It is generally acknowledged that as human beings age, it becomes more difficult for them to lose weight, or even maintain their current weight. People find they have to eat less and/or exercise more to maintain a healthy weight. Which is the most likely explanation of why weight loss/maintenance becomes more difficult as people age?

1. emigration the movement of people from one place to another 2. immigration a situation in which resources are being used up at a faster rate than they can be replenished 3. migration the leaving of one's homeland to settle in a new place 4. overpopulation the movement of people to a new country 5. sustainable development a situation in which the birth rate is not sufficient to replace the existing population 6. underpopulation the ability to meet current needs without reducing the ability to meet future needs 7. unsustainable development the increase in the population of a city 8. urbanization a situation in which the number of people exceeds the available natural resources in an area

Which of the following is an advantage of using embryonic stem cells in medical research? a. the use of embryonic stem cells is much less expensive than the use of adult stem cells. o b. no living tissue is damaged when scientists use embryonic stem cells. o c. embryonic stem cells are able to differentiate into a wider range of cells than adult stem cells. d. there is no controversy surrounding the use of embryonic stem cells.

Select all the offspring phenotypes that could be produced from a bbee x bbee cross (shown above). black fur, red eyes black fur, black eyes white fur, black eyes white fur, red eyes re la heller t est hulle elle l aila el answer : b & c b: black fur ,black eyes c: white fur , black eyes