How do ecologists study populations? Define: a. Geographic Range b. Population D

Question

How do ecologists study populations? Define: a. Geographic Range b. Population Density c. Age Structure d. Growth Rate What factors affect population growth? Contrast immigration and emigration. Compare and Contrast exponential growth and logistic growth. (Be able to recognize the graphs for each) What is carrying capacity? What is a density independent limiting factor? Give an example. What is a density dependent limiting factor? Give an example. How has human population size changed over time? Why do population growth rates differ among countries? Describe Demographic Transition.

Explanation / Answer

1) ecologists study population by geographic range, density, distribution, growth rate, and age structure.

2) a)Geographical range : The area inhabited by a population is called its geographical range . This can be large or small depending on the size of the species.

b)Population density:it refers to the number of individuals per unit area .

c)Age structure :The number of male and females of each age in a population. Most plants and animals cannot reproduce until they reach a certain age.

d)Growth rate : A populations growth rate determines whether the size of the population increases, decreases or stays the same.

3) factors affecting population growth:

4)immigration: immigration is act of entering a foreign country to live.

Emigration: act of leaving a country to live in another.

5)EXPONENTIAL GROWTH:The members of the population will be able to produce offspring and so the population will grow . Those offspring then reproduce and so on until the population grows very large. The size of each generation of offspring will be larger than the generation before it . The larger a population gets , the faster it grows.This is called exponential growth.it has J-shaped growth curve.

Logistic growth: when a population’s growth slows and then stops following a period of exponential growth it occurs.it has S- shaped curve.

6)The carrying capacity is the maximum number of individuals of a particular species that a particular environment can support..

7)density-independent factor:any factor limiting the size of a population whose effect is not dependent on the number of individuals in the population.example earth quake.

8)density-dependent factor: Any factor limiting the size of a population whose effect is dependent on the number of individuals in the population.eg;biotic variables.

9)Like the populations of many other living organisms, the size of the human population tends to increase with time.

10)In poor countries, a woman has 5-10 or more kids and most of them are dead by the age of 6 due to poor health care. And a man can have 10 or more wifes, about 5 children from every wife and that's 50 children in some 10 years or a bit more. In developed countries, every woman has 1-2 children. But people in developed countries are more busy and don't have time to raise children. So in those countries there are more deaths than births.
11)Demographic transition refers to the transition from high birth and death rates to lower birth and death rates as a country or region develops from a pre-industrial to an industrialized economic system.

Related Questions

Navigate

• Browse (All)
• Browse H
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.