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.
Define Quantitative Procedures in Carbohydrates? You have learnt how to identify some individual monosaccharides, disaccharides and polysaccharides. However, if we were asked t
Explain briefly Nucleic Acids (DNA & RNA)? Nucleic Acids (DNA & RNA) : Nucleic acids are the molecules that contain genetic information that is inherited, and are responsibl
Explain the senses taste and smell ? The pigmented cone cells of the retina transmit information to bipolar nerve cells, then to ganglion cells, and on to the optic nerve and t
In general what is the phase of the menstrual cycle when copulation may lead to fecundation? Although this is not a rule, to be effective fecundation in general must happen wit
What are twins? Genetically what are the two types of twins that can be generated? Twins are simultaneously generated (within the mother's uterus) offspring. Twins classify acc
Use the rules of probability to predict the ratios of progeny expected from two parents who are heterozygous for albinism. Note: Albinism is recessive to normal skin color. 1) What
Explain about the PH - Nutritional Biochemistry? You have already studied about pH in your undergraduate years and know what it means. Yes, mathematically we can define pH as e
Determine the posterior superior alveolar nerves The anterior, middle and posterior superior alveolar nerves run in the facial wall of the maxillary sinus between its lining me
why is it necessary to classify living organisms ? what are the advantages of classifying organisms?
Q. How are the major classes of arthropods classified according to the presence of larval stage in their embryonic development? In crustaceans there are others with indirect an
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