Study with the several resources on Docsity
Earn points by helping other students or get them with a premium plan
Prepare for your exams
Study with the several resources on Docsity
Earn points to download
Earn points by helping other students or get them with a premium plan
Community
Ask the community for help and clear up your study doubts
Discover the best universities in your country according to Docsity users
Free resources
Download our free guides on studying techniques, anxiety management strategies, and thesis advice from Docsity tutors
Material Type: Lab; Class: Biology 1 - Introduction; Subject: Biology / Biological Sciences; University: Shippensburg University of Pennsylvania; Term: Forever 1989;
Typology: Lab Reports
1 / 8
This page cannot be seen from the preview
Don't miss anything!
Section 3 Dr. Pablo Delis Student Name 10/1/
List of boldface terms from outline:
Bryophytes are nonvascular because they lack xylem and phloem. The main example of a bryophyte is a haircap moss ( Polytrichum ). Haircap moss consists of two different plants. They are the two generations of the life cycle. The gametophyte has a stem with leaves and rhizoids, but no roots, while the sporophyte is slender and leafless. The lower end of the sporophyte is embedded in the upper end of the gametophyte. The outline then instructs the student to remove the haircup, or calyptra, from the sporophyte. The calyptra develops from archegonium of the gametophyte. Then the student is instructed to remove the lid, or operculum, of the sporangium. After cutting the sporangium in half length wise, the student must mount it and view a ring of miniature teeth called peristome. After crushing the capsule in water on a slide, the student can observe spores with a compound microscope. After that, the student will observe a prepared whole mount slide of protonemas. Protonema is a branched filament that develops by cell division from a spore. It is the earliest stage of the gamete and produces buds, or clusters of cells, that develop into leafy stems. The protonemas have two kinds of branches: photosynthetic filaments, composed of wider cells; and rhizoids, composed of narrower cells. Rhizoids anchor protonema to the substrate in nature. The student should view the slide at 400x to locate photosynthetic filaments and rhizoids. Then the student will view a demonstration slide, Moss leafy shoot w.m., at 100x to see a bud with leaves and rhizoids. Next, the student will view gametangia, the containers that produce gametes through mitosis. Paraphyses are the hairs on the gametangia. Plants have two kinds of gametangia: antheridia, male gametangia with numerous sperm cells; and archegonia, female gametangia with a single egg. In Polytrichum , sperm and eggs are produced by separate gametophytes, but many
in the dehiscence of the sporangium. Next, the students are to view gametophytes. The specimen are a living culture in a liquid medium and a fern prothallium archegonia w.m. The lab then goes into detail about horsetails, or Equisetum in the phylum Pterophyta. This group has whorls, or tiers, of tiny, one-veined leaves. Some species have a whorl of branches with each whorl of leaves. In this species, the sporangia are located in the strobili, or cones, as in most Lycophyta while the gametophytes are green as in most ferns. Next, the lab discusses Lycopodiums, the ground pines and club mosses. It directs the student to locate the roots, stems, leaves, and sporangia of this organism. The third example that is covered by this lab is the heterosporous seedless vascular plants. The example plant of this group of organisms is the spikemoss ( Selaginella ) of the phylum Lycophyta. The majority of Lycophyta are heterosporous. The lab directs the student to locate the roots, stems, one-veined leaves, and stobili with their sporophylls and sporangia. Heterospory means that Selaginella has two kinds of sporangia, spores, and gametophytes. Megasporangia produce megaspores, which undergo mitosis inside the megaspore cell wall to form a female gametophyte. Similarly, microsporangia produce microspores, which undergo mitosis inside the microspore wall to form a male gametophyte. The two types of spores differ in size as well as sex. Both kinds dehisce to expose and release their gametophytes. Fertilization occurs on the ground. Selaginella has motile sperm that swim through water to reach female gametangium, or archeogonium. The lab instructs the student to remove a sporangium from the strobilus, crush it on the microscope slide, add a cover slip, and examine the spores. Then it instructs the student to study the slide Selaginella strobilus l.s. at 100x and 400x.
The fourth and final section of this lab is observing seed plants, gymnosperms and angiosperms. Gymnosperms have four living phyla and also have seed, but are not in a pistil. Angiosperms of the phylum Anthophyta enclose their seeds in a pistil which becomes a fruit. The seed plants are heterosporous. The main example for this section of the lab is a group of gymnosperms, the conifers of phylum Coniferophyta, especially the pines, Pinus. The student will observe a slide of pollen cones, Pinus mature staminate cone c.s & l.s. Around this area, pines shed their pollen by expanding their pollen cones in April or May. The lab instructs the student to find the microsporophylls, the microsporangia (the two pollen sacs), and the pollen grains. The pollen grains are male gametophytes of the seed plants, which later produce two sperm cells. The lab instructs the student to put some pollen grains in water on a microscope slide, cover it, and view them at 400x, observing the two air sacs. Next, the student must also view the prepared slide. First, the student must view the slides of mature seed cones. In the Douglas-fir slide, or Pseudotsuga , the student must locate the cone scales and bracts. In the cones of longleaf pine, or Pinus palustris , the student must find spine-tipped cone scales and blunt bracts. Two seeds are borne on the upper size of each cone scale. They have a "wing" in these species. After that, the student must view seeds and seedlings. On the poster of pinyon pine, or Pinus edulis , the student must locate the seed cone, cone scales, seeds, and seedlings. In the seeds, the student must find the seed coat, mature female gametophyte, and embryo. Finally, other gymnosperms that should be observed are cycads, ginkgo, and Ephedra.
