - Reproduction in bryophytes is still dependent on water! → sperm must be able to swim from antheridia to archegonia See life cycle diagram in notes → notice separate sex organs + roles in reproduction What were key adaptations of Stomata in true stems and leaves → promote xylem transport the evolution of vascular - Play important role in transporting water - loss of water creates plants? sucking effect that keeps water moving throughout plant Vascular tissue in stem: lignified cell walls help plant grow taller (stiff, waterproof) Thicker cutin cuticle protects against pathogens; wax prevents water loss Among the vascular plants, Lycophytes, then pteridophytes, then seed plants when did each emerge? - Lycophytes and pteridophytes - vascular plants that don’t produce seeds + 31.1-31.2, 32.1 textbook notes Tracheophytes - include lycophytes, pteridophytes, and seed-producing plants - Tracheid - type of specialized cell that conducts water and dissolved minerals and provides structural support - - form vascular tissue Gymnosperms (which reproduce using both spores and seeds) and angiosperms (which produce flowers, fruits, and seed endosperm) = seed plants - Ability to produce seeds frees plants from reproductive limitations Plants have transformed earth’s physical environment - increasing conc. of O2 and dec. conc. of CO2 Plant evolution - greatly impacted survival/evolution of animals - Gymnosperms + angiosperms prob sources of food for early mammals, herbivorous dinosaurs - - after meteor hit earth, many plants died along with dinosaurs  - ferns dominated afterward, rise of angiosperms allowed for diversification of beetles and other insects See critical innovations of some seed plant groups (32.1) Gymnosperms - plants that produce exposed seeds (NOT enclosed in fruits) - Modern gymnosperms arose from seedless ancestors - Vascular cambium, wood, inner bark help gymnosperms + woody angiosperms compete effectively - Wood first appeared in ancient seedless plants, progymnosperms - Its vascular tissue had capacity to form eustele (ring around central pith of nonvascular tissue) Cycads - have underground roots, produce coralloid roots Ginkgo biloba = last survivor of once diverse group Conifers = most diverse modern gymnosperm lineage - Reproduce via simple pollen cones and more complex ovule cones - Pollen produces tubes that deliver sperm to egg cells w/in ovules - Seeds with wings (ex. - pine seed) - Conifer tracheids - specialized vascular cells adapted for efficient water and mineral conduction → have pits for water movement and torus (nonporous, flexible) that acts like a valve - Also may have resin ducts to resin to flow through, catch pathogens/herbivores - Adaptations to cold (ex. - many don’t lose leaves during winter) What was the first category of Lycophytes (~415 mya) vascular plants to evolve? - First tracheophyte (vascular plant) - Tracheophytes have tracheids - specialized cells that conduct water/minerals and provide structural support in xylem - Have spore-producing sporangia in club-shaped clusters - Still seedless What are lycophyll? Small, narrow leaves of lycophytes with single, unbranched vein  - but no petiole connecting leaf to stem; leaf emerges from lateral meristem → important distinguishing feature of lycophyll Evolved from stem w vascular tissue → stem and leafy tissue w/o vascular tissue →stem and leafy tissue w vascular tissue → single vascular staring (vein) Are lycophytes’ life cycle Sporophyte dominant! sporophyte-dominant or - Trend that continues for rest of plant evolution gametophyte dominant? Only kind of plants that are gametophyte-dominant are bryophytes What are pteridophytes? Evolved approximately 300 mya Ferns, horsetails, whisk ferns Sporophyte dominant Vascular tissue Also seedless * sporophyte-dominant life cycle What is a sporus in Brown spot on ferns - contain sporangia of ferns pteridophytes? How did true leaves evolve in 2 hypotheses: either independent (separate) leaf evolutions in both pteridophytes? lycophytes and euphyllophytes (incl. Ferns, horsetails, gymnosperms + angiosperms) OR Leaves only evolved once (see phylogenetic tree in notes) What are euphylls? True leaves of vascular plants, with complex venation patterns Evolved from branching stems with vascular tissues to unequal branching to branches in single plane to photosynthetic tissue “webs” branches to branches vascular strains (veins) – Leaves start developing at apical meristem tissue – different than lycophylls, which developed from lateral meristems Lecture 18: Naked seeds - Gymnosperm diversity & intro to angiosperms What are some critical Innovation: tissue that promotes secondary growth → vascular cambium innovations of all seed plant - Allows for growth of secondary xylem (wood) & secondary phloem groups? (inner bark) - Advantage: vascular tissues necessary for plants to grow taller (ex- trees need structural support) Innovation: pollen, ovules, seeds  - Advantage: pollen allows seeds to disperse male gametophytes; ovules provide protection + nutrition to female gametophyte & embryo; seeds - allo plants to reproduce in arid/shady habitats What is heterospory and how Heterospory - the production of different spore types (large and small) did it lead to the evolution of Microspores - small spores that give rise to male gametophytes pollen, ovules, and seeds? Megaspores - large spores that develop in female gametophytes Evolution: sporangium containing many spores that are similar in size → sporangium containing many small microspores (microsporangium) + sporangium containing many large megaspores (megasporangium) → reduction to one megaspore per megasporangium → megaspore enclosed in integuments; forms ovule; when fertilized, ovule grows into a seed! What is the typical life cycle Mature sporophyte produces 2 types of cones - ovule cones (female) and of a naked seed plant pollen cones (male) (gymnosperm)? Inside female megasporangia: megaspores produced by meiosis - Megaspores undergo mitosis → produce female gametophyte with egg - Female gametophyte + egg + integument = ovule Inside microsporangia: microspores produced by meiosis - Microspores undergo mitosis → grow into pollen grains (young male gametophyte) with sperm - Gametophyte + sperm + protective wall = pollen Fertilization occurs when pollen grains are dispersed via wind dispersal & encounter ovules - Pollen grains mature, deliver sperm to egg → fertilization occurs Unicellular zygote undergoes mitosis to form a seed – a multicellular embryo with a seed coat Seed germinates, produces seedling that undergoes mitosis to grow into mature sporophyte What are some ecological 1. Food storage (can store lots of nutrients, which is helpful for advantages of seeds? powering growth in shady environments) 2. Reduced dependence on water - sperm don’t need water to reach egg → wind dispersed pollen and pollen tube evolved along with seeds → allow seed plants to survive in drier environments 3. Dispersal - seeds dispersed by wind + animals 4. Promotes outcrossing - possibility for new genetic combinations (compared to self-pollination) → helps avoid inbreeding  5. Dormancy - seeds can remain dormant for long time until conditions are favorable (seed bank = collection of dormant seeds) 6. Protection - tough seed coat protects against desiccation, mechanical damage, extreme temps *Seeds = key for life on land!! What are the characteristics Gymnosperms - “naked seed” plants of gymnosperms? 300 mya Produce seeds that are open to air (not enclosed in fruit) Contain ovules on scales that fertilized (mostly) by wind-dispersed pollen Most are conifers, which produce pollen and ovule cones Vascular plants - have liquid-conducting tracheids - dead lignified plant cells in xylem that conduct water, minerals, and hormones; also provide structural support Have tiny (but still multicellular) gametophytes What are 5 different types of Cycads gymnosperms? - 300 mya - 300 species today - Primarily tropical/subtropical - Produce male and female cone-like structures - Cones produce odors that attract beetles for pollination - Cycads = early evolutionary example of animal pollination Ginkgo - 270 mya - Only 1 species today: Ginkgo biloba - Seeds have fleshy covering - Trees can live for more than 1000 years - Wind pollinated Conifers - 300 mya - Oldest specimen is bristlecone pine (4700 years old!) - Produce simple pollen cones + complex seed (ovule) cones - Vast majority wind pollinated - Gnetales (gnetophyte) - Clade of conifers consisting of 95 species - 250 mya - Secondary metabolites from stems/branches of Ephedra used in ephedrine and meth What are critical innovations Tracheid torus of gymnosperms? - Allows for water flow in arid or cold conditions  Scales or needle-shaped leaves - Reduces water loss from leaf surfaces Conical shape - Sheds snow to prevent damage Resin - Protects against pathogens and herbivores Why are tracheids and tori an Tracheids - water-conducting cells; lignin-rich; important adaptation for Tracheids arranged in columns, with pits inside that contain tori conifer wood? Tori can act like valves to seal off water and keep air from spreading to rest of tree Do gymnosperms have fruits? No - although juniper (conifer), yew (conifer), and ginkgo seem to have fruit, these structures do not develop from ovary of a flower Juniper “berries” and yew arils are actually modified cones! Ginkgo “fruit” is derived from outer integument of ovule What are some key Vascular tissue in stem - lignified cell walls help plants grow taller adaptations of vascular - Stomata in true stems and leaves plants? - Promote xylem transport - Thicker cuticle with cutin (protects against pathogens) and wax to prevent water loss - Well-developed, true roots How did plants evolve from Bryophytes → lycophytes → monilophytes (pteridophytes?) → gametophyte dominant to gymnosperms, angiosperms sporophyte dominant? Almost all of innovations (leaves, roots, etc.) happened within sporophyte and allowed it to become dominant & gametophyte to become specialized Lecture 19: Flowers - Nature’s Success Story What are differences between Angiosperms produce flowers, not cones angiosperms and Angiosperms have gymnosperms? - Nutritive endosperm in their seeds - Vessel elements in addition to tracheids that increase water conduction - Fruit! - Animal pollinated (mostly) What innovations do Flower - foster pollen dispersal, ovule protection, pollination, and seed angiosperms show and what production are the associated Fruits - foster seed dispersal advantages? Endosperm - provides food to embryo of developing seed Vessels - relatively wide diameter fosters water flow Many secondary compounds (colors, fragrances, etc.) - attract pollinators, deter prey What are the parts of a Some flowers have both male and female structures, some only have male or flower? female Main goal of flower is producing and receiving pollen for reproduction Petal - for pollination Carpel/pistil - for reproduction (female) - Stigma - part that sticks up for receiving pollen, ideally from another plant; sticky to bind pollen to them - Style - helps stigma project - Pollen tube - transfers pollen down to unfertilized ovules - Ovary - well-developed in angiosperms, tissue surrounding ovules will go on to become a flower - Ovule - inside ovary; where unfertilized eggs reside Receptacle - generation of flower organs Stem - transports nutrients to flower Sepal - protection of flower buds (modified leaves for protection) Stamen - reproduction (male) - Anther - part at top - Filament - long part What’s the difference Perfect flower - both male and female parts between a perfect and Imperfect - only male or only female imperfect flower? What are some examples of Clustering of flowers into groups flower diversification? ○ Inflorescences in sunflowers - each little part is an individual flower ○ Potential for pollination in surfaces = huge! Reduction of sepals and petals ○ Grass flowers are wind pollinated ○ No need to attract bees, flies, etc. with well-developed petals (would just get in the way) Fused flower parts ○ Can form a floral tube ○ Orchid column (male + female fused together), tepals (mix btw petal and sepal) How does coevolution relate Coevolution - the process by which 2 species exert natural selection on each to angiosperm other diversification? RESULT: remarkable matches between traits of plants and animals Explains diverse forms of flowers, how plants accomplish effective pollen dispersal Pollination is most effective when there’s a match between the morphology of the flower and pollinator Ex. - bug’s foot long tongue pollinates orchid *coevolution drives the diversity of all flower morphologies How does pollination affect Animal pollination - process in which animals (insects, birds, bats) transfer the coevolution of animals pollen from male flower part (anther) to female flower part (stigma) of and plants? another flower → leads to cross fertilization and seed production - Mutualism interaction; animal gets reward (nectar, eating pollen itself); flower gets opportunity to reproduce Pollinators allow for genetic variability and plant potential for evolutionary change Constancy or fidelity - pollinators learn flower characteristics, visit them preferentially (precise, less wasteful pollen transfer) Flowers attract appropriate pollinator using attractive colors, odors, shapes, sizes What are pollination A specialized set of floral traits that attract and help specific types of animals syndromes and what is the pollinate a plant implication if a pollinator Examples - odorless red flowers with long tubes attract hummingbirds (who becomes extinct or vice can’t see very well, can’t smell very well) versa? - Rotten smelling flowers attract flies - Musky smelling white flowers attract nocturnal animals (bats, moths) *can tell a lot about who’s pollinating a flower just by looking at flower traits What kinds of flowers do bees Blue, purple, yellow, white (not red) because bees’ color vision includes like? ultraviolet (UV), not red Fragrant (bees have good sense of smell) Nectar and abundant pollen What kinds of flowers do Blue, purple, deep pink, orange, red (good color vision) butterflies like? Light floral scent (sense odors with feet) Landing place Nectar in deep, narrow floral tubes (butterflies feed with long tubular tongue) What kinds of flowers do Flowers that open at night; white/bright moths like? Heavy musky odor Nectar in deep narrow floral tubes What kinds of flowers do Red flowers birds like? Damage-resistant perch No fragrance (no sense of smell) Open in daytime Lots of nectar (birds require a lot) Dangling flowers (for hovering hummingbirds) What kinds of flowers do bats Light reflective colors, strong odors, open at night, lots of nectar/pollen, like? pendulous or borne on tree trunks *probably bigger flowers than those that attract moths How have humans shaped the Ancient ancestors of most crops look very different than modern version evolution of plants? Humans have selectively bred / domesticated crops for desirable traits (like producing lots of fruit) → both good and bad consequences Domestication - artificial selection for traits desirable to humans - Agriculture originated ~ 10,000 yrs ago in Middle East - Current version of wheat is much bigger, produces more, but lacks some favorable traits Loss of shattering - process by which ears of wild grain plants break apart and disperse their seeds - Mutation caused some ears of grains to remain intact - Disadvantageous in nature but advantageous for farmers What is a fruit? Develops from ovary, aids dispersal of enclosed seeds, dispersal reduces parent-offspring competition and aids in outcrossing Fruits may be adapted to: attract animals to eat them; for wind dispersal; attach to animal fur, float in water How has seed dispersal Plant may have juicy, sweet fruit with small/tough seeds to readily pass co-evolved to be beneficial to through gut both plants and animals? Plants may signal fruit ripeness with color change What are secondary Secondary metabolism - synthesis of organic compounds not essential for metabolites and what are the cell structure and growth major classes in plants? - Some offer protection against herbivores, pathogens Humans love to exploit plant secondary metabolites 3 major classes in plants: Terpenes and terpenoids  - ~ 25,000 types - Citronella, rubber, turpentine - 5-carbon isoprene unit - aromatic Phenolics (flavonoids and related compounds) - Create some flower/fruit colors - Responsible for cinnamon, nutmeg, ginger, clove, chillies, vanilla flavors - Prevent UV damage - Some are antioxidants including those found in teas, wines, fruits Alkaloids - Contain nitrogen - Potent effects on animal’s nervous system - ~12,000 types, incl caffeine, nicotine, morphine, ephedrine, THC, cocaine, codeine Lecture 22: How to Make a Baby Plant What parts of a flower are Vast majority is diploid (sporophyte) gametophyte and which are Parts that are gametophyte/haploid: ovule (egg) and anther (pollen) sporophyte? - In angiosperms, gametophyte is INSIDE the ovule and INSIDE the pollen grain! → very reduced in angiosperms! How many cells big is the 7 cells female gametophyte in - Female gametophyte within ovule angiosperms? How many nuclei does the - Central cell inside the egg cell has 2 nuclei central cell inside the egg cell of an angiosperm have? How many cells big is the Only 2 cells male gametophyte in angiosperms? One cell does fertilization What are the functions of One cell produces sperm each cell? What is the difference Pollination - transferring pollen from anther of a flower to the stigma between pollination and fertilization? Fertilization - fusion of male gamete (sperm) to female gamete (egg) What is double fertilization? One sperm fertilizes egg to form zygote (2n) (occurs in angiosperms) A separate sperm fertilizes 2 nuclei in central cell, develops endosperm → 3n - Central cell produces nutritive endosperm! Flower to fruit Ovules become seeds  Ovary becomes fruit Ovary wall becomes pericarp (fruit wall) Fruit = structure that encloses and helps disperse seeds What makes up the vast Endosperm - 3n triploid majority of the mass of seeds? Aggregate fruits & multiple Fruit formed from several carpels derived from same flower fruits Individual fruitlets that fuse together multiple fruits - derived from fusion of entire inflorescence (ex- pineapple) 1. Put the following in order based on when they arose in the fossil record: hornworts, mosses, liverworts. 2. What were the key innovations that allowed the ancestors of bryophytes to colonize land? 3. In comparison to streptophytes, all bryophytes produce gametes that are housed in protective ____________. Male gametes, _________, are found in ____________. Female gametes, __________, are housed in ______________. 4. If the cells of a fern gametophyte have 30 chromosomes in them, how many chromosomes would be in in zygote? In an egg? In a frond?