Monthly Archives: August 2015

Food webs and energy transfer

Food_web

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Food chains illustrate the relationship between producers and consumers, showing the different trophic levels in an ecosystem. Because living organisms usually have more than one source of food, these food chains are often linked together, forming food webs. Food webs assist us to identify herbivores, carnivores, omnivores, scavengers, detritivores and decomposers in a community.

Not all relationships within an ecological community are predatory or feeding relationships. Some important relationships are parasitic, mutualistic (both organisms benefit), commensalism (one benefits, the other is not harmed) or parasitism (one benefits and the other is harmed, but usually not killed).

An introduction to ecosystems

Australia-climate

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Australian ecosystems are usually described by a combination of living and non-living components – for example, tropical rainforest, temperate or dry sclerophyll woodlands, alpine meadows or mallee scrublands. The types of communities that live in these ecosystems will be dependent upon the range of temperature and rainfall as well as the soil type, which affects the plants that are able to thrive and therefor the animals that live there. Australian soils are mostly very nutrient poor, due to the fact that the landscape has been exposed to rain, wind and erosion for many millions of years, washing nutrients into the rivers and oceans. An exception to this is the areas where volcanic eruptions have brought nutrients to the surface, such as the western volcanic plains.

A biome is a major community of plants and animals classified according to its predominant vegetation and characterized by the adaptations of its organisms to that particular environment.

YouTube videos:

An introduction to evolution

Equine_evolution

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Good introduction from BBC Earth: How do we know evolution is real?

Evidence for evolution:

Tree of Life Resources:

YouTube Videos:

Reproductive Strategies

antechinus

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Living organisms have evolved many different reproductive strategies to ensure their survival from generation to generation. Scientists sometimes categorize these strategies as “r-selected” (rapid, related to rate) or “K-selected” (related to carrying capacity). You can read a good comparison of r and K-strategies here: Reproductive strategies

Read the ABC Science article: Antechinus go out with a bang and then do “Part B: A case study in reproductive behaviour” on page 150 of your Jacaranda Activity Manual. If you finish, please do the Chapter 12 Review questions and the Activity manual “In Review” for Chapter 12.