AS & A Level Biology - 9700 Paper 1 2016 Summer Zone 1

Which of the cell organelles will be clearly visible under the high power (×400) of the light microscope? [Table_1]

The drawing from an electron micrograph shows a ciliated epithelial cell, magnified \times 1500, which is found in the trachea. Line X-Y shows the widest dimension of the cell. What is the number of these cells that could be found along a 1 cm length of the trachea?

What are correct locations of ribosomes in the typical eukaryotic cell?
1. free in the cytoplasm
2. attached to the outside of the endoplasmic reticulum
3. attached to the inside of the endoplasmic reticulum

Visking tubing is an artificial partially permeable membrane used to demonstrate diffusion. Glucose molecules can pass through the pores in the membrane which are approximately 2.4 nm in diameter.
Which of the following could pass through the pores?

1. bacteria
2. haemoglobin
3. ribosomes
4. glycogen

What are found in both chloroplasts and typical prokaryotic cells?

Two solutions, 1 and 2, one containing starch and sucrose, and the other containing glucose and protein, were tested with a variety of reagents to confirm their identity.
The table shows the conclusions from the results recorded for the various tests.
Which row identifies the two solutions?
[Table_1]

X and Y are two monomers found in biological polymers.
[Image: Monomers X and Y]
Which monomer is found in each of cellulose, glycogen, amylopectin and amylose?

Chitin is a polysaccharide consisting of long straight chains of the monosaccharide acetylglucosamine, linked by 1,4 glycosidic bonds.
Acetylglucosamine is similar in structure to glucose, but contains nitrogen, allowing hydrogen bonds to form between adjacent chains of chitin when they lie parallel to each other.
Which polysaccharide is most similar in structure to chitin?

Which statement about triglycerides is correct?

The diagrams show the structures of two amino acids, one of which has two amine (–NH₂) groups and the other has two carboxylic (–COOH) groups.

A peptide bond is formed between the two amino acids.
Which groups form the peptide bond?

Proteins which transport sugars out of cells have been identified. These proteins are called SWEETs. Each SWEET has seven coiled, cylindrical regions which together make up a pore through the cell surface membrane bilayer, as shown in the diagram.
What describes each of the seven coiled regions (1-7) of a SWEET shown in the diagram?

Influenza virus has an enzyme called neuraminidase which breaks down glycoproteins in the membrane of the cell that the virus will infect. The glycoprotein binds to the active site of neuraminidase by induced fit.
Which statements about the induced fit hypothesis of enzyme action are correct?
1. The active site must have a complementary shape to the substrate for them to bind together.
2. This enzyme is less likely to be affected by non-competitive inhibitors than an enzyme working by the lock and key mechanism.
3. The substrate is converted to product by specific R-groups in the active site just like the lock and key mechanism.

Which row about competitive inhibitors of enzymes is correct?
[Table_1]

The graph shows the effect of increasing the concentration of substrate on the rate of an enzyme-catalysed reaction.

What is limiting the rate of the enzyme-catalysed reaction at 1, 2, 3 and 4 on the graph?

The diagram represents a cell surface membrane of a metabolically active cell and the direction of movement of some molecules through the membrane.

Which row shows a process by which the molecules may be moving through the membrane at each of the points 1, 2, 3 and 4?
[Table_1]

Batrachotoxin is a poison found in frogs in the Columbian jungle. The poison is used by Native Indians to produce poison darts.
The poison works by increasing the permeability of some cell surface membranes to sodium ions, which move out of the cells.
Which statements are correct for cells affected by batrachotoxin?
1. The intracellular fluid has a less negative water potential than the extracellular fluid.
2. The extracellular fluid has a less negative water potential than the intracellular fluid.
3. Water leaves the cells by osmosis, causing the cells to shrink.
4. Water enters the cells by osmosis, causing the cells to swell.

Which processes occur during prophase of the mitotic cell cycle in an animal cell?
[Table_1: Processes occurring during prophase]
key
✓ = true
✗ = false

The protein p53 is produced in a cell in response to DNA damage. This protein stops the cell cycle for a short time just before the DNA is replicated, so that the DNA can be repaired.
At which phase of the cell cycle will this stop occur?

Which feature of stem cells enables them to replace cells in tissues such as the skin?

DNA contains the ......X...... base ......Y...... which is joined to adenine with ......Z...... hydrogen bonds.

Which row correctly completes the statement about DNA?
[Table_1]

The diagram shows the nucleotide sequence of a small section of a gene which is transcribed.

CGCCGCACGGGC

The table shows the amino acids coded for by 10 mRNA codons.

[Table_1]

What is the order of the four amino acids in the polypeptide translated from this small section of a gene?

The statements describe the features of some nucleic acids.
1. carry an amino acid to a ribosome
2. carry a genetic code sequence out of the nucleus
3. carry a genetic code sequence to a ribosome
4. hold amino acids in position for translation
Which functions are carried out by tRNA?

A student was asked to draw a plan diagram of the plant tissue shown in the photomicrograph and to annotate two observable features.
What are correct annotations?

Water that is present inside a root hair cell may leave the cell and pass to the vascular tissue. Through which route must the water travel?

What is a correct definition of the term transpiration?

Which changes to the water potential and the volume of liquid in the phloem sieve tube element occur when sucrose is moved from a photosynthesising leaf into the phloem sieve tube element?
[Table_1]

Which statement supports the theory of active loading of sucrose into companion cells?

The diagram is an external view of the mammalian heart and the associated blood vessels.
Which statement about the blood vessels associated with a normal, healthy heart is correct?

The graph shows changes in blood pressure during one cardiac cycle.

What is happening at time X?

Which does not occur when a red blood cell arrives at the alveolus?

The graph shows the oxygen dissociation curves for haemoglobin of animals that live at high altitude and animals that live at low altitude.
What explains the oxygen dissociation curve at high altitude?

Which statement concerning events that occur in the heart is correct?

What would be seen in an electron micrograph of a bronchus wall?
1. cartilage cells
2. ciliated cells
3. exocytotic vesicles

Which parts of the human gas exchange system may typically contain macrophages? [Table_1]

An oxygen molecule diffuses from the air in an alveolus through cells to haemoglobin in a red blood cell.
What is the minimum number of cell surface membranes through which this molecule must pass?

Which short-term effects of smoking are caused by carbon monoxide?
1. formation of carboxyhaemoglobin
2. increased risk of blood clotting
3. narrowing the lumen of arteries

A person whose immune system is suppressed may become more susceptible to certain diseases.
Which disease will this person not become more susceptible to?

Which disease is treated with drugs that have a similar molecular structure to DNA nucleotides?

Rabies is a viral disease which can be spread to humans by a bite from an infected animal. One method of treatment is to inject the patient with antibodies specific to the rabies virus. Which statements about this treatment are correct?
1. The patient will have natural passive immunity to rabies.
2. The injected antibodies will be broken down by the patient.
3. The patient’s memory cells will be able to produce this antibody more rapidly in the future.
4. The immunity provided will only be of short duration.

What are the functions of T-lymphocytes during an immune response?
1 destroy infected body cells
2 differentiate into memory cells
3 secrete antibodies