b2 6 mark questions

8/17/2019 B2 6 Mark Questions

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Name: _______________________________________________

B2 6 mark questions practice

Date:

Time: 30 minutes

Total marks available: 30

Total marks achieved: ______


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Questions

Q1.

* Mitosis and meiosis are types of cell division. Compare these two types of cell division.

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Q2.

* Describe the structure of DN! includin" the roles of the scientists involved in its discovery.(6

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4/26

Q!.

#he dia"ram shows three duc$weed plants in a bea$er of distilled water.

* %&plain how water! "lucose and mineral salts are transported throu"h a plant.(6

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5/26

Q".

* #he dia"ram shows some of the sta"es that occur in the formation of a human fetus.

'sin" the dia"ram and your own $nowled"e! describe the processes that ta$e place in the formation ofthe fetus from a sperm cell and an e"" cell.

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7/26

Q#.

* Describe the roles of the en(ymes involved in di"estion.(6

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8/26

$%aminer&s 'eport

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+ery few blan$ responses were seen for this ,uestion. -ome candidates wrote two descriptions! one formitosis and one for meiosis! but e&aminers credited this by pic$in" out the comparative points. More ablestudents did write actual comparisons and there were some very clear comparisons made in a table

format.

'esults lus: $%aminer )ommentsor a level 3 response! e&aminers were loo$in" for at least two correct comparisons. #hisresponse is a very "ood level 3 response. #he use of bullet points aids the clarity and isperfectly acceptable! provided more than /ust $ey words are listed.

'esults lus: $%aminer Tipou do not have to write lar"e amounts to score well. -hort snappy sentences! eachcontainin" one piece of information e&pressed usin" scientific terms! is a very clear way of e&pressin" yourself.


9/26

'esults lus: $%aminer )omments#his is another e&ample of some of the hi"h ,uality answers that we saw.


10/26

'esults lus: $%aminer )omments lthou"h this candidate has muddled up most of mitosis and meiosis! they have madeone correct comparative statement about the two processes which ma$es this a level 1response.


11/26

'esults lus: $%aminer )omments

or a level response we were loo$in" for at least two correct statements about celldivision. 2ron" e&planations were i"nored.

'esults lus: $%aminer Tip%ven if you $now very little about the answer to a ,uestion! always write what you do$now. ou are "uaranteed (ero mar$s for a blan$ response but you mi"ht pic$ upmar$s if you write somethin".


12/26

'esults lus: $%aminer )omments#his is an e&ample where the candidate also confused mitosis and meiosis but did notma$e any correct comments.


13/26

Q2.

Many candidates coped very well with this ,uestion. -ome candidates wrote all sorts of detailabout this part of the specification it has clearly been thorou"hly learnt and understood.

'esults lus: $%aminer )omments#his candidate "ave a succinct answer and was awarded full mar$s.

'esults lus: $%aminer )omments#his is a typical 4evel 1 response where both parts of the ,uestion have beenaddressed but in insufficient detail. our mar$s were awarded here.


14/26

'esults lus: $%aminer )omments lthou"h this is a "ood account of the contribution of scientists! the account does notaddress both parts of the ,uestion in sufficient detail to score more than a 4evel mar$. #wo mar$s were awarded.


15/26

Q!.

Most candidates were able to access this ,uestion at level and 1 and the better candidatesmana"ed level 3 consistently. #here was some confusion between the vessels that carry thesubstances around the plant with many candidates believin" "lucose is absorbed throu"h theroots rather than bein" made in the leaves throu"h photosynthesis. 5t was pleasin" to note thatseveral candidates were able to identify that the "lucose is converted to sucrose to betransported in the phloem and there were some e&cellent e&planations of the transpirationstream when tal$in" about water movement throu"h the plant.

'esults lus: $%aminer )omments lthou"h this candidate is a little muddled there is sufficient information that is correctto enable the candidate to "et into band 1. #hey have correctly stated movement ofwater into and throu"h the plant in the &ylem and have correctly identified "lucose6sucrose7 movin" throu"h the phloem althou"h they have the mineral ions a littleconfused and also that the "lucose is ta$en in throu"h the roots. #here is still enou"h

for band 1 and 8 mar$s awarded.

'esults lus: $%aminer Tipor a ,uestion li$e this which is in 3 parts it may be worth writin" 3 headin"s andplacin" the information about the three different substances under the relevantheadin"s.


16/26

'esults lus: $%aminer )omments#his candidate has attained level 3 and 9 mar$s they have correctly identified where"lucose is made and how it is transported around the plant in the phloem as sucrose.#hey have also correctly identified the movement of water and minerals throu"h theplant in the &ylem. Clearly written and a "ood level of )2C.


17/26

Q".

#his 9mar$ ,uestion did cause more problems than the previous one. #his was not surprisin" asthe ,uestion content is more challen"in" and this topic was not addressed to any e&tent in the;une paper. #he candidates were re,uired to tal$ about all three processes 6fertilisation! divisionand differentiation7 to be at a level 3! any two processes for a level 1 and /ust one process for alevel .

'esults lus: $%aminer )omments "ood response addressin" all three processes! so level 3. #he response is clear andthe spellin" is "ood.

'esults lus: $%aminer Tip#o access full mar$s candidates must answer all aspects of a ,uestion.


18/26

'esults lus: $%aminer )omments#his candidate has "iven us relevant information about fertilisation and division! so thisis a level 1 response.


19/26

Q#.

Candidates on the whole coped well with this ,uestion they had clearly been tau"ht the specifice&amples "iven on the specification and many /ust listed these verbatim. #he spellin" of thenames of the en(ymes! substrates and products was surprisin"ly "ood. #he better candidatese&tended their answers and "ave details of en(yme action! such as en(ymes bein" catalysts andthe importance of the active site. 2ea$er candidates made mista$es in matchin" the en(ymewith their correct substrate and product6s7! but we mar$ed positively and pic$ed out as manycorrect points as we could. #he poorest scorin" responses were those that either discusseden(ymes in "eneral without ma$in" any reference to di"estion or those that "ave a va"ueoverview of the di"estive system.

'esults lus: $%aminer )omments#his is an e&ample of an e&cellent response to this ,uestion! "ainin" all si& mar$savailable.

'esults lus: $%aminer Tip lways use your specification when you are preparin" for an e&am. 5t will tell youe&actly what you need to $now and the specific e&amples that you need to learn.


20/26

ark +cheme

).

,ndicative )ontent ark

Q-) * comparison between mitosis and meiosis includin" itosis

• 6"enetically7 identical cells produced

• two dau"hter cells• one division

• diploid dau"hter cells

• identical set of chromosomes

• occurs in the formation of body cells

• for "rowth and repair 6of body tissues7eiosis

• 6"enetically7 nonidentical cells

• four dau"hter cells

• 1 divisions

• haploid dau"hter cells

•

half the number of chromosomes• occurs in the formation of "ametes

• for se&ual reproduction

• results in "enetic variation (6

evel 0 No rewardable content

1 1 /2 • a limited description includin" two points on either meiosis or mitosis

there maybe confusion between the two but this does not ne"ate the level

• the answer communicates ideas usin" simple lan"ua"e and uses limited

scientific terminolo"y

• spellin"! punctuation and "rammar are used with limited accuracy

2 ! /" • a simple description includin" one comparison of meiosis and mitosis or a

detailed description of either mitosis or meiosis

• the answer communicates ideas showin" some evidence of clarity and

or"anisation and uses scientific terminolo"y appropriately

• spellin"! punctuation and "rammar are used with some accuracy

! # /6 • a detailed comparison of both meiosis and mitosis < at least two correct

comparisons made

• the answer communicates ideas clearly and coherently uses a ran"e of

scientific terminolo"y accurately

• spellin"! punctuation and "rammar are used with few errors


21/26

Q2.


Q-) * description includin" some of the followin" points in alo"ical se,uence =oints relatin" to DN structuralfeatures:

•

two strands• double heli&

• 6contains7 bases

• ! #! C! >

• adenine ? paired with thymine ? #

• "uanine ? > paired with cytosine ? C

• hydro"en ? @ bonds /oinin" basesContributions from

-cientists:

• Aray 6crystallo"raphy7 bein" used

• to show helical structure

• to show diameter of molecule

• how base pairs are arran"ed was shown• how strands are arran"ed was shown

• modellin"

• reference to usin" other peopleBs ideas (6


1 1 /2 • a limited description that includes either: at least three DN features 0'

one contribution

• the answer communicates ideas usin" simple lan"ua"e and uses limited

scientific terminolo"y

• spellin"! punctuation and "rammar are used with limited accuracy

2 ! /" • a simple description that includes at least three features of DN and at least

one contribution 0' to features of DN and to contributions.

• the answer communicates ideas showin" some evidence of clarity and

or"anisation and uses scientific terminolo"y appropriately

• spellin"! punctuation and "rammar are used with some accuracy

! # /6 • a detailed description of the structure of DN that includes at least three

features and to contributions.

•the answer communicates ideas clearly and coherently uses a ran"e of

scientific terminolo"y accurately

• spellin"! punctuation and "rammar are used with few errors


22/26

Q!.


Q-) *(ii n e&planationincludin" some of thefollowin" points: water

•

throu"h the &ylem• capillary action

• osmosis into cells

in the leaf

• evaporation from

leaves

• transpiration

stream

• diffusion into the

atmosphere

• throu"h stomata

"lucose• converted to

sucrose

• dissolved in water

• throu"h the phloem

• bidirectionalmineral

salts

• dissolved in water

• throu"h the &ylem

• from root to tip (6


1 1 / 2• a limited e&planation of the transport of

one molecule e.". water moves from roots toleaves

• the answer communicates ideas usin"

simple lan"ua"e and uses limited scientificterminolo"y

• spellin"! punctuation and "rammar are

used with limited accuracy

2 ! / "

• a simple e&planation of the transport of

two molecules includin" correct reference to atleast one of the vessels phloem or &ylem.

• the answer communicates ideas showin"

some evidence of clarity and or"anisation anduses scientific terminolo"y appropriately


used with some accuracy

! # / 6

• a detailed e&planation of the transport of

all three molecules with correct reference tomovement throu"h phloem and &ylem

• the answer communicates ideas clearlyand coherently uses a ran"e of scientificterminolo"y accurately



23/26

used with few errors

Q".


* description includin"

• fertilisation of e""

by sperm

• ref to fusion of

nuclei

• formin" diploid cell

• ref to (y"ote

• 6(y"ote7 divides by

mitosis

•

to form identicalcells

• several mitotic

divisions

• "rowth of foetus

• e&amples of how

fetus "rows e" inhei"ht! mass

• stem cells in

embryo

• specialisation ?

differentiation of 6stem7cells into different celltypes

• e&amples of

different cell types e"neurones! s$in cells

• development of

fetus

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1 1 / 2

• a limited description includin" 1 or more

comments about one process• the answer communicates ideas usin"




2 ! / "

• a simple description includin" 1 or more

comments on 1 processes


some evidence of clarity and or"anisation and

uses scientific terminolo"y appropriately• spellin"! punctuation and "rammar are


! # / 6


24/26

• a detailed description includin" 1 or more

comments on all 3 processes

• the answer communicates ideas clearly

and coherently uses a ran"e of scientificterminolo"y accurately




25/26

Q#.


Q-) * description includin"some of the followin"points in a lo"icalse,uence Names ofen(ymes:

• carbohydrases

• named

carbohydrase e"amylase

• proteases

• named protease e"

pepsin

• lipases

• named

lipase>eneral pointsabout en(yme action:

• brea$down of lar"e

? insoluble ? namedmolecules into small ?soluble ? namedmolecules

• for absorption

• catalysts

• speeds up

reactions

• active sites that

bind to substrate

• idea of

specificity-pecificpoints:

• carbohydrates?

starch are bro$endown

• into su"ars ?

"lucose

• proteins ?named

protein are bro$en

down• into amino acids

• fats ? oils ? lipids ?

named lipid are bro$endown

• into fatty acids

?"lycerol (6


1 1 / 2

• a limited description of en(yme action that

includes at least three points

• the answer communicates ideas usin"




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2 ! / "

• a simple description of en(yme action that

includes at least si& points


some evidence of clarity and or"anisation and

uses scientific terminolo"y appropriately• spellin"! punctuation and "rammar are


! # / 6

• a detailed description of at least nine

points

• the answer communicates ideas clearly

and coherently uses a ran"e of scientificterminolo"y accurately



b2 6 mark questions

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