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. Of what subunits are ribosomes are made? Ribosomes are made of two subunits the small subunit and the large subunit. These subunits are made of proteins and ribosomic RNA (r
economic importance of tubularia
Physical Weathering Mechanical forces acting upon the rocks cause physical weathering. Temperature fluctuations cause expansion and contraction of rock surface resulting in the
Types of polyembryony
What is the difference between taeniasis and cysticercosis? Taeniasis is the parasitic disease caused by the adult tapeworm installed within the human intestine. Cysticercos
What are plankton, benthos and nekton? Plankton, benthos and nekton are the three groups into which aquatic living beings may be divided. The plankton is formed by algae and
Determine the Symptoms of Shigellosis Symptoms: Pathogenicity involves the release of lipopolysaccharide endotoxin, which infects the intestinal mucosa. Shigellosis ranges fro
Define Anaerobic Exercise or Energy System? Thus, exercises which are done for short bursts of time lasting only for few seconds (less than 120 sec) use only anaerobic system o
Why is it necessary to have the second division in meiosis even though cells have already been reduced to haploid number after the first division?
Explain Viscosity of proteins Viscosity reflects resistance to flow. The main single factor influencing the viscosity behavior of protein fluids is the apparent diame
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