Natural selection is a mechanism by which populations adapt and evolve.
Answer: ADAPTIVE COLORATION
Explanation:
Colour and colour patterns play an important role in adaptations of animals. Such adaptive coloration is due to the presence of pigments in cells called CHROMATOPHORES. These cells are involved in coloration and color change which helps an animal to look like another animal to stay protected from predators.
Adaptive coloration may be grouped into :
--> WARNING COLORATION: some animals display bright colours and patterns that announce their presence rather than conceal it. Example is the yellow and black stripes of yellojackets and other wasps which have very painful stings.
--> MIMICRY: colours and patterns are used extensively by mimics. For example, the foul-tasting Actaea butterfly and the poisonous African monarch are mullerian mimics. They resemble each other closely because they have similar colouring and patterns on their bodies.
--> CONCEALING COLORATION: This is used in camouflage. It helps an animal to remain unnoticed by the predator. Certain animals change the colour of their body surfaces to match their environment and so escape detection.
A mutation is a rare, accidental or induced modification of genetic information (DNA or RNA sequence) in the genome.
The consequences of a mutation vary according to the part of the genome affected. A mutation is said to be hereditary if the mutated genetic sequence is passed on to the next generation.
In multicellular animals, germline mutations can be transmitted to offspring, whereas somatic mutations do.
Somatic mutations do not affect cells intended for reproduction, so they are never hereditary:
* Post-zygotic mutations are the mutations that appear in the egg after fertilization. They are rarer and are expressed as mosaic in the individual concerned (the mutation will be present only in the daughter cells originating from the mutated embryonic cell).
* Mutations can appear throughout life on the DNA of any cell; they are then transmitted to the line of the daughter cells. These can, in some cases, become tumor cells and then form cancer.
Answer:
Less energy is transferred at each level of the food chain so the biomass gets smaller. As a result, there are usually fewer than five trophic levels in food chains.
