《植物生物学实验》课程教学大纲
课程代码：
课程负责人：汪小凡，黄双全
课程中文名称：植物生物学实验
课程英文名称：Plant Biology Experiments
课程类别：必修
课程学分数：1.5
课程学时数：54
授课对象：生命科学学院，生物科学专业、生物技术专业
本课程的前导课程：（宋体五号）
一、 教学目的
1. Provide students with comprehensive exposure to the subject of botany and learn about the structure, life history, and evolution of plants
2. Help students to review some botanical principles they have learned from Plant Biology.
3. Guide students from observations to conclusions and to make the transition to botanical principles.
4. Develop students’ ability to search for and notice things that they are interested in or others may overlook.
5. Make the students to understand that simple and straightforward experiments can be the most effective if one interprets the work in depth.
6. Develop students’ ability for “Team Work”.
二、 课程内容与学时分配
Week
| Topic
| Duration (hour)
| Instructor
|
1
| Plant cell
| 3
| Wang X-F
|
2
| Photosynthesis
| 3
| Huang S-Q
|
3
| Mitosis and meiosis
| 3
| Wang X-F
|
4
| Plant tissues (1)
| 3
| Huang S-Q
|
5
| Plant tissues (2)
| 3
| Wang X-F
|
6
| Roots
| 3
| Huang S-Q
|
7
| Stems
| 3
| Wang X-F
|
8
| Leaves
| 3
| Huang S-Q
|
9
| Embryo and seedling development
| 3
| Huang S-Q
|
10
| Algae and fungi
| 3
| Wang X-F
|
11
| Bryophytes
| 3
| Huang S-Q
|
12
| Seedless vascular plants
| 3
| Huang S-Q
|
13
| Gymnosperms
| 3
| Wang X-F
|
14
| Angiosperms (1)
| 3
| Wang X-F
|
15
| Angiosperms (2)
| 3
| Huang S-Q
|
16
| Evolution and morphological diversity
| 3
| Wang X-F
|
17
| Community Ecology
| 3
| Wang X-F
|
18
| Final exam
| 3
| Wang X-F
Huang S-Q
|
Exercise 1 Plant cell
▲Objectives
1. Determine whether a cell is prokaryotic or eukaryotic on the basis of its structure.
2. Prepare a wet mount to view cells with a compound microscope.
3. Describe the structure and function of cellular organelles visible with a light microscope.
4. Stain and examine major cellular organelles.
▲Essential Background
Cells are the basic unit of living organisms because they perform all processes we collectively call “life”. All organisms are made of cells. Although most individual cells are visible only with the aid of a microscope, some may be a meter long (e.g., nerve cells) or as large as a small orange (e.g., the yolk of an ostrich egg). Despite these differences, all cells are designed similarly and share a variety of features. Before this lab, review the general features of cellular structure and function, and the functions of the major organelles in the textbook.
▲Main Topics
1. Examine cyanobacteria.
2. Examine bacteria inyogutt.
3. Examine Elodea cells.
4. Prepare and examine stained onion cells.
5. Prepare and examine stained mitochondria in onion cells.
6. Examine amynoplast and chromoplast.
7. Examine electron micrographs of cellular ultrastructure.
Exercise 2 Photosynthesis
▲Objectives
1. Understand the summary equation for photosynthesis.
2. Understand the light and biochemical reactions involves in photosynthesis.
3. Separate the photosynthetic pigments and measure photosynthesis.
▲Essential Background
Photosynthesis is unquestionably the most important series of chemical reactions that occurs on earth. Indeed, most life depends on photosynthesis for food and oxygen. Photosynthesis is a complex chemical process that converts radiant energy (light) to chemical energy (sugars).
Thus, photosynthesis is the light-dependent and chlorophyll-dependent conversion of carbon dioxide and water to sugars, water, and oxygen. Oxygen is released to the environment, and the sugars are used either to fuel growth of are stored as starch, a polysaccharide. Notice that water is present on both sides of the summary equation; this water, however, is not the same water molecules. The “reactant” water molecules are split to release electrons during the photochemical reactions. The “product” water molecules are assembled from hydrogen and oxygen released during the photochemical and biochemical reactions.
▲Main Topics
1. Examine parenchyma cells in Helianthus stem.
2. Examine aerenchyma cells in Juncus stem.
3. Make a hand section of a petiole of Apium.
4. Examine collenchyma in Helianthus stem.
5. Examine stone cells in Pyrus and Hoya.
6. Examine astrosclereids in Camellia.
7. Examine fibers in stems of Vitis.
8. Examine an intract epidermis from Kalanchoe.
9. Examine trichomes in Urtica.
10. Examine xylem and phloem in stems of cucumber, oak, and pine.
Exercise 3 Mitosis and meiosis
▲Objectives
1. Describe events associated with the cell cycle.
2. Describe events associated with mitosis.
3. Distinguish the phases of mitosis on prepared slides of mitotic cells.
4. Stain and examine chromosomes in mitotic cells.
5. Describe the events of meiosis.
6. Describe similarities and differences between meiosis and mitosis.
7. Understand the most significant events of meiosis.
8. Discuss the relevance of meiosis to sexual reproduction.
▲Essential Background
Cells grow, have specialized functions, and replicate during their life. All of these activities are part of a repeating set of events called the cell cycle. A major feature of the cell cycle is cellular replication, and a major feature of cellular replication is mitosis. Mitosis is replication of the nucleus in eukaryotic cells. Eukaryotic cells, found in plants, animals, fungi and protests, have a membrane-bound nucleus, so when a cell replicates the nucleus also replicates. In contrast, prokaryotic cells lack nuclei and do not undergo mitosis. Motosis is usually associated with cytokinesis, the division of the cell and cytoplasm into two halves, each containing a new nucleus. In certain tissues of plants, cytokinesis is delayed or does not occur at all, and the cells are multinucleate.
▲Main Topics
1. The cell cycle.
2. Mitosis.
3. Cytokinesis.
4. Time lapsed during stages of cell replication.
5. Preparing and staining chromosomes.
6. Stages and events of meiosis.
7. Mitosis vs. meiosis.
Exercise 4 Plant tissues
▲Objectives
9. Describe the characteristics of parenchyma, collenchyma, sclerenchyma, epidermis, and vascular tissue.
10. Understand the structure variations exhibited by the cell types that form different tissues.
▲Essential Background
The structure of plants varies greatly; compare, for example, an ok tree with a cactus. However, structural differences are typically quantitative rather than qualitative. That is, leaves, roots, and stems are made of the same types of cells and tissues; the major structural differences of organs such as stems and leaves result from these tissues merely being arranged differently and occurring in different proportions. All of these differences among plants represent different ways of achieving the same goals, namely survival and reproduction.
▲Main Topics
8. Examine parenchyma cells in Helianthus stem.
9. Examine aerenchyma cells in Juncus stem.
10. Make a hand section of a petiole of Apium.
11. Examine collenchyma in Helianthus stem.
12. Examine stone cells in Pyrus and Hoya.
13. Examine astrosclereids in Camellia.
14. Examine fibers in stems of Vitis.
11. Examine an intract epidermis from Kalanchoe.
12. Examine trichomes in Urtica.
13. Examine xylem and phloem in stems of cucumber, oak, and pine.
Exercise 5 Roots
▲Objectives
1. Describe the functions of roots.
2. Describe the structural and functional differences between tap and fibrous root systems.
3. Describe the structure of roots.
4. Describe the origin of secondary and adventitious root.
▲Essential Background
During seed germination a radicle or young primary root emerges from the seed and grows down. The primary root soon produces numerous secondary roots and forms a root system, whose major functions include absorbing water and minerals, anchoring the plant, and storing food. Root systems have different shapes. For example, a tap root system has a large main root and smaller secondary roots branching from it (as in the carrot). In a fibrous root system, the primary and secondary roots are similar in size (as in many grasses).
▲Main Topics
1. Paper chromatography of photosynthetic pigments.
2. Absorption of light by chlorophyll.
3. Electron transport in chloroplasts.
4. Uptake of carbon dioxide during photosynthesis.
5. Use of light and chlorophyll to produce starch during photosynthesis .
Exercise 6 Stems
▲Objectives
1. Understand the structure and function of stems.
2. Describe the external features of woody stems.
3. Describe the primary structure of monocot stems.
4. Describe the secondary growth of stems.
▲Essential Background
Stems are often the most conspicuous organs of plants, and function for support and transport of water and solutes. Some stems (e.g., those of cacti) also photosynthesize and store food.
▲Main Topics
1. Examine the shoot tip of Coleus.
2. Examine the external features of a woody stem.
3. Study the primary tissues of stems of monocots and dicots.
4. Examine the secondary tissues of woody stems, including bark and lenticels.
Exercise 7 Leaves
▲Objectives
1. Describe the different types of venation of leaves.
2. Describe the internal anatomy of leaves of dicots and monocots.
3. Understand the significance of anatomical differences in leaf anatomy.
4. Describe the adaptations of leaves of mesophytes, xerophytes, and hydrophytes.
5. Understand the structural basis for leaf abscission.
▲Essential Background
With few exceptions, photosynthesis in most plants occurs in leaves. Leaves typically consist of a blade and a petiole. The petiole attaches the leaf blade to the stem. Simple leaves have one blade connected to the petiole, while compound leaves have several leaflets sharing one petiole. Palmate leaflets of a compound leaf arise from a central area, as your fingers arise from your palm. Pinnate leaflets arise in rows along a central midline.
Leaves are also classified according to their venation, or arrangement of veins. Parallel veins extend the entire length of the leaf with little or no cross-linking. Pinnately veined leaves have one major vein (midrib) from which other veins branch. Palmately veined leaves have several main veins are continuous with vascular bundles in stems.
The arrangement of leaves on a stem is called phyllotaxis and characterizes individual plant species. Opposite phyllotaxis refers to two leaves per node located on opposite side of the stem. Alternate phyllotaxis refers to one leaf per node, with leaves appearing first on one side of the stem and then on another. Whorled phyllotaxis refers to more than two leaves per node.
▲Main Topics
1. examine the types of venation in leaves of monocots and dicots.
2. Exanine the structure of simple and compound leaves.
3. Examine the internal structure of leaves of monocots, dicots, and gymnosperms.
4. Examine the structural adaptations of leaves of xerophytic and hydrophytic plants.
5. Examine the structure of the abscssion zone of leaves.
Exercise 8 Embryo and Seedling Development
▲Objectives
1. Describe the major stages of embryo development.
2. Understand the mechanism governing the tetrazolium test for seed viability.
3. Describe epigean and hypogean development in seedlings of bean, pea, and corn.
▲Essential Background
A seed is a mature ovule and includes a seed coat, a food supply, and an embryo. Development of the mature zygote occurs within the seed and before germination. This embryology and its control are complex, but various stages of development are easily observed. The developing embryo grows, absorbs endosperm, and stores nutrients in seed leaves called cotyledons. Development includes the following stages:
1)Proembryo. During development, the zygote divides to form a mass of cells called the embryo. Initially the embryo consists of a basal cell, a suspensor and a two-celled proembryo. The suspensor is the column of cells that pushes the embryo into the endosperm. The endosperm is extensive, but digested during development of the embryo.
2)Globular Stage. Cell division of the proembryo soon produces the globular stage, which is radially symmetrical and has relatively little internal cellular organization.
3)Heart-shaped Stage. Differential division of the globular stage produces bilateral symmetry and two cotyledons that form a heart-shaped embryo.The enlarging cotyledons store digested foo from the endosperm. Tissue differentiation begins, and root and shoot meristems form.
4)Torpedo Stage. The cotyledons and root axis elongate to produce an elongate torpedo stage embryo. Procambial tissue appears; this tissue will later develop into vascular tissue.
5)Mature Embryo. The mature embryo has large, bent cotyledons on each side of the stem apical meristem. The radicle, later to form the root, differentiates toward the suspensor, and includes a root apical meristem and root cap. The hypocotyls is the region between the apical meristem and the radicle. The endosperm is now depleted, and food is stored in the cotyledons. The epicotyl is the region between attachment of the cotyledons and the stem apical meristem. It does not elongate in the mature embryo stage.
Seed viability, or ability to germinate, varies and can be assessed with a tetrazolium test. During germination, aerobic respiration increases dramatically and electrons are transferred by various dehydrogenase enzymes. Dehydrogenases can also transfer electrons to compounds not found in the seed. One of these compounds, 2,3,5-triphenyltetrazolium chloride, can be reduced by dehydrogenases and turns from colorless to red. Reduced tetrazoliyum indicates active respiration (and therefore viability) of cells. More red color of a seed exposed to tetrazolium indicates greater respiration. Dead cells do not reduce tetrazolium. In this manner, a terazolium test of a sample of seeds will measure the viability of that group or lot of seeds.
Seedling development begins when the seed coat ruptures. The growing embryo breaks the seed coat, and the young plant emerges. The endosperm and cotyledons supply food for the young seedling until it establishes a root system and photosynthetic tissue.
During epigean development the cotyledons are pushed above the soil surface by the growing hypogean development the cotyledons remain below the soil surface.
▲Main Topics
1. Examine prepared slides showing the major stages of Capsella embryo development.
2. Examine parts of a corn embryo.
3. perform the tetrazolium test for seed viability.
4. Examine ben, pea, and corn seedlings having epigean and hypogean development.
Exercise 9 Algae
▲Objectives
1. Discuss the distinguishing features of different groups of algae.
2. Discuss the economic importance of algae.
3. Understand “alternation of generation” in green algae.
▲Essential Background
Algae are photosynthetic, eukaryotic organisms typically lacking multicellular sex organs. The major groups of algae are distinguished in part by their energy storage products, cell walls, and color, resulting from the type and abundance of pigments in their plastids. The major groups of algae are green algae, brown algae, golden-brown algae, and red algae. Algae are also distinguished by their cellular organization. Unicellular algal species occur single, unattached cells that may or may not be motile. Filamentous algal species occur as chains of cells attached end to end. These filaments may be few to many cells long and may be unbranched or branched in various patterns. Colonial algae occur as groups of cells attached to each other in a nonfilamentous manner. The cells may be imbedded in a common matrix of gelatin secreted from the cells or attached by thin strands of cytoplasm. All cells of a colony are similar in structure and function and are independent metabolically. Multicellular organization is not typical of protests but describes algae of more complex design than simple colonies. Multicellular species have cells of different kinds and function and show significant interdependence.
▲Main Topics
1. Examine living cultures and prepared slides of Chlamydomonas.
2. Examine syngamy of strains of Chamydomonas.
3. Examine living cultures and prepared slides of Cladophora, Spirogyra, and Volvox.
4. Examine living cultures and prepared slides of dinoflagellates.
5. Examine living cultures and prepared slides of Euglena.
6. Examine a demonstration culture of Physarum.
Exercise 10 Fungi and Lichens
▲Objectives
1. Describe the characteristic features of the kingdom Fungi.
2. Get familiar with different growth forms of lichens.
3. Understand the relationship between Fungi and lichens.
▲Essential Background
Although fungi and plants share some characteristics such as cell walls and attachment to a substrate, fungi are unique and structurally diverse organisms that warrant classification as a separate kingdom. The basic structure of a fungus is hypha (pl. hyphae), a slender filament of cytoplasm and haploid nuclei enclosed by a cell wall. hyphae of some divisions and species have cross walls called septa which separate cytoplasm and one or more nuclei into cells. Other hyphae have incomplete or no septa (i.e., are aseptate) and therefore are coenocytic (multinucleate). Mycelium is a collective term for a cotton-like mass of hyphae constituting an individual organism; it may extensively permeate soil, water, or living tissue. Notably, the cell walls of fungi are usually not cellulose but are made of chitin, the same polysaccharide in the exoskeleton of insects and crustaceans.
Fungi are absorptive heterotrophs. Through their chitinous cell walls fungi secrete enzymes for extracellula digestion of organics in the substrate, after which the digested nutrients are absorbed into the mycelium. Heterotrophs gain their energy from organic molecules made by other organisms. Most fungi gain nourishment from dead organic matter and are called saprophytes. Other fungi feed on living organisms and are parasites. Many parasitic fungi have modified hyphae called haustoria, which are thin extensions of the hyphae that penetrate into living cells and absorb nutrients.
Lichens are brightly colored organisms in which an ascomycete (rarely other fungi) live symbiotically with a photosynthetic alga or cyanobactterium. They reproduce asexually by releasing fragments of tissue or specialized, stess-resistant packets of fungal and algal cells. Each of the two components (fungus and alga) may reproduce sexually by mechanisms characteristic of their division, and the new organisms may continue the lichen association. The durable construction of fungi, linked with the photosynthetic properties of algae, enable lichens to proliferate into the harshest terrestrial habitats, three kinds of growth forms can be found in the field.
▲Main Topics
1. Investigate the diversity of fungi in the field.
2. Examine morphological characteristics of mushroom.
3. Examine lichens on display and in the field; a cross section of a lichen thallus.
Exercise 11 Bryophytes
▲Objectives
1. Describe the life histories and related reproductive structures of mosses and liverworts.
2. Describe the distinguishing features of mosses and liverworts.
▲Essential Background
Bryophytes consist mainly of liverworts, mosses, and hornworts, and represent the most primitive group of terrestrial plants. Bryophytes are green, have rootlike structures called rhizoids, and may have stem and leaflike parts. Bryophytes do not possess vascular tissues, which transport materials between roots and shoots. This absence of vascular tissues in bryophytes typically limits their penetrate the soil very far nor absorb many nutrients. Also, the absence of vascular tissues necessitates that their photosynthetic and nonphotosynthetic tissues be close together. Because vascular tissues, along with supporting tissues, are absent, bryophytes are relatively small and inconspicuous. Despite their diminutive size, however, bryophytes occur throughout the world in habitats ranging from the tropics to Antarctica. There are approximately 20,600 species of bryophytes, more than any other group of plants except the flowering plants. Bryophytes fix CO2, degrade rocks to soil, stabilize soil, and reduce erosion. Humans have used bryophytes in a number of ways, including as fuel, to produce Scotch whiskey, and as packing materials.
The plant body of bryophytes is called thallus. Liverwort thalli are dorsoventrally flattened and bilaterally symmetrical. For comparison, moss thalli are erect and radially symmetrical. Hornwort thalli are similar to those of liverworts.
The life cycle of bryophytes has a distinct alternation of generations in which the gametophyte is the predominant vegetative phase. Bryophytes have multicellular sex organs in which gamete-producing cells are enclosed in a jacket of sterile cells. Antheridia are male sex organs that produce swimming, biflagellate sperm. Bryophytes require free water for sexual reproduction because their sperm must swim to eggs. These sperm fertilize eggs produced in archegonia, the female sex organs. The fertilized egg is called zygote. This zygote divides and matures in the archegonium to produce the sporophyte, which remains ttached to and nutritionally dependent on the gametophyte. The mature sporophyte produces haploid spores via meiosis, each of which can develop into a gametophyte.
▲Main Topics
1. Examine the general life cycle of bryophytes.
2. Examine living Marchantia and compare with a prepared cross section of a thallus.
3. Examine a prepared slide of gammae cups.
4. Examine live or prepared liverworts with mature archegoniophoes bearing archegonia and antheridiophores bearing antheridia.
5. Examine a prepared slide of a sporophyte of Marchantia.
6. Obsreve living mosses.
7. Demonstrate water absorption by Sphagnum.
8. Examine capsules of a living moss sporophyte.
9. Examine living Anthoceros and prepared slides of Anthoceros sporophyte.
Exercise 12 Seedless Vascular Plants
▲Objectives
1. Discuss the similarities and differences between ferns and other plants you have studied.
2. Describe the life cycles of seedless vascular plants.
3. Describe the distinguishing features of Psilotophyta, Equisetophyta, Lycopodophyta, and Pteridophyta.
▲Essential Background
Seedless vascular plants include nonflowering plant having a vascular system of fluid-conducting xylem and phloem. The vascular system connects the leaves, roots, and stems.
Seedless vascular plants include the divisions Pteridophyta, Lycopodophyta, Psilotophyta, and Equisetophyta. Biologists often have referred to these divisions as the lower vascular plants or ferns and their allies. Conversely, gymnosperms and angiosperms have been referred to as higher vascular plants or seed-forming vascular plants. This separation of higher and lower vascular plants was invented by early botanists, who believed that all seed-forming plants must be related, and that plants lacking seeds are similarly related. Later studies of lower vascular plants showed that ferns represent a separate group of seedless plants distinguished by the presence of megaphylls, which are large leaves with several to many veins. The remaining seedless vascular plants possess microphylls and are only somewhat related to ferns; hence the name “fern allies”. Thus, the lower vascular plants include a diverse group of divisions. However, all seedless vascular plants possess sporophylls, which are leaflike structures of the sporophyte generation that bear spores. Sporophylls may be large and have several to many veins or they may be smaller and have one vein.
▲Main Topics
1. Review the life cycle of ferns.
2. Examine sori.
3. Examine fern archegonia and antheridia on prepared slides.
4. Examine living prothallia.
5. Observe living Salvinia and Azolla.
6. Examine the above-ground tissue, rhizome, sporophylls, strobili, and spores of Lycopodium, a club moss.
7. Examine hydrated and dehydrated Selaginella.
8. Examine Psilotum (whisk fern) and Isoetes (quillwort).
9. Examine living Equisetum and prepared slides of strobili.
10. Compare the function of structures common to seedless vascular plants.
Exercise 13 Gymnosperms
▲Objectives
1. Describe the distinguishing features of gymnosperms.
2. Understand the life cycle of pine, a representative gymnosperm.
3. Understand some adaptations of pine to cold, dry environments.
4. Identify the parts and understand the function of cone.
5. Identify the parts and understand the function of a seed.
▲Essential Background
Gymnosperms are plants with exposed seeds borne on scalelike structure called cones. Like ferns, gymnosperms have a well-developed alternation of generations. Unlike ferns, however, gametophytes of gymnosperms are microscopic and completely dependent on the large, free-living sporophyte. Gymnosperms include four divisions: Cycadophyta, Ginkgophyta, Pinophyta, and Gnetophyta.
▲Main Topics
1. Examine a branch and seeds of a cycad.
2. Examine pine twigs with leaves and a terminal bud.
3. Examine a prepared slide of a cross section of a pine leaf.
4. Examine pine branches with male and female cones.
5. Examine a prepared slide of a young staminate cone.
6. Prepare a wet mount of pine pollen.
7. Examine a mature ovulate cone.
8. Examine a prepared slide of an ovulate cone ready for pollination.
9. Examine an ovulate cone sectioned through an ovule.
10. Examine a prepared slide of a pine seed as well as whole pine seeds.
11. Examine additional gymnosperms available in the lab.
Exercise 14 Angiosperms
▲Objectives
1. Understand the life cycle of angiosperms.
2. Understand the events associated with the development of microspores, megaspores, seed, and fruit.
3. Understand why angiosperms are considered to be the most advanced land plants.
▲Essential Background
Flowering plants are the most abundant, diverse, and widespread of all land plants. They owe their success to several factors: their structural diversity, efficient vascular systems, mutualisms, and short generation times. Angiosperms range in size from 1 mm to over 100 m tall. Like gymnosperms, the sporophyte of angiosperms is large and independent of the microscopic gametophyte. This is opposite of the situation in bryophytes. The gametophyte of angiosperms depends totally on the sporophyte. Angiosperms are important to humans since our economy is overwhelmingly based on them.
▲Main Topics
1. Examine models of flower parts.
2. examine wet mount and prepared slides of anther cross sections.
3. Examine living and prepared pollen from various plants.
4. Observe germinating pollen grains.
5. Examine preparedslides of stages of developing ovules.
6. Stain and examine parts of bean seeds.
7. Examine and classify diverse fruits according to their structure.
Exercise 15 Evolution
▲Objectives
1. Demonstrate the effects of selection pressure on genotypic and phenotypic frequencies in a population.
2. Understand the significance of Volvocine line of evolution.
3. Understand how a mutation affecting the plane of cellular division could result in the evolution of morphologically different body forms.
▲Essential Background
Evolution broadly describes genetic change in populations. The existence of genetic change (and therefore evolution) is universally accepted. We know that many mechanisms can change the genetic makeup of populations, but the relative importance of each mechanism is controversial. Stochastic and random events such as mutations (changes in the genetic message of a cell) and catastrophes (e.g., meteor showers, ice ages) are all responsible to some degree for genetic change. However, Charles Darwin and others formulated a theory that many biologists believe explains the major force behind genetic change.
Darwin postulated that organisms that survive and reproduce successfully have genetic traits aiding survival and reproduction. These traits enhance an organism’s fitness, which is its tendency to produce more offspring than competing individuals produce. Because the most fit organisms transmit their traits to their offspring, traits promoting survival and production are selectively passed to the next generation. After many generations the frequency of these traits increases in the population, and the nature of population gradually changes. Darwin called this process natural selection, and proposed natural selection as a major force guiding genetic change and formation of new species.
▲Main Topics
1. Review the terminology associated with Mendelian genetics.
2. Establish a parental population and calculate its allelic and genotypic frequency.
3. Verify the Hardy-Weinberg equilibrium of genotypic frequencies in the offspring of parental population.
4. Determine the effects of 100% negative selection pressure on allelic frequencies.
5. Determine the effects of 20% negative selection pressure on allelic frequencies.
6. Examine members of the Volvocine line of algae having variations in colony complexity.
7. Examine genera of green algae with variations in body form.
Exercise 16 Community ecology
▲Objectives
1. Characterize a terrestrial community in terms of physical factors, plant dominance, and interactions among organisms.
2. Quantify the distribution and abundance of plants in a community.
3. Detect the experimental effects of competition and allelopathy among plants.
▲Essential Background
Ecological communities are extraordinarily complex systems. The assemblage of plants that you observe at any given time is the product of interactions among plants and their physical surroundings, among different species of plants, and among plants and animals. All of these interactions are driven by a flow of energy captured by green plants and passed to herbivores, predators, and decomposers.
It is beyond the scope pf this manual to explain and categorize all the processes occurring in a plant community, but we can assemble some fundamental observations the characterize and distinguish communities.
▲Main Topics
1. Qualitative community assessment.
2. Quantitative community assessment.
3. Plant interactions.
四、教材与参考书
[1]Vodopich D, Moore R: Laboratory Manual of Botany. Wm C Brown Publishers, 1995
[2]汪小凡, 杨继: 植物生物学实验(第二版).高等教育出版社, 2006
五、考核方式（黑体五号）
平时成绩(操作与实验报告)60％；
开放实验10％；
期末考查30％(显微结构辨别: 20/30；植物种类识别: 10/30)。
