Bio 182 Exam 2 study guide about plants PDF

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Exam 2 study guide on chapters 10, 29, 30, 35, 36, 37, 38, and 39...

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BIO-182 Exam 2 Study Guide Directions: This study guide has created from the exam bank of questions. It is designed to give indications about what concepts will be important to review in preparation for the test. Use the PowerPoint slides along with the textbook and notes taken during lecture to study effectively. Do not concentrate solely on the definitions. Chapter 29 ± Plant Diversity I: How Plants Colonized Land x Describe in detail the five derived traits of land plants: o alternation of generations ± sporophyte versus gametophyte Life cycle alternates between multicellular gametophyte and sporophyte Each generation gives rise to the other Gametophyte Gamete-producing plant Multicellular haploid Produces gametes by mitosis that fuse during fertilization Sporophyte Spore-producing plant Multicellular diploid Undergoes meiosis to produce haploid spores (reproductive cells that can undergo mitotic division and develop into gametophyte without fusing with another cell) o multicellular/dependent embryos ± placental transfer cells Zygotes retained in female gametophyte Parental tissue protects developing embryo from harsh environmental conditions and provides nutrients such as sugars and amino acids Embryo has specialized placental transfer cells Enhances transfer of nutrients to the embryo through elaborate ingrowths of the wall surface (plasma membrane and cell wall) Embryophyte is another term for plants because of the dependency of the embryo on the parent o walled spores produced in sporangia ± sporangia versus sporocytes Plant spores produced by meiosis Haploid reproductive cells that can grow into multicellular haploid gametophytes by mitosis Walls made of sporopollenin (allows spores to be dispersed through dry air) Sporangia are multicellular organs of sporophytes that produce spores Diploid sporocytes (mother spores) within sporangium undergo meiosis to produce haploid spores Outer tissue of sporangium protects developing spores until they are released into the air Charophytes also produce spores, but they lack multicellular sporangia and are flagellated, water-dispersed, and lack sporopollenin o multicellular gametangia ± gametangia, antheridia, archegonia Gametangia are multicellular organs on gametophytes that produce gametes Archegonia are female gametangia Egg is fertilized in archegonium Antheridia are male gametangia Produce sperm and releases them into environment Some sperm are flagellated and swim to the eggs through water droplets

o Apical meristems Regions at growing tips of the plant where one or more cells divide repeatedly Cells differentiate into outer epidermis to protect body and various types of internal tissues Generate leaves in most plants x Define these terms: sporopollenin, cuticle, stomata Sporopollenin: durable polymer that covers exposed zygotes of charophyte algae and forms the walls of plants pores, preventing them from drying out or helping them become resistant to harsh environments Cuticle: epidermal covering made of wax and other polymers Acts as water proofing to prevent desiccation Some protection against microbial attack Conserves water Stomata: specialized pores that allow for the uptake of air (CO2) Support photosynthesis by allowing exchange of CO2 and O2 Main pathways of water evaporation (close in response to hot, dry conditions) Characterize the following plant groups, include information about the life cycle, noting which generation is dominant: o Nonvascular plants (bryophytes): protonema, gametophore, rhizoids, foot, seta, capsule, and peristome  Liverworts, hornworts, and mosses o Seedless vascular plants ± tracheid, lignin, phloem, microphylls, megaphylls, sori, homosporous sporophylls, heterosporous sporophylls, megaspores, microspores  Lycophytes ± club mosses, spike mosses, quillworts  Monilophytes ± ferns, horsetails, whisk ferns Understand the ecological/economic importance of mosses and seedless vascular plants. Informal grouping off plants based on vascular tissue Vascular tissue: cells joined into tubes that transport water and nutrients throughout the body Vascular plants: plants that have a complex vascular tissue system Seedless Clades Lycophytes (club mosses and relatives Monilophytes (ferns and relatives NOT a monophyletic group Seed Seed is an embryo packaged with a supply of nutrients inside a protective coat GYMNOSPERMS (naked seed) have seeds not enclosed in chambers ANGIOSPERMS (all flowering plants) have seeds that develop inside chambers that originate within flowers Nonvascular plants (bryophytes) Plants that do not have an extensive transport system NOT a monophyletic group Bryophyte phyla Three phyla: Liverworts (phylum Hepatophyta) Mosses (phylum Bryophyta)

Hornworts (phylum Anthocerophyta) These groups are thought to represent the earliest lineages to diverge from the common ancestor of plants Earliest spores of plants (450-470 million years ago) have similar structural features of liverwort spores Spores from 430 million years ago have similar structures to moss and hornwort spores Dominant stage of bryophytes Multicellular haploid gametophytes Sporophytes present only part of the time Are bryophytes vascular or nonvascular? How does this affect their structure? Nonvascular; depend on water film for sperm Form ground-hugging carpets Body parts are too thin to support a tall plant Absence of vascular tissue (no long-distance transport) Explain what protenoma are and what they form Bryophyte spores are dispersed to a favorable habitat, germinate, and grow into gametophytes Germinating moss spores produce protenoma (mass of green, branched, one-cell-thick filaments) Protenoma has a large surface area that enhances absorption of water and minerals ,QIDYRUDEOHFRQGLWLRQVDSURWHQRPDSURGXFHVRQHRUPRUH³EXGV´ A protenoma with one or more gametophores make up the body of a moss gametophyte How are gametophores produced? (DFK³EXG´KDVDQDSLFDOPHULVWHPWKDWJHQHUDWHVDJDPHte-producing gametophore How do conducting tissue in the center of some mosses affect their structure? Can allow mosses to grow up to 2 feet tall Phylogenetic analysis suggests similarities between vascular tissue and conducting tissue due to analogy Bryophytes do not have roots, how are they anchored to the ground? Rhizoids are root-like structures that anchor gametophytes Not composed of tissue Long, tubular single cells or filaments Lack specialized conducting cells and do not play a role in water and mineral absorption Explain the asexual reproduction of some mosses )RUP³EURRGERGLHV´ Small plantlets that detach from the parent plant and grow into new, genetically identical copies of their parent Define the three features of the bryophyte sporophyte Link to gametophyte Foot (embedded in archegonium) absorbs nutrients from gametophyte Seta (stalk) conducts these materials to the sporangium Sporangium (capsule) produces spores by meiosis Upper part has a ring of interlocking, tooth-like structures called peristome 3HULVWRPH³WHHWK´RSHQXQGHUGU\FRQGLWLRQVDQGFORVHZKHQLWVPRLVW Allows moss spores to be discharged gradually by gusts of wind Are bryophyte sporophytes dependent or independent? Explain Dependent on gametophyte Remains attached to parent gametophyte for supplies of sugars, amino acids, minerals, and water

What are plastids? In sporophyte cells Usually green and photosynthetic when young Difference between bryophyte phyla moss, hornworts, and liverworts sporophyte stage Moss

Hornworts

Liverworts

Size

Large

Large

Small

Complexity

Complex

Complex

Simple

Cuticle

None

Present

None

Stomata

Present

Present

None

Ecological importance of mosses Environment Some colonize bare, sandy soil Help retain nitrogen in soil Some inhabit extreme environments (mountaintops, tundra, deserts) Can survive loss of water and rehydrate Symbiotic relationships Some form symbiotic relationships with cyanobacteria Increase availability of nitrogen in the ecosystem Phenolic compounds in cell walls Absorb damaging levels of UV radiation in deserts or high altitudes Sphagnum (peat moss) 0DMRUFRPSRQHQWRIGHSRVLWVRISDUWLDOO\GHFD\HGRUJDQLFPDWHULDONQRZQDV³SHDW´ Boggy regions with thick layers of peat are called peatlands Sphagnum does not decay readily (phenolic compounds, low temperature, low pH, low oxygen levels) Used as a source of fuel in Europe and Asia Contains large amounts of organic carbon (overharvesting releases carbon and largely contributes to global warming) Origin of vascular plants Ancient relatives had branched sporophytes that were not dependent on gametophytes for nutrition Enabled their bodies to become more complex and have multiple sporangia Competition for space and sunlight increased (leading to formation of forests) Less dependence on water (still some because of flagellated sperm) What are the significant traits of living vascular plants? Life cycles with dominant sporophytes Vascular tissues called xylem and phloem Well-developed roots and leaves (spore-bearing leaves called sporophylls) Is the gametophyte of vascular plants dependent or independent? Gametophyte is independent What does xylem transport?

Transports water with nutrients from soil Conducts most of the water and minerals Includes tracheid (tube-shaped cells that carry water and minerals up from the roots) Lignified water-conducting cells (cell walls strengthened by lignin) What does phloem transport? Flows down (source to sink) Cells arranged into tubes that distribute sugars, amino acids, and other organic products What enabled plants to grow tall? Lignified vascular tissue Stems became stronger Could transport long-distance Outcompete short plants for sunlight Spores could disperse farther (colonize new environments) Describe the evolution of roots Roots evolved in the sporophytes of almost all vascular plants Roots are organs that absorb water and nutrients from the soil May have evolved from subterranean stems Describe the evolution of leaves and the difference between: Microphylls Megaphylls Leaves are structures that serve as the primary photosynthetic organ of vascular plants Microphylls: (lycophytes) small, spine-shaped leaves supported by a single strand of vascular tissue Megaphylls: leaves with highly branched vascular system What are sporophylls? Modified leaves that bear sporangia Vary greatly in structure Fern sporophylls Produce clusters of sporangia known as sori (usually on the undersides of sporophylls) Lycophytes and gymnosperm sporophylls Groups of sporophylls form cone-like structures called strobili Angiosperm sporophylls Called carpels and stamens Explain the homosporous trait of seedless vascular plants Most seedless vascular plants are homosporous One type of sporophyll bearing one type of sporangium that produces one type of cell (typically develop into bisexual gametophytes) What are the two types of sporophylls that heterosporous species possess Megasporophylls have megasporangia, which produce megaspores (develop into female gametophytes) Microsporophylls have microsporangia, which produce microspores (develop into male gametophytes) Two clades of seedless vascular plants Phylum lycophyte (club mosses, spike mosses, quillworts) Phylum monilophyta (ferns, horsetails, and whisk ferns and their relatives) Describe the key traits of lycophytes

Some grow on topical trees as epiphytes (plants that use other plants as a substrate) Others grow on temperate forest floors Some species have tiny gametophytes that live above ground and are photosynthetic Others live below ground, nurtured by symbiotic fungi SPOROPHYTES Have upright stems with many small leaves, and ground hugging stems that produce dichotomously branching roots Spike mosses usually relatively small and grow horizontally Spike mosses and club mosses have sporophylls clustered into club-shaped cones (strobili) Quillworts (named for leaf shape) form a single genus that live in marshy areas or submerged aquatic plants Club mosses are all homosporous Spike mosses and quillworts are heterosporous Club moss spores released in clouds and very rich in oils Giant lycophyte trees thrived for millions of years in moist swamps Surviving species are small herbaceous plants Club mosses and spike mosses have vascular tissue and are not true mosses What are the three types monilophytes? (Most closely related to seed plants than lycophytes; megaphyll leaves and roots) Ferns Have megaphylls Sporophytes have horizontal stems that give rise to fonds (large leaves) divided into leaflets (grow as fiddle tip unfurls) Almost all are homosporous Gametophyte shrivels and dies once sporophyte detaches Sporophytes have stalked sporangia with spring-like devices that catapult spores Horsetails Derived during carboniferous period but now only genus equisetum exists Bushy stems have gritty texture Homosporous (cones release spores and produce bisexual gametophytes) Arthrophytes (jointed plants) stems have joints Rings of small leaves or branches emerge from joints, but stem is main photosynthetic organ Large air canals carry oxygen to the roots Whisk ferns and relatives Resemble ancestral vascular plants BUT more closely related to modern ferns Sporophytes have dichotomously branching stems but no roots Stems have scalelike outgrowths that lack vascular tissue and consists of 3 fused sporangia Homosporous and spores give rise to bisexual gametophytes What is the significance of seedless vascular plants? Increased growth and photosynthesis which decreased CO2 from atmosphere and contributed to global cooling Decaying plants of carboniferous forests eventually became coal

Chapter 30 ± Plant Diversity II: The Evolution of Seed Plants x Understand the gametophyte-sporophyte relationships within the mosses/nonvascular plants, ferns/seedless vascular plants, gymnosperms, and angiosperms plants groups. Gymnosperm and angiosperms: megasporangia (female organ that produces sperm) Gymnosperm: have on integument Angiosperm: have two integuments *\PQRVSHUPVKDYH³QDNHG´VHHGVW\SLFDOO\RQFRQHV Seeds are exposed on sporophylls Cone-bearing plants called conifers Better suited to drier conditions than nonvascular plants Conifers dominant northern latitudes Angiosperms: dominate more terrestrial ecosystems Gymnosperm life cycle: Gametophytes get smaller Development of seeds from fertilized ovules Pollen transfers sperm to ovules x Know the key adaptations that plants made to live on land. Seeds Pollen grains In addition: reduced gametophytes, heterospory, ovules, pollen Explain in detail how seeded plants (gymnosperms and angiosperms) produce eggs in ovules and sperm in pollen grains. x What are the evolutionary advantages of seeds? They remain dormant for days to years (like endospores and cysts) Stored food May be transported long distances by wind or animals x Understand the life cycle of a gymnosperm as illustrated by the life cycle of a pine. Include details about the ploidy (haploid/diploid) of the cycle. PAGE 20 Ovulate cones produces eggs Male cones: give rise to pollen ²> gives rise to sperm Start at embryo (diploid sporophyte) Embryo with seed coat develops into seeds Seed falls to the ground ²> germinates ²> produce a seedling Seedling grows into the mature sporophyte (still diploid) (pine tree) This mature sporophyte produces ovulate (female part: get eggs) and pollen cone (male part: get sperm) Ovulate cone has ovules (think of three components for ovules) Mega sporangium contains megasporocytes (diploid) Integument: protects Micropyle: hole where pollen attaches for fertilization Pollen cones are like ovules Microsporangium contains micro sporocytes (diploid) x

By meiosis, microsporocytes produce pollen grains (haploid) By meiosis, megasporocytes produces mega spores (haploid) when pollen grains land Megaspores produces archegonium by mitosis (haploid) Archegonium by mitosis will produce eggs inside ovule (haploid) Sperm + egg= fertilize end Characterize the following gymnosperm phyla: Cycadophyta, Ginkgophyta, Gnetophyta, and Coniferophyta Cycadophyta (cycads): have large cones and palmlike leaves, have flagellated sperm Gingkophyta (Ginkgo biloba): also has flagellated sperm, high tolerance to air pollution Gnetophyta (three genera: gnetum, ephedra, welwitschia): Gnetum: tropical one (: Welwitschia: desert ones Ephedra: has been used as a decongestant Coniferophyta (conifers like pine, fir, redwood): largest, can carry out photosynthesis year round x Know the function of the floral organs for angiosperms. Reproductive adaptions: include flowers and fruits Anthophyta: single phylum that classifies angiosperms Flower: angiosperm structure specialized for sexual reproduction x

Floral organs: Sepals: enclose the flower Petals: brightly colored and attract pollinators Stamens: produce pollen Consists of a filament (stalk) Also has a sac (anther: pollen is produced) Carpels: produce ovules Consists of an ovary at the base Also has a style: stalk Style leads up to a stigma: where pollen is received x What purpose do fruits serve for angiosperms and how does this aid the variety of dispersal mechanisms? Fruits protect seeds and aid in their dispersal How? Seeds can be carried by wind, water, or animals to new locations x Compare and contrast the physical characteristics of monocots and eudicots (formerly dicots). Monocots - One cotyledon - Leaf veins are parallel - Vascular tissue scattered - No main root: root system is fibrous (XGLFRWV³WUXHGLFRWV´ - Two cotyledons - Leaf veins netlike - Vascular tissue arranged in a ring - Main root (like sunflowers)

Chapter 38 ± Angiosperm Reproduction and Biotechnology x Describe in detail the life cycle of a typical angiosperm. This should include the details of fertilization beginning with the transfer of pollen grains from the anther and ending with seed development. Include details about the ploidy of the cycle. Angiosperm life cycle includes Gametophyte development Embryo sac develops within ovule Two integuments surround a megasporangium One cell in megasporangium undergoes meiosis and produces 4 megaspores (only 1 survives) Megaspores divides without cytokinesis (producing one large cell with eight nuclei) Pollen develops from microspores within microsporangia (pollen sacs) of anthers Microscopes undergoes mitosis to produce two cells (generative and tube cell) Pollen grain has of course ^^ two celled male gametophyte and the spore wall Pollination Transfer of pollen from an anther to a stigma After landing on stigma, a pollen grain produces a pollen tube (which discharges two sperm cells) Double fertilization Fusion of gametes, two sperm reach female gametophytes THIS PROCESS: ensures that endosperm only develops in ovules Seed development Each ovule develops into a seed. Ovary develops into a fruit enclosing the seed When a seed germinates, the embryo develops into a new sporophyte Life cycle: Start at female gametophyte (embryo sac) having a zygote (diploid) and a developing endosperm (triploid) Then you have an embryo (2n), developed endosperm (3n), and seed coat (2n) Seed germinates and becomes a sporophyte plant (flower: 2n) ²> flowers have male and female parts Anther has microsporangium which by mitosis produces microsporocytes (2n) And then by meiosis, microsporocytes produce microspores (n) Microscopes give rise to male gametophyte (pollen) inside pollen tubes Pollen finds its way to the micropyle and by mitosis produces sperm, which then fertilizes egg Ovary has ovules (2n) which inside have mega sporangium These megasporangium by mitosis produce megasporocytes (2n) Then through meiosis, megasporocytes produce megaspores (n) Sperm fertilizes egg (n)...