Bio 1B Pictures Flashcards

Question

From what tissue do lateral roots arise?

Answer 1

Lateral roots originate in the pericycle, the outermost layer of the vascular cylinder of a root, and grows out through the cortex and epidermis.

Answer 2

The older layers of secondary xylem no longer transport water and minerals (a solution called xylem sap). These layers are called heartwood because they are closer to the center of a stem or root. The newest, outer layers of secondary xylem still transport xylem sap and are therefore known as sapwood. That is why a large tree can survive even if the center of its trunk is hollow.

Answer 3

As these meristemetic cells divide, they increase the circumference of the vascular cambium and also add secondary xylem to the inside of the cambium and secondary phloem to the outside. Some initials are elongated and are oriented with their long axis parallel to the axis of the stem or root. They produce cells such as the tracheids, vessel elements, and fibers of the xylem, as well as the sieve-tube elements, companion cells, parenchyma, and fibers of the phloem. The other initials are shorter and are oriented perpendicular to the axis of the stem or root. They produce vascular rays - radial files of cells that connect the secondary xylem with the secondary phloem. The cells of a vascular ray move water and nutrients between the secondary xylem and phloem, store carbohydrates, and aid in wound repair. Most of the thickening is from secondary xylem.

Answer 4

A herbaceous plant (in American botanical use simply herb) is a plant that has leaves and stems that die down at the end of the growing season to the soil level. They have no persistent woody stem above ground.[1] Herbaceous plants may be annuals, biennials or perennials.[2]

Answer 5

Xylem conducts water and dissolved minerals upward from roots into the shoots. Phloem transports sugars, the products of photosynthesis, from where they are made (usually the leaves) to where they are needed - usually roots and sites of growth, such as developing leaves and fruits.

Answer 6

The vascular tissue of a root or stem is collectively called the stele. The arrangement of the stele varies, depending on the species and organ. In angiosperms, for example, the root stele is a solid central vascular cylinder of xylem and phloem, whereas the stele of stems and leaves consists of vascular bundles, separate strands containing xylem and phloem.

Answer 7

Tissues that are neither dermal nor vascular are part of the ground tissue system. Ground tissue that is internal to the vascular tissue is known as pith, and ground tissue that is external to the vascular tissue is called cortex.

Answer 8

It's a ginger stem! Ginger is a horizontal underground stem (rhizome)

Answer 9

The hypocotyl (short for "hypocotyledonous stem",[1] meaning "below seed leaf") is the stem of a germinating seedling, found below the cotyledons (seed leaves) and above the radicle (root). Coleoptile is the pointed protective sheath covering the emerging shoot in monocotyledons such as oats and grasses. Coleoptiles have two vascular bundles, one on either side. Unlike the flag leaves rolled up within, the pre-emergent coleoptile does not accumulate significant protochlorophyll or carotenoids, and so it is generally very pale. Some preemergent coleoptiles do, however, accumulate purple anthocyanin pigments. In plant physiology, the epicotyl is the embryonic shoot above the cotyledons. In most plants the epicotyl will eventually develop into the leaves of the plant. In dicots, the hypocotyl is what appears to be the base stem under the spent withered cotyledons, and the shoot just above that is the epicotyl. In monocot plants, the first shoot that emerges from the ground or from the seed is the epicotyl, from which the first shoots and leaves emerge.

Answer 10

The hypocotyl (short for "hypocotyledonous stem",[1] meaning "below seed leaf") is the stem of a germinating seedling, found below the cotyledons (seed leaves) and above the radicle (root).

Answer 11

Lateral roots arise from the pericycle.

Answer 12

Dicots: Secondary growth often present Monocots: Secondary growth absent

Answer 13

The casparian strip is a material (suberin) on the endodermis that is semi-permeable, and glues it together so water is forced to go through cells.

Answer 14

Generic epidermis cell have no chloroplasts (except the stomata). They are "thin tiles," and may have trichomes for protection from critters and fungal molds. Trichomes also reflect light, and keep it cool. EX:: Stinging nettle

Answer 15

Typical plant cell, and is easy for the meristem to make! Parenchyma cells have thin primary walls and usually remain alive after they become mature. The pith is filled with parenchyma cells. EX: Paper is cellulose made from parenchyma cells.

Answer 16

Collenchyma cells have thin primary walls with some areas of secondary thickening. Collenchyma provides extra structural support, particularly in regions of new growth. Collenchyma cells are found in the cortex of the stem, and are usually found adjacent to outer growing tissues such as the vascular cambium. EX: The "strings" of celery

Answer 17

Sclerenchyma cells have thick lignified secondary walls and often die when mature. Sclerenchyma provides the main structural support to a plant. \>Extremely strong \>Dead \>Can be filled with water or not \>It's for support EX: Fiber cell is a sclerenchyma cell

Answer 18

Meristematic cells are incompletely or not at all differentiated, and are capable of continued cellular division (youthful). Furthermore, the cells are small and protoplasm fills the cell completely. The vacuoles are extremely small. The cytoplasm does not contain differentiated plastids (chloroplasts or chromoplasts), although they are present in rudimentary form (proplastids). Meristematic cells are packed closely together without intercellular cavities. The cell wall is a very thin primary cell wall.

Answer 19

In root nodules, bacteria use energy from the plant to capture nitrogen from the air and convert it to organic forms that the plant can use. See the pink cells with bacteria!

Answer 20

Suberin makes up the cork (the same material as the Casparian strip!). It is hydrophobic and won't soak up water. It is waxy material, and the cells in this area are dead and abundant in suberin.

Answer 21

Unitary organisms: We have determinant growth modular organisms: Have indeterminant growth (EX: plants, because they have meristems). They compete very differently.

Answer 22

Phloem: Made up of the following cell types: sieve cells and companion cells (transport), and parenchyma and fiber cells. Transports sugar & water through pressure. Xylem: Made up of vessel elements, tracheids, and fiber cells. The vessel has a hydrophobic secondary cell wall that seals contents from the outside. Xylem sap moves up the plant through tension.

Answer 23

Xylem sap is transported by tension. Water moves up by adhesion (the tendency of dissimilar particles or surfaces to cling to one another) and cohesion (cohesion refers to the tendency of similar or identical particles/surfaces to cling to one another). The cohesion of water molecules is due to hydrogen bonding between water molecules, while the adhesion of water molecules by hydrogen bonds to the hydrophilic walls of xylem cells helps offset the downward force of gravity. Water moves up to relieve some of the tension. Transpiration results in the pressure potential at the leaf end of the xylem being lower than the pressure potential at the root end. At night, when there is almost no transpiration, root cells continue pumping mineral ions into the xylem of the stele, and the endodermis helps prevent the ions from leaking out. The resulting accumulation of minerals lowers the water potential within the stele. Water flows in from the root coretx, generating root pressure, a push of xylem sap. In most plants, root pressure is a minor mechanism driving the ascent of xylem sap, at most pushing water only a few meters.

Answer 24

General term for cytoplasm

Answer 25

Sugar source is a plant organ that is a net producer of sugar, by photosynthesis or by breakdown of starch. A sugar sink is an organ this is a net consumer or depository of sugar.

Answer 26

Bulk flow by positive pressure: The mechanism of translocation (the phloem's transport of the products of photosynthesis). Phloem sap moves from sites of sugar production (sugar source) to sites of sugar use or storage (sugar sink). In studying angiosperms, researchers have conluded that phloem sap moves through sieve tube by bulk flow driven by positive pressure, known as pressure flow. The loading of sugar into the sieve tube at the source reduces water potential inside the sieve-tube elements. This causes the tube to take up water by osmosis. This generates a positive pressure that forces the sap to flow along the tube. The pressure is relieved by the unloading of sugar and the consequent loss of water at the sink. Phloem saps moves from high to low pressure!

Answer 27

Sucrose manufactured in mesophyll cells can travel to the sieve-tube elements. Sucrose is actively transported into companion cells and sieve-tube elements. Proton pumps generate an H+ gradient, which drives sucrose accumulation with the help of a cotransport protein that couples sucrose transport to the diffusion of H+ back into the cell. \>\>The leaf's sieve cell becomes hypertonic (lots of sugar!). So, the sieve tube takes up water by osmosis. This uptake of water generates a positive pressure that forces the sap to flow along the tube. The pressure is relieved by the unloading of sugar and the consequent loss of water at the sink.

Answer 28

Explains why phloem sap flows from source to sink, and experiments build a strong case for pressure flow as the mechanism of translocation in angiosperms. Experiment: Showed phloem sap near sources has a higher sugar content than phloem sap near sinks. They used aphids that feed on phloem sap. An aphid probes with a hypodermic-like mouthpart called a stylet that penetrates a sieve-tube lement. They seaprated the aphid from the stylets, which then acted as taps exuding sap for hours. They measured the sugar concentration of sap from stylets at different points between a source and sink. Results: The closer the stylet was to a sugar source, the higher its sugar conentration was.

Answer 29

In the phloem, all cells are connected by the same plasma membrane, so the center is symplast. Meanwhile, in the xylem, there is a lignified secondary cell wall that is extremely hydrophobic around the vessel. Since there is no plasma membrane, the center of the vessel is apoplast.

Answer 30

Cavitation occurs when the water column in a vessel breaks. This may occur when the soil is too dry, and their is no water to pull up. It can also occur after freezing temperatures when the frozen water thaws out and there are air bubbles. Cavitation is limited to the vessel, and a vacuum is created in the vessel (with the adhesion of water to the pit, which has a primary cell wall made of cellulose, and a break in the lignified secondary cell wall). Eventually, water can't be transported.

Answer 31

Gymnosperms don't have vessel members, but tracheids! Tracheids are much narrower, which allows for closer adhesion/cohesion. The forces are much stronger because it's narrower. They can grow in drier and colder habitats! Higher elevation plants tend to have needle-like leaves!

Answer 32

Mosses (Phylum Bryophyta) Note: Capsule & Seta make up Sporophyte Sporophyte: dependent on gametophyte stem & rhizome: No Leaves: No Roots: No Strobili: No Spores: Homosporous Gametophyte: dominant Motile sperm: yes

Answer 33

phylum psilophyta EX: Whisk ferns and relatives Each yellow knob on a stem consists of three fused sporangia. Sporophyte: dominant stem & rhizomes: Yes leaves/roots/strobili: no Spores: homosporous Gametophyte: subterranean Motile sperm: yes

Answer 34

Phylum Lycophyta EX: club moss Lycopodium: Sporophyte: dominant stem & rhizomes: yes leaves: microphylls roots: yes strobili: in some spores: homosporous gametophyte: subterranean motile sperm: yes

Answer 35

Phylum Sphenophyta (horse tail) Sporophyte: dominant stems & rhizomes: yes leaves: microphylls roots: yes strobili: yes spores: homosporous Gametophyte: photosynthetic thallus Motile sperm: yes

Answer 36

Phylum pterophyta (ferns) Sporotype: dominant stems & rhizomes: yes; mostly rhizome leaves: megaphylls roots: yes strobili: no spores: mostly homosporous gametophyte: photosynthetic thallus motile sperm: yes

Answer 37

Microphyll is a type of plant leaf, which has traditionally been defined as "an appendage supplied by a single, unbranched vein".[1 Megaphylls, in contrast, are characterised by multiple veins.

Answer 38

Sporangium encases the spores of a fern (a). Water evaporates through the thin cell walls of the annulus cells (along the spine of the structure), shortening one side of the sporangium's arm and ratcheting it back into a primed position (b,c). Because the thick inner walls of the annulus cells resist collapse, the water pressure inside the cells drops and bubbles form in the liquid. The bubbles pop the cell walls outward, thereby restoring the arm to its original form and launching the spores (d,e). Tom Moore

Answer 39

Heterosporous plants are those that produce two types of spores that differ in size and sex. In particular, they produce two morphologically distinct types of sporangia (megasporangia and microsporangia) that create two distinct types of spores (megaspores and microspores). The spores then develop into separate male and female gametophytes. They are different from homosporous plants in which the sporophyte produce a single type of sporangium and then a single type of mother spore cell.

Answer 40

Bryophyte sporophytes grow out of archegonia, and are the smallest and simplest sporophytes of all extant plant groups

Answer 41

Life cycles of plants and algae with alternating haploid and diploid phases are referred to as diplohaplontic (the equivalent terms haplodiplontic, diplobiontic or dibiontic are also in use). EX: Moss life cycle

Answer 42

In plant anatomy, sieve tube elements, also called sieve tube members, are a specialised type of elongated cell in the phloem tissue of flowering plants. The ends of these cells are connected with other sieve tube members, and together they constitute the sieve tube. sieve elements are living cells. They are unique in lacking a nucleus at maturity. At the interface between two sieve tube members in angiosperms are sieve plates, pores in the plant cell walls that facilitate transport of materials between them. Each sieve tube element is normally associated with one or more nucleate companion cells, to which they are connected by plasmodesmata (channels between the cells). Companion cells are derived from the same mother cell as its associated sieve tube member. Sieve tube members have no cell nucleus, ribosomes, or vacuoles. The associated companion cell(s) form sieve tube-companion cell complexes which ameliorate the deficiencies of the enuclate sieve tube member, providing proteins, ATP, and signalling molecules. In leaves, companion cells help in moving the sugar produced by photosynthesis in the mesophyll tissue into the sieve tube elements.

Answer 43

Bryophytes: Include liverworts ("mnium") & mosses ("marchantia").

Answer 44

Seedless vascular plants are different from seedless non-vascular plants in that they have a xylem! 1. Psilophyta (whisk fern) 2. Lcophyta (club moss) 3. Sphenophyta (horse tail) 4. Pterophyta (fern)

Answer 45

Phylum Lycophyta: Selaginella Sporophyte: dominant stem & rhizomes: yes leaves: microphylls roots: yes Strobili: yes Spores: heterosporous Gametophyte: Inside spore wall Motile sperm: yes

Answer 46

The word gymnosperm refers to the principle characteristic of these groups: that they have ovules (which become seeds upon fertilization), and that the ovules are borne exposed (naked) on the surface of sporophylls. Groups: 1. Cycadophyta: cycads 2. Coniferophyta: conifers 3. Ginkgophyta: Ginkgo biloba Gnetophyta: Gnetum, Ephedra, Welwitschia

Answer 47

The spore wall is made from sporopollenin: more complex/dense than lignin! It covers megagametophyte and microgametophyte, and protects them against dessication.

Answer 48

Coniferophyta: The most common and diverse gymnosperm lineage. Conifers are the dominant species of evergreen forests in temperate or boreal area. They are very abundant in CA, and a large portion of conifer diversity is represented in the state, with species of Sequoia, redwoods, pines etc. Sporophyte: dominant Spores: heterosporous Gametophyte: endosporic (gametophyte develops within a spore) Archegonia: Yes Antheridia: No Motile sperm: no Pollen: yes Ovules and seeds: Yes Double fertilization: No Endosperm: No Ovary wall and fruit: No

Answer 49

Cycadophyta Sporophyte: dominant Spores: heterosporous Gametophyte: endosporic (develops within spore) Archegonia: Yes Antheridia: No Motile sperm: Yes Pollen: Yes Ovules and seeds: Yes Double fertilization: No Endosperm: No Ovary wall and fruit: No

Answer 50

Ginkgophyta: EX: Ginkgo biloba Sporophyte: dominant Spores: heterosporous Gametophyte: endoscopic Archegonia: Yes Antheridia: No Motile sperm: yes pollen: yes ovules and seeds: yes Double fertilization: no Endosperm: No Ovary wall and fruit: No

Answer 51

Gnetophyta: Gnetum, Ephedra, Welwitschia See Gnetum

Answer 52

A gymnosperm! Ephedra

Answer 53

Welwitschia: A Gymnosperm. Has a long taproot, and is found in Namibia in Africa

Answer 54

Made up of Gnetum, Ephedra, and Welwitschia Sporophyte: dominant spores: heterosporous gametophyte: endosporic Archegonia: Ephedra (yes), Welwitschia (no), Gnetum (no) Antheridia: No Motile sperm: no Pollen: Yes Ovules and seeds: yes Double fertilization: Ephedra (yes), Welwitschia ?, Gnetum (yes) Endosperm: No Ovary wall and fruit: no

Answer 55

Seedless vascular plants , particularly those in the Sphenophytes and Lycophytes divisions, once formed vast forests (Carboniferous period, which extends from 360-287 million years ago) whose remnants now form coal beds since it is no longer so warm and humid. Cellulose acetate peels from coal exemplify this: http://petrifiedwoodmuseum.org/Anatomy.htm Also, see the following: http://www.mnh.si.edu/ETE/ETE\_Research\_Reconstructions\_Carb\_step1.html

Answer 56

A. Seedless vascular plants that have members with microphylls: Lycophyta (Lycopodium & Selaginella) (club moss) & Sphenophyta (horse tail). B. Megaphylls: Pterophyta (ferns) C. Leaves: Lycophyta, Sphenophyta, & Pterophyta D. Roots: Lycophyta, Sphenophyta, Pterophyta E. Strobili: Lycophyta: Lycopodium (in some), Lycophyta: Selaginella (yes), Sphenophyta F. Jointed Stems: Psilophyta (whisk fern), Lycophyta, Sphenophyta, Pterophyta G. Rhizomes: Psilophyta, Lycophyta, Sphenophyta, Pterophyta H. Branching sporophytes: Psilophyta, Lycophyta, Sphenophyta, Pterophyta

Answer 57

The following seedless vascular plants have members with heterospory: Some Pterophytes (ferns), and the lycophyte groups Selaginela and Isoetes.

Answer 58

Heterospory contributed to further plant evolution since there was more outcrossing among plants since microspores may drift farther from the sporophyte than megaspores. This in turn increases genetic diversity, and promotes plant evolution.

Answer 59

Heterospory promotes outcrossing among plants, since microspores may drift farther from the sporophyte than megaspores. Outcrossing is advantageous since it increases genetic diversity, thus reducing the probability of all individuals being subject to disease or reducing genetic abnormalities. Also, herosporous spores/gametophytes can evolve towards specialization for their unisexual roles (e.g. the female gametophytes can be produced from larger spores and can themselves grow to a size that better supports the new embryo).

Answer 60

The homosporous life cycle evolved before the homosporous life cycle (and seedless vascular plants were the first to evolve heterospory). Most seedless vascular plant species are homosporous: they have one type of sporangium that produces one type of spore, which typically develops into a bisexual gametophyte, as in most ferns. In contrast, a heterosporous species species has two types of sporangia and produces two kinds of spores: Megasporangia on megasporophylls produce megaspores, which develop into female gametophytes; microsporangia on microsporophylls produce microspores, which develop into male gametophytes. All seed plants and a few seedless vascular plants are heterosporous. Homosporous spore production: Sporangium on sporophyll=\>Single type of spore=\>Typically a bisexual gametophyte=\>Eggs & Sperm Heterosporous spore production: Megasporangium on megasporophyll=\>Megaspore=\>Female gametophyte=\>Eggs Microsporangium on microsporophyll=\>Microspore=\>Male gametophyte=\>Sperm

Answer 61

Lignified vascular tissue permitted vascular plants to grow tall. Their stems became strong enough to provide support against gravity, and they could transport water and mineral nutrients high above ground. The ability to grow tall was a major evolutionary innovation: Tall plants could shade other plants, reducing their access to the sunlight needed for photosynthesis. This gave vascular plants a competitive edge over nonvascular plants, which rarely grow above 20 cm in height. Competition for light among vascular plants also increased, and taller growth forms were favored by natural selection - such as treelike plants that formed the first forests about 370 million years ago.

Answer 62

a. Decomposers: they break down organic material and recycle nutrients, allowing other organisms to assimilate essential chemical elements i. Use hypahe to penetrate larger pieces of organic matter, break into smaller parts ii. Release enzymes that decay the material, nutrients are then absorbed b. Mycorrhizal symbiont: an association between a fungus and a vascular plant. The fungus colonizes the host plant roots i. Fungus: direct access to carbohydrates (glucose/sucrose) ii. Plant: able to absorb water and minerals due to a large surface area. Improves the plants absorption capabilities

Answer 63

a. Yeast (Ascomycota) i. Benefit: production of alcoholic beverages and raise bread ii. Harm: can cause infections “yeast infections,” opportunistic infections b. Amanita (Basidiomycota) i. Benefit: popular type of fungus (mushroom) to eat ii. Harm: if eating the wrong kind, is toxic to humans c. Penicillium (Deuteromycota) i. Benefit: can be used as an antibiotic. Effective against many diseases (syphilis/ staph infections) ii. Harm: individuals may be allergic to this medication, causing nausea, hypersensitivity, diarrhea

Answer 64

After meiosis is completed. Meiosis then restores the haploid condition, leading to the formation of spores that enables fungi to disperse.

Answer 65

i. Plasmogamy: the union of the cytoplasms of 2 parent mycelia ii. Karyogamy: the haploid nuclei contributed by the 2 parents fuse, producing diploid cells. Zygotes and other transient structures form during karyogamy, the only diploid stage in most fungi iii. Meiosis: then restores the haploid condition, leading to the formation of spores that enable fungi to disperse. The sexual process of karyogamy and meiosis generate extensive genetic variation, a prerequisite for natural selection iv. Germination: the process where fungi emerge from seeds and spores to begin growth. The spores eject from their reproductive structures

Answer 66

a. Root: a multicellular organ that anchors a vascular plant in the soil, absorbs minerals and water, and often stores carbs. Most eudicots have 1 vertical root (taproot) and the lateral root (branch root). The entire root sysmte helps anchor a plant, in most plants the absorption of water and minerals occur primarily near the tips of the root, where there are a vast number of root hairs to increase surface area. b. Stem: is an organ consisting of an alternating system of nodes, the points at which leaves are attached, and internodes, the stem segments between nodes. In the upper angle formed by each leaf and the stem is an axillary bud, a structure that can form a lateral shoot, commonly called a branch. Most axillary buds of a young shoot are dormant (not growing). Thus elongation of a young shoot is usually concentrated near the shoot tip, which consists of an apical bud, or terminal bud, with developing leaves and a compact series of nodes and internodes c. Leaves: the main photosynthetic organ, although green stems also perform photosynthesis. Leaves vary extensively in form but generally consist of a flattened blade and a stalk, the petiole, which joins the leaf to the stem at a node.

Answer 67

Give the definition of the following modified organs: spine, thorn, rhizome, tuber, stolon, bulb, corm. a. Spine: modified leaves or parts of leaves, extension of leaf veins b. Thorn: modified branches or stems. May be simple or branched c. Rhizome: is a subterranean plant that is found underground, send out roots/shoots from its nodes. Examples: ginger, turmeric and asparagus d. Tuber: forms from thickened rhizomes or stolons. Top side produces shoots that grow into typical stems and leaves while the underside produces roots. Potatoes are forms of tubers that form from enlarged stolons, thickened at the storage organ. e. Stolon: are horizontal connections between organisms. Generally external skeletons. Stolons are stems which grow at the soil surface or just below the ground that for adventatitious roots at the nodes, and new plants from the buds. Potatoes are considered stolons f. Bulb: is a short stem with fleshy leaves or leaf baes that function as food storage organs during dormancy. Also known as scales, contain food reserves to enable the plant to survive adverse conditions. g. indeterminate: refers to the growth that is not terminated. Plant keeps growing and growing. Determinate growth stops once a genetically pre-determined structure has completely formed.

Answer 68

Root primordia (brown spots) as seen on the butt of a freshly cut pineapple crown intended for vegetative reproduction. A primordium (/praɪˈmɔːrdiːəm/; plural: primordia) in embryology, is defined as an organ or tissue in its earliest recognizable stage of development.[1] A primordium is the simplest set of cells capable of triggering growth of the would-to-be organ and the initial foundation from which an organ is able to grow.

Answer 69

Spores are made of durable polymer sporopollenin, tracheids are made of complex polymer lignin and cuticle consists of polyester and wax polymers, which are all very resistant to decomposition(plastic is also polymer chains which is why it creates an environmental issue nowadays).

Answer 70

a. seed coat: the outer protective covering of a seed b. embryo: an organism in its early stages of development, the minute ridumentary plant contained within a seed c. cotyledons: a leaf of the embryo of a seed plant, which upon germination either remains in the seed and emerges, and becomes green. Also known as seed leaf d. epicotyls: the stem of a seedling or embry located between the cotyledons and the first true leaves e. hypocotyls: the part of the axis of a plant embryo or seedling plant that is below the cotyledon f. endosperm: the nutritive tissue within seeds of flowering plants, surrounding and absorbed by the embryo

Answer 71

The radicle: the first part of the seedling (growing from the plant embryo) to emerge from the seed during germination

Answer 72

Symplastic, meaning the transport occurs within the plasma membrane of the cells that controls the traffic of molecules into and out of the protoplast .this continuum from one cytosol of the cell to another collectively called symplast.

Answer 73

First: sieve cells are in gymnosperms (seedless vascular plants) and sieve tube elements- in angiosperms (flowering plants that have seeds in a protective chamber). Second: sieve cells are alive but lack nuclei and other organelles this reduction in cell contents makes the transport of nutrients possible. another adaptation is sieve plates -the end walls between sieve tube elements that have pores that facilitate free flow of fluid. at last, sieve tube elements are surrounded by companion cells (thinner smaller cells with nuclei and all the organelles) that are connected to sieve -tube elements by channels - plasmodesmata. the organelles of the companion cell serve the sieve-tube elements.

Answer 74

Translocation is the mechanism of sugar (and other nutrients) transport in the phloem. The role of membranes is to control what substances enter the cell, as membranes are permeable to some (ex.water), and impermeable to others, or selectively permeable. when the phospholipid bilayer is impermeable to some substance that is necessary for life, they are transported into the cell with the help of transport proteins by active transport that requires ATP.Active transport is the pumping of a solute across a membrane against its electrochemical gradient.(ex. proton pumps). Solutes are substances that are dissolved in a solution (ex. sugar in water). Osmosis is the diffusion of water across a membrane. Water potential is the combined effect of solute concentration (water moves from solution with the lower solute concentration to the higher) and physical pressure (limitation of water inflow into the cell due to the rigid cell wall). Turgor pressure occurs due to the contents of the cell pressing against the cell wall that in turn presses against protoplast (turgor pressure is lost when there is no water inflow - cells dry out and plant wilts) Translocation of phloem sap is from the sites of sugar production (sources) to the sites of sugar usage and storage (sinks). the direction of phloem sap is controlled by positive pressure (called pressure flow) that occurs due to the high pressure at the sources (build up of solutes ); then phloem sa moves to the low pressure sites - sinks.

Answer 75

when sieve-tube elements are formed the organelles and nuclei dissolve. the remains form secondary structure p - proteins (alpha-helix) that sit at the pore of sieve-plates. when injury occurs they thicken and clog the pores preventing the loss of phloem sap. they act as clotting agents.

Answer 76

Cuticle is a waxy hydrophobic layer covering epidermis to prevent water loss. Algae live in the bodies of water, surrounded by it they didn’t need cuticle. Stomata is another adaptation to prevent water loss. it is an opening in the epidermis that is controlled by guard cells. it is necessary for gas exchange but due to the large amount of water loss during the day stomata is closed in most plants and is open at night. lignin is a building material in plants (wood), necessary for land plants to provide ability to grow tall competing for the sunlight. xylem woody tissues make up water transport vessels that are necessary to deliver water up against gravity to the upper parts of a plant. permits plants to grow tall. roots became necessary necessary as plants grew bigger for anchorage and support and to absorb water and nutrients from the soil.

Answer 77

Explanation to diagram starting from spore dispersal ## Footnote Sporangia releases spores that develop into a bisexual photosynthetic gametophyte → mature gametophyte produces archegonia and antheridia →Fertilization → Zygote develops into a new sporophyte → Mature sporophyte develops sori on the underside of the reproductive leaves which are clusters of sporangia → meiosis occurs in the sporangia to produce haploid spores → when sporangia matures it bursts open releasing spores and the cycle starts again.

Answer 78

The foot absorbs nutrients from gametophyte; seta conducts them to sporangium (capsule) where spores are produced; caliptra -a structure that covers the young sporophyte as it develops within the tissues of its gametophyte parent ## Footnote sporophytes are successful as they produce spores that are easily carried around with the wind and have a protective covering.

Answer 79

Life Cycle of moss Explanation to a diagram starting with protonemata growth: Spores develop into threadlike protonemata (a mass of branced, one cell- thick filaments) → → protonemata produces buds that grow into gametophores (gamete producing structure) → → gametophytes develope into male or female → sperm from antheridia swims through a film of water to the egg (within archegonium) → Fertilization → Zygote → develops into a sporophyte embryo → the sporophyte grows a long stalk (seta) that emerges from the archegonium (nutritionally dependent on gametophyte) → development of sporangia (capsules) → meiosis occurs and haploid spores develop in the capsules. when the capsules become mature they pop open and the spores are released: the cycle starts over.

Answer 80

1. they don’t have vessels to transport the water, so they need moist environments for cells’ direct absorption of water. 2. they need water for fertilization to happen : sperm swims through a film of water to an egg.

Answer 81

the dominant stage in the non-vascular plants is the gametophyte that is larger and longer -living than sporophyte stage in all plants. absence of leaves, xylem, and phloem absence of roots - rhizoids instead- long, tubular single cell or filaments of cells that do not play an important role in the absorption of water, but rather anchorage young sporophyte depends on gametophyte for development water is needed for fertilization to occur

Answer 82

photosynthetic gametophyte stage sporophyte stage alternation of generations (diplohaplontic) dependent on water for fertilization no seeds

Answer 83

Which gymnosperm division (a) is the chief source of lumber? (b) was dominant in the age of dinosaurs? (c) has one living species? (d) is most related to flowering plants? ## Footnote A. Conferophytes are the chief source of lumber (such as Redwoods, Sequoias, Dougless firs, etc.). B. Cycadophytes dominated during the age of the dinosaurs . Although only about 130 species survive today, cycads thrived during the Moseozoic era, known as the age of cycads as well as the age of dinosaurs. C. Phylum Ginkgophyta has one living species, ginkgo biloba D. The coniferophyta division is the most closely related to flowering plants (angiosperms)

Answer 84

The male cones are wind pollinators! In the male cone, microsporocytes are inside microsporangia that are exposed on the under-side of the microsporophylls (which are the leaves of the cone: see image below). The microsporocytes undergo meiosis, and each cell gives rise to 4 haploid cells, which are called “microspores.” These microspores then undergo mitosis to form a “pollen grain,” which is made up of two prothalial cells (the remnants of the larger microgametophyte), a generative cell (which produces sperm nuclei!), and the tube cell (which produces the pollen tube). Please note: “pollen grain” = immature microgametophyte. Meanwhile, in the female cone, a megasporocytes (2n) is inside the megasporangium, which develops on top of “scales” (which are “branches”). The megasporangium is enclosed by the integument which protects it. Also, there is an opening in the integument that secretes sticky fluid, and this opening is called the “micropyle.” Anyhow, the megasporocyte (2n) undergoes meiosis and produces 4 megaspores. Three of these megaspores die, and one eventually develops into a megagametophyte… The one remaining megaspore undergoes mitosis to form two archegonia (Please note: 4 archegonia can also form depending on the species). The megagametophyte developes around the two archegonia. Around this, you see the megasporangium, and then the integument. Finally, the pollen grain is transported by the wind to the micropyle in the ovule. The pollen grain germinates, forming a pollen tube from the tube cell that slowly digests its way through the megasporangium. 2 sperm nuclei enter the megagametophyte, and one of the sperm will fertilize the egg. The fertilized egg undergoes mitosis to form an embryonic sporophyte, which soon develops into an embryo (2n). The embryo is surrounded by the megagametophyte. The integument becomes the seed coat. Together, the embryo, megagametophyte, and the seed coat make up the seed!

Answer 85

The fertilized egg undergoes mitosis to form an embryonic sporophyte, which soon develops into an embryo (2n). The embryo is surrounded by the megagametophyte. The integument becomes the seed coat. Together, the embryo, megagametophyte, and the seed coat make up the seed! The storage tissue is composed of the megagametophyte (n), which develops from the surviving megaspore (which was produced from the megasporocyte).

Answer 86

The seeds are better than the spores of seedless plants since they have food reserves in the form of the megagametophyte or endosperm. This means that seeds can travel farther distance before germinating. Seeds also have a protective coat that prevents them from drying out. In a male pine cone, the pollen grain is a male gametophyte enclosed within the pollen wall. In a seedless plant, however, the sperm are flagellated, and must swim to the eggs, and need water to reproduce. In female pine cones, the entire ovule is a complex structure that contains megasporangium (also called the nucellus) and megaspore mother cells. After meiosis, megaspores are produced, only one of which survives to grow into a multicellular megagametophyte (the other three degenerate in situ). Megagametophytes contain archegonia, which in turn contain the female gametes (=egg cells). The entire ovule is surrounded by a vascularized protective layer called the integument or seed coat. Meanwhile, in seedless plants, the “ovule-like” structures have much less protection. For example, in ferns, the sporangia on the sori have very little protection from the elements (and no seed coat!). Moreover, in mosses, the archegonia that contain the seed are exposed to the air.

Answer 87

Seed plants are heterosporous since this is advantageous for plant evolution. The principal difference between homospory and heterospory is the separation of sexes at different points in the life cycle. Nevertheless, the evolutionary implications of this difference are profound. For example, seed plants, which have female gametes in ovules and male gametes in pollen grains, must show some differentiation of male and female gametophytes. Furthermore, an earlier (in the life cycle) separation of the sexes can be regarded as a division of labor, a common theme of evolutionary advancement. It may also be that heterospory promotes outcrossing among plants, since microspores may drift farther from the sporophyte than megaspores. Outcrossing is advantageous since it increases genetic diversity, thus reducing the probability of all individuals being subject to disease or reducing genetic abnormalities.

Answer 88

a. roots: indeterminate b. leaves: determinate c. shoot tips: indeterminate d. internodes: indeterminate

Answer 89

Plant tissue - cellular organizational level intermediate between cells and a complete organism. A tissue is an ensemble of similar cells from the same organ that together carry out a specific function. Organs are then formed by the functional grouping together of multiple tissues. 4 tissue systems – vascular, epidermal, ground and meristematic.

Answer 90

Parenchyma cell: tile shaped cell. Performs metabolic functions, synthesizes and stores organic products. Found in the pith. Collenchyma cell: elongated cells with thicker cell walls than parenchyma. Provide flexible support without restraining growth. Found in the cortex in the stem and some leaves. Epidermal cell: flat “tile” shape, protects against water loss, regulates gas exchange, secretes metabolic compounds and absorbs water and mineral nutrients. Vessel: tubular elongated cells(wider, shorter and thinner walled than tracheid) that are dead at maturity. Water conducting cells. Tracheid: tubular elongated cells that are dead at maturity. Water conducting cells. Sieve tube: long narrow cells, transport sugar and other organic nutrients. Fiber cell: long, slender and tapered. Support and strengthening. Sclereid: boxy irregular cells, support and strengthening. Form hard structures such as seed coats and nut shells. Meristematic: undifferentiated cells that can divide and provide the plant with indeterminate growth.

Answer 91

Chloroplast: organelle that absorbs sunlight and uses it to drive the synthesis of organic compounds from carbon dioxide and water (photosynthesis) phloem: transports sugars from leaves to roots and sites of growth spongy mesophyll: below palisade mesophyll, more loosely arranged with a labyrinth of air spaces through which CO2 and oxygen circulate around the cells and up to the palisade region. palisade mesophyll: consists of one or more layers of parenchyma cells on the upper part of the leaf. cuticle: a waxy coating on the epidermal surface, helps prevent water loss vein: vascular tissue of leaves stomate: pores in the epidermis that allow exchange of CO2 and O2 from surrounding air into photosynthetic cells inside leaf. xylem: conducts water and dissolved minerals upward from roots into the shoots midrib: large vein that runs through middle of leaf guard cell: regulate the opening and closing of stomata leaflet: has no axillary bud at its base petiole: joins leaf to stem at a node blade: flattened part of the leaf that does not wrap around stem, site of photosynthesis

Answer 92

(a) sunken stomata - recessed in cavities called crypts which is an adaptation to reduce the rate of transpiration by protecting the stomata from hot, dry wind. Trichomes help minimize transpiration by breaking up the flow of air allowing the chamber of the crypt to have a higher humidity than the surrounding atmosphere. (b) dense mats of leaf hairs - help reflect the sun © fiber bundles - xeromorphic leaves are small, thick leaves that require additional support

Answer 93

casparian strip – a barrier that blocks entrance of minerals into the vascular cylinder. Located in the transverse and radial walls of each endodermal cell. vascular cylinder - arrangement of vascular tissue as a central cylinder in roots. meristem - plant tissue that remains embryonic as long as the plant lives allowing for indeterminate growth epidermis - outer cell layer, protection symplast – the entire mass of cytosol of all the living cells in a plant as well as the plasmodesmata, the cytoplasmic channels that interconnect them. apoplast – everything that is external to the plasma membranes of living cells and includes cell walls, extracellular spaces and the interior of dead cells such as vessel elements and tracheids. elongation zone cortex - ???? root hair zone - area where root hairs grow endodermis – innermost layer in the cortex root hair – a thin, tubular extension of a root epidermal cell, increases the surface area of a root and therefore absorption. pericycle – outermost cell layer in the vascular cylinder

Answer 94

Located in the root apical meristem functions as the zone of initials. Infrequent division of initial cells in the quiescent center is the source of cells for the root apical meristem. These initial cells and tissue patterns become established in the embryo in the case of the primary root, and in the new lateral meristems in the case of secondary roots.

Answer 95

plasma membrane - screens minerals before being transported into cell active transport - movement of minerals across the plasma membrane against its concentration gradient. endodermis - innermost layer of cells in the root cortex and last checkpoint for the selective passage of minerals from the cortex into vascular cylinder. casparian strip - a belt made of suberin (a waxy material impervious to water and dissolved minerals). The casparian strip forces water and minerals that are passively moving through the apoplast to cross the plasma membrane of an endodermal cell before they can enter the vascular cylinder. plasmodesmata - microscopic channels which traverse the cell walls of plant cells, located in endodermal cells symplast - the continuum of cytoplasm connected by plasmodesmata between cells. apoplast - everything external to the plasma membrane of a plant cell, including cell walls, intercellular spaces, and the space within dead structures such as xylem vessels and tracheids.

Answer 96

Nodules are swellings along a legumes roots composed of plant cells that have been “infected” by Rhizobium bacteria. Inside each nodule rhizobium bacteria assume a form called bacteroids, which are contained within vesicles formed in the root cells. Legume-rhizobium relationships generate more usable nitrogen for plants than all industrial fertilizers used today, and the mutualism provides the right amount of nitrogen at the right time. Mycorrhizae - mycorrhizae hyphae endow the fungus and plant roots with an enormous surface area for absorbing water and minerals, particularly phosphate

Answer 97

Primary Growth:the increase in length of a shoot or root, due to the division of cells at the apical meristems The secondary is responsible for the increase their girth and size laterally. Secondary is the growth is origin woody plant tissues. Secondary growth takes place at two lateral meristems- the vascular cambium, and the cork cambium

Answer 98

Vascular cambium-originates between the xylem and the phloem and makes a cylinder of tissue that is present throughout the length of the stem and root. The cambium layer is what is called meristematic which means that it produces new cells on both the inside and outside of the cylinder. The cells on the inside become secondary xylem cells and the cells on the outside become secondary phloem cells. Xylem- also known as sapwood the older the xylem the closer it is to the center of the stem is called the heartwood and functions only as support ## Footnote Cork cambium- replaces the protective covering on the epidermis. On the outside a layer of protective cork cells impregnated with suberin is produced. On the inside phelloderm may be produced. The cork, cork cambium, and the phelloderm make up the periderm.

Answer 99

Cortex cells beneath the epidermis produce the cork cambium. The cork cambium produces cork. Cork is waterproof because the cell walls are impregnated with of suberin(a waxy substance). Pockets of cells lack suberin. These are called lenticels and function to allow gas exchange. Cork replaces the epidermis on woody stems and roots. The bark of trees consists of cork, cork cambium, cortex, and phloem Cork cells function as a barrier to protect the stem from physical damage and from pathogens The cork cambium + the cork are known as the periderm The "bark" of the tree consists of the periderm + the phloem

Answer 100

A layer of wood formed in a plant during a single period of growth. Growth rings are visible as concentric circles of varying width when a tree is cut crosswise. They represent layers of cells produced by vascular cambium. Most growth rings reflect a full year's growth and are called annual rings. But abrupt changes in the environment, especially in the availability of water, can cause a plant to produce more than one growth ring in a year.

Answer 101

Unlike seedless vascular plants, non-vascular plants do not have an extensive system of vascular tissue, which are cells joined into tubes that transport water and nutrients throughout the plant body. Non-vascular plants also have rhizoids (but not rhizomes/roots). Non-vascular plants tend to be much shorter because they can’t grow as tall.

Answer 102

a. Apoplastic: the movement of ions across a cell wall i. Phloem is considered symplastic: through the cytoplasm of cells

Answer 103

a. Vessels: major water conducting tissue of plants. Found in angiosperms. Conducts the water upward in a plant. Move water (and the minerals) from the root to the leaves (and other parts of the plant) b. Tracheids: Only seen in vascular plants. Contribute to the transport system by providing structural support, thicker secondary walls. Have a higher surface/volume ratio, holds water (via adhesion) when transpiration is not occurring

Answer 104

a. Is osmotic pressure within the cells of a root system that causes sap to rise through a plant stem to the leaves. b. Water flows from the root cortex, generating root pressure, a push of xylem sap. The root pressure sometimes causes more water to enter the leaves than is transpired, resulting in guttation (the exudation of water droplets that can be seen in the morning on the tips or edges of some plant leaves

Answer 105

CLosed carpel: encloses the ovules (and carpel or carpel and accessory parts may become a fruit!) 2+2 microsporangia: 4 microsporangia in the anther: A typical anther contains four microsporangia. The microsporangia form sacs or pockets (locules) in the anther. The two separate locules on each side of an anther may fuse into a single locule. Each microsporangium is lined with a nutritive tissue layer called the tapetum and initially contains diploid pollen mother cells. These undergo meiosis to form haploid spores. The spores may remain attached to each other in a tetrad or separate after meiosis. Each microspore then divides mitotically to form an immature microgametophyte called a pollen grain.

Answer 106

A complete flower has all four whorls of organs and an incomplete flower is missing one or more whorls. Whorls: 1. sepals (collectively calyx): lowermost whorl 2. petals (collectively corolla) 3. stamen (filmanet + anther) 4. carpel (ovary, style, and stigma)

Answer 107

Ovary - chamber that contains the ovules/seeds

Answer 108

The parts of the flower represent modified sporophylls arranged around a central axis (= a strobilius), and are situated on a condensed stem called the receptacle.

Answer 109

In a flower with a superior ovary, sepals, petals, and stamens are attached to the receptacle below the ovary. In a flower with an inferior ovary, sepals, petals, and stamens are attached at the top of the ovary.

Answer 110

A perfect flower has both stamens and carpels; an imperfect flower lacks stamens or carpels

Answer 111

A bract is a modified or specialized leaf

Answer 112

a nectar-secreting glandular organ in a flower (floral) or on a leaf or stem

Answer 113

Pollen is produced in the 'microsporangium' (contained in the anther of an angiosperm flower, male cone of a coniferous plant, or male cone of other seed plants). Pollen itself is not the male gamete.[1] Each pollen grain contains vegetative (non-reproductive) cells (only a single cell in most flowering plants but several in other seed plants) and a generative (reproductive) cell containing two nuclei: a tube nucleus (that produces the pollen tube) and a generative nucleus (that divides to form the two sperm cells). The group of cells is surrounded by a cellulose-rich cell wall called the intine, and a resistant outer wall composed largely of sporopollenin called the exine.

Answer 114

sepals: collectively called the calyx, the lowermost whorl. They are most commonly green and leaf-like. Function to protect the entire flower bud. petals - collectively calyx - attract animal pollinators via a visual signal stamens - Consists of stalk-like filament tipped by an anther. The anthers are the structures in which the pollen grains are produced carpel- female part of the flower consists of three parts: 1. Ovary - the chamber that contains the ovules/seeds. 2 style - tissue through which the pollen tube cell grows to the vicitinity of the ovules; and the 3. stigma - the receptive tissue that recognizes legitimate pollen and promotes the germination of the pollen grain.

Answer 115

As the anther of a flowering plant develops, four patches of tissue differentiate from the main mass of cells. These patches of tissue contain many diploid microsporocyte cells, each of which undergoes meiosis producing a quartet of microspores. Four chambers (pollen sacs) lined with nutritive tapetal cells are visible by the time the microspores are produced. After meiosis, the haploid microspores undergo several changes: The microspore divides by mitosis producing two cells. The first of the cells (the generative cell) is small and is formed inside the second larger cell (the tube cell). The members of each part of the microspores separate from each other. A double-layered wall then develops around each microspore. These steps occur at relatively the same time and when complete, the microspores have become pollen grains. [5]

Answer 116

Gymnosperm: F: 1. Only one megaspore mother cell develops in each megasporangium. 2. Few archegonia develop. M: 3. The microgametophyte is few-celled, 4 There is no antheridium, 5. there is only one functional sperm B. Angiosperms. F: 6. The megagametophyte consists of only 7 cells, 7. There is no archegonium. M: 8. The development of the microgametophyte is restricted to only 2 mitotic events (tube cell & 2 sperm nuclei in generative cell)

Answer 117

Gymnosperms: 1. vascularized integuments protects (encloses) the entire ovule/seed 2. Megasporangium encloses the megaspore, and later the megagametophytes 3. The megagametophyte encloses the zygote, and later the embryo M: 4. The pollen wall protects (encloses) the entire microgametophyte Angiosperms Female: 5. The ovule/seed possesses a double layered integument 6. The ovules/seeds are borne in an ovary

Answer 118

Gymnosperms: 1. the Megagametophyte digests the megasporangium 2. The embryo digests the megagametophyte Angiosperms: 3. The embryo is nourished by the 3N endosperm

Answer 119

The entire 1N phase of the life cycle plus sporangium and embryo is attached to and dependent on the sporophyte

Answer 120

Instead of dispersing with a single celled spore plants keep the spore and let it mature into the gametophyte, the pollen or ovule, before the pollen is released to improve cross fertilization and genetic recombination. Only in pollen producing gymnosperm & angiosperm is the gametophyte life stage miniature, mobile & independent of water; the grain of pollen is the whole male gametophyte. The multicellular pollen travels (by wind or pollinator) to the female gametophyte in the cone or flower for pollination. Then fertilization proceeds without dependence on flagella or water. The seed, as a dormant sporophyte, is the dispersal stage. Two stages of travel provide great cross fertilization and even better range for the offspring's spread.

Answer 121

a. self pollen is rejected by the stigma (self incompatibility) b. stamens and carpels are different lengths, mature at different times c. stamens and carpels are on different plants.

Answer 122

seed contains an embryo and packed with nutrition for embryos future growth and development covered for protection with seed coat and developed from ovule. Fruit developed from ovary wall to protect the seed and to aid in dispersal by wind or animals.

Answer 123

Ovary wall becomes the pericarp, thickened wall of a the fruit.

Answer 124

one of the 2 sperms produced by pollen grain fertilizes the central cell of the egg with the two polar nuclei, forming triploid nucleus that divides to produce endosperm, a food storing tissue of the seed that develops before the embryo does.

Answer 125

Ripening of fruit is timed with the maturation of the seed what is controlled by complex interaction of hormones. (didn’t cover that - don’t need to worry about it)

Answer 126

simple fruit develops from a single carpel or several fused of one flower accessory tissue develops from receptacle or floral tube usually as a result of inferior ovary (strawberry, apple , banana) multiple fruit develops from many carpels of the many flowers that form inflorescence (pineapple) aggregate fruit develops from many separate carpels of the one flower (strawberry, raspberry, blackberry)

Bio 1B Pictures Flashcards

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