学习植生双语植生实lab topic ten

1、Lab Topic Ten: Bryophytes Examine a prepared slide of longitudinal section through an archegonial head of gametophyte of Funaria hygrometrica (葫芦藓）to view archegonia surrounded by sterile structures (paraphysis).Examine a prepared slide of longitudinal section through an antheridial head of gametoph

2、yte of Funaria hygrometrica (葫芦藓） to view antheridia surrounded by sterile structures (paraphysis).ProtonemaExamine a prepared slide of longitudinal section of a capsule (sporangium) to view sporogenous tissue.Lab Topic Eleven: Seedless Vascular PlantsMake a wet mount to observe the structure of a s

3、orus of Adiantam capiuarisven （铁线蕨）and Nephrolepis cordifolia (肾蕨).Examine a prepared slide of mature gametophyte (prothallus) to view archegonia and antheridia.Assignment:Draw a diagram of longitudial section through an archegonial or antheridial head to show archegonia or antheridia of Funaria hyg

4、rometrica . (葫芦藓）Draw a diagram of a sorus of Adiantam capiuarisven （铁线蕨）or Nephrolepis cordifolia (肾蕨) to show sporangia. A “true moss.” Protonema of a moss with a budlike structure, from which the leafy gametophyte will develop. Protonemata are the first stage of the gametophyte generation of moss

5、es and some liverworts. They often resemble filamentous green algae.Gametangia of Mnium（提灯藓属）, a unisexual moss.(a) Longitudinal section through an archegonial head showing the pink-stanied archegonia surrounded by sterile structures called paraphyses. (b) longitudinal section through an antheridial

6、 head showing antheridia surrounded by paraphyses.Cyrtomium falcatum, a homosporous fern. Transverse section of a leaf, showing a sorus on the lower surface. The sporangia are different stages of development and are protected by an umbrellalike indusium. The sporangium has special thickened cells al

7、ong one side which react to changes in humidity. The spores are dispersed by the rapid movement of the dehiscing sporangium Eventually, a large, heart-shaped prothallus is formed (Gametophyte)Lab Topic Twelve: The Angiosperm-FlowersIn terms of evolutionary history of angiosperms, they are a group of

8、 seed plants with special characteristics: flowers, fruits, and distinctive life-cycle features that differ from those of all other plants. This topic is designed to acquaint you with the reproductive structures and life history of this enormously diverse group of plants.1. Flower -Chaenomeles lagen

9、aria (贴梗海棠)Perfect, regular, epigynous floweractinomorphic, or radially symmetrical;Epigynous flower: Floral organization in which the sepals, petals and stamens apparently grow from the top of ovary, which is inferior;Axile placentation：placentae were arranged around (or ovules borne upon) a centra

10、l column of tissue in an ovary with as many locules as there are carpels.Chaenomeles lagenaria2. Flower - Robinia pseudoacacia (刺槐）Papilionaceous flowerZygomorphic or bilaterally symmetrical flower.Diadelphous stamenone stamen filament is separate from the fused nine.A dissected flower of Erythrina

11、cristagalli （海红豆）showing all the major perianth segments removed from their attachment inside the calyx. The five petals consist of one large, oval banner or standard, two elongate keel petals that are fused together enclosing the stamens, and two reduced wings. Nine stamen filaments are united into

12、 a sheath that surrounds the pistil. One stamen filament is separate from the fused nine, a condition referred to as diadelphous stamen(二体雄蕊）3. Examine a prepared slide of transverse section of Lily (Lilium sp.) anther to observe the structure of pollen sacs.4. Examine a prepared slide of transverse

13、 section of Lily (Lilum sp.) ovary, in which you will find three carpels, locules and axile placentation to which the ovules attached.5. At the demonstration microscope, examine a mature embryo sac (mature female gametophyte), which is an eignt-nucleate, seven-celled structure.a young flower bud of

14、Lilium cut in cross sectionNote the single compound pistil in the centre of the section. The pistil is composed of three fused carpels. Two dense staining ovule primordia are evident in each of the three locule. Outside the pistil are six bilobed anthers, three petals and three sepals. Two transvers

15、e sections of Lily (Lilium) anthers. (a)Immature anther, showing the four pollen sacs containing microsporocytes surrounded by the nutritive tapetumMicrosporocytesTapetum(b) Mature anther containing pollen grains. The partitions between adjacent pollen sacs break down during dehiscence, as shown her

16、e.Microspore tetrad. As anther development proceeds, the microsporocytes divide by meiosis to produce a spherical tetrad of four microspores Lilium. Some stages in development of an ovule and embryo sac. (a-1) Two young ovules, each with a single, large megasporocyte surrounded by the nucellus. Inte

17、guments have not begun to develop. (a-2) Close- up of one of the young ovulesa-1a-2(b) Ovule has now developed integuments with a micropyle. The megasporocyte is in the first prophase of meiosis.(c) Ovule with eight nucleate embryo sac (only six of the nuclei can be seen here, four at the micropylar

18、 end and two at the opposite, chalazal end). The polar nuclei have not yet migrated to the center of the sac. The funiculus is the stalk of the ovule.Mature embryo sac Longitudinal section of an ovule with a mature embryo sac (magagametophyte, or female gametophyte). The mature embryo sac is an eigh

19、t-nucleate, seven-celled structure, consisting of three antipodals at chalazal end of ovule, an egg apparatus(egg cell and two synergid) at the micropylar end, and a large central cell with two polar nuclei.Double fertilization in Lilium. Union of sperm and egg nuclei-fertilization-can be seen in the lower half of the micrograph. Triple fusion of the other sperm nucleus and the two polar nuclei has taken place above. The three nuclei known as the antipodal