The point where optic nerves from each eye cross over to the opposite half of the brain is the optic a. chiasm b. disk c. retina d. cornea

The right answer is A. optic chiasm.

The optic chiasm is the part of the brain where the two optic nerves intersect. Each retina is divided into two hemiretins (an internal nasal and an external temporal), the optical pathways of the nasal hemiretins undergoing a decussation (change of side) in the chiasma.

The optical chiasm allows the decussation of a number of axons from the retina, that is to say their change of side to ensure the cross processing of visual information. It is therefore the place where the visual information of the same half-field is collected by the two retinas. This organ located under the encephalon (anterior part) thus allows the stereoscopy (interpretation of the relief).

european union policies. the eu's long-term objective is to achieve levels of air quality that do not result in unacceptable impacts on, and risks to, human health and the environment. eu policies aim to reduce exposure to air pollution by reducing emissions and setting limits and target values for air quality.

the main environmental problems in western europe were: energy production/acid rain, nuclear power/waste, air pollution/climate, heavy metals, pesticides, water pollution, solid waste, and unforeseen accidents. many environmental problems are common to most european countries.

the cell theory states that all living things including animals, as well as plants, are made of cells.