Một đoạn phân tử ADN có 450 nucleotit loại A. Số nuclêôtit loại không bổ sung với nuclêôtit loại A chiếm 40% tổng số nuclêôtit của đoạn ADN đó. Số lượng nuclêôtit loại G của đoạn ADN nói trên là

Over the past 60 years, many amphibian species have experienced significant population declines and some species have become extinct. scientists suspected that local human activities such as the destruction of wetlands, regional pollution, and deforestation were the main reasons for these losses. however, research over the past 20 years reveals significant amphibian population declines in protected areas of the world, such as nature preserves and parks. these global declines suggest widespread problems including increased ultraviolet radiation, acid rain, and disease. in switzerland, for example, 14 of the 20 native amphibian species are threatened with extinction. chytridiomycosis is a fungal disease first identified in 1998 as a cause of massive amphibian deaths. in some severely impacted populations, a few individuals have survived, perhaps because of some natural resistance. if these resistant individuals continue to survive and prosper, new resistant populations might emerge. this would be an example of the founder effect artificial selection genetic drift natural selection sexual selection

Glucose is a form of sugar found in the blood cells use glucose as a source of energy, but too much or too little can cause serious health issues so, the body uses the hormone insulin to regulate glucose n the blood insulin maintain glucose levels in the blood if blood glucose lovels got very high, what would you expect to see happen to insulin levels?

Archaebacteria use for movement. celia flagella pili cell walls