Why are most offspring somewhat different than their parents?
A. Not all the genes of the offspring come from the parents.
B. Many major new mutations occur each time the parents reproduce.
C. The offspring's DNA determines its traits, and the parents do not affect this DNA.
D. The parents' genes are "shuffled together" in the process of sexual reproduction.

Blood made up of red and white blood cells work together to form

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

The breakdown of food is accomplished by enzymes. a. physical b. chemical c. mechanical d. none of the above