Support materials only that illustrate some possible contexts for exploring Science as a Human Endeavour concepts in relation to Science Understanding content.
Embryonic stem cells have the potential to be grown into specialised cells and could enable the repair or replacement of ailing organs and tissues. In the late 1990s, stem cells were successfully removed from available embryos at fertility clinics and the world’s first embryonic stem cell line was established (ACSBL037), prompting excitement in the international scientific community and concern in religious and political circles. Concerns about the potential for unethical human experimentation has prompted some governments to prohibit some types of stem cell research, or to limit government funding for it (ACSBL040). International groups such as the International Society for Stem Cell Research have convened experts in science, ethics and law to develop guidelines for human embryonic stem cell research, with the aim of promoting transparent and uniform practice worldwide (ACSBL037).
Photosynthesis is one of the most important biological processes on Earth but it is quite inefficient; researchers report that natural trade-offs result in very low efficiency in many important food crops. Research is currently underway to engineer or enhance photosynthesis to improve food and fuel production. This includes the development of artificial leaves that convert solar energy to a liquid fuel via a process similar to photosynthesis, and investigation of combining more efficient algal photosynthesis with plant photosynthesis to improve crop productivity (ACSBL041). These advances have the potential to decrease reliance of fossil fuels and improve agricultural sustainability (ACSBL043).
From the nineteenth century it was accepted that some form of semi-permeable barrier must exist around a cell, although there was no evidence to indicate its structure. Various scientists, including Traube, Quincke, Fricke and Gorter and Grendel, contributed to the theory that the cell membrane was composed of a lipid bilayer, and in the 1950s the use of electron microscopy confirmed these results through direct investigation of the membrane (ACSBL039). The first model of the membrane to incorporate the notion of fluidity was proposed by Mueller and Rudin in the 1960s, and it was demonstrated conclusively by Frye and Edidin in 1970. The results of this experiment were used by Singer and Nicolson as evidence for their 1972 proposal of the fluid mosaic model of the cell membrane (ACSBL038). Ongoing research continues to refine this model, such as research into the structure of channel proteins in the membrane (ACSBL038).