During which step of meiosis homologous chromosomes pair up? a) prophase 1 b) anaphase 1 b) telophase 1 c) metaphase1

How is the male reproductive system different from other body systems? it isn’t necessary to vital signs. it monitors other body systems, and adjusts if necessary. it transports items from one system to another. it is the only system that produces hormones in the male.

Asmall number of finches are removed randomly from the wild and placed in a protected bird area. they are given as much food as they need and have plenty of space. why would natural selection not occur in this population? a. there is no reason for genetic mutation to occur. b. the birds compete for limited resources, c. the population has not reached carrying capacity. d. there is no genetic variation in the finches.

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