Question

chapter 4 - population ecology
4.2 - describing populations
a. describes the number of individual organisms present in a given population at a given time.

1. if a population remains steady of increases it is a sign of.
2. if a population decreases or declines quickly it can mean there is a.
3. a rapid change is population size indicates.
4. passenger pigeons, at one time had flocks. they nested in upper and southern. people began to forest. by the end of the, the population was so that pigeon populations were to small. the last pigeon died in.
5. population size is most often estimated using.
6. ecologist count the number in a. then they use the to estimate the number of individuals in the.
7. sampling is helpful for the size of very spread out over an.
8. evidence of wildlife is often used to determine. examples of this would be or.

b. population is a measure of how crowded an area is.

1. population density.
2. in general larger organisms have lower because the require more resources, and thus.
3. how can high population density be beneficial: how can it be problematic.

c. can be distributed randomly, or.

1. population distribution is also called.

Explanation:

Population size refers to the number of individual organisms in a population at a given time. A steady or increasing population can indicate a healthy ecosystem, while a decline can signal problems like habitat loss or over - hunting. Sampling is a common method to estimate population size for widely - spread organisms. Population density measures how crowded an area is, and population distribution can be random, uniform, or clumped.

Answer:

A. Population size

1. A healthy ecosystem
2. A problem (e.g., habitat loss, over - hunting)
3. A change in the ecosystem (e.g., new predator, loss of food source)
4. Enormous; Michigan; Ontario; clear - cut; 1800s; depleted; 1914
5. Sampling
6. Sample area; density; entire population
7. Estimating; large populations; large area
8. Population size; tracks; droppings

B. Density

1. Is calculated by dividing the number of individuals by the area
2. Population densities; need more space
3. Beneficial: easier to find mates, social cooperation; Problematic: increased competition for resources, spread of diseases

C. Individuals; uniformly; clumped

1. Spatial distribution