The strain preservation of the heterozygote seems to be possible in an individual plant with an intermediate characteristic. This can be demonstrated by using the plant having an incomplete dominance characteristic. Using the strain of soybean (Glycine max L.) and tomato (Lycopersicon esculentum Mill.) leaves with the characteristic of incomplete dominance are the plant materials used to teach the concepts involving the phenotypic expression. It is considered that the factor of the phenotypic expression affects the synthesis of the photosynthetic pigment in soybean plant, and the chloroplast number in tomato plant.

Vital staining of germinating pollen grains with neutral red (NR) revealed that, in some members of the Liliaceae, Amaryllidaceae, and Iridaceae, a spindle-shaped, reddish area (NR-area) was observed within each pollen tube by about 10 hours after pollen dispersal on the surface of agar plate, which contained NR at a concentration of 10 μg/ml. The NR-area subsequently divided into two NR-areas. The resultant two NR-areas moved slowly within the pollen tube toward its growing tip. Each of the NR-areas contained a spherical or oblong, transparent region at its center. When some pollen tubes were stained with SYBR Green I, the transparent region emitted a green fluorescence characteristic of DNA- SYBR Green I complex, indicating its correspondence to the nucleus. In the oriental lily‘Siberia’, mitotic figures were observed within pollen tubes at the stage of the division of NR-area. These light and fluorescence microscope observations indicate that the NR-area and the resultant two NR-areas correspond to generative cell and sperm cells, respectively. Electron microscopy demonstrated that many small vacuoles, which were probably the entities responsible for the stainability of the generative cell with NR, were present within the cytoplasm of generative cell in the oriental lily‘Siberia’. The staining of germinating pollen grains with NR can readily be carried out and enable to chase the behavior of generative cell and sperm cells within pollen tubes under the conventional light microscope. The light microscope observation on the behavior of generative and sperm cells within pollen tubes employing the vital staining with NR may be applicable to the classes for teaching the role of pollen in double fertilization in high school biology.

Reviewing the transition of conservation education in high school biology, I researched descriptions in high school biology textbooks from 1948 to 2008. The following results were obtained:1. An emphasis on the descriptions of conservation of living things has changed, consistent with enacted laws concerning protection of nature, from protection of living things as resources, protection of natural monuments, conservation of ecosystems, to conservation of biodiversity.2. Descriptions of the decrease of habitat and the effects on native species of alien species were found. However, the reason why genetic diversity was reduced was not explained, and the reason for the change of environmental quality was also not explained.3. The living things which needed conservation were changed from ones on the natural monuments list to those on the endangered species list. Some text books describe a factor to reach extinction. What is desired is an explanation of what situation biodiversity is in and the reason why biodiversity was reduced. And it is hoped hereafter to teach not only ecosystem diversity and species diversity but also genetic diversity by showing examples around us.

In contrast with the many activities using plant tissues, there have been few experimental studies that observed the animal tissues in the biology class in high schools, and early-grades of college. In the present experiment, a brief and simple method was developed using both an embedding medium for frozen tissue specimens and a broccoli stem as their holder. Before the usage, the water in stems of broccoli were replaced with 20 % ethanol to prevent freezing. Some organs of the mice (C57BL and ICR strains) and chick embryos were fixed with 10 % formalin in phosphate buffered saline. The samples frozen with the embedding medium in the broccoli stem has been sectionned with a razor-blade by hand. The tissue structures of the testis, the kidney, the cerebrum, the cerebellum, the lung and the small intestine, as well as chick embryos could be observed with the slide prepared for a microscope by the present method. Thus, it was shown that the present method was good for the biology class of high schools.

This study was conducted that the high school students taught the primary and lower secondary school student. Before teaching, the high school students already studied advanced science by graduate students. The aim of this study is to develop new science education program as a way of enhancing students’ interest for science. The high school students learned DNA identification and the experiments by graduate students. And they also learned how to teach the primary and lower secondary school students effectively. After learning, the high school students taught the primary and lower secondary school students DNA extract experiment as Teaching Assistant.As a result, the primary and lower secondary school students were interested in DNA extract from the living things around us. The high school students recognized that the science was exciting again and they could acquire the teaching skills for younger students.