Already have an account? Get multiple benefits of using own account!
Login in your account..!
Remember me
Don't have an account? Create your account in less than a minutes,
Forgot password? how can I recover my password now!
Enter right registered email to receive password!
Hydra – Metazoa
The animals of phyla Cnidaria and Ctenophora are made up of only two germ layers: ectoderm which forms the outer covering of the animal and endoderm which is the inner layer and is also known as the gastroderm. However, a non-cellular jelly like substance mesoglea is present between ectoderm and endoderm which acts as a cement to bind the two layers. This layer should not be confused with the third germ layer i.e. mesoderm. Since animals of these two phyla do not have mesoderm, they are said to be diploblastic.
Figure: L.S. Hydra
If we cut a longitudinal section through 'Hydra we see two distinct layers bound together by a non-cellular mesoglea. The two germ layers give rise to many different cell types - as evident from figure. Rest of the animals (platyhelminths to mammals) are all made up of three germ layers viz. ectoderm, endoderm and mesoderm. These animals are triploblastic. If we cut a section say through a horse (a mammal and triploblastic) can we expect to see three layers like you see two layers in diploblastic Hydra? No we will net, because these three germ layers do not .remain as such, they differentiate and modify to give rise to different structures and organs in the body of the horse. The three layers will be distinct only during early embryology. Hence we call them the embryonic layers or the germ layers.
In patients with coronary artery disease an acute coronary syndrome event can precipitate heart failure. Mitral regurgitation occurring as a result of papillary muscle ischemia con
At 1 AM, a researcher places a healthy squid giant axon in a bath of normal squid physiological extracellular saline and internally perfuses the axon with normal squid intracellula
Define Corneal Xerosis - Micronutrient Deficiencies? This is a sign of severe vitamin 'A' deficiency, in which the cornea loses its normal smooth and glistening appearance and
CAR E OF EYES - 1. Eyes should be periodically examined in children. 2. While reading the paper should be held 36 cm. away from eyes and preferable at an angle
In vivo imaging in psychiatry To illustrate the ingenious applications to which in vivo imaging can be put, consider the use of PET in the study of hallucinations by Frith and
Protection Against Insect Bites To minimize insect bites, travellers should wear light-colored, long-sleeved shirts, pants and socks. The most effective topical insect repelle
Name the two hormones produced by the pancreas and say (a) in what circumstances, (b) in what way, they adjust the glucose concentration in the blood.
Q. What kind of exoskeleton do some molluscs present? Some molluscs, like gastropods and bivalves secrete an external calcareous carapace (the shell). Calcium carbonate is a fo
THORACI C CAVITY - Thoracic cavity is air tight. On dorsal side vertebral column present. On ventral side sternum present. On lateral side 12 pairs ribs present. On p
Describe how a phagocyte destroys bacteria. The phagocyte forms a pouch in its cell membrane and engulfs bacteria in the pouch. It then pinches off the pouch to produce a vesi
Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!
whatsapp: +91-977-207-8620
Phone: +91-977-207-8620
Email: [email protected]
All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd