B7 Quiz - Ecosystems

OPEN LOOP: Waste from one part of the process [blank_start]leaves[blank_end] the loop. [blank_start]Waste[blank_end] from the loop [blank_start]cannot[blank_end] be used again. Considered to be [blank_start]unsustainable[blank_end]. The energy in these loops comes from the [blank_start]sun[blank_end] originally.

CLOSED LOOP: Loop can keep going round and round [blank_start]forever[blank_end]. Waste from one part of the loop becomes [blank_start]raw material[blank_end] for the next part. Considered to be environmentally [blank_start]friendly[blank_end]. The [blank_start]energy[blank_end] in these loops comes from the sun originally. Most cycles in [blank_start]nature[blank_end] are this type.

Which of the following are examples of a closed loop system?

The flow of nutrients and minerals is a open loop system.

How does eating plant matter impact on a natural ecosystem?

When organisms produce large numbers of reproductive cells (such as pollen, sperm and eggs) or reproductive structures (such as flowers and fruit), these ensure that reproduction is likely to be successful. The unsuccessful cells and structures are recycled into the ecosystem. They are usually used as nutrients for animals or microorganisms.

No ecosystem is a perfect closed loop system because of...

[blank_start]Desertification[blank_end] is the process of land turning into deserts.

A desert is a place with...

Why does desertification happen? - [blank_start]deforestation[blank_end] - over grazing - intense farming - [blank_start]poor[blank_end] farming techniques ([blank_start]slash[blank_end] and burn) Why do these cause desertification? - leaves and [blank_start]stems[blank_end] slow down the rain, so it hits the ground with less [blank_start]force[blank_end]; without this, the soil quickly [blank_start]loosens[blank_end] and is washed away - vegetation soaks up water from the soil, so reduced [blank_start]vegetation[blank_end] increases the risk of surface [blank_start]flooding[blank_end] - the roots would hold the soil together, preventing it from being [blank_start]blown away[blank_end] Solutions to deforestation? - windbreaks - controlling [blank_start]land use[blank_end] - reforestation/[blank_start]afforestation[blank_end]

In slash and burn agriculture, areas of rainforest are cleared and then burned to create a small piece of farmland.

Define 'ecological services'

Which of the following are NOT examples of ecological services?

Put the steps of the eutrophication process in order.

[blank_start]Bioaccumulation[blank_end] is when toxins build up in a food chain. The animals at the [blank_start]top[blank_end] of the food chain are affected most severely. This is what happens: 1.Small amounts of toxic substances - often from [blank_start]human[blank_end] activity - are taken up by plants. 2.These plants are eaten by [blank_start]primary[blank_end] consumers. 3.The primary consumers are eaten by [blank_start]secondary[blank_end] consumers, and the secondary consumers are [blank_start]eaten[blank_end] by higher level consumers. 4.At each stage ([blank_start]trophic level[blank_end]) of the food chain, harmless substances are excreted but the toxins remain in the tissues of the organisms - so the [blank_start]concentration[blank_end] of toxin becomes most concentrated in the body tissues of the animals at the [blank_start]top[blank_end] of the food chain. An example of bioaccumulation is the use of DDT as an [blank_start]insecticide[blank_end] in the 1950s and 1960s. Birds of prey were badly affected because it made the shells of their eggs very [blank_start]thin[blank_end], causing them to break easily when the birds tried to incubate them.

The size of fish stocks depends on...

Overall, fish stocks are increasing due to pollution and levels of fishing.

What is meant by sustainable fishing?

The following measures can be employed to promote sustainable fishing. Match the measure to the correct explanation.