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!
In the absence of any large scale envirorrmental change that is, in more or less uniform environments, populations often maintain a stable genetic constitution with respect to many traits. Natural selection in the absence of environmental change maintains a genetic homeostasis. This phenomeon is known as normidising selection Several of the phenotypic, traits of individuals can be arranged on a linear scale. The distribution curve of the traits usually takes a bell shape, so that the number of individuals is greater at intermediate values and gradually decrease towards the extremes. Ja. As stated earlier, normalising selection occurs when individuals with intermediate phenotypes are favoured and those with extremes are under selection pressure. This tendency continues generation after generation. If there is a strong selection pressure against the phenotypes occupying the extremes of normal curve, then the population may show less variability although the mean remains the sarne. Natural selection has more often a normalising or stabilising effect on populations with mid-values for the traits and individuals with intermediate values for their traits have better chances of survival. For instance, new born infarits which weigh very less or very more than the average weight have high rate of mortality. Contrarily infants of intermediate weight have less problems of survival. We discuss two examples below, one from nature and the other from the experiments of Dobzhansky and Spassky to explain the concept of normalising selection.
Problems with untreated/ammoniated crop residues Besides the low energy and protein contents, crop residues generally contain low content of minerals such as Calcium, Phosphor
HOMOPO L YSACCHARIDE S (= HOMOGLYCANS) These are complex carbohydrats that are formed by repeated condensation or polymerisation of only one type of monosaccharide monome
mode of digestion in coelenterata
everything about osmosis
Differences between Budding and Fission Both budding and fission are identical in at least one way in that the young ones produced by these procedures are the result of direct
Q. What are the functions of the spleen? Why is a total splenectomy (surgical removal of the spleen) compatible with life? The spleen has many functions: it participates in the
Nutrient Elements of Plants Let us first find out the chemical composition of plants and see which element nature has selected to support their healthy growth. Only then we wi
Classification of Nephrotic Syndrome In childhood, nephrotic syndrome can be divided into minimal lesion nephrofic syndrome and significant lesion nephrotic syndrome dependin
Define Changing Body Composition and Techniques for Measuring Body Composition? Changing body composition has been suggested as a pathway to explain age-related functional decl
Excluding the effects of cardiac output and hormones, describe the other factors that may affect blood pressure and blood flow in a middle-aged man who is exercising in an aerobics
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: +1-415-670-9521
Phone: +1-415-670-9521
Email: [email protected]
All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd