Question

chapter 13 review questions - populations

1. when describing a population, what are three things that must be included?
2. identify the four factors that can change the size of a population
3. identify the two factors that increase population size.
4. identify the two factors that decrease population size.
5. limiting factors prevent a population from growing beyond the carrying capacity. what is a carrying capacity?
6. list three examples of abiotic limiting factors.
7. list three examples of biotic limiting factors.
8. identify one abiotic factor that might limit the growth of the populations.

a. seedlings growing on the forest floor
b. trees growing on the mountainside
c. plants growing in a desert

Explanation:

1. To describe a population, species identity, size, and geographical range are essential. Species identity defines what organisms are in the population, size is the number of individuals, and range shows where they live.
2. The four factors affecting population size are birth rate, death rate, immigration, and emigration. Births and immigrations add individuals, while deaths and emigrations remove them.
3. Birth rate and immigration increase population size. Births produce new members within the population, and immigration brings in individuals from outside.
4. Death rate and emigration decrease population size. Deaths remove individuals, and emigration is when individuals leave the population.
5. Carrying capacity is the maximum number of individuals of a species that an environment can sustain indefinitely. It is determined by available resources like food, water, and space.
6. Abiotic limiting factors are non - living elements. Examples include temperature (extreme heat or cold can limit growth), water availability (drought can harm populations), and soil type (affects plant growth which in turn affects other populations).
7. Biotic limiting factors are living elements. Examples are predators (control prey populations), competitors (for resources like food or space), and parasites (can weaken or kill hosts).

8.
a. For seedlings on the forest floor, light availability is a limiting abiotic factor as taller trees can block sunlight.
b. For trees on the mountainside, temperature and wind can be limiting. Temperatures drop with altitude and strong winds can affect growth.
c. For plants in a desert, water availability is a major limiting abiotic factor due to low precipitation.

Answer:

1. Species identity, population size, geographical range
2. Birth rate, death rate, immigration, emigration
3. Birth rate, immigration
4. Death rate, emigration
5. The maximum number of individuals of a species that an environment can sustain indefinitely
6. Temperature, water availability, soil type
7. Predators, competitors, parasites

8.
a. Light availability
b. Temperature and wind
c. Water availability