Chapter 5- How Populations Grow Flashcards
Population density is
The number of individuals per unit area
What are the four characteristics that describe population
Geographic distribution
Density
Population age structure
Growth rate
What are two ways that a population can increase are
Immigration and increased birth rate
When does exponential growth occurs
Under ideal conditions such as unlimited resources, predation absence, and the absence of diseases
What shaped is the exponential growth rate curve
J shaped
Logistic growth occurs when
The birth rate decreases and and the death rate increases and when the birth rate and death rate occur at the sam state as resources become less available
What shape is the logistic growth curve
S shaped
What is the carrying capacity
The largest number of individuals that a given area can support
Density- Dependent limiting factors
Are limiting factors that depend on population size and density
Competition
Organisms compete for food, water, space, sun etc
Predation
Prey relationships is the best known population control mechanism
Parasitism
Taking nourishment from host organisms which often weakens them causing death and disease
Density independent factors
Population doesn’t influence the limiting factors they affect all populations in similar ways regardless of size
Why did the population grow in the industrial revolution
Everything was improved (hygiene and meds)
There are how many people in the world
7-8 bil
What were the two main improvement categories that made popluation rise in the US
Hygine-sewers and clean water
Antibiotics- drugs that kill bacteria
What is the life expectancy 2017
79-woman
78-man
Demography
Is the study of human population which includes the birth and death rate of a population along with the immigration and emigration numbers
What is the demographic transition
It’s when growth slows or stops when countries get birth control education money and knowledge
When will the earth level off and everyone will finish the demographic transition
When we get to 9-10 billion
Genetic engineering will help us feed all those people and we will not starve
What are 3 prominent killer diseases today
Malaria
Cholera
AIDS
