No questions found
Table 1.1 shows features of three infectious diseases: malaria, tuberculosis (TB) and cholera.
Complete Table 1.1.
[Table_1]
feature | malaria | tuberculosis | cholera
name of pathogen | .......... *falciparum* | *Mycobacterium tuberculosis* | ..........
type of organism | .......... | bacterium | ..........
method of transmission | .......... | .......... | drinking water and food contaminated with human faeces
575
508
507
Table 1.1 shows features of three infectious diseases: malaria, tuberculosis (TB) and cholera.
Complete Table 1.1.
[Table_1]
feature | malaria | tuberculosis | cholera
name of pathogen | .......... *falciparum* | *Mycobacterium tuberculosis* | ..........
type of organism | .......... | bacterium | ..........
method of transmission | .......... | .......... | drinking water and food contaminated with human faeces
517
584
521
Macrophages synthesise intracellular enzymes.
Fig. 2.1 is a summary diagram of events that occur in a macrophage.
(a) (i) Name the process at A.
..............................................................................................................................[1]
(ii) Name the stages of protein synthesis that occur at E and at F.
E ..............................................................................................................................
F ..............................................................................................................................[2]
(iii) Name organelles B, G, H and J.
B ..............................................................................................................................
G ..............................................................................................................................
H ..............................................................................................................................
J ..............................................................................................................................[4]
(b) Describe what happens to the bacteria between C and D.
..............................................................................................................................
..............................................................................................................................
..............................................................................................................................
..............................................................................................................................
..............................................................................................................................
..............................................................................................................................
..............................................................................................................................
..............................................................................................................................[3]
(c) Macrophages are antigen presenting cells (APCs). Antigens from pathogens such as the bacteria shown in Fig. 2.1 are presented to helper T-lymphocytes as shown in Fig. 2.2.
Very few helper T-lymphocytes respond to the presence of APCs by binding in the way shown in Fig. 2.2.
Suggest why this is so.
..............................................................................................................................
..............................................................................................................................
..............................................................................................................................
..............................................................................................................................
..............................................................................................................................
..............................................................................................................................
[2]
520
516
513
Macrophages synthesise intracellular enzymes.
Fig. 2.1 is a summary diagram of events that occur in a macrophage.
(a) (i) Name the process at A.
..............................................................................................................................[1]
(ii) Name the stages of protein synthesis that occur at E and at F.
E ..............................................................................................................................
F ..............................................................................................................................[2]
(iii) Name organelles B, G, H and J.
B ..............................................................................................................................
G ..............................................................................................................................
H ..............................................................................................................................
J ..............................................................................................................................[4]
(b) Describe what happens to the bacteria between C and D.
..............................................................................................................................
..............................................................................................................................
..............................................................................................................................
..............................................................................................................................
..............................................................................................................................
..............................................................................................................................
..............................................................................................................................
..............................................................................................................................[3]
(c) Macrophages are antigen presenting cells (APCs). Antigens from pathogens such as the bacteria shown in Fig. 2.1 are presented to helper T-lymphocytes as shown in Fig. 2.2.
Very few helper T-lymphocytes respond to the presence of APCs by binding in the way shown in Fig. 2.2.
Suggest why this is so.
..............................................................................................................................
..............................................................................................................................
..............................................................................................................................
..............................................................................................................................
..............................................................................................................................
..............................................................................................................................
[2]
558
589
549
A student studied a transverse section of the trachea of a small mammal. The student drew a plan diagram of the section as shown in Fig. 3.1.
[Image_1: Fig. 3.1]
Fig. 3.2 is a photomicrograph of the area labelled M in Fig. 3.1.
[Image_2: Fig. 3.2]
(a) Name:
(i) the type of epithelium at N ........................................................................................................................................[1]
(ii) the structures at O ....................................................................................................................................................[1]
(iii) the tissue at P. ..........................................................................................................................................................[1]
(b) Smooth muscle in the trachea and in the bronchi relaxes during strenuous exercise. Suggest the advantages of relaxing this smooth muscle during periods of strenuous exercise.
.........................................................................................................................................................................................
.........................................................................................................................................................................................
.........................................................................................................................................................................................
.........................................................................................................................................................................................
.........................................................................................................................................................................................[2]
(c) The walls of the trachea and bronchi contain elastic fibres.
Elastic fibres are made of bundles of the fibrous protein elastin.
• Each molecule of elastin is a single polypeptide.
• The primary structure contains a large proportion of the amino acid glycine.
• Glycine has a hydrophobic R group.
• Glycine does not occur at regular intervals in the polypeptide.
• The polypeptide forms random coils that change shape as the elastic fibres are stretched and recoil.
• Elastin molecules are joined to each other by many covalent bonds to form a cross-linked network.
Describe two ways in which the structure of a collagen molecule differs from the structure of an elastin molecule described above.
1 .......................................................................................................................................................................................
.........................................................................................................................................................................................
2 .......................................................................................................................................................................................
.........................................................................................................................................................................................[2]
509
512
505
A student studied a transverse section of the trachea of a small mammal. The student drew a plan diagram of the section as shown in Fig. 3.1.
[Image_1: Fig. 3.1]
Fig. 3.2 is a photomicrograph of the area labelled M in Fig. 3.1.
[Image_2: Fig. 3.2]
(a) Name:
(i) the type of epithelium at N ........................................................................................................................................[1]
(ii) the structures at O ....................................................................................................................................................[1]
(iii) the tissue at P. ..........................................................................................................................................................[1]
(b) Smooth muscle in the trachea and in the bronchi relaxes during strenuous exercise. Suggest the advantages of relaxing this smooth muscle during periods of strenuous exercise.
.........................................................................................................................................................................................
.........................................................................................................................................................................................
.........................................................................................................................................................................................
.........................................................................................................................................................................................
.........................................................................................................................................................................................[2]
(c) The walls of the trachea and bronchi contain elastic fibres.
Elastic fibres are made of bundles of the fibrous protein elastin.
• Each molecule of elastin is a single polypeptide.
• The primary structure contains a large proportion of the amino acid glycine.
• Glycine has a hydrophobic R group.
• Glycine does not occur at regular intervals in the polypeptide.
• The polypeptide forms random coils that change shape as the elastic fibres are stretched and recoil.
• Elastin molecules are joined to each other by many covalent bonds to form a cross-linked network.
Describe two ways in which the structure of a collagen molecule differs from the structure of an elastin molecule described above.
1 .......................................................................................................................................................................................
.........................................................................................................................................................................................
2 .......................................................................................................................................................................................
.........................................................................................................................................................................................[2]
557
558
545
(a) Transpiration is often described as ‘an inevitable consequence of gas exchange in leaves’.
Explain what is meant by this description.
............................................................................................................
............................................................................................................
............................................................................................................
............................................................................................................
............................................................................................................[3]
(b) Explain how hydrogen bonding is involved in the movement of water in the xylem.
............................................................................................................
............................................................................................................
............................................................................................................
............................................................................................................
............................................................................................................[3]
Southern beech trees of the genus \textit{Nothofagus} grow in forests in the South Island of New Zealand.
Fig. 4.1 shows a small part of a forest.
Most of the trees in the forests form a thick canopy of leaves. These are known as canopy trees.
The tallest trees are known as emergent trees. Some trees do not reach the canopy and are
known as suppressed trees.
(c) Use Fig. 4.2A to compare the transpiration rates of the emergent, canopy and suppressed
trees in the forest over 14 hours.
............................................................................................................
............................................................................................................
............................................................................................................
............................................................................................................
............................................................................................................
............................................................................................................
[4]
(d) The factors that affect transpiration rate vary considerably at different places inside forests.
Use the information in Fig. 4.1 and Fig. 4.2 to suggest reasons for the difference in the
transpiration rates of the emergent and suppressed trees.
............................................................................................................
............................................................................................................
............................................................................................................
............................................................................................................
............................................................................................................
............................................................................................................[4]
550
508
582
(a) Transpiration is often described as ‘an inevitable consequence of gas exchange in leaves’.
Explain what is meant by this description.
............................................................................................................
............................................................................................................
............................................................................................................
............................................................................................................
............................................................................................................[3]
(b) Explain how hydrogen bonding is involved in the movement of water in the xylem.
............................................................................................................
............................................................................................................
............................................................................................................
............................................................................................................
............................................................................................................[3]
Southern beech trees of the genus \textit{Nothofagus} grow in forests in the South Island of New Zealand.
Fig. 4.1 shows a small part of a forest.
Most of the trees in the forests form a thick canopy of leaves. These are known as canopy trees.
The tallest trees are known as emergent trees. Some trees do not reach the canopy and are
known as suppressed trees.
(c) Use Fig. 4.2A to compare the transpiration rates of the emergent, canopy and suppressed
trees in the forest over 14 hours.
............................................................................................................
............................................................................................................
............................................................................................................
............................................................................................................
............................................................................................................
............................................................................................................
[4]
(d) The factors that affect transpiration rate vary considerably at different places inside forests.
Use the information in Fig. 4.1 and Fig. 4.2 to suggest reasons for the difference in the
transpiration rates of the emergent and suppressed trees.
............................................................................................................
............................................................................................................
............................................................................................................
............................................................................................................
............................................................................................................
............................................................................................................[4]
572
507
597
(a) Fig. 5.1 is a diagram of part of an animal cell in a stage of mitosis.
!
Fig. 5.1
(i) Draw a diagram in the space below to show the stage of mitosis that follows the stage in Fig. 5.1.
[3]
(ii) Describe the roles of the spindle fibres during mitosis.
..................................................................................................................
..................................................................................................................
..................................................................................................................
..................................................................................................................
.................................................................................................................. [2]
(b) Bone marrow contains many stem cells. Some of these stem cells are responsible for the replacement of red blood cells. During the production of red blood cells a series of changes occur to the cell structure.
Fig. 5.2 shows the production of a red blood cell from one of these stem cells.
!
Fig. 5.2
(i) Outline the changes that occur as cell X becomes a mature red blood cell.
..................................................................................................................
..................................................................................................................
..................................................................................................................
..................................................................................................................
.................................................................................................................. [3]
(ii) Suggest what may happen to cell Y.
.................................................................................................................. [1]
(c) People who travel to high altitude become acclimatised to the conditions.
Athletes often train at high altitude before competing at sea level.
A group of male and female athletes who trained at sea level moved to high altitude for further training. Sports scientists analysed blood samples taken from the athletes to measure any changes in the concentration of haemoglobin in the blood and changes in the haematocrit.
Haematocrit is the volume of red blood cells expressed as a percentage of the total volume of a sample of blood.
The results are shown in Table 5.1.
![Table_1]
(i) Complete Table 5.1 by calculating the percentage increase in haemoglobin concentration.
[1]
(ii) Explain why it is necessary for the athletes to increase the concentration of haemoglobin in their blood when acclimatising to high altitude.
..................................................................................................................
..................................................................................................................
..................................................................................................................
..................................................................................................................
..................................................................................................................
..................................................................................................................
..................................................................................................................
.................................................................................................................. [4]
541
580
524
(a) Fig. 5.1 is a diagram of part of an animal cell in a stage of mitosis.
!
Fig. 5.1
(i) Draw a diagram in the space below to show the stage of mitosis that follows the stage in Fig. 5.1.
[3]
(ii) Describe the roles of the spindle fibres during mitosis.
..................................................................................................................
..................................................................................................................
..................................................................................................................
..................................................................................................................
.................................................................................................................. [2]
(b) Bone marrow contains many stem cells. Some of these stem cells are responsible for the replacement of red blood cells. During the production of red blood cells a series of changes occur to the cell structure.
Fig. 5.2 shows the production of a red blood cell from one of these stem cells.
!
Fig. 5.2
(i) Outline the changes that occur as cell X becomes a mature red blood cell.
..................................................................................................................
..................................................................................................................
..................................................................................................................
..................................................................................................................
.................................................................................................................. [3]
(ii) Suggest what may happen to cell Y.
.................................................................................................................. [1]
(c) People who travel to high altitude become acclimatised to the conditions.
Athletes often train at high altitude before competing at sea level.
A group of male and female athletes who trained at sea level moved to high altitude for further training. Sports scientists analysed blood samples taken from the athletes to measure any changes in the concentration of haemoglobin in the blood and changes in the haematocrit.
Haematocrit is the volume of red blood cells expressed as a percentage of the total volume of a sample of blood.
The results are shown in Table 5.1.
![Table_1]
(i) Complete Table 5.1 by calculating the percentage increase in haemoglobin concentration.
[1]
(ii) Explain why it is necessary for the athletes to increase the concentration of haemoglobin in their blood when acclimatising to high altitude.
..................................................................................................................
..................................................................................................................
..................................................................................................................
..................................................................................................................
..................................................................................................................
..................................................................................................................
..................................................................................................................
.................................................................................................................. [4]
561
523
586
Fig. 6.1 shows an incomplete diagram of the fluid mosaic model of membrane structure. The diagram shows the cell surface membrane of a eukaryotic cell.
(a) State what is meant by the term fluid mosaic.
.......................................................................................................................................................................
.......................................................................................................................................................................
.......................................................................................................................................................................
.......................................................................................................................................................................[2]
(b) State the thickness of a cell surface membrane.
.......................................................................................................................................................................[1]
(c) List four features of cell surface membranes of eukaryotic cells that are not visible in Fig. 6.1.
1 .................................................................................................................................................................
.......................................................................................................................................................................
2 .................................................................................................................................................................
.......................................................................................................................................................................
3 .................................................................................................................................................................
.......................................................................................................................................................................
4 .................................................................................................................................................................[4]
557
529
535
Fig. 6.1 shows an incomplete diagram of the fluid mosaic model of membrane structure. The diagram shows the cell surface membrane of a eukaryotic cell.
(a) State what is meant by the term fluid mosaic.
.......................................................................................................................................................................
.......................................................................................................................................................................
.......................................................................................................................................................................
.......................................................................................................................................................................[2]
(b) State the thickness of a cell surface membrane.
.......................................................................................................................................................................[1]
(c) List four features of cell surface membranes of eukaryotic cells that are not visible in Fig. 6.1.
1 .................................................................................................................................................................
.......................................................................................................................................................................
2 .................................................................................................................................................................
.......................................................................................................................................................................
3 .................................................................................................................................................................
.......................................................................................................................................................................
4 .................................................................................................................................................................[4]
525
541
513
