Ecology Quiz

• Ecology involves the study of how living things interact with each other and their physical environment.
• Living organisms exhibit the characteristics of MRS GREN: Movement, Respiration, Sensitivity, Growth, Reproduction, Excretion, and Nutrition.

Species, Ecosystems, and Niches

• A species is a group of organisms capable of reproducing fertile offspring, sharing similar structural and behavioral traits.
• A population consists of members of the same species living and interacting in a specific area at the same time.
• Population size in an ecosystem depends on biotic (living) and abiotic (non-living) factors.
  • Abiotic factors determine ecosystem type, organism presence and size, like soil type and the amount of kauri trees that is determined by the climate.
  • Biotic factors are the interactions between communities in forests.
• Habitat is where an organism lives, determined by abiotic factors; Pukeko are found near vegetated swamps, streams, or lagoons near grassy areas and pastures.
• Niche is a species role in its environment; a Pukeko eats grass stems, shoots, leaves, and seeds, and also insects and earthworms.
  • No two species can occupy the same niche.
• A community involves interactions of all populations in a habitat; Pukeko eat rushes and compete with weka for nesting spaces.
• An ecosystem represents the interaction between abiotic and biotic factors in a specific area.

Energy Flow in Ecosystems

• All energy in an ecosystem originates from the Sun.
• Plants use photosynthesis to convert light energy into a transferable form.
• Photosynthesis converts carbon dioxide and water into glucose and oxygen, which is then broken down by cells for energy.
• Autotrophs, or producers, perform photosynthesis, using its products in processes like respiration.
• Consumers obtain energy by feeding on other organisms, including herbivores (plant eaters), carnivores (animal eaters), and omnivores (plant and animal eaters).
• Decomposers break down dead materials, returning nutrients to the ecosystem.

Food Chains

• A food chain illustrates energy transfer from one organism to another, starting with a producer.
• Arrows in a food chain indicate the direction of energy flow.
• Plants serve as producers, while animals are categorized as primary, secondary, or tertiary consumers: primary eats plants, secondary eats herbivores and tertiary eats secondary consumers.
• An organism’s position in the chain is its trophic level; energy available decreases at each level.
• Energy is used for life processes, with only 10% transferred to the next level, limiting food chains to usually five trophic levels.

Food Webs

• Most organisms consume multiple food sources.
• A food web is a network of interconnected food chains showing energy flow in a community, where consumers can occupy multiple trophic levels.

Relationships Between Organisms

• Symbiosis is relationship between species, categorized into mutualism, commensalism, and parasitism.
• Mutualism benefits both species; bright mistletoe flowers attract birds that pollinate it.
• Commensalism benefits one species without affecting the other; barnacles benefit growing on whales.
• Parasitism benefits one species while harming the other; mistletoe harms Pohutukawa trees where they grow on.
• Intensive farming practices use fertilizers, herbicides, and pesticides to increase yields, leading to habitat destruction, pollution, and reduced wildlife.

The Carbon Cycle

• Carbon is a key element in living organisms, with plants obtaining it from atmospheric carbon dioxide.
• Animals gain carbon from plants and other organisms.
• The carbon cycle tracks carbon movement between the atmosphere and living things.
• Plants use light and carbon dioxide during photosynthesis to produce glucose, which is then used to make plant tissues.
• When animals ingest plants, carbon is absorbed and used to form animal tissues.
• Fossilization occurs when carbon trapped in dead organisms is compressed into fossil fuels.
• Respiration breaks down glucose using oxygen, releasing carbon dioxide and water.
• Decomposition breaks down dead organisms, releasing carbon back to the environment which allows them to be used by producers.
• Combustion, like burning wood or petrol, releases carbon dioxide into the atmosphere.

Habitat Destruction

• Originally, humans obtained food by gathering and hunting, resulting in smaller environmental impact.
• Agriculture enabled larger populations by modifying the environment, leading to changes in local flora and fauna.
• Larger populations required more food, driving agricultural development where humans altered environments to suit their needs.
• Large areas of diverse forests were replaced with singled crop farmland
• Ecosystem destruction arises from increased land use for food, livestock, resource extraction, pollution, and climate change.
• Alterations to food webs through deforestation leads to soil erosion, flooding and a build up of carbon dioxide.

Pollution

• Pollution means contaminating the Earth's environment by releasing harmful substances.
• Pollutants contaminate the environment.
• Biodegradable pollutants are those that can be broken down by biological agents.
• Non-biodegradable pollutants cannot be broken down by biological agents.

Types of Pollution

• Air Pollution
  • Carbon particles, Sulphur dioxide, Lead and CFC's contaminate the air
• Water Pollution
  • Waste water from factories, homes and fertilizers contaminate the water
• Soil Pollution
  • Polythene, plastic, waste from industries, fertilizers, pesticides and insecticides contaminate the soil
• Noise Pollution
  • Industries, Transportation, entertainment and construction lead to noise pollution

Eutrophication

• Eutrophication occurs when fertilisers are washed off the land by rainwater and enter bodies of water
• An increase of nitrates and phosphates causes algae to grow
• Algae blocks the sun from getting to other aquatic plants.
• These plants die and are consumed by oxygen consuming decomposing bacteria which depletes oxygen levels resulting in the death of all living organisms

Conservation

• A sustainable resource is one which is produced as rapidly as it is removed from the environment
• Biodiversity refers to the variety of different populations in an ecosystem; high biodiversity is important.

Maintaining Biodiversity

• Biodiversity is important for human use because it has medicinal, food and genetic reasons
• Maintaining biodiversity helps protect species, allows genetic engineering and is aesthetically important

Threats to Biodiversity

• Habitat destruction, Introduction of Alien Species, over harvesting, pollution, and climate change effect an areas biodiversity
• Protecting species will help monitor the population and habitats

Conservation Methods

• Conservation programs involve captive breeding and education.
• National parks protect native plants and wildlife by limiting development
• Marine reserves protect areas from activities like fishing.

Test your knowledge of ecological concepts. Questions cover renewable resources, species roles, biodiversity, eutrophication, community interactions, the carbon cycle, ecosystem components, symbiotic relationships, photosynthesis, and food chains.