Which of these is NOT a characteristic shared by all living things?
Question 2 · Both levels
Why is it difficult to decide whether viruses are living?
Question 3 · Both levels
What is a virus made of?
Question 4 · Both levels
A GP will not prescribe an antibiotic for a patient with influenza. Why?
Question 5 · Both levels
Archaea look like bacteria under a microscope: both are single cells with no nucleus. Why are they placed in a separate domain?
Question 6 · Both levels
An organism is multicellular, has no chlorophyll, has cell walls made of chitin and feeds by absorbing digested food from dead leaves. In which kingdom is it classified?
Question 7 · Both levels
Use this key. 1: has a backbone, go to 2; no backbone, go to 3. 2: has feathers, bird; no feathers, go to 4. 3: has six legs, insect; more than six legs, go to 5. 4: has fur, mammal; no fur, reptile. 5: has eight legs, arachnid; more than eight legs, myriapod. An animal has no backbone and eight legs. What is it?
Question 8 · Both levels
Which of these is a disaccharide?
Question 9 · Both levels
What is a triglyceride made of?
Question 10 · Both levels
Which element is found in all proteins but not in carbohydrates or triglycerides?
Question 11 · Both levels
Which mineral is matched with its role in the human body?
Question 12 · Both levels
Which row correctly matches a vitamin with its solubility and the deficiency disease it prevents?
Question 13 · Both levels
On a hot day a runner sweats. Which property of water makes sweating an effective way to cool the body?
Question 14 · Both levels
A student tests four foods. Iodine: W blue-black, X yellow-brown, Y blue-black, Z yellow-brown. Benedict's (heated): W blue, X brick red, Y blue, Z blue. Biuret: W blue, X blue, Y violet, Z violet. Which food contains starch and protein but no reducing sugar?
Question 15 · Both levels
Glucose standards heated with Benedict's reagent in a boiling water bath first change colour after these times: 0.2% in 180 s, 0.4% in 95 s, 0.8% in 50 s and 1.6% in 26 s. A grape juice, diluted by making 1 cm³ up to 40 cm³ with water, changes colour in 95 s under the same conditions. What is the reducing sugar concentration of the undiluted juice?
Question 16 · Both levels
Which components make up one RNA nucleotide?
Question 17 · Both levels
In a sample of double-stranded DNA, 30% of the bases are adenine. What percentage are cytosine?
Question 18 · Both levels
How does ATP provide energy for processes in a cell?
Question 19 · Both levels
People with albinism have two faulty copies of the gene for tyrosinase, an enzyme needed to make the pigment melanin. Which statement best links the gene to the trait?
Question 20 · Both levels
Which structure is found in both prokaryotic and eukaryotic cells?
Question 21 · Both levels
Cells in the flight muscles of a bird contain very many of one organelle. Which organelle, and why?
Question 22 · Both levels
A cheek cell is 24 mm wide in a photograph taken through a light microscope at a magnification of ×400. What is the actual width of the cell?
Question 23 · Both levels
When preparing a slide of onion epidermis, why is the coverslip lowered at an angle, using a mounted needle?
Question 24 · Higher Level
What is the role of NAD+ in aerobic respiration?
Question 25 · Higher Level
In the light-dependent reactions of photosynthesis, what happens to NADP+?
Question 26 · Higher Level
Where is NADPH used in photosynthesis, and what for?
Question 27 · Higher Level
What is a codon?
Question 28 · Higher Level
An mRNA codon reads AUG. What is the anticodon on the tRNA that pairs with it?
Question 29 · Higher Level
There are 64 possible codons but only 20 amino acids. Which conclusion follows?
Question 30 · Higher Level
Bacteria given the human gene for insulin make human insulin. Which feature of the genetic code makes this possible?
Question 31 · Higher Level
What is the main role of the rough endoplasmic reticulum?
Question 32 · Higher Level
What does the Golgi apparatus do?
Question 33 · Higher Level
An electron micrograph of a cell shows a large amount of rough endoplasmic reticulum, many Golgi stacks and many vesicles near the cell membrane. What is the cell's most likely function?
Theory and practical questions
Nutrients in a breakfastWritten question, both levels · 9 marks
A breakfast is a bowl of porridge made with milk, a boiled egg and a glass of orange juice. Porridge oats are rich in starch, milk contains fat, egg white is mostly protein, and orange juice is a source of vitamin C.
(a) Which reagent would show that egg white contains protein? [1]
0 words · one point a mark
0 words · one point a mark
0 words · one point a mark
0 words · one point a mark
A cell that secretes enzymesWritten question, Higher Level · 9 marks
An electron micrograph shows a pancreas cell that secretes digestive enzymes, at a magnification of ×24 000. Structure X is a stack of flattened, curved membrane sacs with many small vesicles around its edges. Structure Y is a network of membranes covered in tiny granules, close to the nucleus. Mitochondria are also visible.
(a) Name structure X. [1]
µm
0 words · one point a mark
0 words · one point a mark
0 words · a sentence
Measuring reducing sugar in apple juiceExperiment and data, both levels · 8 marks
A student makes glucose solutions of known concentration. She heats 2 cm³ of each with 2 cm³ of Benedict's reagent in a boiling water bath for 5 minutes, filters off the brick-red precipitate and measures the absorbance of the remaining blue liquid in a colorimeter. The graph shows her calibration line. She then dilutes apple juice by making 1 cm³ up to 20 cm³ with water and treats it in the same way. Its absorbance is 0.50.