The housefly, Musca domestica, has several advantages for the study of circadian rhythm as an educational model animal. Because of its large body size, the signals of locomotive activity of an adult fly can be automatically recorded by using an infrared photodiode and its sensor. In this study we measured the locomotive activity of the housefly using new apparatus designed for a single adult fly. The record of the whole life of adult flies indicated that the locomotive activity of the housefly is controlled by a biological clock and it shows a circadian rhythm. A comparison between the wild type and the triple mutant, wbp (white eyes, brown body and pointed wings) showed that the mutant has a short periodicity of locomotive activity. The rhythm of locomotion seemed to be associated with the rhythm of the pupal stage in both the wild type and the mutant. These results suggest that the rhythms of a pupa and adult are controlled by a common biological clock. Our findings will provide an educational opportunity for school students to understand the importance of a circadian clock in the whole life cycle of the housefly.
In this paper, an experimental study on the effects of light conditions in natural environment on the seed germination of Plantago virginica L. is described. The study found that germination occurred in the majority of seeds that had been buried in a thin layer of soil (2.5mm in depth) under ariticial illumination. In terms of light exposure, seed germination from the soil surface layer was suppressed by of irradiation of sunlight transmitted through the green leaf of an Indian rubber tree for 3 minutes. However, the germination was not suppresed by sunlight transmitted through the rubber tree’s albino leaf, nor through a yellowish or dead banana leaf. Through such experiments, it can be suggested to students that under a green leaf canopy, transmitted sunlight includes far-red light at a higher ratio which suppresses the germination of photoblastic seeds. Such experiments will contribute to better student understanding of plant life and light action in a natural environment.
In this study, two surverys were conduded: a nationwide survey with pre school teachers along with a field survey in Kanto area. These were carried out in order to discover the degree of preschool teachers’ kawareness, action toward installation, and actual use of biotopes in preschool education. The findings from the surveys revealed that the biotope is useful in preschool education; however, what was also found was that biotopes are not generally being installed in preschools. In the light of these results, the sarvey materials have been reexamined in detail, and two suggested paths of action are proposed. The first suggestion is the creation of a simply but effective management manual for biotopes. The second suggestion involves a reconsideration of the significance of the use of the biotope in early childhood education.
In this study, the characteristics of the germination of Bidens biternata (Lour.) Merr. et Sherff ex Sherff, Bidens pilosa L. and Bidens frondosa L. seeds were compared to obtain basic findings to be used for the development of their teaching materials. The following results were obtained.
(1) There was a characteristic of dormancy in the seeds of Bidens biternata (Lour.) Merr. et Sherff ex Sherff and Bidens frondorsa L..
(2) Bidens pilosa L. showed a high germinating rate several days after seeding, and it was found that the optimum germinating temperature was 30°C. Since its seeds can germinate wherever required, they are easily dealt with as teaching aids, and it was believed that these seeds are appropriate for the learning that requires children and pupils to conduct observation of sprouting and subsequent growth.
(3) The study indicated that gibberellin (GA3) exerts an awakening effect on Bidens biternata (Lour.) Merr. et Sherff ex Sherff. Fron this findings, it is clear that this substance can be utilized as an experimental material for determining the awaking effect on the dormancy of Bidens biternata (Lour.) Merr. et Sherff ex Sherff.