Complete each statement with the correct term from the drop-down menu. Many molecules are moved through the body by
.

provide structure for plants.

determine what people look like.

Cells are surrounded and protected by
.

speed up chemical reactions in the body.

Hemoglobin, a protein, is built by
.

The human body is insulated by

What are the two main phases of a cell cycle

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

Ialready know the answers to these questions and they are on the attachment. but i just need to know why that answer is the correct one. plz asap! this is for a report that i need to email by 10!