AS & A Level Biology - 9700 Paper 1 2015 Summer Zone 2

What is the diameter of a typical plant cell?

A specimen is viewed under a microscope using green light with a wavelength of 510nm.
If the same specimen is viewed under the same conditions, but using red light with a wavelength of 650 nm instead, what effect will this have on the magnification and on the resolution of the microscope?
[Table_1]

What is the function of plasmodesmata in plant cells?

Which size of ribosome is found in both chloroplasts and mitochondria?

Which function is correct for the description of the cell structure? [Table_1]

Ribosomes consist of two subunits, each containing rRNA. An analysis of all the 70S ribosomes from a single cell of the bacterium, Escherichia coli, showed that there were:
• 38 000 rRNA molecules
• 2 main types of rRNA molecule
• 19 000 copies of each type of rRNA molecule
How many 70S ribosomes were there in the E. coli cell?

Which type of bond holds together an $\alpha$-helix or $\beta$-pleated sheet of a protein?

What describes only the quaternary structure of haemoglobin?
1. \( \alpha \)-helix
2. a dipeptide
3. a globular structure
4. the specific order of amino acids
5. four polypeptide chains joined together

The statements are about the properties of water.

1. ability to form hydrogen bonds with other molecules
2. less dense when frozen
3. able to hold a lot of heat

What allows a small insect to rest on the surface of a pond?

Which bonds hold together the structure of cellulose?
1 glycosidic
2 hydrogen
3 ionic

Which bonds are found in glycogen?

Solutions of biological molecules are tested for sugars. The table shows the colours of the solutions after testing.

[Table_1]

Which may contain non-reducing sugars?

Which levels of protein structure are always involved when competitive and non-competitive inhibitors bind to enzymes?
[Table_1]

Which statements are true about the optimum temperature of all enzymes?

1. It is the temperature at which the enzymes work best.
2. It is the highest temperature at which the enzyme will work.
3. It is between 35°C and 40°C.

Which description of cell surface membrane permeability is correct?

The diagram represents a cell surface membrane. Three pathways through the membrane are shown. Which process is represented by each arrow?

Which set of factors will produce the most fluid cell surface membrane? [Table_1]

The protein p53 is produced in a cell in response to DNA damage.
A scientist exposed three groups of cells, X, Y and Z, to different conditions.
[Table_1]
Table 1:
┌──────────────┬─────────────────────────────────┐
│ group of cells │ conditions cells were exposed to │
├──────────────┼─────────────────────────────────┤
│ X │ ionising radiation │
│ Y │ ultra-violet light │
│ Z │ nicotine │
└──────────────┴─────────────────────────────────┘
In which groups of cells would the scientist find large quantities of p53 mRNA?

Which row is correct?
[Table_1]

What is needed to transcribe DNA?

In a ribosome, which bond holds together two adjacent amino acids?

The diagram shows part of a DNA molecule.
How many hydrogen bonds are involved in holding these strands of DNA together?

Which features of these cells make them suitable for their function?
[Table_1]

What is the sequence of events in the translocation of sucrose?

Where does water evaporate from during transpiration?

Which changes to the water potential and the volume of liquid in the phloem occur when amino acids are taken out of a sink in a phloem sieve tube?
[Table_1]

Which reaction takes place in a capillary in the lungs?

Which structure is correctly identified?

Resting muscle has a lower respiration rate than active muscle. The graph shows the oxygen dissociation curves for haemoglobin at carbon dioxide concentrations that are found in a resting muscle and an active muscle. P and Q are at the partial pressures of oxygen found in the lungs. R and S are at the partial pressures of oxygen found in either a resting muscle or an active muscle.



Which statements are correct?
1. The % saturation at P minus the % saturation at S represents the amount of oxygen delivered to a resting muscle.
2. The % saturation at Q represents the amount of oxygen carried to an active muscle.
3. The % saturation at R represents the amount of oxygen required by a resting muscle.
4. The % saturation at P minus the % saturation at Q represents the amount of oxygen delivered to an active muscle.
5. The % saturation at Q minus the % saturation at S represents the amount of oxygen delivered to a resting muscle.

What does not help to maximise uptake of oxygen as blood flows through capillaries in the lungs?

What correctly describes the role of elastic fibres in the lungs?

The diagram represents a section through the wall of a bronchus (not to scale).
In a person with chronic obstructive pulmonary disease (COPD), what happens in each of the numbered structures?

The symptoms of two diseases are listed.

[Table_1: Symptoms]
Disease 1: persistent cough, pain when breathing, loss of weight
Disease 2: shortness of breath, wheezing, fatigue

Which row identifies diseases 1 and 2?

The graph shows the fall in cases of tuberculosis (TB) in a country between 1910 and 2000.

Which factors could have contributed to the fall over this period?
1. pasteurisation of milk
2. the provision of new housing
3. chemical treatment of sewage
4. identification of contacts of people infected with TB

Which row is correct for cholera? [Table_1]

Which action is taken by a B-lymphocyte activated by an antigen?

The synthesis of specific antibodies in response to vaccination is an example of which type of immunity? [Table_1]

At which stage of a food chain in a tropical grassland is the energy transfer least efficient?

A farmer grows a different crop in a field each year for three years. In the fourth year he grows a leguminous crop, such as clover, and then ploughs this into the soil. The next year he starts the rotation again. How does the fourth year crop add mineral ions to the soil? [Table_1]

Of the prey consumed by the lion, into which box does the largest amount of energy go?