Science Term 1 Week 6: Energy, Food Chains, and Limiting Factors

VOCABULARY flashcards covering energy flow in ecosystems, food chain components, ecological limiting factors including Blackman's Law, and various types of symbiotic relationships.

Energy

Defined as the capacity to do work.

Energy flow

The movement of energy through a series of organisms in an ecosystem.

Primary Producers

Organisms at the first trophic level, such as plants, that take energy from sunlight and convert it into organic material through photosynthesis.

Herbivores

Organisms at the second trophic level that use plants as food to perform metabolic functions like breathing, digestion, and growth.

Carnivores

Organisms at the third trophic level that feed on herbivores to derive energy for their growth and sustenance.

Food Chain

A linear network of links in a food web starting from producer organisms and ending at apex predator species, detritivores, or decomposer species.

Food Web

The system of natural interconnections between multiple food chains.

Food Chain Length

A metric quantified by the number of links between a trophic consumer and the base of the web.

Autotrophs

Primary producers that can use either solar energy or chemical energy to create complex organic compounds.

Chemotrophs

Forms of life that gain all their metabolic energy from chemosynthesis driven by hydrothermal vents rather than solar energy.

Decomposers

Organisms, such as bacteria and fungi, that feed on dead animals and break down organic compounds into simple nutrients returned to the soil.

Keystone Species

A species that has a large impact on the surrounding environment and keeps herbivores from depleting all foliage, preventing mass extinction.

Al-Jahiz

The Arab scientist and philosopher who first introduced food chains in the $10^{th}$ century.

Charles Elton

The author who popularized the food chain and introduced the food web concept in a book published in $1927$.

Limiting Factor

Any variable in an environment capable of limiting a process such as growth, abundance, or distribution of a population.

Liebig’s Law of the Minimum

A law stating that the growth of a population is regulated by the scarcest resource, not by those in abundance.

Blackman’s Law of Limiting Factor

A law stating that a biological or ecological process depending on multiple factors will have its rate limited by the slowest factor.

Shelford’s Law of Tolerance

A principle suggesting that the survival success of an organism depends on a complex set of environmental factors.

Density-Dependent Factors

Factors whose effect on a population is determined by the total size of the population, such as predation, disease, and resource availability.

Density-Independent Limiting Factor

A factor capable of limiting population growth, abundance, or distribution irrespective of population density.

Co-limiting Factor

A factor that causes an indirect restrictive effect or increases the effect of a direct limiting factor.

Resources

Substances within an environment required by an organism for growth, maintenance, and reproduction.

Carrying Capacity

The number of organisms within a population that an environment can sustain indefinitely without environmental degradation.

Fundamental Niche

The total range of environmental conditions suitable for an organism to exist in the absence of limiting factors.

Realized Niche

The actual amount of resources or environmental conditions that an organism is able to utilize within an ecosystem.

Symbiosis

A close and long-term interaction between two different species.

Mutualism

A type of symbiosis where both Species A and Species B benefit from the interaction.

Commensalism

A type of symbiosis where Species A benefits while Species B is unaffected.

Parasitism

A symbiotic relationship where the parasite gains benefits from the host, which in turn harms the host without killing it.

Host

The larger organism in a symbiotic relationship on which a smaller organism depends.

Symbiont

The smaller organism in a symbiotic relationship that lives inside the host.

Endoparasites

Parasites living inside the host’s body, such as Plasmodium falciparum.

Ectoparasites

Parasites living outside the host’s body, such as bedbugs.

Mesoparasites

Parasites that enter the opening of a host body and embed themselves only partially.

Fasciola hepatica

Also known as Liver fluke; a parasite that attaches to the liver and moves to tissue and bile.

Taenia solium

A parasite more than $3000^{mm}$ long that lives in the human gastrointestinal tract and spreads through under-cooked pork.