12. Atoms can have different numbers of which of the following? a. electrons
C. neutrons
b. protons
d. all of the above

Why would a drug that damages capsids treat a viral infection? a. capsids prevent the lytic cycle from beginning. b. transduction requires a capsid. c. viruses use capsids to increase genetic variation. d. capsids provide protection for viruses.

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

2. sketch the inside of the bean nodule, and describe or label what you observed with the hand lens.