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.
Illustrate about the Principle of Context A third principle guiding the neuropsychological assessment of children is that environment contexts help to constraint and determine
Phytochrome - Floral Induction Phytochrome a pigment that exists in two different inter convertible forms was discovered by Hendricks and Borthwrick et. al. and was chemically
Q. Clinical Features of gout disease? You may be enjoying good heath but may suddenly get a severe attack. You wake up in the middle of the night, and your big toe feels as if
What is Kingdom Protista in diversity of life? Members of Kingdom Protista are grouped separately from the other eukaryotic kingdoms because most of the organisms have a unicel
Adverse effects of Efavirenz The most common adverse effects have been rash, dizziness, headache, insomnia and inability to concentrate. Vivid dreams, nightmares and hallucinat
Q. How are the three major arthropod classes characterized according to the presence of antennae? Crustaceans have two pairs of antennae insects have one pair arachnids don't h
Q. Can you define termination of the stress Test? Test should be terminated when: 1) PVCS develop in pairs or with increasing frequency or when ventricular tachycardia devel
(a) For any individual : · We should check house, doors and windows and have them repaired whenever necessary. · We shou
REGUL A TIV E THEORY It was propounded by Hens Driesch. He performed experiments on the eggs of sea urchin similar to the experiments performed by Roux. He observed
Q. Explain Shannon-Wiener index? This diversity measure is based on information theory of measure of order (or disorder) within a particular system. For our uses, this order co
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