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.
Describe about the Halstead's discriminating tests Halstead's discriminating tests are viewed as a measure of adaptive abilities, of skills that ensured man's survival on the p
Protein denaturizing can be source by temperature variation, pH change, and changes in the concentration of surrounding solutes and by other processes. Most proteins are denatured
Which types of mammal are included in the Primate group? The Primate group contains a) Lemurs, b) Monkeys, c) Apes and humans.
Types of Oxygenators a) Film Oxygenators b) Disc Oxygenators c) Bubble Oxygenators d) Membrane Oxygenators. Film and Disc Oxygenators are not used for clinical
1. Carbon monoxide (CO): It is colourless, odourless, tasteless gas and is not soluble in water. Source: CO is produced due to: (i) Incomplete combustion of fuels
Life style modification in the management of diabetes mellitus All of us have our own way of living. It becomes a routine when we do things in the same way. But when one falls
How can "basic" neuroscience research help to find cures for neurological disorders? A better understanding of the brain at each level - molecules, cells and neural systems -is
Define Unsafe Water and sanitation - public nutrition? Safe water and sanitation may seem tenuous in their link to food security but their impact is unquestionable. With 19% US
What are the target organs upon which insulin and glucagon act? Glucagon mostly acts upon the liver. Insulin acts in general upon all cells. Both also act upon the adipose tiss
What will happen to resting membrane potential if potassium succinate were injected into the intracellular environment (cytoplasm) of a neuron?
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