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Root hair cells are found on plant roots.
Which feature is present in a root hair cell but not in a sperm cell?
561
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588
What is an example of a tissue?
552
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553
Some examples of substances moving across membranes are listed.
1. glucose molecules into the epithelium that lines the small intestine
2. nitrate ions from a dilute solution in soil into a more concentrated solution in root hair cells
3. water molecules from mesophyll cells into the air spaces of a leaf
For which examples must oxygen be present?
530
571
567
In which diagram would most oxygen molecules diffuse across the membrane per minute?
500
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557
The list shows some statements about enzymes.
1. They all contain the element nitrogen.
2. They are proteins.
3. They can be denatured by cold temperatures.
4. Their specificity is due to the complementary shapes of the active site and the substrate.
Which statements are correct?
516
574
527
Which statement about the structure of DNA is correct?
511
530
523
A doctor tested the urine of four patients for both glucose and protein. The colours of the urine samples after testing are shown in the table. Which patient’s urine contained both protein and glucose?
534
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528
The equation shows the digestion of protein to amino acids.
In the equation, what is protease?
526
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569
The graph shows the effect of increasing light intensity on the rate of photosynthesis.
What are the limiting factors at X and Y?
563
533
525
The substances listed are found in the leaf of a plant. Which substance is obtained from the soil?
586
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543
The cholera bacterium produces toxins that cause chloride ions to be secreted into the small intestine.
What is the immediate effect of this on the water potential of blood in the intestinal capillaries, and on the water potential of the contents of the small intestine?
538
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560
The graph shows the concentration of maltose in different parts of the alimentary canal.
What causes the change in concentration at X?
519
561
501
The diagram shows a bean seedling soon after it has germinated. Where is most water absorbed?
516
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Scientists investigate the movement of substances in a plant.
They cut a ring of tissue from the stem.
Removing the tissue removes some of the transport vessels found around the edge of the stem.
A few days later they notice swelling above the area where the tissue has been removed.
What causes the swelling?
545
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525
The diagram shows the outside of a human heart.
Which structure is a coronary artery?
580
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548
The diagrams represent blood flow in the circulatory systems of fish and humans.
[Image_1: Diagram showing blood flow in fish and human circulation]
In the fish circulation and the human circulation, where is the oxygen concentration highest?
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Campylobacter is a bacterium that can cause food poisoning.
Which word describes Campylobacter?
585
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516
What is the approximate percentage of oxygen in expired air?
589
568
594
Which actions use energy released from respiration?
1. muscle contraction
2. protein synthesis
3. cell division
4. transmitting nerve impulses
593
571
578
What is the word equation for anaerobic respiration in muscle cells?
549
535
583
Which statement about the formation of urea is correct?
528
529
555
What is a response to a low concentration of glucose in the blood?
554
534
583
Which endocrine gland secretes insulin?
533
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556
Which factors affect the growth of plants?
530
530
508
The table shows the recommended daily amounts (RDA) of some nutrients for a person with special dietary requirements, and their actual intake of those nutrients.
What would the person be at risk of developing if they continued with the same daily intake of these nutrients?
532
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594
What are advantages of using sexual reproduction to produce crop plants?
1 It produces genetic variation to help breed new varieties of crop plant.
2 It ensures that crops have the identical characteristics.
3 It quickly produces many identical copies of a plant.
588
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545
Where is the hormone progesterone produced?
1. ovaries
2. placenta
3. uterus
523
537
509
Which row correctly describes mitosis?
587
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556
The diagram shows the flow of energy through a food chain.
Which row correctly labels this energy flow diagram? [Table_1]
552
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582
A man and a woman have four children. The diagram shows the blood groups of the children.
What are the possible genotypes of the father and mother?
531
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How do the leaves of hydrophytes differ from those of xerophytes?
530
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510
Broccoli and cauliflower are crop plants that have been produced from a common wild plant. Which process would be used to produce the broccoli and cauliflower plants from wild plants?
540
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The diagram shows part of the nitrogen cycle.
Which process in the cycle is performed by bacterium X?
505
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573
The graph shows changes in the population size of a microorganism growing in a fermenter. What is the exponential phase?
598
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589
Bacteria are useful in genetic engineering because they possess plasmids. Which statement describes the importance of a plasmid?
521
529
583
Which statement is correct?
563
551
532
What can reduce the occurrence of famine?
542
549
503
What is a consequence of deforestation?
544
519
534
