The moth species biston betularia has two color morphs, or variants. one has a speckled white and black color, while the other is all black. in the early 1800s in england, the distribution was 10,000 speckled morphs to 1 black morph. that distribution changed dramatically between 1900 and 1950. by 1950, the distribution of the speckled morph had declined to less than 3% of the population and the black morph distribution increased to 97%. which statement most likely explains this change? a. a predator of the moth underwent steep decline, which reduced selective pressures on the moth. b. a chance mutation occurred in one black individual, which gave an advantage to the black morph's ability to survive. c. the changes are due to normal random fluctuations that might be observed in any population over time. d. changes in the environment changed each morph's ability to evade predation in different ways.

Animal bodies (and even plant bodies for that matter) are complex enough that life couldn't exist without enzymes. enzymes are usually large, complex biological catalysts that are expensive to make. enzymes speed up the rate of chemical reactions without being used up during the reaction (they can be reused many times). they are highly specific in the reactions they regulate. knowing what enzymes are and how they function, why does this explain why complex life forms could not exist if there were no enzymes.

Svetlana and her mother are very similar. both have blonde hair, a love of scrapbooking, blue eyes, and a thin nose. which statement  most likely  describes svetlana’s traits? svetlana inherited her love of scrapbooking from her mother, but her blue eyes come from her environment.svetlana inherited her blue eyes from her mother, but her love of scrapbooking comes from her environment.svetlana inherited her thin nose from her mother, but her blonde hair comes from her environment.svetlana inherited her blonde hair from her mother, but her thin nose comes from her environment.

Where does all the water go? according to the environmental protection agency (epa), in a typical wetland environment, 39% of the water is outflow; 46% is seepage; 7% evaporates; and 8% remains as water volume in the ecosystem (reference: united states environmental protection agency case studies report 832-r-93-005). chloride compounds as residuals from residential areas are a problem for wetlands. suppose that in a particular wetland environment the following concentrations (mg/l) of chloride compounds were found: outflow, 60.4; seepage, 73.7; remaining due to evaporation, 26.4; in the water volume, 46.8. (a) compute the weighted average of chlorine compound concentration (mg/l) for this ecological system. (round your answer to one decimal place.) mg/l (b) suppose the epa has established an average chlorine compound concentration target of no more than 58 mg/l. does this wetlands system meet the target standard for chlorine compound concentration? yes. the average chlorine compound concentration (mg/l) is too high. yes. the average chlorine compound concentration (mg/l) is lower than the target. no. the average chlorine compound concentration (mg/l) is lower than the target. no. the average chlorine compound concentration (mg/l) is too high.