Plant Biology Key Terms 2

Define receptacle the part of the flower stalk to which the flower parts are attached Define pedicel the stalk of an individual flower in an inflorescence For a flower, the ______ contains the ovules and develops into the fruit wall, while the ______ bears the pollen carpel; stamens What two organs is the shoot apical meristem composed of? stem & leaves What structures make up the phytomere? leaf, node, internode, auxilary bud How does the apical meristem of the shoot differ from that of the root? The shoot apical meristem has no protective cap What is the name for the single outer layers of the shoot apical meristem which result in the the protoderm? How do these cells usually divide? tunica; anticlinally or perpendicular to the meristem- add length What is the plumule? The first bud or embryonic shoot of the plant it has a stemlike axis and one or more young leaves what interior layers of the SAM result in the ground meristem and procambium? How do these cells usually divide? Corpus; periclinally or parallel to the meristem- adds girth The vascular bundles are discontinuous in __________ , scattered in _________ and continuous in the ________ & _____ eudicots; monocots; stem & leaves The procambium of the leaf is initiated in the ______ and develops and expands into the ______________ stem; leaf primordia On a flower the _______ is on the outer edge and arises below the ________ but both are attached to the receptacle. sepals; petals sepals form the ______ and petals form the ______ calyx, corolla The stamens collectively called the __________ consist of a slender stalk called the ______ upon which is borne two-lobed ______ containing four ______ or two pairs of ______ androecium; filament; anthers; microsporangia; pollen sacs The carpels collectively called the __________ and also called the ______ consist of a lower part called the _______ which encloses the ovules; a middle part the________ through which the pollen tube grows and the upper part called the______ which receives the pollen gynoecium; pistil; ovary; style; stigma What does it mean for a flower to be perfect? imperfect? perfect- the flower contains both stamens and carpels imperfect- the flower lacks either the stamens or carpels What does it mean for a plant to be monoecious? dioecious? monoecious- staminate and carpellate flowers occur on the SAME plant dioecious- staminate and carpellate flowers occur on DIFFERENT plants What does it mean for a flower to be complete? incomplete? complete- has all four floral whorls- sepals, petals, carpels, and stamens incomplete- it lacks one of the four: sepal, petal, carpel, or stamen. All imperfect flowers are incomplete Angiosperm literally means? angio= vessel, sperm= seed What is another name for flower? sporophyll What are the four whorls of a flower? sepals, petals, carpels, and stamens Name two characteristics about flowers they have determinate growth, their ovules develop into seeds after fertilization Together the sepals (calyx) and the petals (corolla) form the ________ perianth What does it mean for a flower to be hypogynous? Give an example It means the perianth and the stamens are situated on the receptacle below the ovary; lilies What does it mean for a flower to be epigynous? Give an example It means the perianth and the stamens are on top or above the ovary; apple blossoms What does it mean for a flower to be perigynous? Give an example It means the the petals and stamens are conjoined and attached to the calyx to form a short tube called a hypanthium which arises from the base of the ovary; cherry flowers In the angiosperms, the microgametophyte consists of _____ # of cells and the megagametophyte consists of _____# of cells three; seven Name 4 characteristics that make angiosperm reproduction distinct? gametophytes are greatly reduced, lack antheridia & archegonia, pollination is indirect (lands on stigma, and pollen tube travels thru style & 2 non-motile sperm are released), the fertilized ovule turns into a seed and is enclosed in the ovary (fruit) flowers' petals are said to evolve from? How many veins do petals have? stamens that lost their reproductive capability. They have one vein flowers' sepals are said to evolve from? How many veins do sepals have? sepals are modified leaves, they have many veins How do flowers with bat or bird pollinators differ from flowers that rely on insect pollinators? They are usually odorless, and have large reserves of nectar. Some only open at night (for bats), their petals are usually pulled back or they have strong support for perching How do angiosperms that rely on wind pollination differ from other flowering plants? not showy flowers, lack odor, stigmas are exposed, feathery (ex. corn & grasses) __ # of cells are produced in the original microspore or pollen grain and then the _______ divides producing ___# of cells 2; generative cell; 3 What do all pollen grains contain? How do pollen grains vary? all contain sporopollenin (exine), pectin (intine), starch, oils vary by size and shape What is the axial system? Refers to the secondary vascular tissues. The axial system comprises of the fusiform initials and is arranged vertically or parallel with the main axis of the root or stem. What is the radial system? Refers to the arrangement of the secondary vascular tissues. The radial system comprises of the ray initials and is arranged horizontally What structural feature of wood is responsible for the visibility of growth rings? the secondary vascular tissues Why are lenticels important to plants? They are involved in gas exchange Distinguish between the fascicular cambium and the the interfascicular cambium. The fascicular cambium is the portion of the cambium arising within the vascular bundles, and the interfascicular cambium is the portion of the cambium arising between the vascular bundles (the pith rays or interfascicular regions) Explain why the mesophyll tissue is particularly suited for photosynthesis. It has a large volume of intercellular space that are connected with the outer atmosphere via the stomata and many chloroplasts What are the principal roles of the major and minor veins of leaves? major- transport photosynthates out of the leaf minor- collect the photosynthates from mesophyll cells. What is the style? It is a column of tissue that extends out of the top of the ovary. The pollen tube grows through this to the ovary. What is the stigma? The stigma is the top end of the style that serves as a receptive place for pollen grains to land and germinate What is the ovary? The enlarged basal portion of the gynoecium An imperfect flower is automatically incomplete but not all incomplete flowers are imperfect- explain Imperfect, means the flower does not contain both carpels and stamens, for a flower to be complete, it must contain distinct sepals, petals, stamens, and carpels. However a flower could contain both stamens and carpels and be perfect but not contain sepals and therefore be incomplete. What is a simple fruit? give an example. A simple fruit is a fruit made up of one carpel or several united carpel of a flower. An example of this is the apple What is an aggregate fruit? give an example An aggregate fruit is a fruit made up of one flower with many separate carpels of one gynoecium. An example is a strawberry What is a multiple fruit? give an example. A multiple fruit is made up of the gynoceia of more than one flower. A pineapple is an example. What evidence supports the cohesion-tension theory pressure of water potential has been tested, Flow diminishes first in the twigs then trunk, the shrinking of the trunk during the day- due to negative pressure Distinguish between symplast and apoplast These are two different pathways water can take. In apoplastic pathways the water moves in the intercellular space and on cell walls, however water cannot cross the casparian strip this way. In symplastic pathways the water moves between cells via the plasmodesmata and this CAN cross the casparian strip. What is meant by parthenocarpic fruit? These are fruits without seeds. When auxin is applied to the carpels it is possible for fruits to grow w/o fertlization, making seedless grapes, tomatoes, etc. In what ways is ethylene a unique plant hormone? ethylene is a gaseous hormone and is responsible for the ripening of fruit. Banana growers use it. ______ ia terpenoid consisting of as many as 100,000 isoprene units Rubber Whichof the two statements about Phloem loading and unloading in plants is FALSE: a. Is described by the pressure-flow hypothesis b. Is described by the cohesion-tension theory c. Moves from areas of high solute concentration to low concentration d. Moves from areas of low solute concentration to high concentration e. Moves via the sieve-tube elements b & d Which of the following statements about the primary structure of the stem is FALSE? a. Its vascular bundles resemble those of monocots b. Its vascular bundles are completely surrounded by sclerenchyma cells c. It has a vascular cambium d. It has closed vascular bundles c The two hormones thought to be invlved in gravitropism are? auxin & cytokinin True or False, Angiosperms have archegonia but lack antheridia False True or Flase Lignin is a structural component of the cell wall of plants yet is considered a secondary metabolite. True True or False Interfascicular cambium arises in parenchyma cells between the vascular bundles True True or False Cytokinins are synthesized in roots and transported in the xylem to other parts of the plant. True True or False, Cells in the outermost layer of the tunica-corpus usually divide periclinally False Which of the following statements about xylem and phloem is FALSE? a. They are closely associated spatially b. They are closely associated functionally c. they form a continuous vascular system d. They are involved in long-distance transport e. Xylem transports only water and phloem transports only nutrients e What are 3 propoerties of water that are critical for transpiration in plants? adhesion, cohesion, polarity Describe 2 stem modification and 2 leaf modifications stem- tubers & bulbs (potatoes & onions both for storage) leaves- sepals (for showiness to attract pollinators) needles (to protect from herbivory) Put the following in the correct order to demonstrate how water moves from the soil into the root: Cortical cells Endodermis Epidermis Vascular cylinder Epidermis Cortical Cells Endodermis Vascular cylinder Which tissues are produced by the vascular cambium and which by the cork cambium vascular cambium- secondary phloem & xylem cork cambium- cork & phelloderm, both make up the periderm What hormone controls phototropism in plants? Who discovered this? Auxin; Darwin What are the 3 different theories proposed for how water is moved from root to shoot? Which is the most accepted? Root-pressure, Capillary action, Cohesion-tension. Cohesion tension is the most accepted Describe the Cohesion-Tension theory water moves from areas of high-potential to low potential. This means water is "pulled" from the soil. This first starts in transpiration, as water is lost from the stomata on leaves, an area of water low-potential occurs. Due to water's cohesive properties, water molecules move like a chain to fill this area, finally making the area of low potential occur in the roots, where water from the soil can then move into the roots. This tension created by the "water-chain" has enough pressure to move water from root to shoot. In angiosperms The female gametophyte is a result of ______ and ________ megasporogenesis, megagametogenesis What is the result of megasporogenesis? What steps are involved. The end result of megasporogenesis is the ovule. The mother spore splits meiotically into 4 haploid cells, 3 of these cells degenerate leaving what will be the ovule. What is the result of megagametogenesis? What steps are involved. The end result are 7 cells (1 egg cell, 2 synergids, 3 antipodals, and 1 big central cell w/ 2 nuclei). The nucleus of the megaspore divides mitotically 3 times. In angiosperms, the mature male gametophyte is formed as a result of _________ and ________ microsporogenesis; microgametogenesis What is the result of microsporogenesis. What are the steps involved? The result is a tetrad of pollen grains. Sporogenesis occurs first in the mother spore which under-goes meiosis 2 times to become 4 pollen grains What is the result of microgametogenesis. What are the steps involved? The result is the tube cell & 2 generative cells. A pollen grain splits mitotically into the tube cell & generative cell. Then the generative cell splits again into 2. Describe some basic characteristics about plant hormones Act in low concentrations, function as internal signals, effects can overlap (this is mainly why how plant hormones intiate their effects is NOT fully understood). Often coordinate: cell division, cell growth, differentiation Name the 5 classic plant hormones and a single function of each Auxin- involved in apical dominance Cytokinin- involved in gravitropism Ethylene- involved in the ripening of fruit ABA (abscisic acid) involved in seed dormancy Gibberellic acid- involved in bolting What is the difference between a primary metabolite and a secondary metabolite? A primary metabolite is involved in plant, growth & development and secondary metabolites are involved in protecting the plant from herbivory & seed propagation. Name the 3 main classes of secondary metabolites, give an example of each, and state why the example you provided is significant. Alkaloids (ex. morphine- very important pain killer) Terpenes (ex. taxol- thought to be an anti-carcinogen) Phenols (ex. Flavanoids, thought to be a healthy compound found in wine).