Introduction to Phylum Coelenterate:
Phylum Cnidaria (called as coelenterata) has approx 9000 species. Few are located in fresh water, but greater number are marine. Coelenterates are simplest of eumetazoans. This fascinating group of animals takes its name from large cavity in body which serves as intestine. They have hydra, jelly fish, sea anemones and corals.
Characteristic Features of Coelenterates:
Forms of Coelenterate:
There are 2 forms of individuals in Coelenterates. These forms are:
i) Polyp
ii) Medusa
Polyp is tubular, oral end being free carrying the whorl of tentacles, and aboral end joined to sub stratum by basal disc. Polyp is sedentary, benthic form.
Medusa is free swimming umbrella-like pelagic form, with mouth at the end of manubrium on subumbrellar side.
Categorization of Phylum Coelenterata (Cnidaria):
Depending primarily on whether polyp or medusa is dominant form in life cycle, coelenterates are separated into 4 classes:
Class Hydrozoa:
Class Scyphozoa:
Class Cubozoa:
Class Anthozoa:
External Features of Hydra:
i) Body resembles the narrow elastic tube, closed at one end and open at other
ii) Closed end of hydra is called as foot or basal disc referred to as aboral end
iii) Has conical process, Hypostome or Oral Cone in centre of that is located the irregular or star shaped mouth.
iv) It has slender contractile and hollow tentacles between 6-10 in numbers
v) Body may get the length of 20mm or more when completely extended
vi) Generally have small hydras called as buds joined to them when food supply is in great quantity
vii) They have rounded projections on the body that are sexual organs- testes and ovaries
Adaptive Features of Hydra:
i) Foots secretes the sticky substance for Anchorage and Locomotion
ii) Interstitial cells that is chief agent in repairs, regeneration, budding and reconstructing tissues in growth Nematoblast assists in defense
iii) Hydra generally remains joined by basal disc or foot to objects under water
iv) Movement of hydra are for: capture of prey; reply to stimuli; locomotion
v) Swimming is helped by wave-like movement of tentacles
vi) Hydra is the Carnivorous animal
vii) Egestion is through mouth
viii) Gaseous exchange is performed by almost direct diffusion through cell membrane to surrounding water.
Tutorsglobe: A way to secure high grade in your curriculum (Online Tutoring)
Expand your confidence, grow study skills and improve your grades.
Since 2009, Tutorsglobe has proactively helped millions of students to get better grades in school, college or university and score well in competitive tests with live, one-on-one online tutoring.
Using an advanced developed tutoring system providing little or no wait time, the students are connected on-demand with a tutor at www.tutorsglobe.com. Students work one-on-one, in real-time with a tutor, communicating and studying using a virtual whiteboard technology. Scientific and mathematical notation, symbols, geometric figures, graphing and freehand drawing can be rendered quickly and easily in the advanced whiteboard.
Free to know our price and packages for online biology tutoring. Chat with us or submit request at [email protected]
tutorsglobe.com tertiary treatment assignment help-homework help by online sewage treatment and disposal tutors
www.tutorsglobe.com offers biophysical chemistry homework help, biophysical chemistry assignment help, online tutoring assistance, physical chemistry solutions by online qualified tutor's help.
Avail finest Cognitive Science Assignment Help service today and get authentic and plagiarism free solutions with amazing discounts.
the working of hair dryer is very much simple and most of its mechanisms revolve around its fan. while the dryer is switched on, the electricity travels to the windings of the motor of the fan.
theory and lecture notes of bioelectric signals and electrocardiogram all along with the key concepts of cell membrane potential, action potential, cardiovascular system, electro-stimulation of heart and electrodes. tutorsglobe offers homework help, assignment help and tutor’s assistance on bioelectric signals and electrocardiogram.
Theories of Structure and Bonding tutorial all along with the key concepts of Valence bond theory, Crystal field theory, Octahedral field, Spectrochemical series, Factors affecting crystal field splitting
eeg (electro encephalo graphy) is a superposition of the volume-conductor fields generated through a range of active neuronal current generators.
tutorsglobe.com bio gas assignment help-homework help by online energy crisis tutors
Theory and lecture notes of Aggregate Demand and Inflation all along with the key concepts of aggregate demand and inflation, monetary policy reaction function, Phillips curve equation. Tutorsglobe offers homework help, assignment help and tutor’s assistance on Aggregate Demand and Inflation.
A limited company may contain legal personality, but it is not a human being able of taking decisions and plans regarding to the business and exercising control over it.
tutorsglobe.com distinguishing features of gymnosperms assignment help-homework help by online salient features of gymnosperms tutors
Origin, Evolution and Structure of Stars tutorial all along with the key concepts of Dynamics of Stars, Hydrostatic Equilibrium, Virial theorem, Mean Temperature of a Star, Physical State of Stellar Material, Energy Generation in Stars, Equation of Energy Production
petrochemicals from natural gas tutorial all along with the key concepts of chemical based on direct reactions of methane, carbon disulphide, hydrogen cyanide, chloromethane, synthesis gas, shift conversion, methanation, methyl alcohol and naphtha-based chemicals
www.tutorsglobe.com offers cycloalkanes homework help, cycloalkanes assignment help, online tutoring assistance, organic chemistry solutions by online qualified tutor's help.
tutorsglobe.com kidney transplantation assignment help-homework help by online kidney stone tutors
1939501
Questions Asked
3689
Tutors
1455284
Questions Answered
Start Excelling in your courses, Ask an Expert and get answers for your homework and assignments!!