Answer to Question 1
Larger family size in Africa is related to the rural lifestyle and the fact that subsistence agriculture is still an important way of life for many people in the region. Children are needed laborers to help plant and harvest the crops. In addition, the high child mortality rates encourage people to have more children. Children also provide parents with s form of social security, and the high infant mortality rate means having more children is necessary to ensure a few live to adulthood to care for aging parents. Reductions in infant mortality rates, increased access to birth control, education, empowerment of women, and economic opportunities will play an important role in encouraging smaller families.
Answer to Question 2
Inland barge traffic is possible because of the existence of an intricate system of locks and canals that link the major rivers of the European lowland with coastal ports. In this example, a barge would be pushed up the Rhine and follow a tributary in southern Germany and pass through a canal into the upper Danube and be guided down the Danube.
Three ways that factors affect mortality in response to changes in population density.
Sun size comparison
Sample Size Affects Sampling Error
The family described in Example Case 4
Polyploidy increases fruit size
Detection of 3020insC in CARD15 in a family with Crohn’s disease