bio 2 chap 28 book notes

1) define root (4 things) 2) what kind of plant will have this specific type of root 3) define this specific type of root (2 things) 4) this specific type of root has what advantage for the plant? 5) in plant with this specific type of root, what is restricted?

1) A root is an 1. organ 2. anchors a vascular plant in the soil 3. absorbs minerals and water 4. often stores carbohydrates. 2) Tall, erect plants with large shoot masses generally have a main vertical root, the taproot, 3) taproot - 1. penetrates the soil deeply 2. helps prevent the plant from toppling 4) A taproot, although energetically expensive to make, allows the plant to be taller, thereby giving it access to more favorable light conditions and, in some cases, providing an advantage for pollen and seed dispersal (definition of dispersal from google - action or process of distributing things or people over a wide area) 5) In plants with taproots, the role of absorption is restricted largely to the tips of lateral roots, which branch off from the taproot

see pic 1) A shoot apical meristem is 2) leaf primordia + define 3) Within a bud, ______ 4) Shoot elongation is due to _______

1) A shoot apical meristem is a dome-shaped mass of dividing cells at the shoot tip. 2) Leaves develop from leaf primordia (singular, primordium), projections shaped like a cow's horns that emerge along the sides of the shoot apical meristem. 3) Within a bud, young leaves are spaced close together because the internodes are very short. 4) Shoot elongation is due to the lengthening of internode cells below the shoot tip. pic description: Leaf primordia arise from the flanks of the dome of the apical meristem. This is a longitudinal section of the shoot tip of Coleus (LM).

1) define stem 2) chief function of the stem 3) another function of the stem 4) specific function of the stem 5) each stem consists of _____ ______ of ______ + define 6) and _______ + define 7) apical bud 8) Apical buds are not the only types of buds found in _______. explain second type + define

1) A stem is a plant organ bearing leaves and buds. 2) Its chief function is to elongate and orient the shoot in a way that maximizes photosynthesis by the leaves. 3) Another function of stems is to elevate reproductive structures, thereby facilitating the dispersal of pollen and fruit. 4) Green stems may also perform a limited amount of photosynthesis. 5) Each stem consists of an alternating series of nodes - the points at which leaves are attached 6) and internodes - the stem segments between nodes 7) Most of the growth of a young shoot is concentrated near the growing shoot tip, or apical bud. 8) Apical buds are not the only types of buds found in shoots. In the upper angle (axil) formed by each leaf at every node is an axillary bud, which can potentially form a lateral branch or, in some cases, a thorn or flower.

1) A typical plant must ________from ________ and ________ from ________. 2) The ability to acquire these resources efficiently is traceable to

1) A typical plant must absorb water and minerals from below the ground surface and CO2 and light from above. The ability to acquire these resources efficiently is traceable to the evolution of three basic organs—roots, stems, and leaves.

1) All plant organs—________—are composed of three fundamental tissue types: 2) read

1) All plant organs—roots, stems, and leaves—are composed of three fundamental tissue types: dermal, vascular, and ground. 2) These tissues are continuous throughout the plant, but their specific characteristics and spatial relationships to one another vary in different organs description of pic: Dermal tissue (blue) provides a protective cover for the entire body of a plant. The vascular tissue (purple), which transports materials between the root and shoot systems, is also continuous throughout the plant but is arranged differently in each organ. The ground tissue (yellow), which is responsible for most of the plant's metabolic functions, is located between the dermal tissue and the vascular tissue in each organ.

1) All ______ plants have _______ growth: growth in _______. 2) _______ plants also have _________ growth: growth in ________.

1) All vascular plants have primary growth: growth in length. 2) Woody plants also have secondary growth: growth in thickness.

1) Based on the timing and completeness of a plant species' switch from vegetative to reproductive growth, _____ plants can be categorized as ____ (3) 2) 1st type + define + example 3) 2nd type + define + example 4) 3rd type + define + example

1) Based on the timing and completeness of a plant species' switch from vegetative to reproductive growth, flowering plants can be categorized as annuals, biennials, or perennials. 2) Annuals complete their life cycle—from germination to flowering to seed production to death—in a single year or less. Many wildflowers are annuals, as are most staple food crops, including legumes and cereal grains such as wheat and rice. 3) Biennials, such as turnips, generally require two growing seasons to complete their life cycle, flowering and fruiting only in their second year. 4) Perennials live many years and include trees, shrubs, and some grasses.

primary meristem 1) which cells give rise to them and when 2) 3 types of primary meristems 3) what do these 3 primary meristems (three tissues) do? 4) lateral meristems in ______ plants also have _______, which ______

1) Cells displaced from the meristem may divide several more times as they differentiate into mature cells. During primary growth, these cells give rise to three tissues called primary meristems— 2) the protoderm, ground meristem, and procambium— 3) that will produce, respectively, the three mature tissues of a root or shoot: the dermal, ground, and vascular tissues. 4) The lateral meristems in woody plants also have stem cells, which give rise to all secondary growth.

1) dermal tissue - define 2) function of it^^^ 3) In _____ plants, it consists of a _____ tissue called _____ + define 4) cuticle - where its found + define + structure + function 5) In ______ plants, _______ tissues called _______ ______ the ________ 6) in addition to _____, the epidermis has _______ 7) for example, ______ 8) look at pic + read description of pic

1) Dermal tissue is the plant's outer protective covering. 2) Like our skin, it forms the first line of defense against physical damage and pathogens. 3) In nonwoody plants, it consists of a single tissue called the epidermis - a layer of tightly packed cells. 4) In leaves and most stems, the cuticle, a waxy coating on the epidermal surface, helps prevent water loss. 5) In woody plants, protective tissues called periderm replace the epidermis in older regions of stems and roots. 6) In addition to protecting the plant from water loss and disease, the epidermis has specialized characteristics in each organ. 7) For example, a root hair is an extension of an epidermal cell near the tip of a root. Trichomes are hairlike outgrowths of the shoot epidermis. In some desert species, trichomes reduce water loss and reflect excess light, but their most common function is to defend against herbivores and pathogens by forming a mechanical barrier or secreting chemicals. 8) description of pic: Dermal tissue (blue) provides a protective cover for the entire body of a plant. The vascular tissue (purple), which transports materials between the root and shoot systems, is also continuous throughout the plant but is arranged differently in each organ. The ground tissue (yellow), which is responsible for most of the plant's metabolic functions, is located between the dermal tissue and the vascular tissue in each organ.

(see pic) 1) root hairs - define 2) Most _______ plant roots also form ________, ______ 3) Many plants have _____ adaptations with specialized functions. Some of these arise from _____, and others ________, _________. 4) 3 adaptations of _______ (explain)

1) In most plants, the absorption of water and minerals occurs primarily near the tips of elongating roots, where vast numbers of root hairs, thin, finger-like extensions of root epidermal cells, emerge and increase the surface area of the root enormously. 2) Most terrestrial plant roots also form mycorrhizal associations, symbiotic interactions with soil fungi that increase a plant's ability to absorb minerals. 3) Many plants have root adaptations with specialized functions. Some of these arise from the roots, and others are adventitious, developing from stems or, in rare cases, leaves. 4) 3 adaptations of roots 1. Some modified roots add support and anchorage. 2. Others store water and nutrients 3. absorb oxygen from the air. pic is of root hairs of a radish

1) In most ________ plants, the ______ is the main ______ ______. 2) 4 functions of _______ 3) These functions may have ____. for example, ____. 4) Because of these _____, ______ ______ _______ in ______. 5) in general however, a ____ consists of a _____ and a ___, the ______, which ____ the ____ to the _____ at a ____. 6) _____ and many other _____ lack ______; instead, _____ (read instead part)

1) In most vascular plants, the leaf is the main photosynthetic organ. 2) 4 functions of leaves: 1. intercepts (aka grabs or seizes or catches) light 2. exchange gases with the atmosphere 3. dissipate (dispells, banishes) heat 4. defend themselves from herbivores and pathogens 3) These functions may have conflicting physiological, anatomical, or morphological requirements. For example, a dense covering of hairs may help repel herbivorous insects but may also trap air near the leaf surface, thereby reducing gas exchange and, consequently, photosynthesis. 4) Because of these conflicting demands and trade-offs, leaves vary extensively in form. 5) In general, however, a leaf consists of a flattened blade and a stalk, the petiole, which joins the leaf to the stem at a node. 6) Grasses and many other monocots lack petioles; instead, the base of the leaf forms a sheath that envelops the stem.

see pic for comparison of 2 types of ____ 1) vascular plant focused on in this chapter + 2 reasons why 2) 2 types of this specific vascular plant + define both

1) In this chapter, we focus on vascular plants, mainly angiosperms (flowering plants) because they are the primary producers in many ecosystems and are of great agricultural importance. Taxonomists split angiosperms into two major clades: 1. Monocots typically have a single cotyledon (seed leaf) 2. eudicots typically have two. Monocots and eudicots have other structural differences

1) _____ arises from ______ of the pericycle 2) pericycle - define 2) what happens here

1) Lateral roots arise from meristematically active regions of the pericycle 2) the outermost cell layer in the vascular cylinder, which is adjacent to and just inside the endodermis. 3) The lateral roots destructively push through the cortex and epidermis until they emerge from the established root

1) Monocots and eudicots differ in the arrangement of ________ 2) define this word 3) these for monocots 4) these for eudicots

1) Monocots and eudicots differ in the arrangement of veins 2) veins - the vascular tissue of leaves. remember a vascular plant: (from google) Vascular plants are "tube plants" called tracheophytes. Vascular tissue in plants is comprised of xylem, which are tubes involved in water transport, and phloem, which are tubular cells that distribute food to plant cells. Other defining characteristics include stems, roots and leaves. Vascular plants are more complex than ancestral nonvascular plants. Vascular plants have a type of internal "plumbing" that transports products of photosynthesis, water, nutrients and gases. All types of vascular plants are terrestrial (land) plants not found in freshwater or saltwater biomes. Vascular plants are also defined as eukaryotes, meaning they have a membrane-bound nucleus, which sets them apart from the prokaryotic bacteria and archaea. Vascular plants have photosynthetic pigments and cellulose to support cell walls. Like all plants, they are place-bound; they cannot flee when hungry herbivores come along looking for a meal. 3) Most monocots have parallel major veins of equal diameter that run the length of the blade. 4) Eudicots generally have a branched network of veins arising from a major vein (the midrib) that runs down the center of the blade

1) Plants, like most animals, are composed of ______(3)______ 2) define first thing 3) define second thing

1) Plants, like most animals, are composed of organs, tissues, and cells. 2) An organ consists of several types of tissues that together carry out particular functions. 3) A tissue is a group of cells consisting of one or more cell types that together perform a specialized function.

1) Primary growth arises directly from cells produced by _______ 2) In ______ plants, the plant is produced almost entirely by primary growth, whereas in _____ plants only the ______, ______ parts of the plant represent primary growth. 3) read only

1) Primary growth arises directly from cells produced by apical meristems. 2) In herbaceous plants, the plant is produced almost entirely by primary growth, whereas in woody plants only the nonwoody, more recently formed parts of the plant represent primary growth. 3) Although the elongation of both roots and shoots arises from cells derived from apical meristems, the primary growth of roots and shoots differs in many ways.

1) small plants are at risk of what? 2) because of this, explain next type of root (define) 3) In plants that have ______ roots, including most ________,_____(explain how they function, mention + define important term italicized) 4) good thing about these types of roots (w/ example)

1) Small plants or those that have a trailing growth habit are particularly susceptible to grazing animals that can potentially uproot (uproot google definition - pull (something, especially a tree or plant) out of the ground) the plant and kill it. 2) Such plants are most efficiently anchored by fibrous roots, thin, interweaving roots that spread out below the soil surface. 3) In plants that have fibrous roots, including most monocots, the primary root that emerges from the germinating seed dies early on and does not form a taproot. Instead, many small roots emerge from the stem. Such roots are said to be adventitious, a term describing a plant organ that grows from an unusual source, such as roots arising from stems or leaves. Each root forms its own lateral roots, which in turn form their own lateral roots, thereby creating a thick mat of slender roots. 4) Because this mat of roots holds the topsoil in place, plants such as grasses that have dense fibrous roots are especially good at preventing soil erosion.

skip 1) small plants ______ 2) such plants are most ______ 3) define this second specific type of root 4)

1) Small plants or those that have a trailing growth habit are particularly susceptible to grazing animals that can potentially uproot the plant and kill it. 2) Such plants are most efficiently anchored by fibrous roots 3) fibrous roots - thin, interweaving roots that spread out below the soil surface. 4) In plants that have fibrous roots, including most monocots, the primary root that emerges from the germinating seed dies early on and does not form a taproot. Instead, many small roots emerge from the stem. Such roots are said to be adventitious, a term describing a plant organ that grows from an unusual source, such as roots arising from stems or leaves. Each root forms its own lateral roots, which in turn form their own lateral roots, thereby creating a thick mat of slender roots. Because this mat of roots holds the topsoil in place, plants such as grasses that have dense fibrous roots are especially good at preventing soil erosion.

(i guess just read) 1) The ________ of ________ tissue varies, depending on _____ 2) first example 3) second example 4) third example

1) The arrangement of vascular tissue varies, depending on the species and organ. 2) In angiosperm roots, for example, the vascular tissue forms a central vascular cylinder (or stele) of xylem and phloem. 3) In angiosperm shoots, the vascular tissue consists of vascular bundles, separate strands containing xylem and phloem 4) In leaves, these vascular bundles are called veins.

1) The chief functions of vascular tissue are to _____ (2) 2) vascular tissue composed of ______ (2) 3) first type + define 4) second type + define 5) Both _______ and ______ are composed of ______ including ____ that are ______ for _______

1) The chief functions of vascular tissue are to facilitate the transport of materials through the plant and to provide mechanical support. 2) Vascular tissue is largely composed of two types of transport tissues called xylem and phloem. 3) Xylem summary: moves water & mineral from roots up to the shoots; conducts water and dissolved minerals upward from roots into the shoots. 4) Phloem transports sugars, the products of photosynthesis, from where they are made (usually the leaves) to where they are needed or stored—usually roots and sites of growth, such as developing leaves and fruits. 5) Both xylem and phloem are composed of a variety of cell types, including cells that are highly specialized for transport or support.

1) mesophyll - define 2) where is it 3) consists mainly of ______ for ______ 4) 2 layers of mesophyll in many _____ leaves + name 2 layers 5) 1st type 6) 2nd type

1) The leaf's ground tissue, called the mesophyll (from the Greek mesos, middle, and phyll, leaf) 2) is sandwiched between the upper and lower epidermal layers. 3) Mesophyll consists mainly of parenchyma cells specialized for photosynthesis. 4) The mesophyll in many eudicot leaves has two distinct layers: palisade and spongy. 5) Palisade mesophyll consists of one or more layers of elongated parenchyma cells on the upper part of the leaf. 6) Spongy mesophyll is below the palisade mesophyll. These parenchyma cells are more loosely arranged, with a labyrinth of air spaces through which CO2 and O2 circulate around the cells and up to the palisade region. The air spaces are particularly large in the vicinity of stomata, where CO2 is taken up from the outside air and O2 is released.

(see pic) 1) root cap - define 2) cells of root cap do what that does what 3) growth occurs where in which 3 zones at successive stages of which type of growth

1) The tip of a root is covered by a thimble-like root cap which protects the delicate apical meristem as the root pushes through the abrasive soil during primary growth. 2) The cells of the root cap also secrete a polysaccharide slime that lubricates the soil around the tip of the root. 3) Growth occurs just behind the tip in three overlapping zones of cells at successive stages of primary growth. These are the zones of cell division, elongation, and differentiation description of pic: The root apical meristem produces all the cells of the root and the root cap. Most lengthening of the root occurs in the zone of elongation. In the micrograph, cells undergoing mitosis in the apical meristem are revealed by staining for cyclin, a protein that plays an important role in cell division (LM).

Water-Conducting Cells of the Xylem (read ig) (see pic)

1) The two types of water-conducting cells, tracheids and vessel elements, are tubular, elongated cells that are dead and lignified at functional maturity. 2) Tracheids occur in the xylem of all vascular plants. 3) In addition to tracheids, most angiosperms, as well as a few gymnosperms and a few seedless vascular plants, have vessel elements. 4) When the living cellular contents of a tracheid or vessel element disintegrate, the cell's thickened walls remain behind, forming a nonliving conduit through which water can flow. 5) The secondary walls of tracheids and vessel elements are often interrupted by pits, thinner regions where only primary walls are present 6) Water can migrate laterally between neighboring cells through pits.

1) zone of cell division + 1. includes what + 2. what happens here 2) zone of elongation + 1. happens where + 2. what happens here + 3. does what 3) read? 4) zone of differentiation + 1. also called + 2. what happens here (2)

1) The zone of cell division 1. includes the root apical meristem and its derivatives 2. New root cells are produced in this region, including cells of the root cap. 2) 1. Typically a few millimeters behind the tip of the root is the zone of elongation 2. where most of the growth occurs as root cells elongate—sometimes to more than ten times their original length 3. Cell elongation in this zone pushes the tip farther into the soil 3) Meanwhile, the root apical meristem keeps adding cells to the younger end of the zone of elongation. Even before the root cells finish lengthening, many begin specializing in structure and function; for example, roots hairs start to form. 4) In the zone of differentiation, 1. or zone of maturation 2. cells complete their differentiation and become distinct cell types

1) There are two main types of meristems (name + explain a bit) 2) 1st type 3) 2nd type

1) There are two main types of meristems, apical meristems and lateral meristems, which provide cells for primary and secondary growth. 2) Apical meristems 1. located at the tips of roots and shoots and in axillary buds of shoots 2. provide additional cells that enable growth in length, a process known as primary growth 3) Primary growth allows roots to extend throughout the soil and shoots to increase their exposure to light. 4) In herbaceous (nonwoody) plants, primary growth produces all, or almost all, of the plant body. 5) Woody plants, however, also grow in circumference in the parts of stems and roots that no longer grow in length. This growth in thickness, known as secondary growth, is caused by lateral meristems called the vascular cambium and cork cambium. 6) These cylinders of dividing cells extend along the length of roots and stems. The vascular cambium adds layers of vascular tissue called secondary xylem (wood) and secondary phloem. 7) The cork cambium replaces the epidermis with the thicker, tougher periderm.

1) ground tissue - define 2) 1st type of ground tissue - define 3) 2nd type of ground tissue - define 4) something about ground tissue

1) Tissues that are neither dermal nor vascular are ground tissue. 2) Ground tissue that is internal to the vascular tissue is known as pith 3) ground tissue that is external to the vascular tissue is called cortex. 4) Ground tissue is not just filler. It may include cells specialized for functions such as storage, photosynthesis, support, or short-distance transport.

Water-Conducting Cells of the Xylem continued (read ig) (see pic)

1) Tracheids are long, thin cells with tapered ends. Water moves from cell to cell mainly through the pits, where it does not have to cross thick secondary walls. 2) Vessel elements are generally wider, shorter, thinner walled, and less tapered than the tracheids. They are aligned end to end, forming long pipes known as vessels that in some cases are visible with the naked eye. The end walls of vessel elements have perforation plates that enable water to flow freely through the vessels. 3) The secondary walls of tracheids and vessel elements are hardened with lignin. This hardening provides support and prevents collapse under the tension of water transport.

Sugar-Conducting Cells of the Phloem (read ig) (see pic)

1) Unlike the water-conducting cells of the xylem, the sugar-conducting cells of the phloem are alive at functional maturity. 2) In seedless vascular plants and gymnosperms, sugars and other organic nutrients are transported through long, narrow cells called sieve cells. 3) In the phloem of angiosperms, these nutrients are transported through sieve tubes, which consist of chains of cells that are called sieve-tube elements, or sieve-tube members. 4) Though alive, sieve-tube elements lack a nucleus, ribosomes, a distinct vacuole, and cytoskeletal elements. 5) This reduction in cell contents enables nutrients to pass more easily through the cell. 6) The end walls between sieve-tube elements, called sieve plates, have pores that facilitate the flow of fluid from cell to cell along the sieve tube. 7) Alongside each sieve-tube element is a nonconducting cell called a companion cell, which is connected to the sieve-tube element by numerous plasmodesmata 8) The nucleus and ribosomes of the companion cell serve not only that cell itself but also the adjacent sieve-tube element. 9) In some plants, the companion cells in leaves also help load sugars into the sieve-tube elements, which then transport the sugars to other parts of the plant.

Meristematic Control of the Transition to Flowering and the Life Spans of Plants 1) vegetative growth - define 2) transition from vegetative growth to reproductive growth + define 3) transition triggered by? 4) vegetative and reproductive growth - which is indeterminate and determinate + why? 5) Some plants may also go through a _______ phase during which they are ________.

1) Vegetative growth—the production of leaves, stems, and roots (as well as asexual, or vegetative, reproduction)—is only one phase in a plant's life. 2) Most angiosperms at some point in their life direct some or all of their shoot apical meristems to undergo a transition from vegetative growth to reproductive growth, the production of flowers, fruits, and seeds. 3) This transition is triggered by a combination of environmental cues, such as day length, and internal signals, such as hormones. 4) Unlike vegetative growth, which is indeterminate, reproductive growth is determinate: The production of a flower by a shoot apical meristem stops the primary growth of that shoot. 5) Some plants may also go through a juvenile phase during which they are incapable of reproductive growth.

Rhizomes (read bc have diagram) 1) definition from textbook + Quizlet 2) example (just look ay pic and read description

1) a horizontal shoot that grows just below the surface. definition from Quizlet - underground horizontal stems 2) the base of this iris plant is an example of a rhizome, vertical shoots emerge from axillary buds on the rhizome

Sclerenchyma cells (read ig)

1) also provide support but are much more rigid. 2) The thick secondary cell wall, produced after cell elongation has ceased, contains large amounts of lignin, a strengthening polymer that accounts for more than a quarter of the dry mass of wood. 3) Mature cells are dead and occur in regions that have stopped lengthening, with their rigid secondary walls providing a "skeleton" that supports the plant. 4) Two types of sclerenchyma are sclereids and fibers. Sclereids are boxier than fibers and irregular in shape, with very thick, lignified secondary walls. They impart the hardness to nutshells and seed coats and the gritty texture to pear fruits. Fibers, usually grouped in strands, are long, slender, and tapered.

Tubers (read bc have diagram) 1) define 2) name example + see pic 3) something specific about the example

1) are enlarged ends of rhizomes or stolons specialized for storing food 2) such as these potatoes 3) the "eyes" of a potato are clusters of axillary buds

Collenchyma cells (read ig)

1) are generally elongated and have thicker primary walls than parenchyma cells, though the walls are unevenly thickened. 2) Young stems and petioles often have strands of collenchyma cells just below their epidermis. 3) Collenchyma cells provide flexible support without restraining growth. 4) They remain alive at maturity, elongating with the stems and leaves they support.

Primary Growth (see pic) 1) define 2) made possible by _______ at _______

1) growth in length 2) made possible by apical meristems at the tips of shoots and roots.

Secondary Growth 1) define 2) made possible by ________extending ________

1) growth in thickness 2) Secondary growth is made possible by two lateral meristems extending along the length of a shoot or root where primary growth has ceased.

Stolons (read bc have diagram) 1) define 2) what does it do for plants 3) see pic for example + read description

1) horizontal shoots that grow along the surface 2) these "runners" enable a plant to reproduce asexually, as plantlets grow from axillary buds along each runner 3) shown here on a strawberry plant

reproductive leaves (read for now bc have chart)

1) leaves of some succulents produce adventitious plantlets which fall off the leaf and take root in the soil 2) succulent in pic is Kalanchoe daigremontiana

1) How do plant organs develop? A major difference between plants and most animals is that plant growth is ______ 2) Instead, _______ 3) meristems + define 4) what are plants organs like? how do plants grow in their lifetimes? 5) how do most animals and some plant organs—such as ______, grow in their lifetimes?

1) not limited to an embryonic or juvenile (juvenile means young) period. 2) Instead, growth occurs throughout the plant's life, a process known as indeterminate growth 3) Plants can keep growing because they have perpetually (perpetually means constantly) dividing, unspecialized tissues called meristems that divide when conditions permit, leading to new cells that elongate and become specialized. 4) At any given time, a typical plant has embryonic, developing, and mature organs. Except for dormant (dormant means sleeping) periods, most plants grow continuously. 5) In contrast, most animals and some plant organs—such as leaves, thorns, and flowers—undergo determinate growth; that is, they stop growing after reaching a certain size.

Parenchyma cells (read ig)

1) relatively undifferentiated at maturity. 2) Occurring mainly in the dermal and ground tissues 3) they have large central vacuoles and thin, flexible primary cell walls but lack secondary walls 4) They are metabolically active 5) they synthesize and store many organic products. 6) Photosynthesis, for example, occurs primarily in leaf parenchyma cells, while starch is stored in parenchyma cells of tubers. 7) Some parenchyma cells can also differentiate into other cell types during wound repair pic: in a privet (Ligustrum) leaf (LM)

1) which organs form a _____ system and a _____ system? 2) define the second system 3) ______ plants rely on which systems for survival? 4) describe first system 5) conversely to the _____ system, the ____ system ____ SEE PIC FOR BOTH SYSTEMS

1) roots, stems, and leaves form a root system and a shoot system 2) shoot system - consists of stems and leaves. 3) vascular plants rely on both systems for survival. 4) Roots are almost never photosynthetic; they starve unless photosynthates, the sugars and other carbohydrates produced during photosynthesis, are imported from the shoot system. 5) Conversely to the root system, the shoot system depends on the water and minerals that roots absorb from the soil. DESCRIPTION OF PIC: The plant body is divided into a root system and a shoot system, connected by vascular tissue (purple strands in this diagram) that is continuous throughout the plant. The plant shown is an idealized eudicot.

Pneumatophores (see pic) (read bc have a chart) 1. also known as ____ 2. these roots are produced by ____ like _____ that inhabit _____ 3. something abt them

1. also known as air roots 2. these roots are produced by trees like mangroves, that inhabit tidal swamps summary: they project above the surface to get oxygen By projecting above the water's surface at low tide, they enable the root system to obtain oxygen, which is lacking in the thick, waterlogged mud

The major types of plant cells are (5) (use pnemonic if needed)

1. parenchyma 2. collenchyma 3. sclerenchyma 4. the water-conducting cells of the xylem 5. the sugar-conducting cells of the phloem. (REMEMBER PCS - PARENT --> COLLEN --> SCLEREN + OTHER 2)

Almost all leaves are specialized for photosynthesis. However, some species have leaves with adaptations that enable them to perform additional functions, such as support, protection, storage, or reproduction. name these 4 types of leaves the book gives us (do say this one)

1. tendrils 2. spines 3. storage leaves 4. reproductive leaves

plants respond to challenges and opportunities in their local environment by _______. animals typically respond by ______ read the rest

All adult lions, for example, have four legs and are roughly the same size, but oak trees vary in the number and arrangement of branches. This is because plants respond to challenges and opportunities in their local environment by altering their growth. In contrast, animals typically respond by movement. Illuminating a plant from the side, for example, creates asymmetries in its basic body plan. Branches grow more quickly from the illuminated side of a shoot than from the shaded side, an architectural change that benefits photosynthesis. Changes in growth and development are critical in facilitating the plant's acquisition of resources from the local environment. Vegetative growth—the production of roots, stems, and leaves—is one stage in a plant's life. Most plants also undergo growth relating to sexual reproduction. In angiosperms, reproductive growth is associated with producing flowers

(see pic)

As secondary growth continues, layers of secondary xylem (wood) accumulate, consisting mainly of tracheids, vessel elements, and fibers (see Figure 28.9). Tracheids are the only kind of water-conducting cell found in the xylem tissue of most gymnosperms, whereas both tracheids and vessel elements are found in most angiosperms. The walls of secondary xylem cells are heavily lignified and account for the hardness and strength of wood. In temperate regions, wood that develops early in the spring, known as early (or spring) wood, usually has secondary xylem cells with large diameters and thin cell walls (see Figure 28.19b). This structure maximizes delivery of water to new leaves. Wood produced later in the growing season is called late (or summer) wood. It has thick-walled cells that do not transport as much water but provide more support. Because there is a marked contrast between the large cells of the new early wood and the smaller cells of the late wood of the previous growing season, a year's growth appears as a distinct growth ring in the cross sections of most tree trunks and roots. Therefore, researchers can estimate a tree's age by counting its growth rings. Dendrochronology (from the Greek dendron, trees, and chronos, time) is the science of analyzing tree growth ring patterns. Growth rings can vary in thickness, depending on seasonal growth. Trees grow well in wet and warm years but may grow hardly at all in cold or dry years. Since a thick ring indicates a warm year and a thin ring indicates a cold or dry one, scientists can use ring patterns to study climate changes. As a tree or woody shrub ages, 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. Sapwood allows a large tree to survive even if the center of its trunk is hollow. Because each new layer of secondary xylem has a larger circumference, secondary growth enables the xylem to transport more sap each year, supplying an increasing number of leaves. Heartwood is generally darker than sapwood because of resins and other compounds that permeate the cell cavities and help protect the core of the tree from fungi and wood-boring insects. Only the youngest secondary phloem, closest to the vascular cambium, functions in sugar transport. As a stem or root increases in circumference, the older secondary phloem is sloughed off, which is one reason secondary phloem does not accumulate as extensively as secondary xylem.

storage leaves (read for now bc have chart)

Bulbs, such as this cut onion, have a short underground stem and modified leaves that store food.

The Cork Cambium and the Production of Periderm

During the early stages of secondary growth, the epidermis is pushed outward, causing it to split, dry, and fall off the stem or root. It is replaced by tissues produced by the first cork cambium, a cylinder of dividing cells that arises in the outer cortex of stems and in the outer layer of the pericycle in roots. The cork cambium gives rise to cork cells that accumulate to the exterior of the cork cambium. As cork cells mature, they deposit a waxy, hydrophobic material called suberin in their walls and then die. Because cork cells have suberin and are usually compacted together, most of the periderm is impermeable to water and gases, unlike the epidermis. Cork thus functions as a barrier that helps protect the stem or root from water loss, physical damage, and pathogens. "Cork" is commonly and incorrectly referred to as "bark." In plant biology, bark includes all tissues external to the vascular cambium. Its main components are the secondary phloem (produced by the vascular cambium) and, external to that, the most recent periderm and all the older layers of periderm

read + see pic

Gene Expression and Control of Cell Differentiation Derivative cells can diverge in structure and function even though they share a common genome. Such cell differentiation depends, to a large degree, on the control of gene expression—the regulation of transcription and translation, resulting in the production of specific proteins. Although cell differentiation depends on the control of gene expression, the fate of a plant cell is determined by its final position in the developing organ. Evidence suggests that the activation or inactivation of specific genes involved in cell differentiation depends largely on cell-to-cell communication. For example, two cell types arise in the root epidermis of the model plant Arabidopsis thaliana: root hair cells and hairless epidermal cells. Cell fate is associated with the position of the epidermal cells. The immature epidermal cells that are in contact with two underlying cells of the root cortex differentiate into root hair cells, whereas the immature epidermal cells in contact with only one cortical cell differentiate into mature hairless cells. Differential expression of a gene called GLABRA-2 (from the Latin glaber, bald) is required for the appropriate root hair distribution. Researchers have demonstrated this requirement by coupling the GLABRA-2 gene to a "reporter gene" that causes every cell expressing GLABRA-2 in the root to turn pale blue following a certain treatment. The GLABRA-2 gene is normally expressed only in epidermal cells that will not develop root hairs

lenticels

How can living cells in the interior tissues of woody organs absorb oxygen and respire if they are surrounded by a waxy periderm? Dotting the periderm are small, raised areas called lenticels, in which there is more space between cork cells, enabling living cells within a woody stem or root to exchange gases with the outside air. Lenticels often appear as horizontal slits pic: A summary of primary and secondary growth in a woody shoot

intercalary meristems

In some monocots, particularly grasses, meristematic activity occurs at the bases of stems and leaves. These areas, called intercalary meristems, allow damaged leaves to rapidly regrow, which accounts for the ability of lawns to grow following mowing. The ability of grasses to regrow leaves by intercalary meristems enables the plant to recover more effectively from damage incurred from grazing herbivores (or lawnmowers!).

see the pic

Many land plants display secondary growth, the growth in thickness produced by lateral meristems. The advent of secondary growth during plant evolution allowed the production of novel plant forms ranging from massive forest trees to woody vines. All gymnosperm species and many eudicot species undergo secondary growth, but it is rare in monocots. It occurs in the stems and roots of woody plants, but rarely and only to a limited extent in leaves. Secondary growth consists of the tissues produced by the vascular cambium and cork cambium. The vascular cambium adds secondary xylem (wood) and secondary phloem, thereby increasing vascular flow and support for the shoots. The cork cambium produces a tough, thick covering of waxy cells that protect the stem from water loss and from invasion by insects, bacteria, and fungi. In woody plants, primary growth and secondary growth occur simultaneously. As primary growth adds leaves and lengthens stems and roots in the younger regions of a plant, secondary growth increases the diameter of stems and roots in older regions where primary growth has ceased. The process is similar in shoots and roots. pic explanation: Primary and secondary growth of a woody stem

Primary growth does what?

Primary growth lengthens roots and shoots

The three basic plant organs are

Roots, Stems, and Leaves

read

Some plants have stems with alternative functions, such as food storage or asexual reproduction. Many of these modified stems, including rhizomes, bulbs, stolons, and tubers, are often mistaken for roots

apical dominance

The branching of shoots, which is also part of primary growth, arises from the activation of axillary buds, each of which has its own shoot apical meristem. Because of chemical communication by plant hormones, the closer an axillary bud is to an active apical bud, the more inhibited it is, a phenomenon called apical dominance. If an animal eats the end of the shoot or if shading results in the light being more intense on the side of the shoot, the chemical communication underlying apical dominance is disrupted. As a result, the axillary buds break dormancy and start to grow. Released from dormancy, an axillary bud eventually gives rise to a lateral shoot, complete with its own apical bud, leaves, and axillary buds. When gardeners prune shrubs and pinch back houseplants, they are reducing the number of apical buds a plant has, thereby allowing branches to elongate and giving the plants a fuller, bushier appearance.

read ig

The cells within meristems divide relatively frequently, generating additional cells. Some new cells remain in the meristem and produce more cells, while others differentiate and are incorporated into tissues and organs of the growing plant. Cells that remain as sources of new cells have traditionally been called initials but are increasingly being called stem cells to correspond to animal stem cells, which also perpetually divide and remain functionally unspecialized. The new cells displaced from the meristem, which are known as derivatives, divide until the cells they produce become specialized in mature tissues.

Tissue Organization of Stems (see pic) (currently not on list of stuff to print)

The epidermis covers stems as part of the continuous dermal tissue. Vascular tissue runs the length of a stem in vascular bundles. Unlike lateral roots, which arise from vascular tissue deep within a root and disrupt the vascular cylinder, cortex, and epidermis as they emerge, lateral shoots develop from axillary bud meristems on the stem's surface and disrupt no other tissues. Near the soil surface, in the transition zone between shoot and root, the bundled vascular arrangement of the stem converges with the solid vascular cylinder of the root. In most eudicot species, the vascular tissue of stems consists of vascular bundles arranged in a ring. The xylem in each vascular bundle is adjacent to the pith, and the phloem in each bundle is adjacent to the cortex. In most monocot stems, the vascular bundles are scattered throughout the ground tissue rather than forming a ring. In the stems of both monocots and eudicots, the ground tissue consists mostly of parenchyma cells. However, collenchyma cells just beneath the epidermis strengthen many stems during primary growth. Sclerenchyma cells, especially fiber cells, also provide support in those parts of the stems that are no longer elongating.

(see pic) 1) stomata - define 2) in addition to ____, stomata are _____ for _____ 3) guard cells - define

The epidermis of leaves is interrupted by pores called stomata (singular, stoma), which allow exchange of CO2 and O2 between the surrounding air and the photosynthetic cells inside the leaf. In addition to regulating CO2 uptake for photosynthesis, stomata are major avenues for the evaporative loss of water. The term stoma can refer to the stomatal pore or to the entire stomatal complex, consisting of a pore flanked by two specialized epidermal cells called guard cells, which regulate the opening and closing of the pore.

come back

The primary growth of a root produces its epidermis, ground tissue, and vascular tissue. Root hairs, although typically only living a few weeks, are one of the more prominent features of the root epidermis. Together, they can make up 70-90% of the total root surface area. A 4-month-old rye plant has an estimated 14 billion root hairs. Laid end-to-end, they would cover 10,000 km, one-quarter the length of the equator. The ground tissue of roots, consisting mostly of parenchyma cells, is found in the cortex, the region between the vascular cylinder and epidermis. In addition to storing carbohydrates, cortical cells transport water and salts from the root hairs to the center of the root. The cortex, because of its large intercellular spaces, also allows for the extracellular diffusion of water, minerals, and oxygen from the root hairs inward. The innermost layer of the cortex is called the endodermis, a cylinder one cell thick that forms the boundary with the vascular cylinder. The endodermis is a selective barrier that regulates passage of substances from the soil into the vascular cylinder. In angiosperm roots, the stele is a vascular cylinder, consisting of a solid core of xylem and phloem tissues. In most eudicot roots, the xylem has a starlike appearance in cross section, and the phloem occupies the indentations between the arms of the xylem "star". In many monocot roots, the vascular tissue consists of a central core of unspecialized parenchyma cells surrounded by a ring of alternating xylem and phloem tissues.

read (example of primary and secondary growth working together in a plant)

The relationship between primary and secondary growth is clearly seen in the winter twig of a deciduous tree. At the shoot tip is the dormant apical bud, enclosed by scales that protect its apical meristem. In spring, the bud sheds its scales and begins a new spurt of primary growth, producing a series of nodes and internodes. On each growth segment, the nodes are marked by scars that were left when leaves fell. Above each leaf scar is an axillary bud or a branch formed by an axillary bud. Farther down the twig are bud scars from the whorls of scales that enclosed the apical bud during the previous winter. During each growing season, primary growth extends the shoots, and secondary growth increases the diameter of the parts that formed in previous years.

The Vascular Cambium and Secondary Vascular Tissue (currently not on list of stuff to print)

The vascular cambium, a cylinder of meristematic cells only one cell thick, is wholly responsible for the production of secondary vascular tissue. In a typical woody stem, the vascular cambium is located outside the pith and primary xylem and to the inside of the primary phloem and the cortex. In a typical woody root, the vascular cambium forms exterior to the primary xylem and interior to the primary phloem and pericycle. In cross section, the vascular cambium appears as a ring of meristematic cells. As these cells divide, they increase the cambium's circumference and add secondary xylem to the inside and secondary phloem to the outside. Each ring is larger than the previous ring, increasing the diameter of roots and stems. Some of the initials produced by the vascular cambium 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, axially oriented 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 mostly parenchyma cells that connect the secondary xylem and phloem. These cells move water and nutrients between the secondary xylem and phloem, store carbohydrates and other reserves, and aid in wound repair.

bundle sheath

The vascular tissue of each leaf is continuous with the vascular tissue of the stem. Veins subdivide repeatedly and branch throughout the mesophyll. This network brings xylem and phloem into close contact with the photosynthetic tissue, which obtains water and minerals from the xylem and loads its sugars and other organic products into the phloem for transport to other parts of the plant. The vascular structure also functions as a framework that reinforces the leaf. Each vein is enclosed by a protective bundle sheath, a layer of cells that regulates the movement of substances between the vascular tissue and the mesophyll. Bundle-sheath cells are particularly prominent in leaves of plant species that carry out C4 photosynthesis

buttress roots (read bc have a chart)

because of moist conditions in the tropics, root systems of many of the tallest trees are surprisingly shallow. aerial roots that look like buttresses, such as seen in Gyranthera caribensis in Venezuela, give architectural support to the trunks of trees

The basic morphology of vascular plants reflects their evolutionary history as terrestrial organisms that inhabit and draw resources from two very different environments—

below the ground and above the ground.

Secondary growth does what?

increases the diameter of stems and roots in woody plants

storage roots (see pic) (read bc have a chart)

many plants, such as the common beet, store food and water in these type of roots.

"strangling" aerial roots (see pic) (read bc have a chart)

strangler fig seeds germinate in the crevices of tall trees. aerial roots grow to the ground, wrapping around the host tree and objects such as this Cambodian temple. Shoots grow upwards and shade out the host tree, killing it.

tendrils (read for now bc have chart)

tendrils are typically modified leaves, but some tendrils are modified stems, as in grapevines after it has "lassoed" a support, a tendril forms a coil that brings the plant closer to the support the tendrils by which this pea plant clings to as support are modified leaves

spines (read for now bc have chart)

the spines of cacti, such as this prickly pear, are actually leaves photosynthesis is carried out by the fleshy green stems