Answer:
Two terms might apply for this situation: "<u>jump dispersion</u>" and "human-assisted invasions".
Explanation:
- Dispersion: It refers to the <em>change in an organism's range or distribution area</em>. Different ecological and biogeographical processes might be involved in organisms' dispersion. The term "<u>jump dispersion</u>" refers to a <em>few individuals in a short time that can cross a barrier and occupy a new area</em>. In this situation, the establishment is not always for sure. For this to happen, they must reproduce and start a new population of a certain size that can survive to the new conditions.
- Biologic Invasions: It refers to <em>new species that establish in a new area far or out of their original distribution range</em>. Once established, these species might be <em>considered exotic or invasive, according to their reproductive rate, population growth, and interaction with native species</em>. Biologic invasions are <u><em>natural processes</em></u>, that occur in small groups of individuals that can expand to other ecosystems, and the appearing or despairing of barriers promotes their expansion. <em>But these biologic invasions have accelerated by human beings</em>, referring to this as "<u>human-assisted invasions</u>". These are the cases in which <em>men transport species from one place to the other for different uses or purposes.</em>
It is <em>very common</em> for these species to <em>scape and start new populations</em> in the <em>new area</em>, where they <em>have </em><em>less environmental pressure</em> -fewer predators, more resources, better nitches- than in their origin area, which <em>favors their establishment</em>.
The exposed situation in the example is a case of "human-assisted invasions". It might also be considered as jump dispersion (because a few individuals of the species crossed a barrier and established in a new area) but assisted by humans.
Answer:
plasma membrane of the target cell
Explanation:
There are two main types of acetylcholine (ACh)receptors:
- muscarinic ACh receptors (because muscarin as agonist) which are G-protein coupled receptors that initiate slow response. Mostly, they are located in the central nervous system-CNS (involved in the release of neurotransmitters), heart (control of the heart rate), smooth muscles (contraction).
- nicotinic ACh receptors (nicotin is agonist) which are ligand-gated ion channels involved in the fast response. They are located at neuromuscular junctions but also in CNS (involved in synaptic transmission between two neurons).
Answer:
first 4, then 2, then 1, and lastly 3
Explanation:
First, RNA polymerase binds to the promoter region of a gene on the DNA and initiates transcription. Transcription is the process by which we get mRNA (coding RNA) which is used as a template for protein synthesis. Then, in transcription, the resulting mRNA undergoes modification and maturation. This involves removal of introns, addition of 3'-poly-A tail and 5'-cap. Introns are sequences that do not code for protein and are hence removed. The structure that removes introns is the spliceosome. Thirdly, mature mRNA travels to the cytoplasm. Ribosome (composed of rRNA) binds to mRNA and tRNA to start the process of protein synthesis. The process of formation of protein is called translation. Lastly, the primary structure of protein may undergo folding to form a tertiary structure.
