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.
Porcine rotavirus Piglet diarrhoea and mortality are gaining importance and the viral agent which is highly incriminated in such episodes is porcine rotavirus. The clinical featur
What is the indolacetic acid (IAA)? IAA or Indolacetic acid (indolyl-3-acetic acid) is the major natural auxin made by plants. It promotes plant growth and cellular differentia
Vitamins differ from minerals in that vitamins are compounds, and not elements. Vitamins do not help form bodily structures and thus are needed strictly in small quantities-sometim
Determine about the Sense of Contrast It is the ability to perceive slight changes in luminance between regions which are not separated by definite borders. This is
To study the structure of a seed Soak seeds of bean, pea, pumpkin, sunflower, corn and other large forms. Take away the seed- coats and carefully cut the seeds open. Discover t
Characteristics of Soil Profile The profile characteristics studied in the field consist of locating the soil hor izons (based on its colour description that includes the col
Erythema migrans Oral antibiotic therapy shortens the duration of the rash and generally prevents development of late sequelae. Among the 3 drugs used for this indication, onl
Where in eukaryotic cells does mRNA synthesis occur? To where do these molecules migrate? Messenger RNA molecules are synthesized within the nucleus, pass by pores of the nucle
PEPTID E BOND Peptide or amide bond is a linkage established condensation reaction between amino group of one amino acid and carboxylic group of the second amino acid.
Q. Show Nutrition guidelines for prevention of heart disease? Nutrition guidelines for prevention of heart disease as suggested by WHO are highlighted. Details regardin
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