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Some yeast, sugar and water are mixed in a test-tube. The diagrams show the test-tube at the start and after one hour.
Which process causes this change?
526
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537
Which diagram shows a flower from a monocotyledon?
530
505
502
In which part of the cell is oxygen used to release energy from nutrient molecules?
532
518
577
The actual thickness of the leaf shown in the diagram is 2000μm, but its thickness in the diagram is 50mm.
What is the magnification of the diagram?
508
535
579
The diagram shows two cells. The net movement of water is from cell X to cell Y. What causes water to pass from cell X to cell Y?
535
550
503
For the stomata of a leaf to open, the guard cells accumulate more potassium ions than the surrounding cells.
Which row describes what happens?
[Table showing movement of potassium ions, movement of water in relation to guard cells, and final state of the guard cells]
580
537
575
The structures of antibodies, DNA molecules and enzymes are specific to their actions. Which feature of each molecule makes it specific? [Table_1]
562
557
522
Small molecules are used as the basic units in the synthesis of large food molecules.
Which statement is correct?
572
541
541
A food stain on a table cloth is where meat cooked in oil has been spilt. It is washed in a biological washing powder. Which combination of enzymes should be in the washing powder to remove the stain?
566
535
599
Which graph shows the effect of temperature on the activity of an enzyme?
542
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570
When a tissue from a man is grafted onto a woman it may be rejected by the woman's body.
What is the main cause of this rejection?
576
515
563
The diagram shows a potted plant and the same plant 24 hours later.
What causes the change in the appearance of the plant?
538
545
542
Which graph shows most clearly what will happen to the rate of transpiration as humidity increases?
501
581
593
Which process is an example of translocation?
567
516
563
The diagram shows a section through the human heart.
Which is the right atrioventricular valve?
509
501
521
What is the fluid in the blood called?
573
588
594
The antibodies that give immunity to a disease can be acquired in the following different ways:
1. feeding on breast milk
2. infection by disease
3. vaccination
Which give active immunity?
504
579
524
Which actions increase the volume of the thorax during breathing?
[Table_1]
591
570
581
What are the approximate percentages of oxygen and carbon dioxide in atmospheric air? [Table_1]
517
578
514
Which processes depend on the action of enzymes?
1 digestion
2 osmosis
3 respiration
577
567
512
Lactic acid builds up in the muscles during vigorous exercise.
During recovery, how is this lactic acid removed?
502
579
566
Which diet will cause the liver to produce the most urea?
548
600
569
The diagram represents a simple reflex arc.
What is the sequence of nerve cells through which an impulse passes during a reflex action?
552
587
593
What are the effects of adrenaline?
[Table_1]
536
524
569
The diagram shows the density of rods and cones across a horizontal section of the retina. What is the position of the optic nerve?
591
545
571
In which conditions will seeds germinate most quickly?
535
537
505
What are the characteristics of asexual reproduction?
[Image_1: Table showing fusion of gamete nuclei and genetic variety in the offspring]
527
517
527
Where are oestrogen and progesterone produced during the menstrual cycle?
[Table_1]
562
514
503
Which structure will be found in the nucleus of a body cell in a woman?
521
594
540
When a cell divides, these events occur.
1. The DNA inside the cell is duplicated exactly.
2. Daughter cells are produced with the same chromosome number as the parent cell.
Which type of division has occurred?
538
519
528
In the inheritance of ABO blood groups, when two parents have the genotypes $I^A I^A$ and $I^A I^o$, what is the blood group of their offspring?
586
537
552
The diagram shows a hydrophyte in a river.
Which statement about the submerged leaves is correct?
581
549
504
Some disease-causing bacteria survive treatment with an antibiotic. Which statement about the surviving bacteria is correct?
586
524
519
The diagram shows a pyramid of biomass for a food chain in a woodland ecosystem.
What is the pyramid of numbers for this food chain?
532
548
549
In the food chain below, the population of snakes is halved owing to a viral disease.
grass $\rightarrow$ locusts $\rightarrow$ snakes $\rightarrow$ eagles
What effect does this have on the other members of the food chain?
517
580
509
A gene for insulin is taken from a human cell and placed in a bacterium.
The bacterium can then make human insulin.
What is this process called?
521
558
514
When human DNA is inserted into the plasmid DNA of bacteria, which enzyme is used to cut the DNA?
563
502
586
The diagram shows the positions of four farms and the concentrations of nitrate at different points in a river. Which farm is likely to have been using too much fertiliser on its land?
554
518
520
A large amount of herbicide is applied to a field. However, some of the herbicide is washed into a nearby lake.
What is the effect of the herbicide on the weeds in the field and on the plants in the lake?
[Table_1]
550
560
561
