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!
Spiral Cleavage - Metazoa
In Spiral Cleavage, however, the third and fourth cleavage planes are oblique to the polar axis and the resulting blastomeres do not lie on top of one another but above the furrows between the cells. The spindles during the third cleavage are arranged in the form of a spiral, therefore, the name spiral cleavage. This type of cleavage is seen in all invertebrate except the echinoderms (i.e. in annelids, molluscs, arthropods nemertenes and polyclad planarians).
Figure: Spiral cleavage showing transition from 4 to 8 to 16 cell stage
Spirally cleaving embryos are said to have mosaic or determinate form of development. This means that the organ forming regions of the egg are strictly localised in the egg from the very beginning and the fate of the blastomeres is determined early. If the blastomeres are separated, each will continue to develop up to a certain time as though it was a part of the whole and give rise to defective, partial embryos. In the early embryos an unidentified cytoplasmic factor is segregated into one of the blastomeres, the mesentoblast (this is also called the '4 d' cell) which gives rise to the future mesoderm.
Q. Which is better-scrubbing the instruments or ultrasonic bath to clean the instruments? Ultrasonic bath to clean the instruments is better than hand scrubbing the instruments
Explain Unresorbable Barriers - Root Perforation MTA exhabits excellent tissue biocompatible non resorbable barrier and restorative material. It represents an extraord
A genetic trait which is considered to be harmful in the present day might prove to be beneficial in future. For example by removing the trait for sickle cell we may increase the s
Teratology: It is the study of abnormal embryos. In other words teratology is the study of abnormalities of physiological development. It is often use as the study of birth defect
Q. Show the list of symptoms? The list of symptoms includes: • Bulky, pale, loose, greasy and foul smelling stools. • Anorexia, feeling of fullness, pain abdomen. The
Q. Does the chemical reaction to unite amino acids liberate or incorporate atoms? What are the chemical entities liberated or incorporated in this reaction? The union of amin
Explain the Reduction in free radical generation - Vitamin E? 1) Reduction in free radical generation: Vitamin E acts synergistically with selenium thereby reducing susceptibil
Q. Show Foods that damage GI mucosa? Foods that damage GI mucosa: A number of spices, herbs and other condiments have been found to have little or no irritating effect on the m
(a)State the law of independent assortment. (b )Using punnett square demonstrate the law of independent assortment in a dihybrid cross including two heterozygous parents.
TYPE S OF LYSOSOMES (1 ) Primary Lysosomes or storage granules or protolysosome - The primary lysosomes are smaller in size, they contain hydrolytic enzyme in the form
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