An organism or part having or consisting of many cells.
Aim
When dividing the world into zoogeographical regions, Alfred Russel Wallace stipulated a set of criteria by which regions should be determined, foremost the use of generic rather than species distributions. Yet, recent updates of Wallace's scheme have not followed his reasoning, probably explaining in part the discrepancies found. Using a recently developed quantitative method, we evaluated the world's zoogeographical regions following his criteria as closely as possible.
Location
Global.
Methods
We subjected presence–absence data from range maps of birds, mammals and amphibians to an innovative clustering algorithm, affinity propagation. We used genera as our taxonomic rank, although species and familial ranks were also assessed, to evaluate how divergence from Wallace's criteria influences the results. We also accepted Wallace's argument that bats and migratory birds should be excluded (although he was contradictory about the birds) and devised a procedure to determine the optimal number of regions to eliminate subjectivity in delimiting the number of regions.
Results
Regions attained using genera (eight for mammals and birds and six for amphibians) strongly coincided with the regions proposed by Wallace. The regions for amphibians were nearly identical to Wallace's scheme, whereas we obtained two new ‘regions’ for mammals and two for birds that largely coincide with Wallace's subregions. As argued by Wallace, there are strong reasons not to consider these as being equivalent to the six main regions. Species distributions generated many small regions related to contemporary climate and vegetation patterns, whereas at the familial rank regions were very broad. The differences between our generic maps and Wallace's all involve areas which he identified as being uncertain in his regionalization.
Main conclusions
Despite more than 135 years of additional knowledge of distributions, the shuffling of generic concepts, and the development of computers and complex analytical techniques, Wallace's zoogeographical regions appear to be no less valid than they were when he proposed them. Recent studies re‐evaluating Wallace's scheme should not be considered updates as such because they have not followed Wallace's reasoning, and all computer‐based analyses, including this one, are subject to the vagaries of the particular methods used.
Answer:
The correct sequence is 21543.
Explanation:
The procedure by which the signaling molecules known as neurotransmitters are discharged by the neuron's axon terminal and combines and reacts with the receptors present on the dendrites of another neuron or postsynaptic neuron is termed as neurotransmission.
The following are the steps followed in the process of neurotransmission:
a. Exocytosis of neurotransmitter gets stimulated by calcium.
b. The diffusion of neurotransmitter takes place across the synaptic cleft.
c. The binding of neurotransmitters takes place with the receptor.
d. After the binding opening of ion channels takes place.
e. The permeability of the postsynaptic membrane gets changed.
Endocytosis is taking stuff in while exocytosis is getting rid of the stuff and putting it out
Answer:
b. "I will begin doing exercises to strengthen the muscles of my back."
Explanation:
The teaching has been effective when the patient states "I will begin doing exercises to strengthen the muscles of my back." because by doing so, the muscles that support his back will be strengthened, which will help him to maintain a correct posture and to make fewer efforts when lifting thing. He should not lift things above the level of his elbows even if he keeps him back straight and bends his knees and hips to lift.
