Th answer is D its the best answer that fits the question .
N light microscopy, oil immersion is a technique used to increase the resolving power of a microscope. This is achieved by immersing both the objective lens and the specimen in a transparent oil of high refractive index, thereby increasing the numerical aperture of the objective lens.
There are four forces of evolution: mutation, gene flow, genetic drift, and natural selection.
<span>It is called a substrate. </span>
Answer:
Lignin.
Explanation:
The structural integrity of plant spores is lignin that is present in many parts of the plant. This lignin provides hardness to the plant body which help them to stand the plant erect. If this lignin is not present in the plant body the plant will not stand erected. This lignin is present in large amount in the stem of plant body so that's why the lignin provides structural integrity to plant spores