Ecological relationships describe the interactions between and among organisms within their environment. These interactions may have positive, negative or neutral effects on either species' ability to survive and reproduce, or "fitness." By classifying these effects, ecologists have derived five major types of species interactions: predation, competition, mutualism, commensalism and amensalism.
Predation: One Wins, One Loses
Predation includes any interaction between two species in which one species benefits by obtaining resources from and to the detriment of the other. While it's most often associated with the classic predator-prey interaction, in which one species kills and consumes another, not all predation interactions result in the death of one organism. In the case of herbivory, a herbivore often consumes only part of the plant. While this action may result in injury to the plant, it may also result in seed dispersal. Many ecologists include parasitic interactions in discussions of predation. In such relationships, the parasite causes harm to the host over time, possibly even death. As an example, parasitic tapeworms attach themselves to the intestinal lining of dogs, humans and other mammals, consuming partially digested food and depriving the host of nutrients, thus lowering the host's fitness.
Competition: The Double Negative
Competition exists when multiple organisms vie for the same, limiting resource. Because the use of a limited resource by one species decreases availability to the other, competition lowers the fitness of both. Competition can be interspecific, between different species, or intraspecific, between individuals of the same species. In the 1930s, Russian ecologist Georgy Gause proposed that two species competing for the same limiting resource cannot coexist in the same place at the same time. As a consequence, one species may be driven to extinction, or evolution reduces the competition.
Explanation: Transcription is a process where a DNA strand is used to make a copy of mRNA. A complementary mRNA strand is made from the DNA strand. This mRNA is then later used to make proteins. In this process the junk information, present in DNA in form of introns is also spliced.
DNA is a double stranded structure, which is present in helical structure and both the strands are twisted together. In order to make the mRNA copy with the help of the enzyme RNA polymerase, DNA must open up. Then only RNA polymerase will be able to access the nucleotides of DNA.
the name porifera means pore bearer in latin. a sponges body is covered by a skin, one cell thick. this skin has lots of small pores ad a few large openings. the small openings are the entrances to a complex system of channels. these collar cells pump water through the entire sponge and filter out food for the sponge cell to eat
