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.
Determine the following term - Amniote egg Eggs that shelter the developing embryo in a water-filled sac—the amnion. Characteristic of the amniote animals, which include reptil
Q. Why is it said that during photosynthesis carbon dioxide is improved to form glucose? During photosynthesis carbon dioxide is energetically improve with hydrogen from water.
Fire Protection - Factors Affecting Occupational Health Fire protection and extinguishing devices require to be installed at proper places in the work place and proper notices
Explain the two forms of hemicellulose There are two forms of hemicellulose - Hemicellulose A and B - Hemicellulose A is precipitated upon neutralization of an alkaline extract
Heteromorphic Types - Intra specific Incompatibility Plants of the same species produce flowers that differ in morphology. This involves two (distyly) or three (tristyly) morp
Purifying antigens present in small quantities as a mixture by relating an antibody to an antigen.
What is the effect of physical activity on health? The Surgeon General's report (1996) summarizes the effects of physical activity on health as follows. Overall Mortality: H
Why are the recombinant DNA technology and the nucleus transplantation technology still dangerous? A recombinant DNA technology and the nucleus transplantation technology (clon
Microorganisms and Plants can synthesize all of the 20 standard amino acids. Mammals, furthermore, cannot synthesize all 20 and must obtain some of them in their diet. Those amin
Explain Sinus Venosus Defect with Partial Anomalous Venous Connection ? In this defect the atrial septal defect is situated just below the orifice of superior vena cava above
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