Wildlife biologists are attempting to monitor the population size of the insect pest known as the gypsy moth (lymantria dispar) during the summer months. to estimate the total population size of these insects living in a 50 square kilometer forest, biologists have sampled 10 random trees, counting the number of eggs and larvae on each selected tree. which factor should be modified to improve the overall experimental design? a) the sample size should be increased. b) data should be collected all year long. c) weather conditions should be controlled. d) researchers should include other insect species.

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

Many organs are involved in the processes of keeping the blood and the body clean. when poisonous or harmful substances are in the blood, they are absorbed by the and released in a less harmful form. when wastes are present in the blood, they are filtered out and removed from the body by the

Explain why process 2 is so important to sexual reproduction identify processes 1 and 3 state one difference between the cells produced by process 1 and cells produced by process 3