Plant cultivation by various kinds of soil was introduced in upper secondary school biology classes to allow students to notice that the growth of plants depends on the characteristics of soil. Soil samples were collected around the school.

For each soil sample, the percentage of seed germination of Brassica rapa L. and the length of its seedlings were measured. The respiratory rate of each soil sample and the number and species of animals living in the soil were also measured. Some physicochemical characteristics of soil samples were determined to examine their correlation with biological measures. Through these exercises, students could realize the diversity of soil and understand the relationship between organisms and soil.

In the conjugation of a ciliate Euplotes octocarinatus, gamones which the organism excretes into culture medium play important roles in partner recognition. In this study, the method for checking the activity of gamones, the relationship between its storage conditions and the activity, and its stability during heat treatment were examined. The results show that gamones can be useful as a teaching material for understanding the mechanism of conjugation.

In lower secondary schools, experiments about heredity are actually difficult to do in science classes because they take a long time. In this research, a computer software aiming to simulate of the law of heredity was developed to supplement experiments about heredity. The materials used were the fruit fly (Drosophila melanogaster), rose moss (Portulaca grandijlora Hook. “Jewel”) and killifish (Oryzias latipes). The contents of the software are as follows:

1. Hybridization experiments using the parents. One parent was dominant and the other was recessive. That is, in case of rose moss, the one parent was dominant having red-colored flowers; the other was recessive having white-colored flowers.

2. Characteristics of the first generation offspring (F₁). All individuals had dominant characteristics.

3. Hybridization experiments using the F₁ offspring.

4. Counting the characteristics of the second generation offspring (F₂).

5. Getting the results, i. e., the Law of Dominance.

Every process mentioned above was explained using photographs. The developed software was used in the science classes of a lower secondary school. It was shown that this software was effective in promoting the interest of the students and in finding some points for improvement.

From questionnaires to teachers at 2-year colleges in California and from biology textbooks, the teaching of natural science and biology in American 2-year colleges is considered together with the explanations included in some college catalogs.

In these 2-year colleges, there are a great number of students enrolling but they are educated in small groups. Education in these 2-year colleges is similar to the general education at 4-year colleges. In science education, laboratory work is considered to be as important as lectures. To complete an associate degree at a 2-year college, lectures with laboratory work is required as they are in any transfer program. This is one of the major differences in science education between America and Japan.

Biology education covers broad biological areas and lays emphasis on correlation of those areas. Textbooks always contain scientific methods, biochemistry, taxonomy, and environmental science. It was suggested that teachers educate students who have various levels of ability and that they use various techniques in evaluating students.

These results are compared with science education in Japanese junior colleges.