Revision Summary of B2 -OCR

All the basics needed

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  • Created on: 13-01-12 18:42
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Revision summary -B2 (OCR Gateway)
1. Difference between a natural and artificial ecosystem with examples:
Natural ecosystem: Is where humans don't control the processes going on within it.
Examples: Woodlands or lakes
Artificial ecosystem: where humans deliberately control the growth of certain living organisms and get
rid of others which threaten their wellbeing.
Examples: fish farm or greenhouse
2. Why are some ecosystems still unexplored?
Areas of rainforest are so dense that they're difficult
Deep oceans are rarely visited because special vehicles are needed to withstand the high
pressure. Also reason there's no light so it's to see what is there.
3. Difference between plants and animals:
Plant kingdom: organisms must contain chloroplasts, able to make their own food using
photosynthesis. Plants are fixed in the ground by their roots so their movements are confined to
spreading out to catch as much light and water as possible.
Animal kingdom: compact bodes(able to move around from place to place), they can't make their
own food so they have to find things to eat e.g. plants or other animals.
4. Name two different kingdoms:
Vertebrates and invertebrates
5. What all vertebrates have in common:
Obviously backbone
Internal skeleton: help the animals move and protect their internal organs
6. Five different types of vertebrates

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Binomial system: what do the two parts mean?
First part: the genus that the organism belongs to.
Genus= a group closely-related species
Second part: refers to the species
8. What is a species?
A group of closely related organisms that can breed to produce fertile offspring.
9. Why might two closely related species look very different?
They often share a recent common ancestor, so they're closely related in evolutionary terms.
They often look very alike and tend to live in similar types of habitat.…read more

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What's the difference between a parasitic and mutualistic relationship?
Parasites: live off a host; take what they need to survive without giving anything back. This often harms
the host.
For example: Fleas: dogs gain nothing from having fleas
Mutualism: is a relationship where both organisms benefit.
For example: oxpeckers live off the backs of buffalo, not only do they eat pests on the buffalo, like ticks,
flies and maggots. They also alert the animal to any predators that are nearby hissing.
16.…read more

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Why is glucose easily transported as a plant?
Glucose is soluble, which makes it really good for transporting to other places in the plant, it's also a
small molecule-so it can diffuse in and out easily.
21. Three uses of glucose in plants:
1) Respiration (for): plants use some of glucose for respiration. This releases energy so they can covert
the rest of glucose in to various other useful substances.…read more

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In glaciers if it's too cold for the decay microbes to work
c) Peat bogs are too acidic for decay microbes (A fully preserved man they named `Pete Marsh' was
found in a bog).
25. How fossils found in rocks support the theory of evolution:
`'The theory of evolution suggests that all the animals and plants on Earth gradually `'evolved'' over
millions of years, rather than simply popping into existence.…read more

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Lichens are used to monitor air quality-they're damaged by pollution, the cleaner the air the greater
the diversity of lichens that survive.
Other species have adapted to live in polluted conditions so if you see a lot of them you know there's
a problem.
Bloodworms, water lice, rat-tailed maggots and sludgeworms all indicate polluted water. But out of
these, rat-tailed maggots and sludgeworms indicate a very high level of pollution.
30.…read more

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Humans cause pollution which harms many living things. E.g. pesticides and other pollutants in rivers
contributed to others becoming endangered.
5) We're increasing the competition between species. For example, red squirrels are now endangered
because of the competition from grey squirrels-which we introduced to Britain.
33. What is a sustainable environment?
Sustainable development meets the needs of today's population without harming the ability of future
generations to meet their own needs.
34.…read more


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