Once a month, Esteban helps his sister with a newspaper route. He gets paid $20 for his work. After his first day helping, he wanted to buy himself a baseball video game. Instead, he bought his sister a gift for her birthday. Read the scenario and use the drop-down menus to answer the questions that follow. What is the opportunity cost of Esteban’s decision? What resource prevented Esteban from getting both a video game and a gift?

1. variations in a population of moths allow for some of its members to be able to adapt to environmental changes. the better adapted of the moths will be able to survive the change and thus prevail as the “fittest” of the species. (a) describe three mechanisms in which variation can occur within a species population. (b) explain which mechanism or mechanisms would be responsible for the survival of a population of peppered moths better than white moths in an environment affected by industrial soot. justify your answer.

Milk production during breastfeeding is increased by the suckling of a newborn from his mother's nipple. this type of feedback mechanism best describes a positive or negative

Which set of terms best describes a community of miners who live out in the countryside of west virginia and use specialized geographical equipment to analyze the composition of rocks