EXAM I Vocab Flashcards
1
Q
CAM
A
C4 plants that open their stomata at night to take up carbon dioxide. // CAM - Crassulacean Acid Metabolism CAM plants - Very well adapted to dry conditions – desert plants and succulents - Open stomata at night, close during day - Store CO 2 as C 4 acids (malate) for release and fixation during the day CAM Plants Fig. 8.19 - Stomata open during cool nights – CO 2 comes in and fixed into C4 acid - C4 acids stored in vacuoles - Stomata close during hot day - C4 acids exported to chloroplast,
2
Q
3-phosphoglycerate
A
Carbon Fixation (Phase 1) In carbon fixation, CO 2 becomes incorporated into ribulose bisphosphate (RuBP), a five-carbon sugar. The product of the reaction is a six-carbon intermediate that immediately splits in half to form two molecules of 3-phosphoglycerate (3PG). The enzyme that catalyzes this step is named RuBP carboxylase/oxygenase, or rubisco. It is the most abundant protein in chloroplasts and perhaps the most abundant protein on Earth This observation underscores the massive amount of carbon fixation that happens in the biosphere. Reduction and Carbohydrate Production (Phase 2) In the second phase, ATP is used to convert 3PG to 1,3-bisphosphoglyc- erate. Next, electrons from NADPH reduce 1,3-bisphosphoglycer- ate to glyceraldehyde-3-phosphate (G3P). G3P is a carbohydrate with three carbon atoms. The key difference between 3PG and G3P is that G3P has a C—H bond, whereas the analogous carbon in 3PG forms a C—O bond (Figure 8.15). The C—H bond can occur because the G3P molecule has been reduced by the addi- tion of two electrons from NADPH.
3
Q
Absorption /Action spectrum
A
The absorption spectrum plots a pigments ability to absorb light against wavelength; the action spectrum plots photosynthetic rate against wavelength Absorption: A diagram that depicts the wavelengths of electromagnetic radiation that are absorbed by a pigment. Action: The rate of photosynthesis plotted as a function of different wavelengths of light.//
4
Q
Adventitious roots
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A root that is produced on the surfaces of stems (and sometimes leaves) of vascular plants; also, roots that develop at the bases of stem cuttings.
5
Q
Aggregate fruit
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Aggregate fruits - Develop from a cluster of separate carpels - Each flower contains many ovaries - E.g. strawberry, blackberry, magnolia, raspberry // Differences in the shape, color, fragrance, and moisture content of wild fruits reflect evolutionary adaptation for effec- tive seed dispersal. Though many fruits and seeds are dispersed by wind or water or by attaching to animal fur, others are con- sumed by fruit-eating animals that are attracted by fruit color and fragrance. Blackberries provide a good example of fruits adapted for animal dispersal. Blackberry flowers produce many separate pistils, each containing a single ovule (Figure 39.19a). Following pollination and fertilization, the ovary of each pistil develops into a sweet, juicy fruitlet containing a single seed. As the individual fruitlets develop, they fuse together at the sides. Consequently, the many fruitlets produced by a single black- berry flower are dispersed together, in a structure known as an aggregate fruit (Figure 39.19b). Attracted by the color, birds consume the whole aggregate and excrete the seeds, thereby dispersing many at a time. Many other types of fruits occur and these likewise represent adaptations that foster seed dispersal (refer back to Figure 30.21). Although a fruit is usually defined as a mature ovary containing seeds, commercial seedless fruits such as watermelon are produced by genetic modification or treatment with artificial auxin. Strawberries are aggregate fruits, many fruits that all develop from a single flower having multiple pistils
6
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Algae
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(singular, alga) A term that applies to about 10 phyla of protists that include both photosynthetic and nonphotosynthetic species; often also includes cyanobacteria.
7
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Alternation of generations
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The phenomenon that occurs in plants and some protists in which the life cycle alternates between multicellular diploid organisms, called sporophytes, and multicellular haploid organisms, called gametophytes.
8
Q
Angiosperm
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A flowering plant. The term means enclosed seed, which reflects the presence of seeds within fruits.
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Annual
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A plant that dies after producing seed during its first year of life.
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Anther
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The uppermost part of a flower stamen, consisting of a cluster of microsporangia that produce and release pollen.
11
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Antheridia
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Round or elongate gametangia that produce sperm in plants.
12
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Apical
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- The region of a plant seedling that produces the leaves and flowers.
13
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Apical meristem
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In plants, a group of actively dividing cells at a growing tip.
14
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Apomixis
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A natural asexual reproductive process in which plant fruits and seeds are produced in the absence of fertilization.
15
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Archegonia
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Flask-shaped plant gametangia that enclose an egg cell.
16
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Archegonium
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Bryophyte: The sperm-producing gametangium is the antheridium and the egg-producing gametangium is the archegonium.
17
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Asexual reproduction
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A reproductive strategy that occurs when offspring are produced from a single parent, without the fusion of gametes from two parents. The offspring are therefore clones of the parent
18
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ATP
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A molecule that is a common energy source for all cells.
19
Q
Axillary
A
- axillary bud A bud that occurs in the axil, the upper angle where a twig or leaf emerges from a stem. 2. axillary meristem A meristem produced in the axil, the upper angle where a twig or leaf emerges from a stem. Axillary meristems generate axillary buds, which can produce flowers or branches.
20
Q
Bryophyte
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Liverworts, mosses, and hornworts, the modern nonvascular land plants.
21
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C4 metabolism
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C4 plant A plant that uses PEP carboxylase to initially fix CO2 into a four-carbon molecule and later uses rubisco to fix CO2 into simple sugars; an adaptation to hot, dry environments.
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Q
Calvin (C3) cycle
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C3 plant A plant that incorporates CO2 into organic molecules via RuBP to make 3PG, a three-carbon molecule.
23
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Carboniferous
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Carboniferous - Dominance of woody lycopods – 350 mya - Extensive coal deposits form from plants growing in the carboniferous (fossils in coal)
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Q
Carotenoid
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A type of photosynthetic or protective pigment found in plastids that imparts a color that ranges from yellow to orange to red.
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Carpel
A flower shoot organ that produces ovules that contain female gametophytes. // Fruits form from the carpel - The carpel is composed of : - the ovary (lower part) - the style (middle part) - the stigma (top part) - The carpel develops into the fruit wall (pericarp) after fertilization
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Cell wall
A relatively rigid, porous structure located outside the plasma membrane of prokaryotic, plant, fungal, and certain protist cells; provides support and protection. // Cell walls – primary and secondary, middle lamella // Cell walls Fig. 10.13 - Primary cell wall – flexible, cellulose - Secondary cell wall – cellulose, lignin, other components
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Cellulose
The main macromolecule of the primary cell wall of plants and many algae; a polymer made of repeating molecules of glucose attached end to end.
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Chara
Characean green algae – ancestors of Land Plants
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Chemical energy
The potential energy contained within covalent bonds in molecules. // Chemical energy from the light reactions (ATP, NADPH), are used by the light-independent (dark) reactions to fix CO 2 to organic C (sugar) Calvin Cycle for CO 2 fixation Fig. 8.15
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Chlorophyll
chlorophyll A photosynthetic green pigment found in the chloroplasts of plants, algae, and some bacteria. chlorophyll a A type of chlorophyll pigment found in plants, algae, and cyanobacteria. chlorophyll b A type of chlorophyll pigment found in plants, green algae, and some other photosynthetic organisms. // Chlorophyll - light harvesting, action spectra
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Chloroplast
A semiautonomous organelle found in plant and algal cells that carries out photosynthesis. // - Typical leaf palisade cell contains 30 – 40 chloroplasts - Cell is 30-40 um diam. = 0.00004 m - Chloroplast is 2-10 um diam = 0.000002 m Green chlorophyll pigment in chloroplasts Light spectrum (wavelength - energy) Fig. 8.4 - Why are leaves Green? - Chloroplasts reflect green, absorb red and blue light (source of light for photosynthesis)
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Climate change
GLOBAL CLIMATE CHANGE - Increasing atmospheric CO 2 conc. - useful for photosynthesis? - Increasing temperature – plant stress? - Changing precipitation patterns – water availability for plants? - Availability of other nutrients? - Biological mitigation strategies – all involve photosynthesis
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Co-evolution
The process by which two or more species of organisms influence each other’s evolutionary pathway.
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Cold stratification
Seed Dormancy (during dispersal) - Dormancy – a period of inactivity during which growth ceases – Breaking dormancy – plant resumes growth if moisture, temperature or day length requirements right – best chance that seeds will germinate at good time - Desert – after rain - Cold climate – in spring (cold stratification)
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Collenchyma
collenchyma cells Flexible cells that make up collenchyma tissue. collenchyma tissue A plant ground tissue that provides support to plant organs. // Fig. 35.7 - Thick primary walls Usually grouped in strands or cylinders - Can elongate and expand with stem and leaf growth - Alive at functional maturity - Function – flexible support for herbaceous and young woody plants
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Companion cells
Companion cells – alongside each sieve tube member - Plasmodesmata connect sieve tube member to companion cell - Companion cell nucleus serves sieve tube member Phloem – sieve elements and companion cells, sieve plates – solutes from leaves and around the plant
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Compound leaf
A compound leaf divided into leaflets.
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Cone
Seeds and pollen on separate strobili (cones) of sporophylls // Sporangia located in cones - Heterosporous – male and female gametes develop from separate cones
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conifer
conifers A phylum of gymnosperm plants, Coniferophyta.
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Cork cambium
A secondary meristem in a plant that produces cork tissue. (BARK)
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Corolla
The petals of a flower, which occur in the whorl to the inside of the calyx and the outside of the stamens.
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Corolla tube
Flowers pollinated by moths - Open at night - White or pale - Heavy fragrance - Corolla tube (fused petals) as long as tongue of moth
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Cotyledons
Seeds - Consist of seed coat, endosperm, embryo - Endosperm (3n) – Rich in nutrients for developing embryo – In many dicots, food reserve of endosperm is restocked in cotyledons, so mature seed will lack endosperm Monocots and Dicots Fig. 39.18. 39.21 Cotyledons – ‘seed leaves’ DICOTS - Two cotyledons e.g. peanut, bean MONOCOTS - One cotyledon e.g. Corn kernel
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Crassulacean acid metabolism
CAM - Crassulacean Acid Metabolism CAM plants - Very well adapted to dry conditions – desert plants and succulents - Open stomata at night, close during day - Store CO 2 as C 4 acids (malate) for release and fixation during the day CAM Plants Fig. 8.19 - Stomata open during cool nights – CO 2 comes in and fixed into C4 acid - C4 acids stored in vacuoles - Stomata close during hot day - C4 acids exported to chloroplast,
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Cuticle
A coating of wax and cutin that helps to reduce water loss from plant surfaces. Also, a nonliving covering that serves to both support and protect an animal.
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cycad
A phylum of gymnosperm plants, Cycadophyta. // Division Cycadophyta – The Cycads Fig. 30.3 Common in fossil record – contemporary with dinosaurs Currently 100 species – tropical and warm temperate Palm-like leaves Seeds and pollen on separate strobili (cones) of sporophylls Male and female strobili on different individuals - dioecious Macrozamia –Australian cycad
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Cytoplasm
Cytoplasm: Site of metabolism. Plasmodesmata Fig. 10.14 - cytoplasmic channels that pass through pores in primary and secondary cell walls
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Deciduous angiosperms
Cool Temperate forests - Dominated by deciduous angiosperms Perennials common on forest floor - Spring ephemerals - grow and flower rapidly in spring before shaded out by trees - Very few annual species
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Dehiscent
Fruit types - Simple – Fleshy e.g. apricot – Dry e.g. oak – Dehiscent – tissues of mature ovary wall break open releasing seeds e.g. birch – Indehiscent – seeds remain in fruit after fruit is shed from parent plant e.g. apple Simple Dehiscent – tissues of mature ovary wall break open releasing seeds e.g. birch
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Dendrochronology
Dendrochronology – determine age of wood (art fraud – picture frames, wooden musical instruments) e.g. Lindbergh kidnapping (1932) - wood anatomist matched wood from a floorboard in the home of the accused to a repaired ladder left at the crime scene
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Dermal tissue
The covering on various parts of a plant. // Dermal tissue - Epidermis – single layer of tightly packed cells - Cuticle – waxy coating secreted by epidermis of leaves and stems to conserve water - Root hairs – specialized epidermal cells for water and mineral absorption
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Desert plants
CAM - Crassulacean Acid Metabolism CAM plants - Very well adapted to dry conditions – desert plants and succulents - Open stomata at night, close during day - Store CO 2 as C 4 acids (malate) for release and fixation during the day CAM Plants
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Determinate plant growth
Plant Growth - Determinate – organism stops growing after it reaches a certain size (e.g. humans) Meristems – apical and lateral; indeterminate plant growth
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Dicot
Monocots vs Dicots vascular system Dicots – net veination Monocots – parallel veination Flower form: Monocots – 3s, Dicots – 4,5s DICOTS - Two cotyledons e.g. peanut, bean
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Dioecious
The term to describe plants that produce staminate and carpellate flowers on separate plants // Dioecious – male and female plants separate (must outcross)
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Dioecy
Monoecy and dioecy Monoecious – male and female flowers separate but on the same plant e.g. Zea mays (corn) (encourages outcrossing) Dioecious – male and female plants separate (must outcross)
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Diploid
Refers to cells containing two sets of chromosomes; designated as 2n.
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Diploid/sporophyte dominant
Species in which the diploid organism is the prevalent organism in the life cycle. Animals are an example.
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dominant
dominant A term that describes the displayed trait in a heterozygote. dominant species A species that has a large effect in a community because of its high abundance or high biomass.
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Double fertilization
n angiosperms, the process in which two different fertilization events occur, producing both a zygote and the first cell of a nutritive endosperm tissue.
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Electron transport
A group of protein complexes and small organic molecules within the inner membranes of mitochondria and chloroplasts and the plasma membrane of prokaryotes. The components accept and donate electrons to each other in a linear manner and produce a H electrochemical gradient.
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embryo
The early stages of development in a multicellular organism during which the organization of the organism is largely formed.
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Endosperm
A nutritive tissue that increases the efficiency with which food is stored and used in the seeds of flowering plants. // - Endosperm (3n) – Rich in nutrients for developing embryo – In many dicots, food reserve of endosperm is restocked in cotyledons, so mature seed will lack endosperm // Fertilization of two polar nuclei -\> endosperm (3n)
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Ephedra
Division Gnetophyta Fig. 30.11 - 3 genera – Gnetum, Ephedra and Welwitchsia - Once thought to be a transition between Gymnosperms and Angiosperms - Now believed to be closely related to Conifers (recent molecular data) Characteristics of Gnetophytes - Leaves of Gnetum have net venation - Floral like strobilus - Vessels present in xylem - Double fertilization recently found in Ephedra and Gnetum Welwitschia
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Ephemerals
Cool Temperate forests - Dominated by deciduous angiosperms Perennials common on forest floor - Spring ephemerals - grow and flower rapidly in spring before shaded out by trees
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Epidermis
A layer of dermal tissue that helps protect a plant from damage. // Dermal tissue - Epidermis – single layer of tightly packed cells
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Epiphyte
Epiphytes Depend on other plants for mechanical support – get up higher in canopy Broad-leafed tropical rainforest plants // Tropical rainforest - Greatest diversity of angiosperms - Adapted to low light (forest floor) - Epiphytes and lianas common – adaptation of growth form to compete with trees for light
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Evolutionary innovation
Major evolutionary innovations of Angiosperms – Xylem – vessel elements in addition to tracheids found in conifers – Flowers - attract pollinators (Radiation of flower species accompanies by radiation in insect species) – Double fertilization
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fern
Ferns - Most common of the seedless vascular plants - 12,000 species - Larger leaves – megaphylls (fronds) - Branching veins - Tip curled in early spring (fiddleheads) - Sporophyte dominant but haploid phase macroscopic - Produce spores in specialized sporangia usually on underside of leaf - Sporangia in clusters called sori (sorus singl.) - Sporangia may have an annulus – spore dispersal // Generalized life cycle – alternation of generation – haploid or diploid dominant. (Key examples mosses, ferns)
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Fertilization
The union of two gametes, such as an egg cell with a sperm cell, to form a zygote. // - Fertilization of egg -\> zygote -\> embryo -\> mature plant - Fertilization of two polar nuclei -\> endosperm (3n)
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Fibres
Fibers - Long slender and tapering in bundles (Rope, flax)
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Fibrous roots
Fibrous roots are examples of adventitious roots, structures that are produced on the sur- faces of stems (and sometimes leaves) of both monocots and eudicots. Roots that develop at the bases of stem cuttings are
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Fleshy fruit
There are a range of different types of fruits Fruit types - Simple – Fleshy e.g. apricot // Explain how seed dispersal may differ for fleshy fruits (e.g. apple, peach) from dry fruits (e.g. maple)
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Floral mimicry
Bee Pollination with floral mimicry - Flower resembles female bee - Can produce female scents (pheromones) - Pseudo-copulation achieves pollen collection
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Flower
A reproductive shoot; a short stem that produces reproductive organs instead of leaves.
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Forensic plant anatomy
Anatomy – root growth, anatomy can determine disturbance and time of burial; plant cell types in victim stomach contents (sclerids, tracheids, vessel cells, silica bodies from grasses); wood fragments can be traced to furniture or forest locations
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Fossil
Plant Fossils - Oldest known land plant fossils are microscopic ~476 mya – Sheets of waxy cuticle (protect against…?) – Spores with sporopollenin walls // Recognizable preserved remains of past life on Earth.
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Fruit
A structure that develops from flower organs, encloses seeds, and fosters seed dispersal in the environment. 2. fruiting bodies The visible fungal reproductive structures that are composed of densely packed hyphae that typically grow out of the substrate.
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Gametangium
Specialized structures produced by many land plants in which developing gametes are protected by a jacket of tissue.
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Gamete
A haploid cell that is involved with sexual reproduction, such as a sperm or egg cell.
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Gametophyte
In plants and many multicellular protists, the haploid stage that produces gametes by mitosis
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Gas exchange
The process of moving oxygen and carbon dioxide in opposite directions between the environment and blood and between blood and cells. // Control of gas exchange - stomata
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gemmae
Figure 29.3 Liverworts. (a) The common liverwort Marchantia polymorpha, with raised, umbrella-shaped structures that bear sexually produced sporophytes on the undersides. Mature sporophytes generate spores, then release them. (b) A close-up of M. polymorpha showing surface cups that contain multicellular, frisbee-shaped asexual structures known as gemmae that are dispersed by wind and grow into new liverworts. (c) A species of liverwort having leaflike structures and so known as a leafy liverwort.
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Genetic diversity
Why do plants do sexual reproduction ? Genetic Diversity Ensuring gamete (pollen) exchange – cross pollination How do plants avoid self-fertilization? Promoting cross-pollination and prevent self-fertilization: - Structural features of flower - Monoecy and Dioecy - Timing of gamete maturity - Genetic ‘self-incompatible’ mechanisms - Specialized pollinators – encourage cross- pollination
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Germination
n plants, the process in which an embryo absorbs water, becomes metabolically active, and grows out of the seed coat, producing a seedling. // Germination - plant resumes the growth of plant which was temporarily suspended when seed became dormant
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Gingko
Division Gingkophyta - Gingko - “Living fossil”- currently only 1 species – Gingko biloba - Leaves have dichotomous venation - Seeds fruit-like - Common street trees
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gnetophyte
A phylum of gymnosperms; Gnetophyta. // Division Gnetophyta Fig. 30.11 - 3 genera – Gnetum, Ephedra and Welwitchsia - Once thought to be a transition between Gymnosperms and Angiosperms - Now believed to be closely related to Conifers (recent molecular data) Characteristics of Gnetophytes - Leaves of Gnetum have net venation - Floral like strobilus - Vessels present in xylem - Double fertilization recently found in Ephedra and Gnetum Welwitschia - S African distribution - Grows in a ring - Record sizes - 1.2 m tall and 8.7 m wide
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Grana (granum)
A structure composed of stacked membrane-bound thylakoids within a chloroplast. // - Grana - stacks of thylakoid membranes (sing. granum) // Thylakoids (grana) contain chlorophyll and accessory pigments that absorb light Thylakoids - function in the light reactions (photosynthesis) - converting light energy to chemical energy
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Ground tissue
ground meristem In plants, a type of primary plant tissue meristem that gives rise to ground tissue. ground tissue Most of the body of a plant, which has a variety of functions, including photosynthesis, storage of carbohydrates, and support. Ground tissue can be subdivided into three types: parenchyma, collenchyma, and sclerenchyma.
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Guard cells
Guard cells regulate gas and water vapor movement by opening and closing stoma // A specialized plant cell that allows epidermal pores (stomata) to close when conditions are too dry and to open under moist conditions, allowing the entry of CO2 needed for photosynthesis.
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Gymnosperm
A plant that produces seeds that are exposed rather than seeds enclosed in fruits. // Characteristics – - Leaves and vascular tissue - Gametophyte small and dependent on sporophyte - Male gametophyte retained inside spore wall – pollen - Embryo is protected, provided with nutrition from the seed
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Haploid
Containing one set of chromosomes; designated as 1n. Species in which the haploid organism is the prevalent organism in the life cycle. Examples include fungi and some protists.
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Haploid/gametophyte
In mosses, the haploid gametophyte is a visible multicellular organism, whereas the diploid sporophyte is smaller and survives within the haploid organism. In other plants, such as ferns (Figure 15.15c), both the diploid sporophyte and haploid gametophyte can grow independently. The sporophyte is considerably larger and is the organism we commonly think of as a fern. In seed-bearing plants, such as roses and oak trees, the diploid sporophyte is the large multicellular plant, whereas the gametophyte is com- posed of only a few cells and is formed within the sporophyte. // Because pollen is a haploid gametophyte, the pollen genome contains only one pollen-compatibility allele. // The angiosperm life cycle is characterized by a heteromorphic alternation of generations between an inconspicuous haploid gametophyte
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Herb / herbaceous
A plant that produces little or no wood and is composed mostly of primary vascular tissues
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heterosporus
n plants, the formation of two different types of spores: microspores and megaspores; microspores produce male gametophytes, and megaspores produce female gametophytes
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homosporous
Homosporous – unisexual or bisexual gametophytes // Most modern lycophytes and pteridophytes release one type of spore that develops into one type of gametophyte. Such plants are considered to be homosporous, and their gameto- phytes live independently and produce both male and female gametangia (see Figure 29.12). // Most ferns are homosporous. // Homosporous = Sporophyte\>Single type of spore\>Bisexual gametophyte\>Eggs & sperm Heterosporous = Sporophye\>Microspore\>Male gametophyte Sporophyte\>Megaspore\>Female gametophyte
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Hornwort - Anthocera
A phylum of bryophytes; Anthocerophyta // - Similar in appearance to liverworts - Sporophytes are elongated capsules growing out of gametophytes // - Moist and wet habitats, lack true leaves - Liverworts and hornworts - totally nonvascular, mosses – some limited vasculature - Need water to complete the life cycle - No woody tissue for support
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Imbibition
Germination and growth of seedling Imbibition – absorption of water due to dryness of seed (expands) - seed ruptures seed coat - metabolic changes in embryo causes resumption of cell division and growth // Germination – imbibition, germination, role of endosperm
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Indehiscent
– Indehiscent – seeds remain in fruit after fruit is shed from parent plant e.g. apple // 4. Simple Indehiscent – seeds remain in fruit after fruit is shed from parent plant e.g. apple // - Simple – single ovary on a single flower produces a fruit – Fleshy: seed surrounded by fleshy pericarp – Dry: lacks fleshy pericarp - Indehiscent: seeds remain closed - Dehiscent: seeds open
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Indeterminate plant growth
Growth in which plant shoot apical meristems continuously produce new stem tissues and leaves, as long as conditions remain favorable.
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Internode
The region of a plant stem between adjacent nodes.
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Lateral meristem
secondary meristem A meristem in woody plants forming a ring of actively dividing cells that encircle the stem. // Lateral Meristems - Responsible for secondary (outwards) growth 2 types of lateral meristems: Vascular cambium – In stems and roots of perennials and woody trees – Increases tree girth – Forms xylem to inside, phloem to outside Cork Cambium – produces bark
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Leaf
leaf primordia Small outgrowths that occur at the sides of a shoot apical meristem and develop into young leaves. leaf vein In plants, a bundle of vascular tissue in a leaf. leaves Flattened plant organs that emerge from stems and function in photosynthesis.
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Liana
Tropical rainforest - Greatest diversity of angiosperms - Adapted to low light (forest floor) - Epiphytes and lianas common – adaptation of growth form to compete with trees for light ///woody vines, known as lianas
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Light reactions
The first of two stages in the process of photosynthesis. During the light reactions, photosystem II and photosystem I absorb light energy and produce ATP, NADPH, and O 2 .//Light reactions – light dependent reactions – convert solar energy to chemical energy (ATP, NADPH)
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Light-independent (dark) reactions
Dark-reactions – light independent reactions – CO 2 fixation into organic sugars // Stroma - functions in the light-independent reactions (dark reactions), which fix carbon dioxide and H 2 O into sugars – (Calvin Cycle) // Chemical energy from the light reactions (ATP, NADPH), are used by the light-independent (dark) reactions to fix CO 2 to organic C (sugar) Calvin Cycle for CO 2 fixation Fig. 8.15
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Lignin
A tough polymer that adds strength and decay resistance to cell walls of tracheids, vessel elements, and other cells of plants.
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Liverwort
A phylum of bryophytes; formally called Hepatophyta. // Liverworts and hornworts - totally nonvascular, mosses – some limited vasculature - Need water to complete the life cycle - No woody tissue for support
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megasporangium \*
However, seed plants produce two distinct types of spores in two different types of sporangia, a trait known as heterospory. Small microspores develop within microsporangia, and larger megaspores develop within megasporangia. Male gametophytes develop from the microspores, and the pollen that develops from these microspores is released from microsporangia. // A further step in seed evolution may have been the pro- duction of only one megaspore per sporangium rather than multiple spores per sporangium, which is common in seedless plants. Reduction of megaspore numbers (from those present in seedless plants) would have allowed plants to channel more nutrients into each megaspore. A final step might have been the retention of megasporangia on parental sporophytes by the development of integuments (Figure 29.24)
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Megaspore
In seed plants and some seedless plants, a large spore that produces a female gametophyte within the spore wall.
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Meiosis
meiosis The process by which haploid cells are produced from a cell that was originally diploid. meiosis I The first division of meiosis in which the homologues are separated into different cells. meiosis II The second division of meiosis in which sister chromatids are separated into different cells.
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Meristem
In plants, an organized tissue that includes actively dividing cells and a reservoir of stem cells. // Meristems Fig. 35.8, 35.24 Two kinds in plants – Apical and Lateral
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Meristematic tissue
Meristems Fig. 35.8, 35.24 Two kinds in plants – Apical and Lateral 1. Apical - Responsible for primary growth - Found in roots and stems - At apex of terminal buds in stems Apical meristem of a shoot - Dome shaped - All types of tissues (epidermal, ground, vascular) are derived from apical meristem - Leaf primordia flank apical meristem - Axillary buds develop from meristematic tissue at base of leaf primordia Lateral Meristems - Responsible for secondary (outwards) growth 2 types of lateral meristems: Vascular cambium – In stems and roots of perennials and woody trees – Increases tree girth – Forms xylem to inside, phloem to outside Cork Cambium – produces bark
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Mesophyll
The internal tissue of a plant leaf; the site of photosynthesis. // - Mesophyll (meso – middle, phyll- leaf) - Palisade mesophyll – top // Mesophyll Tissue Palisade layer – main site of photosynthesis Spongy mesophyll – loose packing of cells facilitates gas diffusion. Some photosynthesis occurs here - Spongy mesophyll - bottom
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metabolism
The sum total of all chemical reactions that occur within an organism. Also, a specific set of chemical reactions occurring at the cellular level.
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Microphylls
Among the vascu- lar plants, lycophytes produce the simplest and most ancient type of leaves. Modern lycophytes have tiny leaves, known as lycophylls or microphylls, which typically have only a single unbranched vein (Figure 29.22a). Some experts think that these small leaves are modified sporangia.
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Microspore /microsporangium
" In seed plants and some seedless plants, a relatively small spore that produces a male gametophyte within the spore wall" // Small microspores develop within microsporangia
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Middle lamella
An extracellular layer in plants composed primarily of carbohydrate; cements adjacent plant cell walls together. // - Middle Lamella –pectin-rich layer that cements together cell walls of adjacent cells
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Mitosis
In eukaryotes, the process in which nuclear division results in two nuclei, each of which receives the same complement of chromosomes.
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Monoecy
The term to describe plants that produce carpellate and staminate flowers on the same plant. // Monoecy and dioecy Monoecious – male and female flowers separate but on the same plant e.g. Zea mays (corn) (encourages outcrossing) Dioecious – male and female plants separate (must outcross)
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Multiple fruit
6. Multiple fruit - Gynoecia of a ripened inflorescence – many flowers with many ovaries fused - Floral parts are squeezed between expanding ovaries - E.g. pineapple, mulberry // Pineapples (Figure 30.21e) are juicy multiple fruits that develop when many ovaries of an inflorescence fuse together. Such multiple fruits are larger and attract relatively large ani- mals that have the ability to disperse seeds for long distances. Mulberries and figs are additional examples of multiple fruits that provide similar benefits.
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NADPH
Nicotinamide adenine dinucleotide phosphate; an energy intermediate that provides the energy and electrons to drive the Calvin cycle during photosynthesis.
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Nectar
Many flowers have fused petals that form floral tubes. Such tubes tend to accumulate sugar-rich nectar that provides a reward for pollinators, animals that transfer pollen among plants.
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Nectar guides
Bee pollinated flowers - Showy, brightly colored petals – blue or yellow - Nectar guides - Distinct markings seen by bees (ultraviolet illumination) Visual Nectar Guides
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Node
The region of a plant stem from which one or more leaves, branches, or buds emerge.
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Organic C
Chemical energy from the light reactions (ATP, NADPH), are used by the light-independent (dark) reactions to fix CO 2 to organic C (sugar) Calvin Cycle for CO 2 fixation Fig. 8.15
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Out-crossing
Adaptation to out-crossing : Co-evolution with specialized animal pollinators Resulting in enormous floral diversity // Monoecious – male and female flowers separate but on the same plant e.g. Zea mays (corn) (encourages outcrossing) Dioecious – male and female plants separate (must outcross) // Asexual reproduction Text Fig. 39.5 - Despite specifically evolved complex sexual reproduction processes and strategies to maximise outcrossing… // Self-pollination - Results in less genetic diversity than outcrossing
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Palisade mesophyll
Leaf structure Fig. 8.2 Tissue organisation - Epidermis - Mesophyll (meso – middle, phyll- leaf) - Palisade mesophyll – top - Spongy mesophyll - bottom - Vascular tissue
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Parenchyma
parenchyma cell A type of plant cell that is thin- walled and alive at maturity. parenchyma tissue A plant ground tissue that is composed of parenchyma cells. // Least specialized plant cells ‘workhorse cells’ - Primary walls thin and flexible, no secondary walls - Alive at functional maturity - Functions – Metabolism, Photosynthesis, Starch storage in stems and roots, Abundant in the fleshy part of fruit, Regeneration of more specialized cells in case of damage (Totipotent ‘stem cells’ of plants)
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Pectin
Middle Lamella –pectin-rich layer that cements together cell walls of adjacent cells // vesicles containing pectin (cell-wall precursor)
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Perennial
A plant that lives for more than 2 years, often producing seeds each year after it reaches reproductive maturity.
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Petal
A flower organ that usually serves to attract insects or other animals for pollen transport.
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Petiole
A stalk that connects a leaf to the stem of a plant.
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Phloem
A specialized conducting tissue in a plant’s stem. // Food’ conducting cells – from leaves to roots but also to anywhere in plant In chains like pipes joined together Alive at maturity although seive tube elements lack nucleus, ribosomes and vacuoles
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Phylogeny
The evolutionary history of a species or group of species.
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Pigment
A molecule that can absorb light energy. // Different pigments absorb different wavelengths of light – absorption spectra (a graph plotting pigment absorption against wavelength) Fig. 8.6, 8.7 photosynthetic pigments – chlorophyll a, b, carotenoids
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Pistil
A flower structure that may consist of a single carpel or multiple, fused carpels and is differentiated into stigma, style, and ovary.
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Pits
A thin-walled circular area in a plant cell wall where secondary wall materials such as lignin are absent and through which water moves.
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Plantlets
Asexual reproduction – genetic clones of parent – rhizomes, stolons, plantlets, apomixis. Important for many plants esp. in stable environments
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Plasmamembrane
The biomembrane that separates the internal contents of a cell from its external environment.
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Plasmodesmata
(plural, plasmodesmata) A membrane-lined, ER-containing channel that connects the cytoplasm of adjacent plant cells. // Plasmodesmata Fig. 10.14 - cytoplasmic channels that pass through pores in primary and secondary cell walls - Plasmodesmata - small tubes joining plant cells - living bridges between cells allowing molecules to pass from cell to cell - Provide cell-to-cell communication
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Polar nuclei
Fruits:- Fertilization of two polar nuclei -\> endosperm (3n) // Most important are the egg cell, the female gamete situated near the micropyle, and the central cell containing two polar nuclei. // The tube bursts and releases the two sperm nuclei. One sperm fuses with the egg to form a zygote. The other fuses with the polar nuclei to form the triploid endosperm nucleus.
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Pollen
In seed plants, tiny male gametophytes enclosed by sporopollenin-containing microspore walls.
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Pollen tube
In seed plants, a long, thin tube produced by a pollen grain that delivers sperm to the ovule.
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Pollination
The process in which pollen grains are transported to an angiosperm flower or a gymnosperm cone primarily by means of wind or animal pollinators. // Pollination replaces swimming as transport of sperm to egg //
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Pollinator
An animal that carries pollen between angiosperm flowers or cones of gymnosperms.
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Protist
A eukaryotic organism that is not a member of the animal, plant, or fungal kingdoms; lives in moist habitats and is typically microscopic in size.
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Pteridophyte
A phylum of vascular plants having euphylls, but not seeds; Pteridophyta.
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Rhizoid
rhizobia The collective term for proteobacteria involved in nitrogen-fixation symbioses with plants.
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Rhizomes
- Asexual reproduction – genetic clones of parent – rhizomes, stolons, plantlets, apomixis. Important for many plants esp. in stable environments // But some stems, known as rhizomes, occur under- ground and grow horizontally. For example, potato tubers are the swollen, food-storing tips of rhizomes. Grass stems also grow horizontally, as either rhizomes just beneath the soil sur- face or stolons, which grow along the soil surface // The psilophytes have dichotomously branching stems that grow from rhizomes (modified stems).
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Root cap
Root Cap – protective layer of cells, continuously sloughed off // The region of rapidly dividing cells at plant root tips. root meristem The collection of cells at the root tip that generate all of the tissues of a plant root.
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Root hairs
Root hairs – specialized epidermal cells for water and mineral absorption // A specialized, long, thin root epidermal cell that functions to absorb water and minerals, usually from soil.
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Rubisco
The enzyme that catalyzes the first step in the Calvin cycle in which CO2 is incorporated into an organic molecule.
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Sclerenchyma
Sclerenchyma Figure 35.7 - Thick secondary walls - Strengthened by lignin - Cannot elongate with growth - Often lack protoplasts at maturity – i.e. dead at functional maturity - Function – support Fibers - Long slender and tapering in bundles (Rope, flax) Sclereids (stone cells) - Short, irregular shape, make hard seed coat and nut shells - Gritty texture in pears // A rigid plant ground tissue composed of tough-walled fibers and sclereids.
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seed
A reproductive structure having specialized tissues that enclose plant embryos; produced by gymnosperms and flowering plants, usually as the result of sexual reproduction.
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Seed coat
A hard and tough covering that develops from the ovule’s integuments and protects a plant embryo.
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Seed dispersal
Purpose and advantages of fruit (for the plant)? - Seed dispersal - Protects seed(s) // dispersive mutualism A mutually beneficial interaction often involving plants and pollinators that disperse their pollen, and plants and fruit eaters that disperse the plant’s seeds.
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Seed dormancy
A phase of metabolic slowdown in a plant. // Seeds are a dried and dormant form of plant life – a potential plant Seed Dormancy (during dispersal) - Dormancy – a period of inactivity during which growth ceases – Breaking dormancy – plant resumes growth if moisture, temperature or day length requirements right – best chance that seeds will germinate at good time - Desert – after rain - Cold climate – in spring (cold stratification) - Chapparal - after fires (clears away brush) - Animal dispersal necessary – must pass through digestive tract to weaken seed coat
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seed plants
The informal name for gymnosperms and angiosperms.
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Self-fertilization (not asexual)
Fertilization that involves the union of a female gamete and male gamete from the same individual.
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Selfing (self-fertilization)
Asexual reproduction Figure 39.22 – new plants formed from parent plant – no meiosis and no fusion of gametes involved - does not avoid ‘selfing’ but produces clones //
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Sepal
A flower organ that occurs in a whorl located outside whorls of petals of eudicot plants.
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Sheath
Leaves - petiole and sheaths, blades, compound leaves // In contrast, corn and other monocots have leaf blades that grow directly from the stem, encircling it to form a leaf sheath (Figure 35.13b). // In corn, the epicotyl of the embryo is enclosed by a sheath called a coleoptile; the radicle is enclosed by a sheath called the coleorhiza.
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Sieve tube elements
A component of the phloem // Sieve tube elements (sugar solute conducting cells - phloem) tissues of flowering plants; thin-walled cells arranged end to end to form transport pipes.
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Spongy mesophyll
Spongy mesophyll - bottom // spongy parenchyma Photosynthetic ground tissue of the plant leaf mesophyll that contains round cells separated by abundant air spaces.
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Sporophyte
The diploid generation of plants or multicellular protists that have a sporic life cycle; this generation produces haploid spores by the process of meiosis.
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Sporopollenin
The tough material that composes much of the walls of plant spores and helps to prevent cellular damage during transport in air.
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Stamen
A flower organ that produces the male gametophyte, pollen.
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Starch
A polysaccharide composed of repeating glucose units that is produced by the cells of plants and some algal protists.
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Stigma
In a flower, the topmost portion of the pistil, which receives and recognizes pollen of the appropriate species or genotype.
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Stolons
Asexual reproduction – genetic clones of parent – rhizomes, stolons, plantlets, apomixis. Important for many plants esp. in stable environments // Grass stems also grow horizontally, as either rhizomes just beneath the soil sur- face or stolons, which grow along the soil surface.
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Stomata
Surface pores on plant surfaces that can be closed to retain water or open to allow the entry of CO 2 needed for photosynthesis and the exit of oxygen and water vapor.
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Stone cells/sclerids
Star- or stone-shaped plant cells having tough, lignified cell walls.
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Strobili
Horsetails - Ancient lineage, tree-like in Carboniferous - Whorled tiny leaves, true roots - Sporangia on strobili // cycads: Seeds and pollen on separate strobili (cones) of sporophylls Male and female strobili on different individuals - dioecious Macrozamia –Australian cycad // What to look for: leaves (microphylls, megaphylls), sporophylls/strobili/sori, rhizomes (with roots)
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Stroma
The fluid-filled region of the chloroplast between the thylakoid membrane and the inner membrane.
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Style
In a flower, the elongate portion of the pistil through which the pollen tube grows.
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Succulents
CAM - Crassulacean Acid Metabolism CAM plants - Very well adapted to dry conditions – desert plants and succulents // CAM plants are water-storing succulents such as cacti, brome- liads (including pineapple), and sedums. To avoid water loss, CAM plants keep their stomata closed during the day and open them at night, when it is cooler and the relative humidity is higher. //
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Sucrose
Products of photosynthesis - Sugar used throughout plant - cellular respiration - Transported as sucrose C 12 H 22 O 11 in phloem // Alternatively, the disac- charide sucrose may be made and transported out of the leaf to other parts of the plant.
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Syngamy
sperm and egg (n) come together to create zygote (2n) - in alternation of generations
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Tamarack
Division Coniferophyta – the Conifers - Usually large trees (pines, spruces, tamarack, cedars, cypresses, redwoods) - Only 550 species but dominate boreal regions - Among the tallest, largest, oldest organisms on planet - Evergreen - Leaves are needles (megaphylls) covered with waxy cuticle // Tamarack die-off at Cedarburg Bog - 1000 ha wetland complex – UWM Field Station - In 2003, mass die-off of mature tamarack trees – may be related to cold winter with little snow-cover?
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Tap root
taproot system The root system of eudicots, consisting of one main root with many branch roots.
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Thylakoid membrane
thylakoid A flattened, platelike membranous region found in cyanobacterial cells and the chloroplasts of photosynthetic protists and plants; the location of the light reactions of photosynthesis. thylakoid lumen The fluid-filled compartment within the thylakoid. thylakoid membrane A membrane within the chloroplast that forms many flattened, fluid- filled tubules that enclose a single, convoluted compartment. It contains chlorophyll and is the site where the light-dependent reactions of photosynthesis occurs.
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Totipotent
The ability of a fertilized egg to produce all of the cell types in the adult organism; also the ability of unspecialized plant cells to regenerate an adult plant.
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Tracheids
A type of dead, lignified plant cell in xylem that conducts water, along with dissolved minerals; also provides structural support.
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Tree rings
Vascular cambium creates tree rings - Tree rings – used for aging trees, research on historical climate changes http://www.ncdc.noaa.gov/paleo/treering.html http://web.utk.edu/~grissino/ http://myweb.dal.ca/jvandomm/forensicbotany
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Vacuole
Specialized compartments found in eukaryotic cells that function in storage, the regulation of cell volume, and degradation.
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Vascular
For success invasion onto land, plants had to evolve structural support, vascular system (lignin support), desiccation resistance (cuticle, stomata) // Adaptations of Vascular Plants Stems and Leaves with waxy cuticles Vascular tissue to transport solutes – This allows the plant to get bigger Vascular tissue throughout the plant – dead cells become xylem // Monocots vs Dicots vascular system Dicots – net veination Monocots – parallel veination Flower form: Monocots – 3s, Dicots – 4,5s // - Vascular – Tracheids and vessel elements (solute and water conducting cells - xylem) – Sieve tube elements (sugar solute conducting cells - phloem) // Vascular cambium – In stems and roots of perennials and woody trees – Increases tree girth – Forms xylem to inside, phloem to outside //
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Vascular bundle
Primary plant vascular tissues that occur in a cluster.
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Vascular cambium
A secondary meristematic tissue of plants that produces both wood and inner bark.
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Vascular plants
A plant that contains vascular tissue. Includes all modern plant species except liverworts, hornworts, and mosses.
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Vascular tissue
Plant tissue that provides both structural support and conduction of water, minerals, and organic compounds.
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Vessel element
vessel In a plant, a pipeline-like file of dead, water- conducting vessel elements. vessel element A type of plant cell in xylem that conducts water, along with dissolved minerals and certain organic compounds. // Xylem – vessel elements in addition to tracheids found in conifers
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Water use efficiency
Advantages of C4 and CAM Photosynthesis - Higher C fixation efficiency - Can photosynthesize when it is hot and dry - Much higher water use efficiency (lower transpiration)
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Welwitschia
Double fertilization recently found in Ephedra and Gnetum Welwitschia - S African distribution - Grows in a ring - Record sizes - 1.2 m tall and 8.7 m wide Welwitschia – reproductive cones // Welwitschia, the third gnetophyte genus, has only one living representative species. Welwitschia mirabilis is a strange-looking plant that grows in the coastal Namib Desert of southwestern Africa, one of the driest places on Earth (Fig- ure 30.11c). A long taproot anchors a stubby stem that barely emerges from the ground. Two very long leaves grow from the stem but rapidly become wind-shredded into many strips. The plant is thought to obtain most of its water from coastal fog, explaining how W. mirabilis can grow and reproduce in such a dry place. //
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Xerophytic adaptations (xerophytes)
Xerophytic adaptations - Tend to be bulbous or succulent - No or few leaves - Often thick waxy cuticle or covered with hairs to reduce water loss and reflect light //
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Xylem
A specialized conducting tissue in plants that transports water, minerals, and some organic compounds.
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Zone of differentiation
Zone of Differentiation – root hairs, vascular tissue // zone of maturation The area above the zone of elongation in a plant root where root cell differentiation and tissue specialization occur.
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Zone of division
Zone of Division – meristem produces cells to either side
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Zone of elongation
The area above the root apical meristem of a plant where cells extend by water uptake, thereby dramatically increasing root length.
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Zygote
A diploid cell formed by the fusion of two haploid gametes.
