Guided Notes on Populations and Natural Resources Chapter 27, Section 1

Oxygen, carbon dioxide, and water are examples of natural resources that living things use every day.

2. To meet their most basic needs, most organisms are adapted to their immediate environment. They live in a balance with the natural resources their environment provides.

3. Other organisms alter their environment to better meet their needs 3. Other organisms alter their environment to better meet their needs. This has both positive and negative impacts.

4. Of all organisms, humans have an unequaled capacity to modify their environments. This allows us to live in every terrestrial environment on Earth. As a result, humans also have the greatest impact on Earth’s natural resources.

5. Population growth is defined as an increase in the size of a population over time. A graph of a growing population resembles a J-shaped curve at first.

6. Exponential growth is a pattern of growth in which a population grows faster as it increases in size.

7. Many of Earth’s resources are in limited supply, and therefore, most populations cannot continue to grow forever. Eventually, a limiting factor, such as the availability of food, water, or clean air, will cause a population to stop increasing.

8. The carrying capacity is the number of organisms that any given environment can support. A population that is at the carrying capacity for its environment is in equilibrium.

9. Environmental factors that affect population growth, such as storms, droughts, floods, and pollution are density-independent factors. These factors affect all populations that they come in contact with, regardless of size.

10. Density-dependent factors, such as disease, parasites, and lack of food , increasingly affect a population as its size increases.

11. The human population is expected to continue to grow for at least another 50 years. As the population continues to increase, human demand for natural resources will continue to increase steadily.