In the southeastern United States, marshes are dominated by two species of smooth cordgrass; Spartina alterniflora dominates the
seaward edge of the marsh, while Spartina patens dominates the high marsh. You work with researchers and determine that if S. patensis is removed from the high marsh, S. alterniflora will occupy all of the marsh, into the high marsh. If, however, S. alterniflora is removed from the seaward side of the marsh, S. patens will only grow a small portion further seaward, and it does not seem to tolerate being submerged for long periods during high tide. Which of the following is a conclusion you can draw based on this experiment? 1- S. alterniflora is prevented from colonizing the high marsh under normal growing conditions due to predation, resulting in a more seaward realized niche.
2- When S. alterniflora is removed, S. patens can grow in all areas of its fundamental niche, indicating that its distribution is limited by competition to a smaller realized niche.
3- The fundamental niche of S. alterniflora is expanded by its mutualistic relationship with S. patens.
4- When S. patensis is removed, S. alterniflora can grow in all areas of its fundamental niche, indicating that its distribution is limited by competition to a smaller realized niche.
5- The experiment indicates that S. alterflora is a superior competitor and that is why it is found on the seaward side of marshes.
In the given question, S. alterniflora grows in the seaward marsh whereas S. patensis grows in the high marsh. When S. alterniflora is removed, the S. patensis grows to a smaller portion whereas if S. patensis is removed, the S. alterniflora covers all the land.
This shows that although both are different species but they share a niche and the marsh land is the fundamental niche of the S. alterniflora as it can grow in all parts and therefore its distribution is limited by only a realised niche.
For example, if the seeds that the bird needs to eat is bigger, over time it will adapt to get a bigger beak to eat the bigger seed. The birds that have adapted reproduce and soon more and more birds that have a bigger beak for the bigger seed are more common. If the type of food available changes than the bird will most likely adapt to eat that food.
A karyotype is a picture in which the chromosomes of a cell
have been stained so that the banding patterns of the chromosomes appear. This
way it is possible to view abnormalities in the chromosomes. Disorders such as aneuploidy can be diagnosed by karyotype.
It can also help identify local abnormalities on chromosomes such as abnormalities
in chromosome length, and location of the
centromere.
