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 preceding section we emphasised the fact that cvolution or the continuous adaptations to the environment can take place only when pheiiotypes exhibit variability. In the absense of variability, the chances arc that existing living organisms would become extinct since with the change in the environment these organisms would die without leaving progeny. Fortunatcly in living systems mutations and recombinations generate the required variability. However, organisms often strive to arrive at populations which are more or less uniform. This is possible because selection process acts in such a way that a certain degree of uniformity of phenotype is imposed among individuals of n population. If an individual were to be vcry different in some way from thc rest of the population. he would be less well adapted to the environment as compared to other members of the population and therefore unable to compete successfully with them. However, in a continuously changing environment, a slight phenotypic variability should be maintained in a population. In a changing environment no phenotype remains optimally adapted for long. This is the precise reason why variability needs to be generated continuously in a population and used to develop adaptations in the way Darwin suggested. We shall look into the mechanisms that generate variability.
57. While planning for an artificial hybridisation programme involving dioecious plants, which of the following steps will be irrelevant A usting of pollen on stigma B Collection
make assignment multiple alleles
High blood pressure (hypertension) has gained considerable significance because it will eventually damage end organs like the heart, brain, kidneys and the eyes. It is estimated th
Plants are the source of a large variety of biochemicals which are metabolites of both primary and secondary metabolism. But secondary metabolites are of much greater interest s
Water soluble Vitamin A Water soluble vitamin A is a yellowish green, slightly turbid, fluorescent liquid of faint characteristic odour. The taste is at first faintly sweet an
Tetanus This is an infectious, non-febrile disease of animals and man, and is characterised by spasmodic tetany and hyperaesthesia. The causative agent is Clostridium tetani,
Soils of Tropical and Temperate Forests Although soils of tropical forests are generally poor in nutrients they are able to maintain high productivity under natural conditions
Q. What are the main functions of the cytoskeleton? As the name indicates, the cytoskeleton is accountable for the support of the normal shape of the cell it also acts as a fac
FLUI D MOSAIC MODEL Proposed by Nicholson and Singer (1972) Proteins and lipids are arranged in a mosaic fashion. Lipids and proteins are in a semi fluid structure.
How do taenias classify according to the division of sexes? Taenias are monoecious (hermaphrodite), the similar individual has female and male reproductive organs and undergoes
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