B Qzp
Figure 18.31 Common slime mold sporangia. A. Lamproderma, x 25. B. Lycogala, x 10. B. courtesy L. L. Steimley sporangia Fig. 18.31 , each containing thousands of minute, one-celled spores. The sporangia often are globe shaped, but in some species, they develop as long or wide stationary bodies that may resemble a jumbled network of tubes, or they may resemble erect hairs or end up as a shapeless blob. The sporangia may or may not have slender stalks, depending on the species. Others exhibit...
Learning Online
Visit our web page at www.mhhe.com botany for interesting case studies, practice quizzes, current articles, and animations within the Online Learning Center to help you understand the material in this chapter. You'll also find active links to these topics Flowers and Fruits Fruits and Seeds Coevolution Ornamental Plants Economic and Ecological Importance of Gymnosperms Economic and Ecological Importance of Angiosperms Barton, L. V. 1992. Seed preservation and longevity. New York State Mutual...
Common Vegetables And Their Nutritional Values
Note The nutritional values NV given are per 100 grams 3.5 ounces , edible portion, as determined by the United States Department of Agriculture. NV spears cooked in water 20 calories protein, 2.2 gm fats, 0.2 gm vit. A, 900 I.U. vit. B1, 0.16 mg vit. B2, 0.18 mg niacin, 1.5 mg vit. C, 26 mg fiber, 0.7gm calcium, 21 mg phosphorus, 50 mg iron, 0.6 mg sodium, 1.0 mg potassium, 208 mg Asparagus can be started from seed, but time until the first harvest can be reduced by a year or two if planting...
Phytochromes And Cryptochromes
Experiments that were conducted after Garner and Allard's discoveries prompted researchers to look for a pigment that controlled photoperiodism. They had already found that the initiation of flowering could be inhibited if plants are exposed to even a brief period of red light during the night, which suggested the existence of a light-sensitive pigment. Within a few years, such a pigment was discovered. It was not visible, however, and a special pigment-analysis instrument had to be constructed...
Use of Limonoid Sprays
Limonoids are bitter substances found in the rinds, seeds, and juice of citrus fruits especially grapefruit . If the rinds and seeds of two or three fruits are ground up, soaked overnight in a pint of water, and the solid material is strained out, the liquid may then be sprayed on plants. The bitter principle apparently stops or reduces the feeding of larvae on the foliage. In experiments, limonoid sprays have proved effective against corn earworm, fall armyworm, tobacco budworm, and pink...
Human Relevance Of Gymnosperms
What do we plant when we plant the tree We plant the ship, which will cross the sea. We plant the mast to carry the sails We plant the planks to withstand the gales The keel, the keelson, the beam, the knee We plant the ship when we plant the tree. What do we plant when we plant the tree We plant the houses for you and me. We plant the rafters, the shingles, the floors, We plant the studding, the lath, the doors, The beams, the siding, all parts that be We plant the house when we plant the...
Leafy Liverworts
Leafy liverworts Fig. 20.8 are often abundant in tropical forests and in fog belts. They always have two rows of partially overlapping leaves whose cells contain distinctive oil bodies. The leaves have no midribs, and unlike the leaves of mosses, they often have folds and lobes. In the Figure 20.8 Frullania, a leafy liverwort. Figure 20.8 Frullania, a leafy liverwort. tropics, the lobes form little water pockets in which tiny animals are nearly always present. It has been suggested these water...
Structure Form and Classes
Many different organisms have been called mosses. In fact, almost any greenish covering or growth on tree trunks and forest floors has probably been called moss at one time or another. Examples include lichens e.g., reindeer moss , red algae e.g., Irish moss , flowering plants e.g., Spanish moss , and club mosses. Club mosses look somewhat like large true mosses but are vascular plants with xylem and phloem. About 15,000 species of mosses are currently known. These are divided into three...
Cyanobacteria Chloroplasts and Oxygen
Cyanobacteria that occur symbiotically in other organisms commonly lack a cell wall and appear to function essentially as chloroplasts. When a eukaryotic cell containing chloro-plasts divides, the chloroplasts divide at the same time. The cells of cyanobacteria occurring within the cells of other organisms divide in similar fashion, leading to speculation that chloroplasts originated as cyanobacteria or prochlorobacteria discussed after the cyanobacteria , living within other cells. Fossils of...
Review Questions Bky
1. Using S, P, and B as abbreviations for sugar, phosphate, and base, respectively, draw a DNA double helix in the arrangement you would see if you untwisted the helix so you were looking at a ladder structure. 2. If a DNA molecule had a string of cytosine-thymine base pairs, how would it differ in width from a normal molecule 4. Using the genetic code, determine the amino acid sequence produced by the following gene DNA sequence. Remember that during transcription, RNA forms complementary base...
Phylum Magnoliophyta The Flowering Plants
The plants of members of this phylum vary greatly in size, shape, texture, form, and longevity. The phylum includes, for example, the tiny duckweeds that may be less than 1 millimeter long, all the grasses and palms, many aquatic and epiphytic plants, and most shrubs and trees, including the huge Eucalyptus regnans trees of Tasmania that rival the redwoods in total volume. A few flowering plants are parasitic. Dodders, for example, occasionally cause serious crop losses as they twine about...
Atp
Figure 10.5 A simplified summary of photosynthetic reactions. dioxide from the air and RuBP are combined and then converted during the light-independent reactions Fig. 10.5 . Some grasses and also many plants of arid regions fix carbon differently. They produce a 4-carbon acid as the first product, followed by the Calvin cycle. This 4-carbon pathway is discussed, along with another variation found mostly in desert plants, in the next section, A Closer Look at Photosynthesis. A great deal has...
Form Metabolism and Reproduction
The cells of cyanobacteria often occur in chains or in hairlike filaments, which are sometimes branched. Several species occur in irregular, spherical, or platelike colonies, the individual cells being held together by the gelatinous sheaths they secrete Fig. 17.11 . The sheaths may be colorless or Figure 17.11 Representative cyanobacteria, x2500. Figure 17.11 Representative cyanobacteria, x2500. pigmented with various shades of yellow, red, brown, green, blue, violet, or blue-black, which...
Apical Dominance
For centuries, gardeners and nursery workers have often deliberately removed terminal buds of plants to promote bushier growth, knowing that the buds are involved in apical dominance. Apical dominance is the suppression of the growth of the lateral or axillary buds, each of which can form a branch with its own terminal bud. Apical dominance is believed to be brought about by an auxinlike inhibitor in a terminal bud. It is strong in trees with conical shapes and little branching toward the top...
Alternation Of Generations
As we have noted, meiosis occurs at some point in the life cycle of all organisms that reproduce sexually. The chromosomes that result from the process constitute a complete set in each cell, since one member of every original pair ends up in each cell. The original chromosomal complement, consisting of two complete sets of chromosomes, is restored when gametes unite, forming a zygote. Any cell having one set of chromosomes is said to be haploid, and any cell with two sets of chromosomes is...
Cellular Components
Most chemical reactions that take place in cells occur in the protoplasm, as part of a dynamic series of events that make the plant a living entity. Each organelle within the protoplast has a primary function, and the flow of metabolites products of chemical synthesis or breakdown from one organelle to another is necessary for a balance of events that take place. Envision a journey through the plant cell as an exciting voyage in which information is stored primarily in the nucleus, processed in...
Phylum Polypodiophyta The Ferns
When I was a small child, my family had a large potted fern on each side of a fireplace. I became quite attached to the plants, and believing I was removing a disease, I carefully scraped off the little brownish patches that appeared from time to time on the lower surfaces of the leaves. It wasn't until I got to college I learned that instead of controlling a disease, I had inadvertently been frustrating the sex life of my favorite plants If we could take a worldwide opinion poll about...
Secondary Succession
Secondary succession, which occurs more rapidly than primary succession, may take place if soil is already present and there are surviving species in the vicinity. In fact, survivors strongly condition subsequent succession. Many secondary successions follow human disturbances e.g., land that was cleared when timber was harvested or land converted to farmland . Other secondary successions follow fires. Grasses and other herbaceous plants become established on burned or logged land. These...
Info Obp
Lemongrass oil, source of Lentil Lettuce Lichen symbiotic association of an alga and a fungus Lichen, foliose Fig. 19.34 Lichen, foliose Fig. 19.355 Lichen, fruticose North African sheep Lichen, litmus Lichen, natural dye Lichen, perfume stabilizer Lichen, reindeer reindeer moss member of Phylum Ascomycota, Kingdom Fungi1 Physcia sp. Parmelia sp. Parmelia spp., Usnea spp., and others Evernia spp. Cladonia spp., Cetraria islandica Liverwort, leafy Fig. 20.8 Liverworts, leafy Lizard Lobeline...
Vwv
Figure 1Q.7 Life cycle of a sac fungus. When hyphae of two different strains of a sac fungus become closely associated, male antheridia may be formed on one and female ascogonia on the other. Male nuclei migrate into an ascogonium and pair but do not fuse with the female nuclei present. Then new hyphae ascogenous hyphae , whose cells each contain a pair of nuclei, grow from the ascogonium. In a process involving fusion of the pairs of nuclei followed by meiosis , fingerlike asci, each...
Grassland
Naturally occurring grasslands are found toward the interiors of continental masses Fig. 26.5 . They tend to intergrade with forests, woodlands, or deserts at their margins, depending on precipitation patterns and amounts. A grassland may receive as little as 25 centimeters 10 inches of rainfall or as much as 100 centimeters 39 inches annually. Temperatures can range from 45 C 113 F in midsummer to -45 C -50 F in midwinter. North American grasslands known as prairies grew on fertile soils and...
Mycorrhizae
More than three-quarters of all seed plant species have various fungi associated with their roots. The association is mutualistic that is, both the fungus and the root benefit from it but are dependent upon the association for normal development. Mutualism is a form of symbiosis see page 300. The fungus is able to absorb and concentrate phosphorus much better than it can be absorbed by the root hairs. In fact, if mycorrhizal fungi have been killed by fumigation or are otherwise absent, many...
Replication Duplication of Information
DNA must duplicate itself precisely in order to pass along its information from generation to generation. DNA replication occurs during the S phase of the cell cycle see Chapter 3 . Differences between the DNA of one organism and that of another lie in the sequence of the four possible types of ladder rungs and their total number. If the four nucleotides are synthesized in living cells, then what tells the cell exactly how to put them together to form DNA molecules with proper nucleotide...
Info Xmq
Since tendrils and spines can be either modified leaves or modified stems, how might you determine the origin of a given specimen Visit our web page at www.mhhe.com botany for interesting case studies, practice quizzes, current articles, and animations within the Online Learning Center to help you understand the material in this chapter. You'll also find active links to these topics Characteristics of Plants Architectural Pattern of Plants Leaves and the Movement of Water Economic Uses of...
A 1
Figure 3.4 Anatomy of a young leaf cell. A. Generalized drawing. B. Transmission electron micrograph of a small leaf cell with cross sections of two chloroplasts visible, x20,000. A. From Sylvia S. Mader, Biology, 7th edition. 2001 The McGraw-Hill Companies. All rights reserved. B. Newcomb Wergin BPS. Figure 3.4 Anatomy of a young leaf cell. A. Generalized drawing. B. Transmission electron micrograph of a small leaf cell with cross sections of two chloroplasts visible, x20,000. A. From Sylvia...
Prophase I
The main features of prophase I are as follows 1 The chromosomes coil, becoming shorter and thicker as they do so, and their two-stranded nature becomes apparent the chromosomes also become aligned in pairs. 2 The nuclear envelope and the nucleolus disassociate. 3 Parts of each closely associated pair of chromosomes may be exchanged with each other, and then the chromosomes separate Fig. 12.2 see also Fig. 12.4A, B . As with prophase of mitosis, the beginning of this phase is marked by the...
Asexual Plant Propagation
In recent years, we have heard amazing stories about scientists who have cloned animals such as sheep and cows. Botanists are far ahead in that arena. They have been cloning plants for centuries Many plants are easy to propagate asexually, using vegetative parts rather than seeds. For example, crown division is a simple technique in which a plant is separated into several pieces, each of which contains a crown and a portion of the root system Fig. 14.17 . This is commonly used for many...
Review Questions
1. Distinguish between a tiny root and a root hair. What is the function of a root hair 2. What is the difference between parasitic roots and mycorrhizae 3. If you were shown cross sections of a young root and a young stem from the same dicot plant, how could you tell them apart 4. What is the function of the root cap, and from which meristem does it originate 5. How do endodermal cells differ from other types of cells 6. Where do branch roots originate 7. List some spices and drugs obtained...
The Rose Family Rosaceae
The Rose Family includes more than 3,000 species of trees, shrubs, and herbs distributed throughout much of the world. The flowers characteristically have the basal parts fused into a cup, with petals, sepals, and numerous stamens attached to the cup's rim Fig. 24.8 . The family is divided into subfamilies on the basis of flower structure and fruits. The flowers of one group have inferior ovaries and produce pomes for fruits. Flowers of other groups have ovaries that are superior or partly...
Monocots
1. Seed with two cotyledons seed leaves 2. Flower parts mostly in fours or fives or multiples of four or five 3. Leaf with a distinct network of primary veins 4. Vascular cambium, and frequently cork cambium, present 5. Vascular bundles of stem in a ring 6. Pollen grains mostly with three apertures thin areas in the wall see Figures 23.6 and 23.7 1. Seed with one cotyledon seed leaf 2. Flower parts in threes or multiples of three 3. Leaf with more or less parallel primary veins 4. Vascular...
Phylum Ascomycota The Ascomycetes Sac Fungi
Should you happen one summer to be touring or visiting in the south of France, you might be startled to see men and women with coils of rope slung around their shoulders pushing pigs in wheelbarrows. They happen to be wheeling the pigs into the woods to help them find truffles. Truffles are gourmet mushrooms, which grow mostly between 2.5 and 15 centimeters 1 and 6 inches beneath the surface of the ground, usually near oak trees. They are somewhat prunelike in appearance and may be more than 10...
Photoperiodism
In the early 1900s, two American plant physiologists, Wightman W. Garner and Henry A. Allard, became curious about a tobacco plant growing at a research center in Beltsville, Maryland. The plant grew 3 to 4 meters 10 to 13 feet tall during the summer but failed to flower in August when the normal-sized tobacco plants flowered. They brought the giant plant into a greenhouse for protection during the winter and were surprised when it flowered in December. Garner and Allard decided to conduct some...
Wood And Its Uses
The use of wood by humans for fuel, clubs, and other purposes dates back into antiquity, and present uses are so numerous that it would be impossible to list in a work of this type more than the most important ones. Before discussing the economic importance of wood, let's take a brief look at its properties. In a living tree, up to 50 of the weight of the wood comes from the water content. Before the wood can be used, seasoning reduces the moisture content to 10 or less, either by air-drying it...
Root Nodules
Although almost 80 of our atmosphere consists of nitrogen gas, plants cannot convert the nitrogen gas to usable forms. A few species of bacteria, however, produce enzymes with which they can convert nitrogen into nitrates and other nitrogenous substances readily absorbed by roots. Members of the Legume Family Fabaceae , which includes peas and beans, and a few other plants such as alders, form associations with certain soil bacteria that result in the production of numerous small swellings...
A Key To Major Groups Of Organisms Exclusive Of Kingdom Animalia
Unicellular, prokaryotic organisms with cell walls 2. Cell walls with muramic acid Bacteria 2. Cell walls without muramic Archaea Unicellular, colonial, filamentous, or multicellular eukaryotic organisms, with or without cell walls 3. Organisms whose female and usually male reproductive structures consist of a single cell or with sterile cells surrounding the one-celled reproductive structures zygotes not developing into embryos 4. Organisms unicellular, filamentous, or plasmodial i.e., with...
Higher Plant Cells Versus Animal Cells
All animals have either internal or external skeletons or skeleton-like systems to support their tissues. Animal cells do not have cell walls instead, the plasma membrane, called the cell membrane by most zoologists animal scientists , forms the outer boundary of animal cells. Higher plant cells have walls that are thickened and rigid to varying degrees, with a framework of cellulose fibrils. Higher plant cells also have plasmodesmata connecting the protoplasts with each other through...
The Nitrogen Cycle
Most of the nitrogen in living organisms is in the protoplasmic proteins of their cells, with much of protoplasm being water. Nitrogen, the most abundant element in our atmosphere, constitutes about 18 of the protein. There are nearly 69,000 metric tons of nitrogen in the air over each hectare of land 35,000 tons per acre , but the total amount of nitrogen in the soil seldom exceeds 3.9 metric tons per hectare 2 tons per acre and is usually considerably less. This discrepancy results from the...
C 1
Figure 8.Q Representative drupes. A. Peaches. B. Almonds. C. Olives. contains a watery endosperm see Chapter 23 commonly but incorrectly referred to as milk. It is surrounded by the thick, hard endocarp typical of drupes. Other examples of drupes include the stone fruits e.g., apricots, cherries, peaches, plums, olives, and almonds . In almonds, the husk, which dries somewhat and splits at maturity, is removed before marketing, and it is the endocarp that we crack to obtain the seed. Berry...
Info Mym
Figure 11.12 Tobacco seedlings grown in the dark. The source of gravity is at the bottom of the pictures. Normal wild type seedlings in the top row are all more or less perpendicular to the gravity. The seedlings in the bottom row are mutants with much less starch than normal plants. The mutant seedlings are disoriented, suggesting that any amyloplasts of typical mass function as statoliths in the perception of gravity. However, mutants of other species lacking amyloplasts do respond to...
Oh
Figure 2.10 Structures of glucose top and fructose bottom molecules. The numbers of atoms and locations of bonds are easy to see in the upper linear diagrams, but when these molecules are in solution, they are in the form of rings, as shown in the lower diagrams. a starch molecule to become available as an energy source in cells, it has to be hydrolyzed that is, it has to be broken up into individual glucose molecules through the restoration of a water molecule for each unit. Throughout the...
The Buttercup Family Ranunculaceae
Nearly all the 1,500 members of the Buttercup Family are herbaceous. The flowers, whose petals often vary in number, have numerous stamens and several to many pistils with superior ovaries Fig. 24.2 . Most have dissected leaves with no stipules and with petioles that are slightly expanded at the base. Well-known representatives include ornamental plants such as buttercup, columbine, larkspur, anemone, monkshood, and Clematis Fig. 24.3 . Most members of the Buttercup Family are concentrated in...
P 1
palisade mesophyll pal-uh-sayd' mez'uh-fil mesophyll having one or more relatively uniform rows of tightly packed, elongate, columnar parenchyma chlorenchyma cells beneath the upper epidermis of a leaf p. 115 palmately compound palmately veined pahl'mayt-lee kom'pownd pahl'mayt-lee vaynd having leaflets or principal veins radiating out from a common point p. 110, 112 1. Ribosomes, which are considered organelles, are an exception in that they are not bounded by a membrane. papilla pl. papillae...
Tissue Patterns In Stems
Primary xylem, primary phloem, and the pith, if present, make up a central cylinder called the stele in most younger and a few older stems and roots. The simplest form of stele, called a protostele, consists of a solid core of conducting tissues in which the phloem usually surrounds the xylem. Protosteles were common in primitive seed plants that are now extinct and are also found in whisk ferns, club mosses see Chapter 21 , and other relatives of ferns. Siphonosteles, which are tubular with...
Other Green Alg
As indicated earlier, the green algae constitute a very diverse group, with an extraordinary variety of forms and chloro-plast shapes. Obviously, each species has to reproduce in order to perpetuate itself. Most undergo both sexual and asexual reproduction, but a few do not. For example, the globally distributed algae that make parts of some tree trunks appear as though they had received a light brushing or spattering of green paint usually are unicellular or colonial forms that reproduce only...
Cell Structure And Communication
Plant cells typically have a cell wall surrounding the protoplasm, which consists of all the living components of a cell. These living components are bounded by a membrane called the plasma membrane. All cellular components between the plasma membrane and a relatively large body called the nucleus are known as cytoplasm. Within the cytoplasm is a souplike fluid called cytosol, in which various bodies called organelles are dispersed. Organelles are persistent structures of various shapes and...
Gymnosperm Leaf Secretory Cell
Pacific Islands, plants originating in, 463, 464 Paleobotany, 8 Palisade mesophyll, 115 Palm, 66, 99, 132, 146 Palmately compound leaves, 110 Palmately veined leaves, 112, 113 Pantothenic acid, 189-90 Papaveraceae, 467-68 Papaverine, 468 Papavoviruses, 317 Papillae, 331 Parallel veins in leaves, 112, 113, 114 Paramylon, 341, 342 Paraphyses, 389-90 Para rubber tree, 97, 472-73 Parasitism bacterial, 304 fungi, 357, 373 lichens, 375 roots, 75, 76 Parenchyma, 55-56 cells, 55, 56 tissue generation P...
Discussion Questions
1. Most plant meristems are located at the tips of shoots and roots and in cylindrical layers within stems and roots. What could happen if they were present in leaves 2. The cambium produces xylem toward the center of a tree and phloem toward the outside. Do you think it would make any difference if the positions of the xylem and phloem were reversed Why Visit our web page at www.mhhe.com botany for interesting case studies, practice quizes, current articles, and animations within the Online...
Dormancy And Quiescence
As the days grow shorter in the fall, cells produce sugars and amino acids that lower the point at which cold damage will occur. Protective bud scales develop on buds, and leaves become senescent. As cell metabolism slows down, many plants that are now prepared for winter become dormant. Dormancy may be defined as a period of growth inactivity in seeds, buds, bulbs, and other plant organs even when environmental requirements of temperature, water, or day length are met. Quiescence is a state in...
Distinctions Between Kingdoms Protista And Fungi
In the past, the true fungi, slime molds, and bacteria were all placed in a single division of the Plant Kingdom. Once the fundamental differences between prokaryotic and eukaryotic cells became known, however, the bacteria were placed in the prokaryotic Kingdom Monera. Then it became increasingly apparent that the metabolism, reproduction, and general lines Figure 1Q.1B Colonies of fungi growing on the surface of stale brewed coffee. Figure 1Q.1B Colonies of fungi growing on the surface of...