Answer:
the answer is D. lack of genetic variation
Explanation:
yes, what do you need help with?
Answer:
(2) low power: 100 small pollen grains
high power: 25 large pollen grains
Explanation:
Compound light microscopes are devices used to greatly magnify objects. They have several objective lenses, a low-power lens magnifies 10 times (10X) the objects, and the high-power lens magnifies them 40 times (40X).
For that reason, when observing the pollen grains with the high-power lens the student will see them bigger than with the low-power lens. However, the field of view (the visible area through a lens) is reduced when a higher power lens is used, so fewer pollen grains will be seen.
The answer therefore is the option of higher number of pollen grains of small size for the low-power lens, and lower number of pollen grains of larger size for the high-power lens.
Answer:
More Information
Explanation:
New things are found over time, thus changing knowledge.
Answer:
Nuclear magnetic resonance (NMR) technology can penetrate materials without destroying samples, and has the advantages of fast, accurate and high resolution. As a means of studying material properties, it has been widely used in the fields of environment, medical imaging, material structure identification, biochemical analysis, food analysis, coal chemistry, soil science and so on. In the field of soil science, the carbon in soil organic matter samples from forest surface was analyzed by solid NMR technology Dignac, etc. With the help of various experimental techniques, the functional relationship between carbon-nitrogen ratio and element content was obtained, and the change rule of carbon-nitrogen content was confirmed in specific areas. In medical imaging, image formation is the spatial distribution of longitudinal relaxation time and transverse relaxation time and the display of nuclear density reflected by NMR signals. In the field of polymer materials, NMR technology can be used to study the adsorption, desorption and diffusion of polymers in solvents containing different particles. In the field of environment, nuclear magnetic resonance (NMR) has shown its unique importance in studying water uptake in soil and soil wettability.
Explanation:
http://www.creative-biostructure.com/nmr-services_28.htm
l
