Potentially Infectious Material

Results

The male strobili of gymnosperm coniferphyta(figure 3)appeared as a small, staminate cone that contained pollen, in the form of tiny, microspores for fertilization. The pollen had air bladders that looked like wing-like extensions.[6] Though the observed sample was only a branch, it was understood that the male strobili usually form on the bottom branches of Pine trees away from the female strobili of the had a sticky sap on its stems.  Comparatively, the male stamen and female carpel of the angiosperm tulip flower (figure 4) were located together, inside the petals, just above the receptacle. It was observed that pollen, in the form of tiny grains, were stored inside the tiny perforations in the upward-reaching anthers.[7] Female gametes for pollination were contained in ovules that appeared on the inside of the ovary.[8] Similar to gymnosperm coniferphyta, there were two different types of spores, making the tulips heterosporous. The angiosperm tulip flower enclosed its reproductive parts inside its petals and had a waxy cuticle.[9] It was also understood that this organism undergoes a process of alternation of generations.

Discussion

In the gymnosperm coniferphyta, location of the male and female reproductive parts plays a key role in preventing self-pollination in the same plant. Spores from the male strobili are very likely to pollinate a different plant being that the female cones are on the top of the plant. In regards to the female strobili, the way in which the woody shelves are formed allow for pollen to land and germination to occur. The air bladders on the pollen act to create a structure that is less dense, floats and settles farther away; this is an important feature that helps to prevent self-pollination and that encourages genetic diversity.[10] The sap on the plant acts as a defense mechanism and can help the plant to heal when it is damaged.[11] In the angiosperm tulip flower, the closely located sexual parts inhibit self-fertilization as well as genetic diversity; some of the pollen that is released from the anthers falls onto the plant’s stamen as well as onto the stamen of other plants. Similar to the sap, the waxy cuticle of the tulip flower allows for it to hold water. The tulip’s ability to undergo alternation of generations assures that it utilizes both the sporophyte and gametophyte to continue the propagation of its species.[12]

Works Cited

Moore R. & Vodopich, D., Biology Laboratory Manual, McGraw-Hill Companies, Inc., 2011.

Pappas, C., Principles of Biology Laboratory, 2012.

Introduction

Platyhelminthes are flatworms that are dorsoventrally[1] compressed, and have no internal body cavity that is surrounded by tissue, making them acoelomates.[2] Nematodes are roundworms that have organs, such as a uterus, existing in two spaces, or body cavities, between their digestive tract and their body wall, making them pseudocoelomates.[3] Both flatworms and roundworms can be found living in freshwater, terrestrial and parasitic environments.[4] Parasitic Platyhelminthes and Nematodes both require multi-host cycles to survive.

Materials and Methods

A preserved specimen of a flatworm was observed under a dissecting microscope. A prepared slide of a section of Taenia was observed under a compound microscope at 40x. Preserved specimens of Ascaris lumbroicoides and Taenia were observed in a dissecting pan during a demonstration by the lab professor.

Results

Taenia appeared as a flatworm with partitioned body sections called proglottids. A hooking device called a scolex was seen at the anterior end of the organism. In each proglottid there contained packets[5] of sexual organs; there were both testes and ovaries. Proglottids nearest the scolex were less mature than proglottids farthest from the scolex. The most posterior[6] proglottids were gravid and were swollen with eggs. Each proglottid had a genital pore. Though it was unseen in the demonstration, it was understood that there was a digestive tube that ran down the center of the organism.

Ascaris lumbroicoides appeared as a roundworm that was light tan in color and about six to nine inches in length. The male was observed to be smaller in length than the female and the male had a hooked posterior end.[7] Though it was unseen in the demonstration, it was understood that there is a larger female Ascaris population than males.[8] The mouth was observed at the anterior end of the organism and the anus was observed at the posterior end. Though it was unseen in the demonstration, it was understood that this organism had two, sort-of body cavities containing sexual organs and that, because of the mouth and anus setup, it had a unidirectional digestive tract.[9]

Discussion

In terms of the partitioned body sections, or proglottids, which were a characteristic of the flatworm, sections that were the most posterior were more swollen and were pregnant with fertilized eggs.[10] This system of partitioned segments that, as they develop become pregnant, is important to the persistence of the species because even if multiple sections of proglottids were to become detached from the scolex, or vice versa, fertilized eggs, of which the flatworm makes thousands[11], would still be around to maintain the species. The inclusion of eggs in every, gravid, proglottid is crucial. In addition, the presence of both female and male sexual parts in almost every proglottid is important because it is a feature that guarantees more reproduction of the species. The scolex had a series of suckers and this is important for helping the organism to attach to its host for nutrition. More importantly, the scolex also holds the job of producing more proglottids, which means more flatworms to come.[12]

Regarding the larger size and higher population of female Ascaris, these observations and understandings are crucial to the survival of the species because more females that are bigger in size means there will be more eggs produced, which in turn means there will be more survival of Ascaris. The pseudocoelom is a crucial component to have for the development of organs, which in turn will contribute to the species’s evolutionary development.[13] The complete digestive tract, including the mouth and the anus, is efficient for feeding because it is an organized and specialized feature.[14]

Works Cited

Moore R. & Vodopich, D., Biology Laboratory Manual, McGraw-Hill Companies, Inc., 2011.

Pappas, C., Principles of Biology Laboratory, 2012.

Todd, N., Principles of Biology Lecture, 2012.