wjec mark sheme summer 2005 - thiacin...f212 mark scheme june 2010 question expected answer mark...
Post on 02-Aug-2020
12 Views
Preview:
TRANSCRIPT
WJEC
Classification, Evolution &
Biodiversity
Class Questions
Mark Scheme
21
UNIT B1 5
Question Answers/Explanatory Notes MarksAvailable
1. (a) (i) red squirrel
panda
any whale/dolphin
tiger
Any suitable 3 species [1]
(ii) (ii) poaching/overfishing/overhunting
habitat destruction/deforestation
competition from introduced species (not: increased competition)
pollution (not: climate change unequal)
Any suitable 2 reasons leading to endangerment Not just population effect
[1]
(b) (i) Cochlea [1]
(ii) Perilymph [1]
(iii) Basilar [1]
[5]
2. (a) Chordata
Pisces/Fish [2]
(b) Unable to reproduce/interbreed with each other to produce fertile/viable offspring; (not; they cannot reproduce)
Any sensible reason for not interbreeding, e.g. behaviour. (not: geographical isolation)
Have different characteristics/features/appearance.
Any 2 [2]
(c) Reference to DNA/genetic fingerprinting/base sequencing/ immunological comparison;
Close similarities should be present between the species. (i.e. technique and related result)
[2]
F212 Mark Scheme June 2010
Question Expected Answer Mark Additional Guidance 2 (a) placing, living things / organisms / named organisms, into,
groups / categories / taxa / named taxonomic groups ;based on / AW, similarity / difference ;
2
ACCEPT ‘grouping living things’ Look for the idea of similar organisms being placed in the same group or different organisms being placed in different groups
2 (b) (i)
1
2
3
4
5
morphology / anatomy / (observable / physical) features / appearance / AW ; biochemistry / cytochrome C ; genes / DNA / genetics / RNA ; behaviour / physiology / embryology ; idea of shared, evolutionary past / phylogeny ;
3 max
ACCEPT suitable examples for mps 1 to 4
1 CREDIT cell features e.g. nucleus / membrane- bound organelles / cell wall / prokaryotic-eukaryotic features / unicellular
2 CREDIT component of cell wall
3 IGNORE chromosomes
4 ACCEPT ‘how they feed’ / nutrition / ‘how they reproduce’
5 ACCEPT ‘how closely related’ IGNORE refs to interbreeding / fertile offspring
2 (b) (ii) T S R W U Q ; ; ;
3
Mark the order of letters (ignoring the dotted lines) All 6 in correct order = 3 marks If any incorrect, then credit T S in order at beginning = 1 mark U Q in order at end = 1 mark R before W anywhere in the sequence = 1 mark
5
F212 Mark Scheme June 2010
Question Expected Answer Mark Additional Guidance 2 (c)
1
2
3
4
5
6
3 domains AND 5 kingdoms ; domains are, bacteria / eubacteria, AND, archaea / archaebacteria, AND, eukarya / eukaryotes ; kingdoms are prokaryotes AND protoctists AND fungi AND plants AND animals ; eukaryotes split into different kingdoms / all eukaryotes are in the same domain ; all prokaryotes are in the same kingdom / prokaryotes split into different domains ; domain classification based on, rRNA / ribosomes / RNA polymerase / protein synthesis / enzymes / flagella / membrane structure ; 4 max
ACCEPT phonetic spellings throughout ACCEPT alternative terms for names of kingdoms and domains throughout (e.g. plants / plantae)
2 ACCEPT ‘eukaryota’
3 DO NOT CREDIT protists / protozoa
6 IGNORE RNA unqualified DO NOT CREDIT other forms of RNA
ACCEPT any detail of protein synthesis
Total 12
6
� � ����� � � � � � � � � � � (��� ��)�
�� � �� �
������������ ���� (�$�������� ����������� ������� �&� %��$���"� ������%��������� *� �����������%�� � �� *� ������� �&� �%���$����"�&����!� � � �� � � �
����� (�$�������� ����������� ������� �&� %��$����"�&�����%�� * ����� *� ������#���%�� �� *� ������� �&� ���$����"�&����!� ���
�"�� � ������� ��� !���������������������� �*�� �� � �"���%� *� ��!�� ������*����%��+,!�� �������� �������������������������������������������� � ����$�� �����������!����������� � � � � � � � � � � � (��� ��-��
��
Mark Scheme � General Certificate of Education (A-level) Biology � Unit 2: The Variety of Living Organisms � January 2011
Question Marking Guidance Mark Comments
3(a) Kingdom, phylum and class;; 2 Lose 1 mark for each error (i.e. omission or incorrect response). Sequence not essential.
3(b)(i) Shows evolutionary relationship; 1
3(b)(ii) 26; 1
3(c)(i) 1. Base sequence will be similar/some bases in common;
2. These bases will bind together/hydrogen bonds/complementary pairs;
2 Do not accept same here.
Accept converse providing that it is clear that the converse argument is being made.
3(c)(ii) 1. Relationship is closer/more complementary bases/more base pairs;
2. More hydrogen bonds; 3. More heat energy needed (to separate bonds);
2 max
Do not allow stronger hydrogen bonds.
Not higher temperature as this is in question.
Mark Scheme � General Certificate of Education (A-level) Biology � BIOL2 � January 2012
5
Question Marking Guidelines Mark Comments
3(a)(i) Synodontis batensoda / S. batensoda;
1 Ignore spellings
3(a)(ii) Mochokus niloticus; 1 Ignore spellings
3(b) 5; 1
3(c)(i) Fertile offspring produced; 1 Allow suitable description of offspring being fertile.
3(c)(ii) 1. Attracts/recognises same species;
2. Attracts/recognises mate/opposite sex;
3. Indication of sexual maturity/ fertility / synchronises mating;
4. Stimulates release of gametes;
5. Form pair bond;
2 max Attracts mate of the same species = two marks.
3. ��������� ���������
Mark Scheme – General Certificate of Education (A-level) Biology – BIOL2 – January 2013
5
Question Marking Guidance Mark Comments
3(a) Kingdom Animalia
Phylum Chordata
Class Mammalia
Order Carnivora
Family Felidae
Genus Panthera
Species pardus
2 One mark for each correct column
Do not award mark for last column if ‘Pardus’ is clearly stated
Accept: Panthera pardus in final box
3(b) (For the leopard and cheetah)
1. More hydrogen bonds (form);
2. Similar DNA sequence(s) / similar base sequence(s) / more complementary bases / more base pairs;
2 Accept converse argument for leopard and puma
Neutral: similar DNA
2. Idea of ‘more’ must be clear
3(c)(i) 1. Drop in population / many killed / only single female left;
2. Idea of reduced/low genetic variation/diversity / reduction in (variety of) alleles / smaller gene pool;
2
3(c)(ii) 1. Mutation affecting sperm cell or production (in small population);
2. Errors during meiosis;
3. Inbreeding / closely related cheetahs breed;
4. High chance of inheriting allele / high frequency of allele (in the population);
2 max
4. Accept: high frequency of homozygous/two recessive alleles
Mark Scheme – General Certificate of Education (A-level) Biology – BIOL2 – June 2013
6
Question Marking Guidance Mark Comments
3(a)(i) 1. Groups within groups;
2. No overlap (between groups);
2 1. Accept: idea of larger groups at the top / smaller groups at the bottom
3(a)(ii) (Grouped according to) evolutionary links/history/relationships / common ancestry;
1 Neutral: closely related
Neutral: genetically similar
3(b)(i) 1. (Only) one amino acid different / least differences / similar amino acid sequence / similar primary structure;
2. (So) similar DNA sequence/ base sequence;
2
3(b)(ii) 1. Compared with humans / not compared with each other;
2. Differences may be at different positions / different amino acids affected / does not show where the differences are (in the sequence);
1 max Accept: degenerate code / more than one triplet (codes) for an amino acid
3(b)(iii) 1. All organisms respire/have cytochrome c;
2. (Cytochrome c structure) is more conserved / less varied (between organisms);
1 max Accept: converse arguments for haemoglobin
1. Accept ‘more’ instead of ‘all’
1. Accept ‘animals’ instead of organisms’
2. Neutral: cytochrome c is conserved
BY2
1. One mark for each line:-
Animalia: Fungi: Protoctista: Plantae: Prokaryotae. [5] (no mark if extra ticks present)
[Total 5 marks]
2. (a) Wings of birds and bats. [1]
(b) (i) Adaptive radiation (Allow Speciation / Natural Selection) [1]
(ii) No competition from other birds / vacant niches / subsequent intraspecific competition (Any two) [2]
(c) Unable to interbreed and produce fertile offspring [1] (allow: breed together. Not: unable to breed)
(d) DNA profiling/hybridisation (comparing DNA or equivalent e.g. fingerprinting) (not: looking at DNA/electrophoresis unqualified) [1]
[Total 6 marks]
11
Question MarkScheme
4 (a) Chordata/chordates (accept vertebrata/vertebrates). 1
(b) (i) Pentadactyl (limb). 1
(ii) B. 1
(ii) Phoca. 1
(c) (i) Homologues/homologous. (not: analogous/adaptive radiation) 1
(ii) They suggest the existence of shared/common ancestors
(not: similar ancestors)
1
(d) (i) 6. 1
(ii) Macroderma gigas. 1
(e)
1
9 MARKS
12
Question Answer Mark
2. (a) (i) Arthropoda 1
(ii) jointed legs max
exoskeleton
fluid-filled body cavity / haemocoel/ open circulatory system
2
Segmentation/ segmented body NOT large brain
(b) (i) a group of organisms that can interbreed / breed with each other to
produce fertile offspring
1
(ii) Genus 1
(iii) DNA base sequencing / hybridisation/ sequencing analysis/ DNA
electrophoresis Not DNA analysis/ analysis alone
genetic fingerprinting or profiling/
amino acid sequencing of proteins / differences in protein structure
(not: biochemical methods unqualified) NOT compare DNA/ genes
1
(iv) high level of similarity shows that they are closely related / converse
argument. Needs to relate to 2 a (iii)
1
Question Total 7
11 © WJEC CBAC Ltd.
GCE BIOLOGY - BY2
Mark Scheme - January 2013
Question Marking details Marks Available
1 (a) A species is a group of organisms that {can interbreed/
reproduce};
(under natural conditions) produce fertile offspring;
2
(b) (i) birds; 1
(ii) Borneo {1.61/ 1.62/1.6}; 1
(iii) (Least at poles to) {greatest/ increasing} at equator; 1
(c) (i) X at second split from left or anywhere along that line; 1
(ii) Same genus( but different species)/ tells us the genus; 1
(d) (i) homologous; 1
(ii) analogous;
1
Question 1 total [9]
�������������� ���� �� � ��� ����$ ��� ��3���!��$���!������ ��0 � �""��%�� %����&� � � '��
����� 0 ���$������%�����" �� ���� � ���� !�� ����$ ��� ��3���!�#��!�$$ � ������������ ����� �#% � �"�� # 0� �������3�������3#���3����"�� �%��� #����� ���� #� �� �%��� �!�$$ � �� �&� � � � '�
����� ���� 4��%!��� ��������������
5�3 ��� 6���!��������� ����� ��� ����� 7 �������������� 8��3"�!�!� �9 ���� ������" �� �� � �������������'�����" ������ ����� �����
� � � �� � � � � � � � � ���� ����� :��� 3������ ���� �� ��%����!�$$ � ���% � ��&� � � � � '��
���� �
Biology - AQA GCE Mark Scheme 2010 June series
9
Question Part Sub Part Marking Guidance Mark Comments 6 (a) Most closely (related) to chimpanzee / most recent common
ancestor; Least (related) to dogfish / least recent common ancestor;
1 1
����������� ������� ������chimpanzee as equivalent to second mark point. Allow answers which compare similarity in DNA/genetic material. Marks should not be awarded for answers which only compare amino acid sequences without any indication of relationships. Al������� ������������� ����and �����for dogfish
6 (b) Is present in all eukaryotes; 1
6 (c) Reference to base triplet/triplet code / more bases than amino acids / longer base sequence than amino acid sequence; Introns/non-coding DNA; Same amino acid may be coded for / DNA code is degenerate;
1 1 1
2 max Different (base) triplets code for same amino acid = 2 marks Reject different amino acids are formed/produced. Ignore reference to codon.
F212 Mark Scheme June 2011
Question Expected Answers Mark Additional Guidance 6 (a) (i)
3 parts to body ; head + thorax + tail ; segmented ; lateral spines / spines from both sides of head ; thorax / tail , similar shape ;
3 max
Mark the first answer on each numbered line. ACCEPT wherever seen ACCEPT ‘a lateral spine’ ACCEPT description of thorax / tail shape
6 (a) (ii) anterior spine (from head) on A ;longer lateral spines on B ;less rounded / AW , head on B ;any other reasonable difference ; ;
2 max
Mark the first answer on each numbered line. Answers must state either species A or species B ACCEPT ora throughout e.g. (greater) fusion of tail segments in B
grooves around edge of head in B outline of tail section (more) curved in A
A has more segments CREDIT any clear description of a difference
6 (b) 1
23
4
56
idea of fossils show changes over time ;idea that there are methods to date fossils ;idea of simplest / most different from modern , species /
AW , in oldest rocks ; idea of showing , links / relationships , between , groups /
species / organisms / taxa ; many fossils organisms no longer exist ;idea of compare DNA extracted from some fossils ; 2 max
2
4
ACCEPT it is possible to date fossils
ACCEPT ref to common ancestor of two species Answers could refer to links between species A and species B
Total [7]
14
F212 Mark Scheme January 2012
Question Answer Marks Guidance 4 (a)
taxonomy / taxonomic ; hierarchy ; phylogeny / phylogenetic ;
3 Mark the first answer. If the answer is correct and an additional answer is given that is incorrect or contradicts the correct answer then = 0 marks ACCEPT phonetic spelling throughout
ACCEPT hierarchical system
(b) (i)
1 (cells have) no cell wall ;
2 heterotrophic ; 3 eukaryotic ; 4 multicellular ; 5 (fertilized eggs develop into), blastula / ball of cells ; 6 high degree of mobility / AW ;
2 max Mark the first answer on each prompt line.
1 DO NOT CREDIT absence of a qualified cell wall, e.g. ‘no cellulose cell wall’
2 ACCEPT phonetic spelling 3 ACCEPT named eukaryotic cell feature 4 IGNORE references to tissues
6 DO NOT CREDIT unqualified references to movement
ACCEPT refs to mobility during part of life cycle
IGNORE cilia / flagella
(ii)
Eukaryota(e) / Eukarya / eukaryote(s) ;
1 Mark the first answer. If the answer is correct and an additional answer is given that is incorrect or contradicts the correct answer then = 0 marksIGNORE case of initial letter
14
F212 Mark Scheme January 2012
Question Answer Marks Guidance (iii)
1 all are in same family as all, are closely related ;
2 kea and kaka are both, same genus / Nestor ; ora for kakapo
3 kea and kaka, are more closely related / share more recent common ancestor, (than with kakapo) ;
4 kea and kaka have more genes in common / AW (than with kakapo) ;
5 example of genetic similarity (between kaka and kea) evident from Fig 4.1 ;
6 differences between, kea and kaka / all three, are great enough for each to be described as a different species ;
4 max Candidates may refer to individual species using common or scientific names. ACCEPT use of either or both. IGNORE case of initial letter
1 idea of link between family and close relationship must be made
3 ACCEPT ora for less close relationship between kakapo and others
4 ACCEPT ora 4 Answers must refer to genes / genetics / DNA
4 IGNORE cytochrome c
5 E.g. kaka and kea both brown / kaka and kea both have similar shaped beaks
5 IGNORE unqualified references to appearance
(c) (i) differences ; in / within / between, species ;
2
ACCEPT within a population
15
F212 Mark Scheme January 2012
Question Answer Marks Guidance (c) (ii)
genetic differences / different alleles / inherited differences ;
environment / diet / disease ;
2 Mark the first suggestion on each prompt line. ACCEPT different genes
ACCEPT mutation
ACCEPT sex
IGNORE ‘different habitat’
(c) (iii)
only small number have been sampled / AW ;
idea that individuals sampled may not be representative of population ; data collected when population was larger / smaller population may mean range has changed ;
2 Mark the first two reasons – ignore prompt lines. ACCEPT ‘whole population has not been sampled’
IGNORE rare unqualified ACCEPT larger ones more likely to be caught / measured
ACCEPT individuals sampled from one area might be different from average of whole population
16
F212 Mark Scheme January 2012
Question Answer Marks Guidance 4 (d)
Name
1 speciation ;
Mechanism – max 2 marks
2 isolation / separation, (of populations) ;
3 further detail of isolating mechanism ;
4 mutation / genetic variation ;
5 natural selection / description of natural selection ;
6 different selection pressure(s) (in different environment) ;
7 (enough) time to allow changes in population to
prevent interbreeding / AW ;
3 max
1 IGNORE ‘natural selection’ on name line
2 IGNORE barrier
3 e.g. river, mountain, reproductive, geographical, temporal, polyploidy, qualified barrier
3 IGNORE allopatric / sympatric unqualified
5 description must mention differential survival and genes being passed on
6 IGNORE selection pressure unqualified 6 ‘different’ can be described using an example
Total 19
17
F212 Mark Scheme June 2012
8
Question Answer Marks Guidance 2 (a) �
kingdom�membrane
-bound organelles�
cell wall� type(s) of nutrition�
� � �������������
and�����������;�
������ �� ���Protoctista�;� � � �
�� ��� ����;� � �
������ ����Plantae�;� �
����� ���������
��������������� ��;�
�
�
�� ��� ����;� � �
�
6
Mark the first answer in each box. ��������� ���� ������������������������� ���� ����������� ������������������ ������������� �����������0 marks ���� IGNORE�� ����������������ACCEPT����������� ��� IGNORE�� �����������������ACCEPT����������� ���
(b) ���������; �
1 Mark the first answer. ��������� ���� ������������������������� ���� ����������� ������������������ ������������� �����������0 marks � ALLOW������ �������������������IGNORE�� ���������������
�
F212 Mark Scheme June 2012
9
Question Answer Marks Guidance (c)
1 2 3 4 5 6 7 8 �
Assume answers refer to 3 domain classification unless otherwise stated �� ��������������� ���� �!"#���$"#���������� ���
������������ ; �
idea that �������������������� ����� ���� ����%������ �����%������ � ;������������� ���#&� ����%������ �; ora idea that������������� ��������� ���#&� ������������������������������ ; ���'��������������������� ���� ������������(����) ; ���������������� ���#&� ���%������ ����������; ora � idea that������������� ������������������������� ������ �����������%������%����� �;���'��������������������� ������ ���� ������������*����+ ; ��
3 max CREDIT�,�������� �������������� ������������IGNORE�� �����������������
1 CREDIT�����������'���������'������ 3 ����%������ ����� ������������� ����� ������������������������������������-����% �����(�����)�� 4 ACCEPT�������� ������ �������������4 ACCEPT����������������4 IGNORE����������'����� ������� ��� ��� ��������������� �������� 5 IGNORE �����(����)������������ 5��.�.���������� �������������������������������������������������������$"#���/��� ���#0�� ���������� ��������������������������!"#���������������� ���������� 6 IGNORE � ������������ ���������� .�#� ������ �� ������������%������ ����������������������� ���������.�6����%������ ����������������� �������������� ������������ ������ ����-����% �����*�����+��6 IGNORE������ ������ 7 IGNORE����������'����� ������� ��� ��� ��������������� �������� 8 IGNORE �����*����+������������ 8 �.�.�������%������ ����� �������������������������������� ���123���� ��� ������������� /����������!"#�������� ��� ���� ���� ���.�
� � � Total 10 �
����� ������ � � ��� ������
���
�� ������� ���� �� ����� ������� ��� ���� � �
������������� ���!�
Echiniscus�"��������"�������"�� �������"������������"��
�� ������ �#��������� ����� ����$���$��%�� &�������������������������������������������������������������������������������������������������������������������������������''()*����������������������������������������������������������''()*������������������������� ��''()*�������� �+�,-.(�����������������������!��''()*��������������������������������!�+�,-.(����������������������
�� �/�� � ���
���������� ������!�
���������� ������������������������������������������� �"�
�������������������� �������������
����������� ��������������"��������������������������������!����������
�������������������!���������������"� idea that������������������������������
������� �������������������������������"������ ����������"�
�������������������"�����"���
#�� ��+�,-.(�$��������%�����������������&�������������0����������������������������������������
���������������'���������''()*�����������������������������������''()*��������+�,-.(�������������������������� ��''()*��������� � ����������������������� (����������
������������ ��''()*���������"�����������������$��������%� ��''()*�$�������)* ��������������������������������������������
����%��!��+�+�������������������,����������������� ��
����� ������ � � ��� ������
���
�� ������� ���� �� ����� ������� ��� ���� � ���������������"�
�������������������������� ��������������������������������������������������������������������������� (�"�� ����-+#������������"��
'� $�������������������������������%�1���������$���+�,-.(�$���%��������%�����������������������,�!��+�+��
����%����������������������!������%����������������������������
�''()*�����������������������������������!��+�+���$��������������������������������%�1��$���$�����������%��������������������������������������%�����
����������������%�1���������$�������$����+�,-.(������������������������������''()*�2��������������%����''()*�.�-+/����
� � � *���% ��� ��
������������ �����������������������������������
��
����� ���� !�� � �����������"����� ����� ����� ��
#� $�%$�%� &'��������(��������� ����'����(�)*+,��-��������(����������� ����'��� �� ������������'����"��� ��"�����(���$��%�.�//����"������� ��,�
�����
�������'����(�)���������������
#� $�%$��%� ������������0����(���"�1�"�����$�(�������2�����%���"����0����(��2�����,��������2�����������2����� �������������0���,�
�����
��3��� ���������2��� ����������0���'��"�"��(� ������������(������� ���2�����*�
#� $0%$�%� 4�"���"�����������2.�2���������'��.�� �����2����������1�",��5����(����0���"��.'��"���.2��������,��6��� �$0� ��%����2� � ���(�������"�(�� ����*�*����� .�� ���� �,�
��������7�
�
#� $0%$��%� $4�"���"%���������1���� ���(�(��"��������,��$4�"���"%����(�'�����0� � �.������,��$4�"���"%�0��2�� ���"��.���������,�
��������7�
����'�����������(������� ��8�����(��"9������"��� �0�����"� �"�
�
Mark Scheme � General Certificate of Education (A-level) Biology � BIOL2 � January 2012
9
Question Marking Guidelines Mark Comments
7(a)(i) Produces a more reliable mean/average / makes sure sample was representative / reduce effect of extreme values / identify anomalies;
1 Ignore references to chance
7(a)(ii) Removes bias; 1
7(b) Two marks for correct answer of 5.8;;
One mark for incorrect answer that clearly shows denominator as 216;
2
7(c) 1. Increase in variety of plants/shrubs/grass;
2. More habitats/niches;
3. Greater variety of food sources / more food sources;
3
3. Answers only referri������������� ������� ���������� ���
Mark Scheme – General Certificate of Education (A-level) Biology – Unit 2: The Variety of Living Organisms – June 2012
9
Question Marking Guidelines Marks Comments
7(a) Removes bias; 1
7(b)(i) 1. 1.28 / 1.29 / 1.285 / 1.3;;
2. Answer incorrect but shows clear understanding of �;
2 1. Ignore more than 3dp
2. ����������� �����������denominator written out. Incorrect denominator but evidence of understanding gains mark
7(b)(ii) Diversity index would be lower (NO MARK)
1. Fewer species / Beech aphid/Large white butterfly/7-spot ladybird absent /only three species / species diversity lower;
2. Mostly one species / mostly bird-cherry aphid;
3. Fewer plant species;
2 max Assume wheat field if site unspecified
1. Allow species richness in context of few species
3. Allow one type of food source if clearly plant
7(c) For:
1. Data support the claim / evidence supports claim;
Against:
2. Only wheat field / only comparing with wood / one type of habitat /only insects considered;
2 max
1. Ignore reference to correlation/causation
7(d) 1. Greater variety of plants;
2. Another habitat / more habitats / places to live / niches;
3. Another food source / more food types;
2 max
3. Answers referring to 'more food' should not be credited. Allow reference to either animal or plant as foods
top related