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!
Population Regulation
The number of individuals in a natural population varies with time. If the size of a population declines too drastically due to some reason, it may become extinct, but may later be re-established by immigration from other populations. On the other hand, increase in size of a population is not infinite since the carrying capacity of the environment always imposes a restriction upon it. In spite of such fluctuations, however, an outstanding feature of most large populations is that their average size changes relatively little over the years and certainly less than is expected from their biotic potentials. This indicates that population sizes are regulated in such a way that small population grow fast, larger populations grow more slowly and still larger populations decline.
Let us see what brings about such ecological homeostasis. In low-diversity, physically stressed ecosystems or in those subjected to irregular or unpredictable external perturbations, populations tend to be regulated by physical components such as weather, water, chemical limiting factors, pollution etc. In high diversity ecosystems, or in those which are not physically stressed, populations tend to be biologically controlled. In all ecosystems there is a strong tendency for all populations to evolve through natural selection towards self-regulation such as failure of reproduction and self-inflicted mortality. Even though this is difficult to achieve under external stress. It is because over-population is not in best interests of any population. Thus it can be said that limitation of number in any population is brought about by the action and interaction of two basic regulatory processes namely density dependent and density independent factors. We will discuss these processes in the following subsections.
MN blood group in humans is under the control of two co-dominant alleles M and N. Blood typing results of a population having of 1349 individuals showed that: - 363 persons h
Q. Show Takhtajans System of Classification? Another important phytogenetic system was proposed by Takhtajan, the famous Russian Palaeobotanist working at Komarov Botanical Ins
Explain Use of food Additives - method of food preservation? Food additives may be defined as substances added intentionally to food, generally, in small quantities to improve
Explain the Combating drug-resistant diseases? The growth of drug-resistant strains of disease-causing bacteria threatens the current effectiveness of cheap antibiotics. This i
Q. What are the endocrine glands involved in the menstrual cycle? What are the hormones in action? The endocrine glands that secrete hormones involved in the menstrual cycle ar
Normal 0 false false false EN-IN X-NONE X-NONE MicrosoftInternetExplorer4 Determine the Yersin
Q. How can the hypothesis that asserts that chloroplasts as well as mitochondria were primitive prokaryotes that related in mutualism with primitive anaerobic eukaryotic cells be c
Silver point extended below canal orifice - Ultra-sonic tip - Microtube tape: The post removal system (PRS) Trephine bur Masserann kit - Do trimming by
Neck Inspect and palpate the neck for any mass, check if neck is short, and webbed which is indicative of Turner's syndrome. Palpate posteriorly along cervical spine; later
Q. How different are the actions of antibodies against virus and against bacteria? Why is the cellular immune response activated in case of chronic viral infection? The antibod
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