In plant seeds, the photoreceptor phytochrome is responsible for the process termed photomorphogenesis<span>. This occurs when a seed initially situated in an environment of complete darkness is exposed to light. A brief exposure to electromagnetic radiation, particularly that whose wavelength is within the red and far-red lights, results in the activation of the photorecepter phytochrome within the seed. This in turn sends a signal through the signal transduction pathway into the nucleus, and triggers hundreds of genes responsible for growth and development</span>
Answer:
Habitat is a place in which organisms live, and niche is the way in which an organism fits into its habitat
A DNA mutation is a permanent alteration in the DNA sequence that makes up a gene, such that the sequence differs from what is found in most people. Mutations range in size; they can affect anywhere from a single DNA building block (base pair) to a large segment of a chromosome that includes multiple genes. DNA mutations can affect an offspring can result in abnormal protein products. Mutations can also introduce new alleles into a population of organisms and increase the population's genetic variation.
If the predator that feeds off the dart frogs goes extinct or migrates to a different area then the dart fronts will have a much larger population. This means that the resources the dart frogs rely on will start to deminish and their prey will have smaller numbers