Answer:
The oblique illumination is
used by the microscopists to resolve N. Spencrii in the Dark Field Condensers.
Explanation:
It was found that the use of oblique light was required to resolve the striae. Oblique illumination was the first step toward dark field microscopy. In dark field, light
seems to radiate from the specimen while all the rest of the field is black. Resolution is as good as that in bright field while contrast is enhanced.
In dark field microscopy, no
direct light from the condenser enters the objective lens. Only light
that is reflected, refracted or diffracted by the specimen enters the objective. The dark field condenser produces a circle of light. The
light is at an extremely oblique angle to the surface of the slide. This
oblique light comes to a focus on the specimen. It then diverges so
strongly that no direct light enters the objective. This type
of illumination is a hollow cone of light.
Is that a question? I dont think i can help answer that
Answer:
The answer is B. Cross-sectional
Explanation:
Cross-sectional research can define as a research that involves using different groups of people who differ in the variables of interest but share other characteristics. Cross-sectional research are studies which based on observations that take place in different groups at one time.
Cross-sectional study can be define as an observational research that analyze data of variables collected at one given point in time across a sample population.
