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.
What is a recessive gene? With the birth of a child, it gets its genes from both parents. Some genes 'override' other genes. Using hair color as instance: If single parent i
Foraminiferans - Protozoan Foraminiferans are largely benthic marine species. They have multi chambered calcareous tests or shells with numerous pores, hence the name foramini
what is the differences between spherical symmetry and radial symmetry
define?
Sertoli cells are found in: 1. ovaries and secrete progesterone 2. adrenal cortex and secrete adrenaline 3. seminiferous tubules and provide nutrition to germ cells 4.
Types of Mechanism - Stress Condition Plants have evolved a variety of mechanisms to withstand stress conditions. In many cases we can precisely define the way plants enable t
Q What are the retroviruses? How do they reproduce and what is the role of the enzyme reverse transcriptase? Retroviruses are viruses whose genetic material is RNA, HIV and the
Metals and Alloys in alloplastic implant materials Most of the dental implant systems are made of metals or their alloys. Currently commercially pure titanium and its alloy Ti-
How does photoperiodism affect the flowering of some plants? The Flowering is an easy and typical to observe example of photoperiodism. Most of flowering plants flower only dur
Which of the following is a false statement regarding the activity of DNA polymerase during the replication process? A. DNA polymerase reads the template strand in the 5' to 3
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