mixed exam questions unit 2

7/23/2019 Mixed Exam Questions Unit 2

1/14

AS - Spring Break - 2013

1. The photograph below shows a section through a mitochondrion as seen using an electron microscope.

A

C BProf. R. Bellairs/Wellcome Photo Library

(a) Name the parts labelled A, B and C.

A ................................................................................................................................

B ................................................................................................................................

C ................................................................................................................................(3)

(b) Describe the role of mitochondria.

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2. The diagram below shows the structure of a chromosome as it might appear at the end of prophase of

mitosis.

AB

(a) Name the parts labelled A and B.

A .................................................................................................................................


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AS - Spring Break - 2013B .................................................................................................................................

(2)

(b) During metaphase of mitosis, the chromosomes become attached to the e!uator of the spindle.

Name the stage of mitosis that follows metaphase and describe the e"ents that occur in this stage.

#tage ...........................................................................................................................

$"ents occurring ........................................................................................................

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(c) $%plain the significance of the stage &ou ha"e named and described in (b).

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(d) itosis forms part of the cell c&cle. Name one other stage of the cell c&cle and state what occurs in

the stage that &ou ha"e named.

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....................................................................................................................................()(Total 8 marks)

3. The diagram below shows the structure of a bacterium, a t&pical proar&otic cell.

A

B

C

(a) Name A, B and C as labelled on the diagram.


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AS - Spring Break - 2013A ...............................................................................................................................

B ...............................................................................................................................

C ...............................................................................................................................(3)

(b) Complete the table below to show threedifferences between a proar&otic cell and a

euar&otic cell.

*roar&otic cell $uar&otic cell

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3

(3)

(Total 6 marks)

4. The diagram below shows a germinating pollen grain as seen using a light microscope.

A

(a) Name the parts labelled A and B.

A ...............................................................................................................................

B ...............................................................................................................................()

(b) Describe the roles of the two male nuclei during fertilisation.

++++++++++++++++++.++++++++++++++..

++++++++++++++++++.++++++++++++++..

++++++++++++++++++.++++++++++++++..

++++++++++++++++++.++++++++++++++..

++++++++++++++++++.++++++++++++++..


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AS - Spring Break - 2013++++++++++++++++++.++++++++++++++..

++++++++++++++++++.++++++++++++++..

++++++++++++++++++.++++++++++++++..()

(c) An in"estigation was carried out into the effect of sucrose concentration on the germination of

pollen grains from two species of plants,Bauhiniapurpureaand Camelliajaponica. The results

are shown in the graph below.

3 -

.

-

' .

' -

.

-

- ' - - 3 - , -

# u c r o s e c o n c e n t r a t i o n ( / )

0 e r m i n a t i o nr a t e ( / )

B . p u r p u r e a

C . j a p o n i c a

Graph J. B. E. Summer !!"# p. "$!

(i) 1hat is the optimum concentration of sucrose for the germination of pollen grains from both

species2

+++..++++++++++++.+++++++++++++++(')

(ii) Compare the germination rate of these two species as the concentration of sucrose increases

from -/.

+++..++++++++++++.+++++++++++++++

+++..++++++++++++.+++++++++++++++

+++..++++++++++++.+++++++++++++++

+++..++++++++++++.+++++++++++++++

+++..++++++++++++.+++++++++++++++

+++..++++++++++++.+++++++++++++++(3)(Total 10 marks)

5. #ome bacteria were grown in a culture with radioacti"e amino acids. The& used the labelled amino acids

to s&nthesise proteins which were incorporated into their cells.


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AS - Spring Break - 2013The bacteria were then washed thoroughl& and mi%ed with some white blood cells. The amount of

radioacti"it& taen up b& the white blood cells was measured at inter"als of two hours for hours.

The white blood cells were phagoc&tic and engulfed (too up) the bacteria b& a process

called phagoc&tosis. *hagoc&tosis is a form of endoc&tosis. This process is illustrated in the diagram

below.

B a c t e r i u m e m b r a n e e % t e n s i o n s * h a g o s o m e

( p h a g o c & t i c " a c u o l e )

1 h i t e b l o o d c e l l

N u c l e u s

&sosomes then fuse with the phagosome and release their contents into it.

The table below shows the le"el of radioacti"it& found inside and outside the white blood cells during the hour period.

Time after mi%ing cells

together4hours

5adioacti"it& inside white

blood cells4arbitrar& units

5adioacti"it& outside white

blood cells4arbitrar& units

-

6

7

'-

''

'6

'7

-

-

'6

7

6'

8-

8

88'

3

'

'-

7

7-

6

3

'9

'-

7

79

38

9

8-

8

8

(a) (i) Describe the structure of a l&sosome.

+++++++++++++.++.+++++++++++++++

+++++++++++++.++.+++++++++++++++

+++++++++++++.++.+++++++++++++++


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AS - Spring Break - 2013+++++++++++++.++.+++++++++++++++()

(ii) Describe the roles of l&sosomes.

+++++++++++++.++.+++++++++++++++

+++++++++++++.++.+++++++++++++++

+++++++++++++.++.+++++++++++++++

+++++++++++++.++.+++++++++++++++()

(b) Describe the changes in the le"el of radioacti"it& found inside the white blood cells during the

period of hours.

++++++++++++++++++.+++++++++++++++

++++++++++++++++++.+++++++++++++++

++++++++++++++++++.+++++++++++++++

++++++++++++++++++.+++++++++++++++

++++++++++++++++++.+++++++++++++++

++++++++++++++++++.+++++++++++++++(3)

(c) #uggest what is happening to the bacteria inside the phagosomes between '- and

' hours.

++++++++++++++++++.+++++++++++++++

++++++++++++++++++.+++++++++++++++

(d) $%plain wh& the amount of radioacti"it& increases outside the white blood cells after ' hours.

++++++++++++++++++.+++++++++++++++

++++++++++++++++++.+++++++++++++++

++++++++++++++++++.+++++++++++++++

++++++++++++++++++.+++++++++++++++()

(e) #uggest wh& the white blood cells did not tae up all the radioacti"it&.

++++++++++++++++++.+++++++++++++++

++++++++++++++++++.+++++++++++++++(')(Total 11 marks)

6. (a) The diagram below shows a stage in the di"ision of a cell taen from the testis of an animal. The


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AS - Spring Break - 2013...............................................................................................................................................

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(Total 10 marks)

7. The siting of a new sewage treatment wors and the discharge of its effluent need careful consideration in

order to minimise ecological damage. =igure ' shows two possible sites for a new sewage wors near to

the coast in North De"on.

Figure 1 Plan o !ro!ose" sites or se#age treatment #orks$ un"ergroun"

!i!elines an" marine "is%harge !i!elines

&ite 2 p > field &ite 1 a > field

! > field b > conser"ation area

r > field

s > cliff grassland


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AS - Spring Break - 2013t > roc& shore

This de"elopment would in"ol"e the permanent siting of the buildings for the main sewage treatment

plant, an underground pipeline and a marine discharge pipe. A strip of land '- metres wide would need to

be remo"ed during the la&ing of the underground pipeline. The land would be returned to its pre"ious

condition after the wor is completed.

An ecological assessment must be carried out before an& de"elopment can go ahead. The assessment

compares the possible effects of the de"elopment on the terrestrial areas of the two sites. The first stage is

to assign each area to a particular ecological categor&, using the criteria in =igure .

Figure 2 'riteria or assigning e%ologi%al %ategories to an area

'riteria

?er& high species di"ersit& andhighest number of different

habitats or rare habitats@@@

?er& low species di"ersit& andlowest number of different

habitats or rare habitats

%ologi%al %ategor

@@@ '

The second stage is to calculate the impact of the proposed de"elopment within each area using the

following formula

area (m) ecological categor& > units of damage

=inall&, consideration is gi"en to whether the damage is re"ersible or irre"ersible. =igure 3 shows the

results of this ecological assessment sur"e& for #ite ' and #ite .

Figure 3 * %om!arison o the results o the e%ologi%al assessment sur+e or &ite 1 an" &ite 2

&ite 1

Area T&pe of

de"elopmentArea4m

$cological

categor&

nits of

damage

5e"ersible

damage

:rre"ersible

damage

a Building '- -- ' --- ' ---

bE *ipeline '- --- 8- --- 8- ---

Totals 88' --- 8- --- ' ---

&ite 2

Area T&pe of

de"elopment Area4m

$cological

categor&

nits of

damage

5e"ersible

damage

:rre"ersible

damage

p Building ' ---

!E *ipeline -- '


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AS - Spring Break - 2013rE *ipeline 3 --- '

sE *ipeline --

tE *ipeline --- '- ---

Totals

E in"ol"es la&ing of underground pipeline onl&.

%ata a&apte& from JBE 'ol ( )umber Summer "**+

a) #uggest wh& some damage is considered to be re"ersible and some damage is considered to be

irre"ersible.

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(b) Complete the data for #ite in =igure 3.(3)

(c) sing the data in =igure 3, compare the ecological effect that the de"elopment of the sewage

treatment wors would ha"e at #ite ' and #ite .

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(d) #tate what is meant b& s!e%ies "i+ersit.

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(e) The ecological impact on the marine en"ironment also needs to be considered. sing information

from =igure ', suggest three factors affecting the marine en"ironment that should be considered

when comparing #ite ' with #ite .

' +++++++++++++++++++++++++++++++++...

+++++++++++++++++++++++++++++++++...


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AS - Spring Break - 20133 +++++++++++++++++++++++++++++++++...(3)

(f) #uggest wh& an accidental discharge of ra# sewage from the treatment wors might lead to an

increase in the numbers of carni"orous fish around the discharge pipe.

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(Total 16 marks)

8. *lant cells ha"e a cell wall made of cellulose, whereas animal cells do not ha"e a cell wall.

(a) #tate three other structural features found in plant cells but not in animal cells.

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b) The photograph below shows a trans"erse section through the stem of a stinging nettle

(,rtica &ioica), as seen through a light microscope. Diagrams * and F show some cells from

two regions of the section.


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AS - Spring Break - 2013

-lfre& Pasiea /Science Photo Library

(i) Name the t&pe of cell found at * and at F.

* ........................................................................................................................

F ........................................................................................................................()

(ii) $%plain how the structure of the cell walls found at * and F pro"ides the strength to

help support the whole plant.

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(c) #tinging nettles can be grown on land unsuitable for crops.

(i) #uggest onepossible use of har"ested nettle stems.

...........................................................................................................................(')

(ii) $%plain how crops of nettles could be used as a sustainable resource.


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AS - Spring Break - 2013...........................................................................................................................

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,. (a) Describe how the structure of a %&lem "essel helps it to carr& out the function of water transport in

plants.

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(b) $%plain how water mo"es through %&lem "essels in the transpiration stream.

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(c) ineral ions are carried in the transpiration stream. #tate the importance of each of the following

ions for plant growth.

(i) Calcium ions

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(ii) agnesium ions

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(iii) Nitrate ions

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AS - Spring Break - 2013...........................................................................................................................

(3)

(Total , marks)

mixed exam questions unit 2

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