command word: explain – give reasons or mechanisms to address how or why something happens...
TRANSCRIPT
Command word:Explain – Give reasons or mechanisms to address how or why something happens
Connectives:Whereas, alternatively, unlike, equally, consequently, unless, if, as long as, however, such as, for instance, this means, . . .
Question
Animal clones occur naturally. It is
now possible to produce animal clone
artificially. The embryos produced
contain embryonic stem cells.
Explain how an adult body cell can be
used to produce a cloned embryo and
suggest the possible uses of this
technique.
Value6 marks
RouteStem cells
Mark band
1-2
3-4
5-6
Success criteria
Describes cloning process but sequence is poorly understood, steps/terms are missing. Candidate may suggest a use for the cloned embryos. SPAG weak
Describes cloning process without misuse of terms such as nucleus, egg cell, but description is incomplete / confused. Candidate suggests a use for
cloned embryos. Variable SPAG.
Describes cloning with correct science and with a logical sequence. Candidate suggests more than one use for cloned embryos, or suggests and develops one use for cloned embryos. Excellent SPAG
Science Points• egg cell removed from female • nucleus removed from egg cell • nucleus taken from adult body cell which is
to be cloned • inserted into the unfertilised empty egg cell
• cells divide to form embryo • electric shock [or other stimulus] applied
to trigger cell division (not in Spec) either in vitro growth of embryo or implantation in
• suitable female • embryos are a source of embryonic stem cells • stem cells can be used to treat disease • this is because they are unspecialised • may be used to clone e.g. endangered species, • valuable stock or sporting animals
RouteStem cells
QWC Additional Travel Card
QWC Additional Travel Card
Command word:Explain – Give reasons or mechanisms to address how or why something happens
Connectives:Whereas, alternatively, unlike, equally, consequently, unless, if, as long as, however, such as, for instance, this means, . . .
Question
Myosin is a protein that is found in
muscle cells but not in nerve cells.
Explain the processes that lead to
myosin being made and why it is only
produced in muscle cells.
Value6 marks
RouteProtein Synthesis/ Gene switching
Mark band
1-2
3-4
5-6
Success criteria
Mentions amino acids/ bases/ DNA / RNA/ genes AND an extra aspect. SPAG
weak
Discusses amino acids/ bases/ DNA / RNA in an appropriate fashion, and
appreciates that there is a code/instruction set and gives further detail. Good use of specialist terms,
some may not be used. SPAG is generally good.
Shows a grasp of all the aspects underlined by discussing switching of genes, links protein to amino acids/
bases/ DNA / RNA. Faultless SPAG
Science PointsNucleus
information stored in nucleus / within the DNA /
sequence of bases / code for order of amino
acids / base sequence in nucleus is copied
Transport of information copied information goes
to cytoplasm / where protein is assembled /
using mRNA / different proteins are made from
different sequences of amino acids
Switching muscle and nerve cells have same
genes / but specialised cells have only some
genes switched on / nerve cells do not have gene
for myosin switched on / muscle cells do have
gene for myosin switched on
RouteProtein Synthesis/ Gene switching
QWC Additional Travel Card
QWC Additional Travel Card
Command word:Describe - Set out facts or characteristics.What/when/where.
Connectives:Whereas, alternatively, unlike, equally, consequently, unless, if, as long as, however, such as, for instance, this means, . . .
Question
Tony takes a cutting from a tree.
He dips the cutting into a powder.
Describe the processes that will
help the cutting develop into a
new, identical tree.
Value6 marks
RouteGrowth and development
Mark band
1-2
3-4
5-6
Success criteriaResponse refers only to the
process or to the change in cells to form specialised tissues.
Variable SPAG.
Description of the process may be jumbled or miss some detail. There is good use of specialist terms, some may not be used. SPAG is
good.
Clear description of the processes involved with the powder and the reason for being identical, in the correct order. Faultless SPA.G
Science Points• cutting includes meristems • meristems are a source of unspecialised
cells • powder contains plant hormone • powder causes unspecialised cells to
develop into roots/helps cells develop • (unspecialised cells develop) into new
tissues/organs • cutting is a clone • because it has identical genes/DNA/cells
as the parent • discusses the growing conditions needed
to make the clone identical to the original accept references to named new tissues e.g. phloem, xylem accept references to named new organs e.g. leaves/needles
RouteGrowth and development
QWC Additional Travel Card
QWC Additional Travel Card
Command word:Explain – Give reasons or mechanisms to address how or why something happens
Connectives:Whereas, alternatively, unlike, equally, consequently, unless, if, as long as, however, such as, for instance, this means, . . .
Question
Joe puts a glass jar containing a bean seedling next to a window. After several days he notices that the tip of the seedling stem has grown towards the window.
Explain how the seedling stem grows towards the light coming through the window.
Value6 marks
RoutePhototropism
Mark band
1-2
3-4
5-6
Success criteriaAnswer refers to phototropism and/or diffusion of auxin but without describing the details
correctly. SPAG weak.
Answer may correctly identify some aspects of auxin activity at the shoot tip under conditions of directional light .SPAG good.
Answer correctly describes the production, distribution and
effect of auxin at the shoot tip under conditions of directional
light. Excellent SPAG.
Science Points• auxin is produced by the tip of the stem • auxin diffuses down into the lower
tissues of the stem (strong) directional light causes the auxin to diffuse towards the darker side of the stem
• auxin promotes cell division/growth • higher auxin concentration on the darker
side of the stem increases the division/growth rate on this side
• more/faster division/growth on the darker side produces a stem that is curved towards the directional light source
• this is phototropism *****Ignore references to the shoot “bending” towards the light without this being linked to growth
RoutePhototropism
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QWC Additional Travel Card
Command word:Outline – Set out key facts, steps or characteristics.
Connectives:Whereas, alternatively, unlike, equally, consequently, unless, if, as long as, however, such as, for instance, this means, . . .
Question
A fertilised egg is called a zygote. A zygote is a single cell. A zygote develops into an adult made of many hundreds of different types of cells.
Outline in detail how a human zygote changed into an adult person.
Value6 marks
RouteGrowth and development
Success criteriaA brief description of how the zygote becomes a human. Some key words but very limited.
Poor SPAG.
Clear description including at least 3-4 points. of how zygote becomes a human.
Variable SPAG.
A clearly structured, balanced and detailed description of
how the zygote becomes a full organism. Excellent SPAG.
Mark band
1-2
3-4
5-6
Science Points•The zygote divides by mitosis to produce 2 identical cells.•Cell division continues to make 4, 8 and 16 cells.•At the 8 cell stage the cells start to specialise.•This happens when some genes are switched off. •Only genes needed for the cells function will stay switched on. •Genes code for proteins. For example the gene for amylase would stay switched on in salivary gland cells. (or other example)•Groups of cells are called tissues.•Tissues can be grouped together and organised into organs that do a specific job. Organs work together to become systems and organisms. •Examples of cellular organisation (muscle cell-muscle tissue-heart-cardiovascular system-human adult organism)
RouteGrowth and development
QWC Additional Travel Card
QWC Additional Travel Card