Biology 1020 Study Guide: Exam 4 Spring 2025

Flashcards covering key concepts from Ecology and Population Ecology for Biology 1020 Exam 4.

Ecology

The study of interactions of organisms with each other and their environment.

Organism

A single individual of a species.

Population

Groups of organisms of the same species.

Community

All populations in a given area and their interactions.

Ecosystem

Interactions between the biotic and abiotic environment.

Greenhouse Effect

The process by which energy traveling to Earth is absorbed and radiated as heat, with some heat being trapped by the atmosphere.

Greenhouse Gases

Gases that trap heat in the atmosphere, including Carbon Dioxide (CO2), Methane (CH4), and Nitrous Oxide (N2O).

Carbon Dioxide (CO2)

The most abundant greenhouse gas, contributing significantly to climate change.

Past Climate Study (How Scientists study)

Analysis of ice core data to understand historical climate changes.

Present Climate (How Scientists study)

Direct Measurements of Temperature

Future Climate (How Scientists study)

Mathematical models

Population Density

The number of individuals per unit area.

Natality

Birth Rate

Mortality

Death Rate

Immigration

Oneway movement into a population

Emigration

Oneway movement out of a population

Biotic Potential

The maximum growth rate of a population under ideal conditions.

(Every individual survives + Reproduces)

Carrying Capacity

The maximum number of individuals an environment can support.

Steady State

Population stability where population numbers remain fairly constant.

Population Crash

A sudden and sharp decline in the size of a population, typically exceeding the carrying capacity.

Competition

A density-dependent factor where individuals of the same or different species compete for resources.

Predation

An ecological interaction where one organism (the predator) hunts and eats another organism (the prey).

Density Dependent Factors

Factors whose effects on the size or growth of a population vary w/population density, such as competition, predation, disease, pollution, and Intrinsic Mechanisms

Intrinsic Mechanisms

Internal factors that affect population dynamics, such as reproduction rates, survival rates, and behavior of organisms.

Intrinsic Mechanisms (Types of Responses)

Physiological + Psychological

Density Independent Factors

Not dependent on number of individuals in a population

Food Chain

A linear representation of energy transfer between organisms.

Food Web

A complex network of feeding relationships among organisms.

Species Diversity

The variety and abundance of different species within a community.

Keystone Species

Species that have a disproportionately large effect on their environment relative to their abundance.

Trophic Cascade

An ecological phenomenon triggered by the addition or removal of a keystone species, affecting multiple trophic levels.

Biological Magnification

The increasing concentration of toxins in organisms at each trophic level, often harmful to populations.

Endocrine Disruption

Chemical interference with the endocrine (hormonal) system, which can impact population dynamics.