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!
Members belonging to different species refrain from mating because of the behavioural differences between them. Such behavioural differences usually centre around specific courtship patterns which the species have evolved. The behaviour patterns are more conspicuous in animals rather than in plants. And among animals, once again, the courtship behaviour is more pronounced among terrestrial and fresh water organisms than in marine forms. Mayr points out that in those forms where there is an elaborate courtship behaviour the interspecific hybrids are rare. Closely related species that do not have pair-binding courtship rituals do commonly give rise to hybrids. Mayr is of the opinion that in species where there is a courtship behaviour pattern, the "engagement" may be broken if the pairs do not belong to the same species, A detailed study of the courtship behaviour of six species of Drosophila showed that courtship and mating could be divided into six phases. If there is incompatibility at any one of these six phases, the potential mates break off and the courtship is discontinued. Under laboratory conditions, the interspecific crosses have not been successful and the courtship was terminated even in the first stage. What is more interesting here is that even to a trained observer differences in courtship behaviour exhibited by different species may appear to be trivial and insignificant. But the species recbgnise the specific signals and respond suitably. In certain other forms differences in courtship behaviour between species could be very pronounced, The courtship dances of the different species of Uca (shore crab) could be recognised from a distance. This is also true of mating dances of salamanders, turtles and birds.
Q. Explain about Steatorrhoea? Steatorrhoea is a symptom of the disorders of fat metabolism and malabsorption syndrome and can be defined as n condition of foul-smelling bulky
Figure shows the flow of energy through the trees in a forest ecosystem.The numbers represent inputs and outputs of energy in kilojoules per m 2 per year. (a) (i) On Figure,
Define Can or receptacle and Labeling and packing? Can/receptacle - This may be performed manually or by using sophisticated filling machinery. The ratio of liquid to solid in
What is Class Amphibia ? Class Amphibia takes its name from the Greek words "amphi" and "bios." Amphi means "both sides," or "both types," and bios means "life." This name-bo
what is the bioindicator of water pollution.
Bond specificity Some enzymes act on a particular bond (glycosidic, peptide, ester etc.). Examples: pepsin, trypsin, chymotrypsin etc. are all only acting on
What are the uses of microorganisms
Q. In the phase when the cell is not dividing interphase is there activity within the cell nucleus? In the interphase there is intense metabolic activity in the cell nucleus th
Q. Why do ribosomes move along mRNA during translation? During translation the ribosome always exposes two mRNA codons to be translated by moving along the mRNA, when a peptide
Define Descending type of paper chromatography? In descending chromatography, the movement or flow of mobile phase is in downward direction. In this technique the solvent is ke
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