AS & A Level Biology - 9700 Paper 1 2015 Winter Zone 3

Which size of ribosome is found in chloroplasts?

Different units are used when measuring biological specimens.
In which rows are the same measurements correctly expressed in each of the units shown in the column headings?
[Table_1]

Which features of cilia and root hairs are correct?
[Table_1]

The diagram shows a typical animal cell. Each labelled structure is involved with the synthesis of biological molecules. Within which structures are glycoproteins, proteins and steroids synthesised?

What is present in a Vibrio cholerae cell?

What is correct for a typical prokaryotic cell?
[Table_1]

The table shows the results of tests carried out on a sample of biological molecules.
[Table_1]
Which shows the types of molecules present in the sample?

The synthesis of biological molecules requires the formation of bonds. Which row is correct? [Table_1]

Which row describes a triglyceride? [Table_1]

High concentrations of urea break all bonds, except covalent bonds, in protein molecules. Which level of protein structure would remain unchanged when a protein is treated with urea?

Haemoglobin, a globular protein, consists of four polypeptide chains, two alpha chains and two beta chains. In normal individuals, in the DNA which codes for each beta chain, the sixth triplet has a code for glutamic acid. In individuals with sickle cell anaemia this base triplet mutates and codes for valine. What does this mutation change in the haemoglobin molecule?

The graph shows the concentration of one of the substances which is involved in an enzyme-catalysed reaction.
Which substance is shown by line X?

What describes the induced fit mode of action of an enzyme?

Line X represents the course of an enzyme-catalysed reaction under optimum conditions.
Line Y shows the action of the same enzyme on the same substrate but with one variable changed: substrate concentration or pH or temperature.

Which changes to the variables could give the results shown by line Y?
1. decreased substrate concentration
2. higher pH
3. lower temperature

Which descriptions are correct about transport across cell surface membranes?

Which statements about the fluid mosaic model of a membrane are correct?
1 Saturated fatty acid tails inhibit the movement of phospholipids in the membrane.
2 Glycoproteins in the outer layer of the membrane can move.
3 Channel proteins are fixed in position.

The diagram shows apparatus set up to investigate diffusion.
What shows net diffusion of glucose and water molecules?

The photomicrograph shows a cell undergoing mitosis.

What is happening in this cell?

Which row shows the products of mitosis, reduction division (meiosis) and fertilisation?
[Table_1]

Which statements describe how a gene mutation can lead to the production of a non-functional protein?
1. During transcription an incorrect nucleotide is added to a DNA molecule.
2. A codon in the mRNA transcribed from the mutated gene is changed.
3. The order of the bases in an anticodon on tRNA is altered during translation.

Some antibiotics kill prokaryotes by binding to RNA polymerase.
What effect will this have on protein synthesis?

Which row correctly describes cytosine? [Table_1]

The photomicrograph shows a transverse section of a leaf.
Which cell has the least negative water potential?

The diagram shows the results of an experiment on transpiration using two different leaves. Each leaf was left on a balance in daylight in a closed room and their mass recorded at 1 hour intervals.

Which conclusions could be correct?
1. The loss in mass is mainly due to evaporation of water.
2. The stomata in both leaves close after 1 hour.
3. Leaf 1 has a larger surface area than leaf 2.

Which processes are involved in the transport of sucrose in plants?

1. active transport
2. mass flow
3. osmosis

Which changes to the water potential and the volume of liquid in the phloem occur when carbohydrate is moved from phloem sieve tubes into a sink?
[Table_1]

Which reactions take place in a capillary in an active tissue?
1. the formation of carbonic acid from carbon dioxide and water
2. the formation of carbaminohaemoglobin from carbon dioxide and haemoglobin
3. the formation of haemoglobinic acid from haemoglobin and hydrogen ions
4. the formation of carbon dioxide and water from hydrogen carbonate ions and hydrogen ions

What is present in the blood in human veins?
1      collagen
2      carbonic anhydrase
3      oxyhaemoglobin

The diagram shows the electrical activity in cardiac muscle during one heart beat.
What is happening at each of the labelled stages in the cardiac cycle?

Which statement about the pulmonary artery is correct?

Red blood cells may contain a molecule known as 2,3-bisphoglycerate (2,3BPG). When 2,3BPG binds to haemoglobin a higher partial pressure of oxygen is needed to bring about 50% saturation of haemoglobin with oxygen.
Which statement about the effect of 2,3BPG is correct?

What is a correct location of cartilage and smooth muscle in the human gas exchange system? [Table_1]

Which factors maintain the diffusion gradient for carbon dioxide at the surface of the alveoli?
1. blood flow past the alveoli
2. breathing movement exchanging air in the lungs
3. thin epithelial lining of the alveoli

The surface tension of the layer of liquid lining the alveoli tends to pull the walls inwards so alveoli could collapse.
Which statements could explain how this is prevented?

1. alveolar fluid is moved around by cilia
2. elastic fibres keep the alveoli open
3. epithelial cells secrete a chemical that reduces the cohesion in water

The data shows how the number of human deaths caused by the bacterium \textit{Staphylococcus aureus} has changed over a period of five years.
Methicillin is an antibiotic used to treat a disease caused by S. aureus. MRSA is methicillin-resistant S. aureus.
[Table_1:
\begin{tabular}{|c|c|c|} \hline \text{year} & \text{total number of deaths caused by S. aureus} & \text{total number of deaths caused by MRSA} \\ \hline 1 & 369 & 355 \\ 2 & 452 & 431 \\ 3 & 456 & 681 \\ 4 & 420 & 890 \\ 5 & 428 & 1512 \\ \hline \end{tabular}]
Which statement is not supported by this data?

What describes natural active immunity?

The bacterium that causes the disease tetanus produces a toxin that acts as an antigen.
The graph shows the concentration of an antibody in the blood of two people, G and H.
On day 0, G was injected with antibodies to the tetanus toxin and H was injected with the vaccine for tetanus.



What would be the result after G and H were infected with the tetanus bacteria on day 20?

What name is given to all the organisms of the same species living in an area?

The table shows the results of a field study of four species in a food chain in an area of woodland.

[Table_1]

What is the energy flow in the food chain?

The diagram shows a simplified nitrogen cycle. Which arrow represents the activity of nitrogen-fixing bacteria?