Interactions in Ecosystems

Comprehensive flashcards covering Chapter 3: Interactions in Ecosystems, including biomes, biotic/abiotic factors, symbiotic relationships, energy flow, recycling, and human impacts.

What is the difference between a biome and an ecosystem?

A biome is a broad classification of an area based on climate and organisms (e.g., forest), while an ecosystem refers to the specific interactions between living organisms and their non-living environment within that area.

What are the five major biomes found on Earth?

Aquatic, desert, forest, grassland, and tundra.

Define 'biotic factors' and provide examples.

Biotic factors relate to living things or organic matter produced by them. Examples include animals, plants, fungi, bacteria, and waste materials such as faeces and bones.

Define 'abiotic factors' and provide examples.

Abiotic factors relate to the non-living things in an ecosystem. Examples include temperature, light, water, salinity, humidity, wind speed, and pH.

What are the seven life processes demonstrated by all living things?

Movement (move by themselves), respiration (convert food into energy), sensitivity (respond to the environment), growth (grow and develop), reproduction, excretion (excrete waste), and nutrition (take in food).

What is the distinction between a habitat and an ecosystem?

An ecosystem is compared to a suburb where an organism lives, while its habitat is its specific 'address' or the place where its needs for food, water, shelter, and reproduction are met.

Explain the three types of adaptations used by organisms.

1. Structural: physical features (e.g., kangaroo's long tail). 2. Behavioural: actions plants or animals take (e.g., nocturnal behavior). 3. Physiological: internal processes (e.g., efficient kidneys in desert animals).

What are the levels of organisation in an ecosystem from smallest to largest?

Individual, population, community, ecosystem, and biome.

Define 'abundance' in an ecological context.

The number of individuals of a species within a community or an ecosystem.

What is an 'ecological niche'?

The role and space that an organism fills in an ecosystem, including its habitat, feeding relationships, and all interactions with biotic and abiotic factors.

Contrast interspecific and intraspecific competition.

Interspecific competition occurs between members of different species (e.g., kangaroos and sheep), while intraspecific competition occurs between members of the same species.

Define the three major types of symbiosis.

1. Mutualism: both organisms benefit (+/+). 2. Commensalism: one benefits, the other is unaffected (+/0). 3. Parasitism: one benefits (parasite) and the other is harmed (host) (+/-).

Distinguish between ectoparasites and endoparasites.

Ectoparasites live on the outer surface of a host (e.g., lice and ticks), whereas endoparasites live inside the host's body (e.g., tapeworms).

What is the chemical word equation for cellular respiration?

$$\text{glucose} + \text{oxygen} \rightarrow \text{energy} + \text{carbon dioxide} + \text{water}$$

What is the word equation for photosynthesis?

$$\text{carbon dioxide} + \text{water} \xrightarrow{\text{light}} \text{glucose} + \text{oxygen}$$

Define 'chemotrophs'.

Organisms that obtain energy through chemical processes in their environment rather than from sunlight.

How do the teeth of carnivores differ from herbivores?

Carnivores have large, well-developed canines for catching and killing prey, and carnassial teeth for shearing meat. Herbivores often lack upper incisors or canines and have large, flat molars for grinding plant material.

What does the '10% rule' describe in a food web?

It states that only about 10% of the energy is passed from one trophic level to the next; the rest is lost as heat, undigested waste (egestion), or metabolic waste (excretion).

What are 'mesopredators'?

Predators in a mid-ranking trophic level that usually hunt smaller animals.

Define 'detritus' and its role in the brown food chain.

Detritus is dead organic waste or debris. It serves as the starting point for the brown food chain, where scavengers, detritivores, and decomposers recycle nutrients back into the ecosystem.

Distinguish between detritivores and decomposers.

Detritivores ingest and digest dead matter (e.g., earthworms), while decomposers (e.g., bacteria and fungi) secrete enzymes to break down organic material externally and absorb the products.

Describe the three levels of biodiversity.

1. Genetic diversity: differences in genes within a single species. 2. Species diversity: the variety and abundance of different species in an area. 3. Ecosystem diversity: the variety of ecosystem types in an area.

What is 'firestick farming' (or cool burning)?

A land management practice used by Aboriginal and Torres Strait Islander Peoples involving low-intensity, stage-based burns to clear undergrowth, promote plant growth, and prevent intense wildfires.

Define 'biological control' and provide one successful and one problematic example.

Biological control is the introduction of a natural enemy to limit an invasive species. A successful example is the cactus moth for the prickly pear; a problematic example is the cane toad.

What is 'biopiracy'?

The commercial exploitation of naturally occurring biological material, often without fair compensation to the communities where the material originated.