Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Ross Nematoda By Liviu, Ross, and Yuchen http://media-2.web.britannica.com/eb-media/47/9847-004-9B39C5BB.jpg Ross Overview • Nematodes are slender worm-like animals that are usually microscopic, but can grow to as long as 2 inches, or even a meter, long. • Their bodies will often have ridges, rings, warts, bristles, hooks, etc. • The main difference between nematodes (roundworms) and all other worms is that these are NOT SEGMENTED. http://www.eb.tuebingen.mpg.de/core-facilities/microscopy-unit/sem_pictures/nematode.jpg Ross Phylum & Sample Animals • Phylum: Nematoda • Sample animals: Roundworms. That’s it. • Metazoa: Animals with fixed body plan – Eumatzoa: All animals but sponges • Bilateria: Bilaterally Symmetric https://yhsbiology.wikispaces.com/file/view/roundworm.jpg/47735587/roundworm.jpg Yuchen Body Cavity and Symmetry • Body Cavity - Nematodes have fake body cavities and thus are called Pseudocoelomate. The cavity is partially lined by tissue derived from the mesoderm. The other is separated by the digestive cavity that is not derived from the mesoderm. • They are bilateral - if you cut them from the mouth you can only get one plane of symmetry. Think worms. http://piginpond.com/bbs/board.php?bo_table=wallpaper&wr_id=195&page=2 Yuchen Circulatory and Nervous System • They DO NOT have a circulatory system ;_; • They DO have an Nervous system which form an central ring near the anterior end of the nematode that forms a pseudo-brain. The rest is 4 nerve chords that run along the 4 sides (dorsal, ventral and laterals) of the worm. The dorsal is responsible more motor control while the laterals are for sensory. The thickest chord ventral combines the two functions. http://piginpond.com/bbs/board.php?bo_table=wallpaper&wr_id=190&page=2 Ross Digestive System •Food enters and exits the worm in this order: oral cavity, pharynx, intestines, anus •Roundworms have no stomach •The oral cavity is coated with a tough material called cuticle http://www.inquisitr.com/wp-content/raccoon-roundworm.jpg Ross Excretory System • Longitudinal excretory ducts. The waste is simply filtered through these ducts and taken outside of the worm. • In simpler species, a unicellular gland called a renette cell pumps out toxins through an excretory pore. http://s3.amazonaws.com/pixblix_production/art_images/1023/red-wave-abstract-background.jpg Ross Muscle System/Locomotion • Underneath the epidermis lies a layer of muscle cells. These muscles are longitudinal (test question), meaning that they are unable to elongate the body and do not inch like earthworms or snakes do. • Their movement is characterized by alternating contractions of the muscle, which looks like a thrashing or a wagging tail. http://piginpond.com/bbs/board.php?bo_table=wallpaper&wr_id=199 Ross Skeletal Type • The cuticle is the closest thing a roundworm has to a skeleton because the cuticle is used for movement and support. There are no distinct joints. http://piginpond.com/bbs/board.php?bo_table=wallpaper&wr_id=203 Liviu Cengher Sensory structures/features • Sensory Bristles along the cuticle. (sensilla) 1.1 1.2 • Sensory organs at posterior, involved in reproduction. (phasmids) 1.5 1.3 1.4 • Two Amphids located on the head 1.6 1.7 Amphids: Specialized Sensillia that can sense better than normal ones on the cuticle http://piginpond.com/bbs/board.php?bo_table=wallpaper&wr_id=153&page=5 1.8 Liviu Cengher Reproduction 2.1 • Both sexes possess one or two tubular gonads • In males, the sperm are produced at the end of the gonad, and migrate along its length as they mature. • In females, the ovaries each open into an oviduct and then a glandular uterus Male Rep. Organ 2.2 http://piginpond.com/bbs/board.php?bo_table=wallpaper&wr_id=141&page=6 Female Rep. Organ 2.3 Liviu Cengher Gas exchange Diffusion across the cuticle. 3.1 O2, CO2, ETC. 3.2 O2 CO2 http://piginpond.com/bbs/board.php?bo_table=wallpaper&wr_id=164&page=4 Liviu Cengher Other unique features, sketches 14.1 They have a tough Cuticle (a mass of cellular material and nuclei without separate membranes that coats the body) which is periodically shed. The word "nematode" comes from a Greek word Νεμα (Nema), which means "thread”. * * 14.2 14.3 * Nematodes are able to suspend their life processes completely when conditions are unfavorable, then return to life when favorable conditions return. This is called cryptobiosis. * * http://piginpond.com/bbs/board.php?bo_table=wallpaper&wr_id=163&page=4 * Ross Pictures http://www.wormatlas.org/ver1/handbook/fig.s/IntroFIG2.jpg http://piginpond.com/bbs/board.php?bo_table=wallpaper&wr_id=188&page=2 Ross Test Question 1 Food is processed in nematodes in which order? a. Pharynx, stomach, intestines, anus b. Oral cavity, pharynx, stomach, excretory ducts c. Pharynx, intestines, excretory ducts d. Oral cavity, intestines, anus e. Oral cavity, pharynx, intestines, anus ANSWER: E. http://piginpond.com/bbs/board.php?bo_table=wallpaper&wr_id=194&page=2 Ross Test Question 2 Nematodes have all of the following systems EXCEPT a. Excretory b. Circulatory c. Skeletal d. Nervous e. Digestive ANSWER: B. http://piginpond.com/bbs/board.php?bo_table=wallpaper&wr_id=88&page=11 Liviu Cengher Test Questions 3 & 4 Which of these breathe through their tough cuticle? a. b. c. d. Onychophora Arthropoda Nematoda Mollusca Which of these feel through sensillia on their tough cuticle? a. b. c. d. Nematoda Brachiopoda Cnidaria Annelida 3. C 4. A Those Things (because our ppt is on nematodes obviously) http://piginpond.com/bbs/board.php?bo_table=wallpaper&wr_id=166&page=4 Liviu Cengher Bibliography Info: • http://www.ucmp.berkeley.edu/phyla/ecdysozoa/nematoda.html • http://www.sci.sdsu.edu/classes/bio201/Nematodes.html • http://www.cals.ncsu.edu/course/zo150/mozley/fall/studyaids.html • http://www.esn-online.org/Nematodes • http://www.ucmp.berkeley.edu/phyla/ecdysozoa/nematoda.html • http://www.wormatlas.org/male/malehomepage.htm Pictures: • 11.1 Created by Liviu Cengher • 11.2 http://web.pml.ac.uk/nematode/nematodes/index.htm • 11.3 http://www.cals.ncsu.edu/course/zo150/mozley/fall/studyaids.html • 11.4 http://www.wormatlas.org/maleHandbook/figsMale/MaleEpiFIG14A.jpg • 11.5 http://www.esn-online.org/Nematode%20picture%20of%20the%20week • 11.6 http://web.pml.ac.uk/nematode/nematodes/index.htm • 11.7 http://tolweb.org/Nematoda/2472 • 11.8 http://web.pml.ac.uk/nematode/nematodes/index.htm • 12.1-12.3 http://www.cals.ncsu.edu/course/zo150/mozley/fall/studyaids.html • 13.1 http://bioweb.uwlax.edu/bio203/s2007/eddy_greg/images/nematode.jpg • 13.2 http://www.ucmp.berkeley.edu/phyla/ecdysozoa/nematoda.html • 14.1 http://tolweb.org/Nematoda/2472 • 14.2 http://www.esn-online.org/Nematode%20picture%20of%20the%20week • * PowerPoint Clipart http://piginpond.com/bbs/board.php?bo_table=wallpaper&wr_id=171&page=4