No questions found
Match the description for each of statements A to E to a correct cell structure.
A. Double membrane-bound organelle, absent in animal cells, that produces ATP.
..........................................................................................................................
B. Partially permeable membrane surrounding the large permanent vacuole of plant cells.
..........................................................................................................................
C. Formed from microtubules during mitosis.
..........................................................................................................................
D. Has peptidoglycan as one of its major components.
..........................................................................................................................
E. Site of assembly of 80S ribosomes.
..........................................................................................................................
585
574
583
Match the description for each of statements A to E to a correct cell structure.
A. Double membrane-bound organelle, absent in animal cells, that produces ATP.
..........................................................................................................................
B. Partially permeable membrane surrounding the large permanent vacuole of plant cells.
..........................................................................................................................
C. Formed from microtubules during mitosis.
..........................................................................................................................
D. Has peptidoglycan as one of its major components.
..........................................................................................................................
E. Site of assembly of 80S ribosomes.
..........................................................................................................................
590
519
578
(a) A student carried out an experiment using Visking tubing to investigate osmosis. The student prepared a sucrose solution to represent phloem sap at the source. This was put into Visking tubing that was tied at one end, so that the tubing was approximately 75% full.
The rest of the procedure is summarised in Fig. 2.1. The tubing was removed after 20 minutes, dried and re-weighed.
(i) Complete Fig. 2.1 to show the appearance of the Visking tubing inside the test-tube after 20 minutes.
(a) (ii) State, with reasons, whether there would be a change in the mass of the Visking tubing containing the sucrose solution after 20 minutes.
..............................................................................................................................................
..............................................................................................................................................
..............................................................................................................................................
..............................................................................................................................................
..............................................................................................................................................
..............................................................................................................................................
..............................................................................................................................................
(b) Explain how osmosis is involved in the mass flow of phloem sap.
..............................................................................................................................................
..............................................................................................................................................
..............................................................................................................................................
..............................................................................................................................................
..............................................................................................................................................
..............................................................................................................................................
..............................................................................................................................................
..............................................................................................................................................
(c) Amino acids synthesised in the mesophyll cells of leaves are also transported in phloem sap to other locations where they are used to synthesise polypeptides.
Amino acids are joined by peptide bonds to form the polypeptides.
Two amino acids are shown below. Describe the formation of a peptide bond between these two amino acids. You may use the space below.
..............................................................................................................................................
..............................................................................................................................................
..............................................................................................................................................
..............................................................................................................................................
586
510
597
(a) A student carried out an experiment using Visking tubing to investigate osmosis. The student prepared a sucrose solution to represent phloem sap at the source. This was put into Visking tubing that was tied at one end, so that the tubing was approximately 75% full.
The rest of the procedure is summarised in Fig. 2.1. The tubing was removed after 20 minutes, dried and re-weighed.
(i) Complete Fig. 2.1 to show the appearance of the Visking tubing inside the test-tube after 20 minutes.
(a) (ii) State, with reasons, whether there would be a change in the mass of the Visking tubing containing the sucrose solution after 20 minutes.
..............................................................................................................................................
..............................................................................................................................................
..............................................................................................................................................
..............................................................................................................................................
..............................................................................................................................................
..............................................................................................................................................
..............................................................................................................................................
(b) Explain how osmosis is involved in the mass flow of phloem sap.
..............................................................................................................................................
..............................................................................................................................................
..............................................................................................................................................
..............................................................................................................................................
..............................................................................................................................................
..............................................................................................................................................
..............................................................................................................................................
..............................................................................................................................................
(c) Amino acids synthesised in the mesophyll cells of leaves are also transported in phloem sap to other locations where they are used to synthesise polypeptides.
Amino acids are joined by peptide bonds to form the polypeptides.
Two amino acids are shown below. Describe the formation of a peptide bond between these two amino acids. You may use the space below.
..............................................................................................................................................
..............................................................................................................................................
..............................................................................................................................................
..............................................................................................................................................
541
504
575
High fructose corn syrup, made from maize, can be used as a replacement for sucrose to sweeten food and drink products. Commercial production of high fructose corn syrup involves the enzyme glucose isomerase, extracted from bacteria.
(a) Fructose and sucrose are both sugars.
State two structural differences between fructose and sucrose.
1 .............................................................................................................................................................................................
.......................................................................................................................................................................................................
.......................................................................................................................................................................................................
2 ..............................................................................................................................................................................................
.......................................................................................................................................................................................................
...............................................................................................................................................................................................[2]
(b) The glucose isomerase used in the production of high fructose corn syrup is extracted from a strain of a bacterium, *Thermus thermophilus*, which is found in hot springs. The enzyme has an optimum temperature of 95 °C.
Suggest and explain the advantages of using glucose isomerase from *T. thermophilus* to produce high fructose corn syrup, rather than using glucose isomerase that has an optimum temperature of 37 °C.
...............................................................................................................................................................................................................
...............................................................................................................................................................................................................
...............................................................................................................................................................................................................
...............................................................................................................................................................................................................
...............................................................................................................................................................................................................
....................................................................................................................................................................................................[3]
(c) The commercial production of high fructose corn syrup uses immobilised glucose isomerase.
Fig. 3.1 shows the effect of pH on the activity of immobilised glucose isomerase compared to glucose isomerase free in solution.
With reference to Fig. 3.1, describe the differences shown between the immobilised enzyme and the free enzyme as pH changes.
............................................................................................................................................................................................................................
............................................................................................................................................................................................................................
............................................................................................................................................................................................................................
............................................................................................................................................................................................................................
............................................................................................................................................................................................................................
.................................................................................................................................................................................................................[3]
(d) The amino acid sequence of the enzyme glucose isomerase has been determined. The first five amino acids of this sequence are shown in Table 3.1.
Table 3.2 (on page 11) shows the genetic code (mRNA codons).
A student was asked to use Table 3.2 to work out an mRNA nucleotide sequence that would correspond to the first five amino acids of glucose isomerase. The student’s sequence is shown in Table 3.1.
[Table_1]
(i) Complete Table 3.1 using a ✓ or a ✗ to indicate whether the student has used Table 3.2 correctly to identify the codons for each amino acid in the nucleotide sequence. [1]
(ii) Discuss, with reasons, how an mRNA nucleotide sequence worked out to correspond to the first five amino acids using Table 3.2 may not be the same as the mRNA nucleotide sequence for those amino acids present in the bacterial cell.
.............................................................................................................................................................................................................
.............................................................................................................................................................................................................
.............................................................................................................................................................................................................
.............................................................................................................................................................................................................
.............................................................................................................................................................................................................
...............................................................................................................................................................................................[3]
572
530
542
High fructose corn syrup, made from maize, can be used as a replacement for sucrose to sweeten food and drink products. Commercial production of high fructose corn syrup involves the enzyme glucose isomerase, extracted from bacteria.
(a) Fructose and sucrose are both sugars.
State two structural differences between fructose and sucrose.
1 .............................................................................................................................................................................................
.......................................................................................................................................................................................................
.......................................................................................................................................................................................................
2 ..............................................................................................................................................................................................
.......................................................................................................................................................................................................
...............................................................................................................................................................................................[2]
(b) The glucose isomerase used in the production of high fructose corn syrup is extracted from a strain of a bacterium, *Thermus thermophilus*, which is found in hot springs. The enzyme has an optimum temperature of 95 °C.
Suggest and explain the advantages of using glucose isomerase from *T. thermophilus* to produce high fructose corn syrup, rather than using glucose isomerase that has an optimum temperature of 37 °C.
...............................................................................................................................................................................................................
...............................................................................................................................................................................................................
...............................................................................................................................................................................................................
...............................................................................................................................................................................................................
...............................................................................................................................................................................................................
....................................................................................................................................................................................................[3]
(c) The commercial production of high fructose corn syrup uses immobilised glucose isomerase.
Fig. 3.1 shows the effect of pH on the activity of immobilised glucose isomerase compared to glucose isomerase free in solution.
With reference to Fig. 3.1, describe the differences shown between the immobilised enzyme and the free enzyme as pH changes.
............................................................................................................................................................................................................................
............................................................................................................................................................................................................................
............................................................................................................................................................................................................................
............................................................................................................................................................................................................................
............................................................................................................................................................................................................................
.................................................................................................................................................................................................................[3]
(d) The amino acid sequence of the enzyme glucose isomerase has been determined. The first five amino acids of this sequence are shown in Table 3.1.
Table 3.2 (on page 11) shows the genetic code (mRNA codons).
A student was asked to use Table 3.2 to work out an mRNA nucleotide sequence that would correspond to the first five amino acids of glucose isomerase. The student’s sequence is shown in Table 3.1.
[Table_1]
(i) Complete Table 3.1 using a ✓ or a ✗ to indicate whether the student has used Table 3.2 correctly to identify the codons for each amino acid in the nucleotide sequence. [1]
(ii) Discuss, with reasons, how an mRNA nucleotide sequence worked out to correspond to the first five amino acids using Table 3.2 may not be the same as the mRNA nucleotide sequence for those amino acids present in the bacterial cell.
.............................................................................................................................................................................................................
.............................................................................................................................................................................................................
.............................................................................................................................................................................................................
.............................................................................................................................................................................................................
.............................................................................................................................................................................................................
...............................................................................................................................................................................................[3]
551
540
526
(a) The elastic layer shown in Fig. 4.1, located between the endothelium and the tunica media, is one feature that suggests that the blood vessel is the renal artery and not the renal vein, which may be of a similar size.
Complete the sentence to state one additional structural feature, visible in Fig. 4.1, that would identify the blood vessel as an artery.
This is an artery because it has ....................................................................................
............................................................................................................................
............................................................................................................................
............................................................................................................................[1]
(b) Explain the relationship between the structure of the tunica media and the function of an artery, such as the renal artery.
............................................................................................................................
............................................................................................................................
............................................................................................................................
............................................................................................................................
............................................................................................................................[2]
(c) The actual diameter of the lumen of the renal artery at the point X–Y in Fig. 4.1 is 5.2 mm.
Calculate the magnification of the image shown in Fig. 4.1. Write down the formula you will use to make your calculation and show your working.
magnification × ....................................[3]
(d) Blood plasma contains approximately 90% water. Many of the properties of water are due to its ability to form hydrogen bonds.
Outline how the properties of water make it ideal as the largest component of plasma.
............................................................................................................................
............................................................................................................................
............................................................................................................................
............................................................................................................................
............................................................................................................................[3]
547
534
545
(a) The elastic layer shown in Fig. 4.1, located between the endothelium and the tunica media, is one feature that suggests that the blood vessel is the renal artery and not the renal vein, which may be of a similar size.
Complete the sentence to state one additional structural feature, visible in Fig. 4.1, that would identify the blood vessel as an artery.
This is an artery because it has ....................................................................................
............................................................................................................................
............................................................................................................................
............................................................................................................................[1]
(b) Explain the relationship between the structure of the tunica media and the function of an artery, such as the renal artery.
............................................................................................................................
............................................................................................................................
............................................................................................................................
............................................................................................................................
............................................................................................................................[2]
(c) The actual diameter of the lumen of the renal artery at the point X–Y in Fig. 4.1 is 5.2 mm.
Calculate the magnification of the image shown in Fig. 4.1. Write down the formula you will use to make your calculation and show your working.
magnification × ....................................[3]
(d) Blood plasma contains approximately 90% water. Many of the properties of water are due to its ability to form hydrogen bonds.
Outline how the properties of water make it ideal as the largest component of plasma.
............................................................................................................................
............................................................................................................................
............................................................................................................................
............................................................................................................................
............................................................................................................................[3]
576
534
515
A disease can be described as infectious or non-infectious.
(a) Lung cancer is a non-infectious disease.
(i) Explain the term non-infectious disease.
non-infectious ........................................................
........................................................................
........................................................................
disease ............................................................
........................................................................
........................................................ [2]
(ii) In a person with lung cancer one or more healthy cells undergo changes to produce cancerous cells that can form a tumour.
Suggest and explain the cellular changes that occur in the development of lung cancer.
...........................................................
...........................................................
...........................................................
...........................................................
...........................................................
...........................................................
...........................................................
...........................................................
...........................................................
........................................................... [4]
(b) Fig. 5.1 is a summary of some infectious diseases.
Use the information in Fig. 5.1 to answer parts (i) to (iv).
(i) Name the type of pathogen represented by A and B.
A ........................................................ [2]
B ........................................................
(ii) State the mode of transmission represented by C.
........................................................ [1]
(iii) Name the disease represented by D.
........................................................ [1]
(iv) Name the causative organism represented by E.
........................................................ [1]
(c) Explain how vaccination can control infectious diseases.
...........................................................
...........................................................
...........................................................
...........................................................
...........................................................
...........................................................
........................................................... [3]
535
565
535
A disease can be described as infectious or non-infectious.
(a) Lung cancer is a non-infectious disease.
(i) Explain the term non-infectious disease.
non-infectious ........................................................
........................................................................
........................................................................
disease ............................................................
........................................................................
........................................................ [2]
(ii) In a person with lung cancer one or more healthy cells undergo changes to produce cancerous cells that can form a tumour.
Suggest and explain the cellular changes that occur in the development of lung cancer.
...........................................................
...........................................................
...........................................................
...........................................................
...........................................................
...........................................................
...........................................................
...........................................................
...........................................................
........................................................... [4]
(b) Fig. 5.1 is a summary of some infectious diseases.
Use the information in Fig. 5.1 to answer parts (i) to (iv).
(i) Name the type of pathogen represented by A and B.
A ........................................................ [2]
B ........................................................
(ii) State the mode of transmission represented by C.
........................................................ [1]
(iii) Name the disease represented by D.
........................................................ [1]
(iv) Name the causative organism represented by E.
........................................................ [1]
(c) Explain how vaccination can control infectious diseases.
...........................................................
...........................................................
...........................................................
...........................................................
...........................................................
...........................................................
........................................................... [3]
513
535
546
(a) Fig. 6.1 represents one complete cell cycle for a eukaryotic cell.
(i) Complete Fig. 6.1 by naming the stages represented by J, K and L.
(ii) Name the stage in the cell cycle in which semi-conservative replication of DNA occurs.
.................................................................................................................................[1]
(b) (i) State the location in the body where development and maturation of the neutrophil occurs.
..............................................................................................................................................[1]
(ii) Describe the shape of the nucleus in the mature neutrophil.
..............................................................................................................................................[1]
(iii) State the alternative name of the cell structures described in Fig. 6.2 as “granules”.
..............................................................................................................................................[1]
(c) (i) Primary granules contain proteins known as defensins. These bind to cell surface membranes of bacteria and form very small pores in the membrane.
Suggest how defensins contribute to the role of the neutrophil in killing bacteria.
..............................................................................................................................................
..............................................................................................................................................
..............................................................................................................................................
..............................................................................................................................................[2]
(ii) Secondary granules contain lysozyme. This is an enzyme that breaks bonds in peptidoglycan molecules.
Explain how the action of lysozyme will lead to the destruction of the bacterial cell.
..............................................................................................................................................
..............................................................................................................................................
..............................................................................................................................................
..............................................................................................................................................[2]
560
583
565
(a) Fig. 6.1 represents one complete cell cycle for a eukaryotic cell.
(i) Complete Fig. 6.1 by naming the stages represented by J, K and L.
(ii) Name the stage in the cell cycle in which semi-conservative replication of DNA occurs.
.................................................................................................................................[1]
(b) (i) State the location in the body where development and maturation of the neutrophil occurs.
..............................................................................................................................................[1]
(ii) Describe the shape of the nucleus in the mature neutrophil.
..............................................................................................................................................[1]
(iii) State the alternative name of the cell structures described in Fig. 6.2 as “granules”.
..............................................................................................................................................[1]
(c) (i) Primary granules contain proteins known as defensins. These bind to cell surface membranes of bacteria and form very small pores in the membrane.
Suggest how defensins contribute to the role of the neutrophil in killing bacteria.
..............................................................................................................................................
..............................................................................................................................................
..............................................................................................................................................
..............................................................................................................................................[2]
(ii) Secondary granules contain lysozyme. This is an enzyme that breaks bonds in peptidoglycan molecules.
Explain how the action of lysozyme will lead to the destruction of the bacterial cell.
..............................................................................................................................................
..............................................................................................................................................
..............................................................................................................................................
..............................................................................................................................................[2]
550
528
575
