There are different types of microscopes used in the classroom today. One type is the monocular compound microscope which has a single eyepiece. Monocular compound microscopes can be used by students in studying different specimens in their science class. Monocular compound microscopes can be used in studying the nutrient procurement in plants.
To keep alive, organisms need materials for the synthesis of new pro¬toplasm for both growth and repair; and they need materials that will serve them as sources of energy. They obtain these materials, or nutrients, from the environment.
Organisms can be divided into two classes on the basis of their methods of nutrition. Fully autotrophic organisms can subsist in an exclusively inorganic environment because they can manufacture their own organic compounds from inorganic raw materials taken from the surrounding media. Since the molecules of these raw mate¬rials are small enough and soluble enough to pass through cell mem¬branes, autotrophic organisms do not need to digest, their nutrients before taking them into their cells. This microorganisms could be studied under monocular compound microscopes. As you would guess, most autotrophs are photosynthetic, although a few are chemosynthetic. The green plants are by far the most important of the earth’s auto¬trophic organisms.
Heterotrophic organisms, which include most bacteria, fungi, and animals, are incapable of manufacturing their own complex organic compounds from simple inorganic nutrients. Hence they must obtain prefabri¬cated organic molecules from the environment. Many of the organic molecules found in nature are too large to be absorbed unaltered through cell membranes, and they must first be digested or broken down into smaller, more easily absorbable molecular units.
It is clear, then, that autotrophic and heterotrophic organisms differ both in their nutrient requirements and in the problems associated with nutrient procurement. And it is not surprising that they should have evolved radically different adaptations in response to the dif¬ferent selection pressures acting upon them.
Nutrient Procurement by Green Plants
Green plants need three classes of nutrients: carbon dioxide, water, and minerals. Carbon dioxide, together with the other components of air, moves into the internal spaces of the leaf through openings in the epidermis called stomata which can be magnified using monocular compound microscopes. Inside the leaf, the air circulates throughout the numerous intercellular spaces. Once inside, carbon dioxide dissolves in the film of water on the surfaces of the leaf cells and diffuses into the cells, where it is used as a raw material for photosynthesis. The numerous structures of a green plant can be studied in detail using monocular compound microscopes.
Aquatic plants such as algae usually lack specialized procurement organs, so they absorb their nutrients through the general body sur¬face. Most higher land plants take in water and minerals primarily through their roots, though most house and garden plants have been found able to absorb nutrients through their leaves if minerals in a water solution are sprayed on them.