Outline how the amphipathic properties of phospholipids help determine membrane structure. [4]
-3 points, unless you can draw a 4 mark diagram of the cell membrane in one minute. Then +10
Triglycerides are used as energy stores by living organisms. Describe their structure and properties. [4]
a. made of carbon, hydrogen and oxygen
OR
are a group of lipids;
b. (made of) one glycerol molecule and three fatty acids;
c. formed by condensation reactions;
d. fatty acids may be saturated or unsaturated;
e. unsaturated fatty acids can be cis or trans (isomers);
Properties:
f. hydrophobic/insoluble/not very soluble in water/soluble in non-polar solvents
OR
can be liquid or solid at room temperature;
g. release/store large quantity of energy
OR
release/store more energy than carbohydrates (during cell respiration)/ OWTTE
OR
long term storage of energy;
h. do not conduct heat well / heat insulators (as in fat layers/blubber);
Max [3] if only mention structure.
Accept labelled diagrams.
+16, unless Metal or Florencia is on your team. Then you have to draw the structure of alpha glucose in one minute or 0 points
Explain the stages and processes of meiosis leading to genetic variation. [7]
Drawings which are annotated to explain are acceptable.
-5
Ask Ms. Burns a question from any other DP course.
If she got it right, +1
If she got it wrong, -5
Explain the roles of named hormones in the development and function of the sexual reproductive systems in males and females. [7]
Max 2 per hormone.
Must include testosterone for full marks.
+1
Which statement distinguishes between the roles of free and bound ribosomes?
A. Free ribosomes synthesize proteins for use inside the cell, whereas bound ribosomes synthesize proteins mainly for export.
B. Free ribosomes synthesize proteins mainly for export, whereas bound ribosomes synthesize proteins for use inside the cell.
C. Free ribosomes synthesize proteins, whereas bound ribosomes do not.
D. Bound ribosomes synthesize proteins, whereas free ribosomes do not.
A. Free ribosomes synthesize proteins for use inside the cell, whereas bound ribosomes synthesize proteins mainly for export.
+6
Describe the structure of cellulose molecules. [3]
Markscheme
+7 if you a person from your team can hold a plank for one minute
Outline the processes occurring during interphase in the cell cycle. [4]
-5 unless someone on your team can draw the cell cycle in one minute. Then no points lost
Outline how stem cells develop into specialized cells during development of the embryo. [2]
-5
Describe how non-disjunction can cause Down syndrome. [4]
Mpe. Requires reference to gamete or zygote.
+5
Why do onions make you cry?
a) They're emotionally manipulative
b) They release sulfur compounds that irritate your eyes
c) They're jealous of garlic’s popularity
d) It's their defense mechanism against chefs
a) They're emotionally manipulative
Technically they release sulfur compounds, but a) is the better answer
+19 if you picked a)
+1 if you picked b)
What is the best science?
Biology. Obviously.
+10 if you got this right
-20 if you got this wrong
What percentage of DNA do bananas and humans share? (closest % wins the question)
Approximately 60%
+20
Describe the role of two named hormones in the regulation of blood sugar levels. [4]
a. Insulin and glucagon released (from the pancreas to regulate blood glucose
levels);
b. blood glucose levels are regulated by negative feedback;
At least 1 of these:
c. when blood glucose levels are above normal, insulin is released from the β/beta-
cells of the pancreas;
d. insulin stimulates cells to take up glucose;
At least 1 of these:
e. when blood glucose levels are below normal, glucagon is released from the
α/alpha-cells of the pancreas;
f. glucagon stimulates the release of glucose, from glycogen stored in the liver;
a. It is sufficient to say the hormones are insulin and glucagon.
For maximum marks students must give marking point c or d and marking point e or f.
Accept labelled table or diagram.
Either +10 or trade points with the other team
+10 points if you get your team to guess five vocabulary words in one minute
Alveoli
Antibody
Negative Feedback Loop
Pulmonary Vein
Platelets
Describe how substances cross the cell membrane by facilitated diffusion. [4]
+1
-4
Explain the role of RNA in translation, resulting in the formation of polypeptide chains. [7]
-5
Outline the process of saltatory conduction. [2]
+5
Explain how cells in the bloodstream cause a specific immune response. [7]
+20
What distinguishes simple diffusion from facilitated diffusion?
A. Simple diffusion occurs in both prokaryotes and eukaryotes, while facilitated diffusion only occurs in eukaryotes.
B. Energy is not required for simple diffusion, while facilitated diffusion requires ATP.
C. The rate of facilitated diffusion depends on the number of transport proteins in the membrane, while simple diffusion does not.
D. Simple diffusion can only move substances along the concentration gradient, while facilitated diffusion can move substances along or against the concentration gradient.
C. The rate of facilitated diffusion depends on the number of transport proteins in the membrane, while simple diffusion does not.
-5 points
Outline protein structure. [4]
Amino Acid structure [1 mark max]
Contains an amine group
Contains a COOH
R group
Protein composition:
a. (proteins) are made of (20) amino acids;
Primary structure:
b. amino acids are linked by peptide bonds;
c. joined by condensation;
d. joined/linked into polypeptides;
Secondary and tertiary structure:
e. interactions between/sequence amino acids lead to the 3-dimensional
conformation/shape of proteins;
Quaternary structure:
f. (some) proteins many consist of more than one polypeptide/amino acid chain
linked together;
-5
Outline the reason that DNA replication is described as semi-conservative. [3]
+3 for your team
-2 for every other team
Describe what occurs in a neuron when an action potential is propagated along the axon. [4]
+10
Distinguish between the structure of arteries and veins. [2]
+8, unless you are the tallest team in the room, then -3