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. Define Direct Visualisation of Coronary Arteries? Ans. Coronary arteries cad be directly visualized using two-dimensional echocardiography, especially in patients with
Do plants placed under an environment drier than the habitat where they are used to living have a reduction or an increase in the time during which their stomata remain open? I
JOINTS - The structural arrangement of tissues which connect 2 or more bones together at their place of meeting is called a joint. Study of joint is arthrology. Joint make the
Explain the Pipettes - Food Microbiology? Sterile glass pipettes or disposable pipettes can be used for transferring the known volume of liquid or culture aseptically. Steriliz
Cell membrane lining the inner surface of the cell wall The cell membrane lining the inner surface of the cell wall is made up of phospholipids (45%) and proteins (55%). Some
Chloroplasts is the disk-like organelles with the double membrane found in eukaryotic plant cells; contain thylakoids and are the site of the photosynthesis. ATP is produced durin
Minerals :- Iron Food Source Cereals, legumes, meat contamination from iron utensils and soil Nutritional Functional role Essential nutrient: Deficiency lead
heart beat
What are the two divisions of meiosis? What are the main events that happen in those divisions? Meiosis is divided into first meiotic division, or meiosis I, and second meiotic
Third Week - Embryonic Development Throughout the third week of development the ICM separates from the uophoblast and forms the flattened embryonic disc, which at first consi
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