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OCR 21st Century Biology - B7 and Ideas in Context

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could you post the answers?

1. What is meant by the term 'Biodiversity'?

The range of living organisms in one habitat or ecosystem.

2. Why is it important for a habit to have large numbers of plant and animal species living in it?

So the animals can feed off each other to have enough energy supply.
To reduce the effects on other organisms in the food chain.

3. If one species disappears from a habitat, what effects could this have?

Causes changes in number of organisms/species in the same food chain. They may increase, decrease or disappear.

4. If there were 600 invasive species noted in Europe in 1982, how many are there estimated to be now?

600 X 1.75 = 1050

5. For what reasons might species be introduced to an area intentionally?

For biological control
For oranamental value (E.g plants from other climates)
Crops which are useful for commercial purposes

6. By what means might species be introduced to an area unintentionally?

In the air
Through import transporation (sea cargoes, lorries ect)
Accidently in clothing, luggage, food

7. The ruddy duck and harlequin ladybird are described as 'agressive' species. What is meant by this?

They are stronger and more insistent in their behaviour in:
Competing for food
Courtship behaviour
Competing for breeding space
More successful in mating tactics

8. Looking at maps, the harlequin ladybird was most mainly found in the SE England in 2004.

a) From this, where does it seem most likely to have come from?

Nw Europe (France, Belgium, Holland ect)

b) By what means could it travel?

By the wind in flight
Aircraft
Import transportation
Fishing boats

c) How would you compare the rate of invasion between 2003-2006?

Exponential growth

9. How can biodiversity be reduced by introducing more species into a habitat/area/ecosystem?

If the new species is aggressive, it will successfully 'defeat' competing species to reduce their numbers. Some may become extinct or migrate elsewhere.

10. Without a license, animals and plants may not be taken from one country to another and so it is regulated. What sort of species can be carried without anyone being aware of it, and in what form?

Bacteria
Viruses
Parasites
Fungi
Eggs/seeds

11. In what ways can invasive species cause £12 billion worth of damage?

Insects damage crops
Healthcare costs due to illness/disease from Asian Tiger Mosquito
Knotweed causes damage to buildings and infrastructure

12.

a) What is Biological control of species?

Use of natural predators to reduce the number of pests

b) Give two examples of a species controlled by their natural predators.

An insect native to Japan eats teh Japanese Knotweed
Spiders prey upon most small insects

13. What non-biological methods are often used to control:

a) Insects
b) Weeds/plants

Use of natural predators
Pesticides

Reply 81

Freddy-Francis

Original post by Aidn

Sorry about that, i'll edit the last post with it in it and put it here as well just incase! :smile:

THanks xD
I have to do maths, Biology and R.E all at once :frown:

Reply 82

Aidn

Original post by Freddy-Francis

THanks xD
I have to do maths, Biology and R.E all at once :frown:

Feel bad for you man!
I have RE and biology 11th and 12th of june
but I did my maths early in january, so it's cool!

Reply 83

Ambitions

Hey,
Can someone please answer this question:
Why does the courting behaviour of rubber ducks reduce biodiversity?

Oh, and what does “aggressive courting behaviour” even mean? ahaa :P
Thank you, any help would be much appreciated!

Reply 84

Ambitions

Opps, I mean ruddy ducks* :P

Reply 85

Coke1

Still haven't even started for this exam. Biology isn't a subject I am focusing on

Reply 86

L_Vieru

Original post by Ambitions

It means they aggressively mate with other ducks, basically the ruddy duck has ants in its pants and feels the need to get jiggy with any duck it sees (I don't know if I'd get the marks for saying that xD)
Reduces biodiversity because the ducks that are endangered will not be able to mate with other ducks of their species because they have competition with the ruddy duck, which is more agressive when it comes to mating. Soon there will be more ruddy-type ducks than any other duck, which is why biodiversity falls, I think.

Reply 87

joe1545

Biology's always been an easy subject, but this exam looks hard, theres 7 topics, the revision book doesnt provide much help and its 48 for an A* :frown:

Reply 88

yugiohtheawesome

Original post by joe1545

Biology's always been an easy subject, but this exam looks hard, theres 7 topics, the revision book doesnt provide much help and its 48 for an A* :frown:

omg that's a high grade boundary. There goes my chance of an A* :frown:

Reply 89

joe1545

Original post by yugiohtheawesome

omg that's a high grade boundary. There goes my chance of an A* :frown:

That was only in one paper, although i am yet to see one in which below 40 is an A*

Reply 90

yugiohtheawesome

Original post by joe1545

That was only in one paper, although i am yet to see one in which below 40 is an A*

Yeah, I'm looking at the past papers now and all the grade boundaries are quite high :frown:

Doesn't help that I have a history exam that day either..... :colone:

Reply 91

izzyd16

Original post by Freddy-Francis

And look at this stuff for IIC. Trust me if you revise this i guarantee you good marks. :biggrin:

Hope you guys like it!

Thankyouuuu! You are so helpful, i seriously had no clue about this pre-release! :biggrin:

Reply 92

izzyd16

Original post by Freddy-Francis

THanks xD
I have to do maths, Biology and R.E all at once :frown:

I have to do maths, biology, R.E, Geography and History. Not good. :biggrin:

Reply 93

Freddy-Francis

Original post by izzyd16

Thankyouuuu! You are so helpful, i seriously had no clue about this pre-release! :biggrin:

No Prob xD

Reply 94

joe1545

Original post by yugiohtheawesome

Yeah, I'm looking at the past papers now and all the grade boundaries are quite high :frown:

Doesn't help that I have a history exam that day either..... :colone:

Same i have my History Exam too, that i am not looking forward too

Reply 95

L_Vieru

Original post by joe1545

Same i have my History Exam too, that i am not looking forward too

It's a bit off topic but which which topics are you doing in History? Treaty of Versailles, League of Nations, Road to Ww2, Nazi Germany by any chance?

Reply 96

IndigoRainbow

yeah i'm doing those ones! urrghh not looking forward to it.. how much revision have you done for it? :smile:

Reply 97

science-oliver

i'm only going off the specification and it says state the
advantages of a pyramid of numbers
advantages of a pyramid of biomass

I know pyramid of biomass, shows the mass of the organism
the size of the organism
and can show the energy at each level

However what are the advantages of a pyramid of numbers and are their any other advantages of a pyramid of biomass?

Reply 98

BethanyHope

not feeling very prepared for this exam :s-smilie:

i have biology, history, maths and ict next week...

Reply 99

theworld

Can anyone please help me with what i need to get for A/A* in the 7's?? It would be much appreciated..

B123= 41/50
B456= 38/50
C/W = 36/40

C123= 44/50
C456= 38/50
C/W= 34/40 (IT WENT DOWN FROM 36 :angry: