The primary difficulty is the fact that we do not know all of the organisms that currently exist in the world along with those that existed in the past.
Answer:
A. Classification of organisms
D or a those are the best questions..............XD this question though! anyways see yah later and maybe a brainly?
Answer;
Retinohypothalamic path
A small branch of the optic nerve, known as the retinohypothalamic path extends directly from the retina to the SCN.
Explanation;
The SCN is an abbreviations for suprachiasmatic nucleus or nuclei; which is a region in the hypothalamus. that is responsible for controlling circadian rhythms.
Retinohypothalamic path is a neural input pathway that extends directly from the retina to the SCN.
Scientific information refers to the classification, collection, dissemination, and retrieval of recorded knowledge treated both as a pure and as an applied science. The two features of a scientific information source, which may suggest that the information is not reliable are:
1. The information is based on data that are not peer-reviewed, that is, the information has not been reviewed by the experts in the field, or is not encouraged by an accord of experts in the field.
2. The references are not cited, that is, it not clear or not known that from where the information originated.