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Population Ecology

Mia Gonzalez

Mia Gonzalez

8 min read

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Study Guide Overview

This study guide covers population ecology, focusing on populations, factors affecting their survival, and mathematical models for population growth. Key concepts include biotic and abiotic factors, exponential and logistic growth, carrying capacity (K), and limiting factors (density-dependent and density-independent). The guide provides equations, examples, practice questions, and tips for the AP Biology exam.

AP Biology: Population Ecology - Your Night-Before Review 🚀

Hey there, future AP Bio superstar! Let's get you feeling confident about population ecology. This guide is designed to be your quick, high-impact review for tonight. We'll hit the key points, make connections, and get you ready to ace that exam!

What is a Population?

A population is a group of individuals of the same species living in the same area. Think of it like this:

  • 🐝 A hive of bees
  • 🌲 A forest of pine trees
  • 🧑‍🤝‍🧑 Humans in a city

Populations aren't static; they change in size, density, and distribution due to:

  • Resource availability
  • Species interactions
  • Genetic makeup (affecting adaptation)

Population ecology is all about understanding these dynamics and how they affect the health and growth of species. This knowledge is crucial for conservation and ecosystem management.

Key Concept

Populations are dynamic and change over time due to various factors. Understanding these changes is key to conservation efforts.

Factors Affecting Population Survival

A population's survival depends on a mix of biotic (living) and abiotic (non-living) factors:

Biotic Factors

  • Competition: Individuals within or between species fighting for resources (food, water, mates).
  • Predation: One species (predator) eats another (prey).
  • Disease: Pathogens can decimate populations.

Abiotic Factors

  • Resources: Access to food, water, oxygen, shelter.
  • Habitat: A suitable place to live and reproduce. 🌱
  • Climate: Temperature, precipitation, and extreme weather. 🌧️
Exam Tip

Remember, these factors interact! A change in one can ripple through the entire system.

Mathematical Equations for Population Growth

Basic Population Change

The simplest equation:

dN / dt = B - D

Where:

  • dN/dt = change in population over time
  • B = birth rate
  • D = death rate
Quick Fact

Positive dN/dt means the population is growing, negative means it's shrinking.

Example: If a population has 42 births and 17 deaths in a year: dN/dt = 42 - 17 = +25 (population increased by 25) 🦎

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Exponential Growth

Occurs when a population grows at a constant rate, like compound interest.

Conditions:

  • Unlimited resourc...

Question 1 of 12

Which of the following best describes a population in ecological terms? 🤔

A group of different species living in the same area

A group of individuals of the same species living in the same area

All living organisms in a specific habitat

A single individual of a species in a habitat