Population Characteristics Population density – the number of organisms per unit area

Population Characteristics Spatial distribution – is the pattern of spacing of a population within an area

Spatial Distribution Uniform Clumped Random

Population Ranges No population, not even the human population, occupies all habitats in the biosphere Abiotic factors – temperature, humidity, rainfall or sunlight Biotic factors – predators competitors, parasites

Population-Limiting Factors Density-independent factors – any factor in the environment that does not depend on the number of members in a population per unit area Drought or flooding, extreme heat or cold, tornadoes and hurricanes.

Density-dependent Factor Any factor in the environment that depends on the number of members in a population per unit area. Predation, disease, parasites, competition.

Population Growth Rate How fast a given population grows. Terms Natality – birthrate, the number of individuals born in a given time period Emigration – number of individuals moving away from a population Immigration – number of individuals moving into a population

Exponential Growth Model Carrying capacity S-curve Lag phase

Carrying capacity The maximum number of individuals in a species that an environment can support for the long-term Limited by energy, water, oxygen, nutrients Use this term to describe when a population is stable

R-strategists Small organisms – fruit fly, mouse, locust Short life span Produce many Little or no energy to rear young

K-strategists Large organisms – elephants Long life span Produce few Time invested in care for the young

Human Population Human population growth changes over time

Terms Demography – the study of human population size, density, distribution, movement, and birth and death rates

Human Population on Earth

Trends in Human Population Growth Demographic transition – a change in a population from high birth and death rates to low birth and death rates Zero population growth – when the birth rate equals the death rate Age structure – the number of males and females in each of three age groups of a population, pre- reproductive, reproductive and post-reproductive

Orca

I Purpose: What is the difference between a food chain and a food web?

II Materials: paper, pen

III Procedures/IV Data & Observations

III Procedures/IV Data & Observations List Producers and Consumers Identify with H = herbivore, C = carnivore, O = omnivore, S = scavenger Create a trophic level pyramid

Trophic Level Pyramid

Create three food chains

Create three food chains phytoplankton krill orca

Create a Food Web Create on your own!

V Calculations and Results Draw a graph 22 boxes across X 20 boxes up

VI Questions Answer questions 1 – 8 Answer thoughtfully! Homeostasis |ˌhōmēəˈstāsis|noun ( pl. -ses |-sēz|) the tendency toward a relatively stable equilibrium between interdependent elements, esp. as maintained by physiological processes

VII Discussion Briefly discuss how this could affect 2 other organisms

Conclusion Answer your purpose

Conclusion Answer your purpose Go back to the first question and answer

Animal Rights Hearing Next week’s Lab Need to look up your group’s point of view! Find and bring in an article on your group