Write An Essay On Planarians

1. Many experiments were conducted during the 1950s and 1960s with chick embryos and they showed that two patches of tissue essentially controlled the development of the pattern of bones inside limbs.  Describe at

In the science world, Tetrahymena is a uni-cellular organism found in most fresh water ponds, streams and lakes. Tetrahymena cells can tolerate many environments and are notably used as a model organism in eukaryotic cell biology and research. A model organism can be defined as an organism that is easy to culture in a laboratory and shares many similar processes and genes with complex multi-cellular organisms, for example, cells in the human body. The use of Tetrahymena as a model organism has led to the discovery of ribozymes, telomere structure and even the motor protein, dynein.

SUFFOLK COUNTY COMMUNITY COLLEGE MICHAEL J. GRANT CAMPUS, BRENTWOOD NY BIO 150—MODERN BIOLOGY I INSTRUCTOR: DR. JAMES F. REMSEN, JR. ADDENDUM TO COURSE OUTLINE Instructor email: remsenj@sunysuffolk.edu Phone: (631) 851-6824 Office: Sagtikos 110 Office Hours Spring 2013: M Tu Th 11:00 A.M.-12:15 P.M. W 6:00-7:15 P.M. (Virtual) This addendum addresses how I run my classroom and what I expect of students above and beyond what is presented in the syllabus. I also offer tips for success in the course, and advice to help you determine if this course will meet your career goals once you complete it. Please take this information in the spirit in which it is offered: to foster a better learning environment, and to help you avoid outcomes that are

Dugesia tigrina are flatworms of the Turbellaria class that can live in saltwater or freshwater environments (Reddien and Alvarado 2004). These flatworms are also known as planaria and are notorious for their great ability of regeneration. The purpose of this experiment was to test if the regrowth of the planarian limbs was affected by light.

regrow legs in around four months, and some have been observed regrowing less vital parts of their

processed rather than consumed whole. In front of the jaw, large protruding teeth were likely used to seize struggling prey as they were dragged ashore. This is supported by the retention of forelimbs and hindlimbs which is a basal trait of protocetids. Moving back in the jaw deeply rooted teeth with triangular edges are specialized for shearing.

Invertebrates (animals without a spinal cord) such as the flatworm or planarian can regenerate both the head from a tail piece, and the tail from a head piece. Among vertebrates (animals with a spinal cord), fish can regenerate parts of the brain, eye, kidney, heart and fins. Frogs can regenerate the limb, tail, brain and eye tissue as tadpoles but not as adults. And salamanders can regenerate the limb, heart, tail, brain, eye tissues, kidney, brain and spinal cord throughout life.

The planaria regenerated due to the huge amounts of stem cells in its body. The stem cells were able to help the planaria regenerate a head and grow to its original size. If the planaria did not have any stem cells, it would not have been able to regenerate and would have died after being its head was cut off. An experimental error that occurred was that one of the planaria died due to living conditions and was not able to completely

What is dissection? Dissection is the “process of disassembling and observing something to determine its internal structure and as an aid to discerning the functions and relationships of its components” (Dissection). The term is most often used concerning the dissection of plants and animals, including humans. Comparative anatomy is the investigation of similitudes and contrasts in the life structures of various species. It is firmly identified with transformative science and phylogeny. Comparative anatomy has gradually and long been utilized as evidence for evolution; it indicates that various organisms share a common ancestor. Dissection of cats in an anatomy class is a common occurrence and believed to be a great learning mechanism for students. Schools and education systems utilize the availability of a cat because they are vertebrates and include a great amount of similarity in structures as humans, as students learn the anatomy and physiology of the human body. Advantages of dissecting a cat include a sensory factor that a visual study is unable to provide. A fact of being a human is that a great many people recall things they can touch or work on accomplishing more than they recollect data that they examined. By analyzing a creature in individual and touching it, the material encounters can give a general, better learning background that may help them in future classes if science or medical sciences will be examined. I hold the belief that the

These flatworms are bi-directionally regenerating creatures which means a cut body can form a brand new tail from the posterior cut and a new head from the anterior cut. Using this skill, they are able to clone themselves, and reproduce asexually. While taking down observations, there were tail droppings. Tail droppings occur when a planaria attaches itself to a surface and pulls away, separating into two pieces. This is one form of reproduction, the other form is called fragmentation. Fragmentation is just like tail droppings, but instead of separating into two pieces, the tail dropping divides up into more pieces. Furthermore, planarians have an abundant amount of stem cell-like cells that are capable of converting into the cell needed for regenerating tissue, and are available when it is required. When they lose a portion of itself, pale white coloured cells filled with stem cell-like cells starts to form, this is blastema. Those cells will transform into the desired cell and will begin to divide, which will result in a new body part to replace the missing part. This could be seen during the lab, the worms were distinctly transparent, or a pale colour, in the areas where they were dissected. These flatworms are organisms, and organisms need to eat, or get nutrients. Once their head is cut off and they are just a tail, it is really easy for them to obtain food. The cells in the tail will self-destruct to provide energy for the growing planarian until the head and tail are proportionate to each other, where it will then continue feeding and growing like before it got transected. Humans too, are capable of regeneration, but just to a certain extent. Everyday the human body creates more blood, new skin, and much more, which is regeneration. Unfortunately, limbs regenerating is unthinkable. That is why studying animals like the planarians and

After the Planaria has been cut, the wound is covered with a thin layer of epithelial cells (Newmark & Sánchez Alvarado, 2002,

Introduction: Many model organisms have been used in order to advance human medicine. The primary one being the lab mouse, but there are several other different species that give rise to advancements in human treatment. Planaria and axolotls have been a prominent source of how signaling mechanisms work in order to regenerate parts in eukaryotic organisms. If researchers can figure out how to turn these signaling pathways on in the conserved regeneration part of the human genome, then doctors will likely be able to use this to their advantage. This can be achieved by manipulating human signaling pathways to regenerate tissues within the heart, lungs, nervous system, and even systems with multiple tissue types like the limbs. This is where the study of axolotls comes in.

During the course of the past thirty years, the study of model organisms has become more significant in the study of embryological development. A model organism is a species that is easy to cultivate and monitor in a laboratory environment and is used to represent broad groups of organisms. Examples of successful and important model organisms include the Ascidia, Zebrafish, and Medeka species. Through intense researching of these organisms, scientists have been able to gain valuable insight into the developmental processes of many complex vertebrates, including humans.

The animal kingdom consists of about 800,000 known species (to include those that have been proven to exist). All animals have multiple cells and therefore rely on the cells of other living or dead organisms for their sustenance (growth and development). Animals develop from small groups of unspecialized cells and the animals with simple cells grow their missing body parts through regeneration. There are 36 phyla in the kingdom Animalia, for instance, Porifera, Annelida, Mollusca, Arthropoda, Echinodermata and Chordata among others (Dudley, 2002).

The study of the prehistoric era has resulted in many findings, which has opened the door for many sciences. There have been great strides made in the exploration of prehistoric humans, in that modern day society has gained insight into the past. This should not be judged as having been an easy feat. Earlier researchers would have had us believe that prehistoric intelligence was not possible among “savages.” However, humankind’s natural instinct is to pursue knowledge and move forward. All the advances made throughout history testify to that. How could it be that intelligence was not a factor in the ability of prehistoric humans to sustain life as they knew it?