Aspects of Biology

Populations of animals require a continuing food supply. The supply is the amount of food in a given environment, while the demand is the amount of food needed by the population. When demand exceeds supply, famine may result. So long as the supply does not exceed demand and can be replenished on a schedule that matches demand, the population will flourish.

The body has certain nutritional needs, meaning requirements for the compounds that are present in food. Nutrients are those substances that nourish the body in one of three ways: 1) they provide the body with fuel for energy; 2) they supply materials for the building of body tissues; and 3) they furnish the materials that help the work of cells. The nutrients needed by the body come in different groups--carbohydrates, fats, proteins, vitamins, and minerals.

These are the nutrients needed by animal populations, and the question of supply and demand applies to each of these nutrients. Organisms may know instinctively which specific foods supply the needed materials to the body and seek these f

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ed that the population would continue growing unchecked, while in our own time we have approached zero population growth and have at least demonstrated that we can slow the rate of growth through the application of certain techniques and social changes. 3. The higher plants have true stems, roots, and leaves. They also contain vascular tissue and are known as vascular plants. These plants have roots that can go deep into the soil, an adaptation that makes it easier for them to acquire water and minerals. The leaves make the food through photosynthesis. The leaves have an outer covering that holds in moisture. the stems are strong enough to hold the leaves up where they can receive the sunlight needed for producing energy. The vascular tissues carry water and dissolved food to all parts of the plant. The human being makes use of nearly every part of plants, though not of all plants. Certain plants produce leaves which are edible, while other plants may have stems or roots that serve as food to the human being. The stem of some plants is very strong, such as that of the tree. The stem in that case produces wood used by the human being for a variety of purposes. The root of the plant draws the needed substances fro
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Some common words found in the essay are:
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Approximate Word count = 1386
Approximate Pages = 6 (250 words per page)