3. Movement into and out of cells
A section of Biology, 0610
Listing 10 of 315 questions
shows part of the water cycle. water in streams, rivers, lakes and seas atmosphere soil plants P Q R S Using words from the list, identify the processes P, Q, R and S. drainage egestion evaporation photosynthesis rainfall transpiration P Q R S State two ways in which water may leave the body of a mammal. Describe how water in a plant may become water in the cells of an animal. shows apparatus which can be used to measure the rate of water uptake by a plant shoot. stop clock air bubble scale Three sets of this apparatus, using shoots from the same tree, were used at the same time. The experiment was carried out with four different sets of external conditions A, B, C and D. The time for the air bubble to move 10 cm was measured and recorded in Table 8.1. Table 8.1 external conditions time for air bubble to move 10 cm / s shoot 1 shoot 2 shoot 3 A dry, still air at 15 °C B dry, still air at 25 °C C dry, moving air at 25 °C D humid, still air at 15 °C State which shoot took up water most quickly under all conditions. Suggest a difference between the shoots that could explain these results. Suggest why the results under condition D were different from the results under condition A.
0610_w13_qp_23
THEORY
2013
Paper 2, Variant 3
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For Examiner's Use This question is about transport in plants. Two pea plants, D and E, were supplied with substances containing the radioactive isotopes, carbon-14 (14C) or phosphorus-32 (32P), as shown in . A leaf of plant D was exposed to radioactive carbon dioxide. Plant E was placed into a solution containing radioactive phosphate ions. nutrient solution fruit seed growing point flower clear plastic bag with added radioactive carbon dioxide plant D plant E nutrient solution with added radioactive phosphate ions After several hours the plants were analysed for the presence of the radioactive isotopes. Sucrose containing 14C was found throughout plant D. Compounds containing 32P were found throughout plant E. Complete Table 4.1 to show: • the tissue in which each substance is transported; • one possible sink for each substance. Table 4.1 pea plant D E substance transported sucrose phosphate ions transport tissue sink For Examiner's Use State one substance, other than sucrose, that is produced in leaves and translocated to other parts of the plant. Outline how sucrose is produced from carbon dioxide in pea plants. State two uses of sucrose within a pea plant. Explain how ions, such as phosphate ions, are absorbed by plant roots.
0610_w13_qp_32
THEORY
2013
Paper 3, Variant 2
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Chemical fertilisers are used to improve crop productivity. Outline how chemical fertilisers improve the productivity of crops. For Examiner's Use State the conditions necessary for seeds to germinate. Describe the effects of increasing the concentration of sulfuric acid on the growth of roots and shoots of the seedlings. You will gain credit if you use data from in your answer. Acid rain is formed when sulfur dioxide (SO2) and oxides of nitrogen (NOdissolve in rain water. Explain why concentrations of sulfur dioxide in the atmosphere have increased over the last 150 years. Figure 2.1 © T D Etherton & D E Bauman; Biology of Somatotropin in Growth and Lactation of Domestic Animals; Physiological Reviews; Vol.78, No.3; July 1998; http://physrev.physiology.org/content/78/3/745.html. Figure 6.1 © G Fleet et al; Acid rain in the classroom: a student research project; Journal of Biological Education; 1987. For Examiner's Use Describe three effects of acid rain on organisms and their environment.
0610_w13_qp_33
THEORY
2013
Paper 3, Variant 3
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Ecologists study plants and animals in their natural environment. Some ecologists inserted probes into the water-conducting tissue in trees, as shown in . The ecologists measured the time taken for water to move up from probe 1 to probe 2. probe 1 data logger probe 2 tree Name the water-conducting tissue into which the two probes were inserted. Describe how the structure of this water-conducting tissue is adapted to its function. Explain the mechanism of water movement from the roots up the tree to the leaves. shows the rate of water conduction up three different trees in a forest over 24 hours. time / h rate of water conduction / dm3 per hour 0.5 1.0 1.5 2.0 2.5 tree A tree B tree C Describe the rate of water conduction in tree A, during this 24 hour period. You will gain credit for using the data in to support your answer. Suggest how the ecologists used the data in to calculate the total volume of water used by a tree in 24 hours. In , tree A is a tall tree, tree B is a medium-height tree and tree C is a short tree. Suggest reasons for the different rates of water conduction in the three trees. Loggers often cut down the tall trees in a forest. Describe the effects on the forest ecosystem of cutting down trees.
0610_w14_qp_31
THEORY
2014
Paper 3, Variant 1
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shows an animal cell and a plant cell as seen with a light microscope. animal cell plant cell Table 1.1 shows some structural features of the animal cell and the plant cell in . Complete the table by • finishing the row for nucleus • adding three structural features, visible in , and indicating whether they are present (✓) or absent (✗) in the animal cell and in the plant cell. Table 1.1 structural feature animal cell plant cell cell wall ✗ ✓ nucleus The cells were kept in a dilute salt solution. They were then transferred to distilled water. Explain what will happen to each of these two cells when they are placed into distilled water. Magnesium is a plant nutrient. Scientists think that magnesium is involved in the transport of sucrose from the leaves to the rest of a plant. Name the tissue that transports sucrose in plants. The scientists grew some tomato plants with their roots in a solution that contained all the mineral nutrients that plants require. After a while, the plants were divided into two groups. • Group A continued to receive the solution containing all the nutrients. • Group B received a solution that did not contain any magnesium. After 12 days, measurements were made on the leaves and the results are shown in . A B 3.5 3.0 2.5 2.0 1.5 1.0 0.5 0.0 rate of movement of sucrose out of the leaves / arbitrary units A B sucrose concentration in the leaves / arbitrary units group group Describe the effect of magnesium deficiency on the transport of sucrose out of the leaves and the sucrose concentration in the leaves. transport of sucrose out of the leaves concentration of sucrose in the leaves The plants in Group B remained in the magnesium-deficient solution for longer than 12 days. At the end of this time they showed symptoms of magnesium deficiency. Describe and explain the symptoms that the plants would show.
0610_w14_qp_33
THEORY
2014
Paper 3, Variant 3
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Water moves into plants from the soil and exits through the leaves. Explain how water moves from the soil into the root. Water reaches the leaves from the roots through the xylem. shows images of stomata on the lower surfaces of leaves of two varieties of olive plant, A and B. Both are shown at the same magnification. A B Describe the function of stomata. Compare the density of stomata between the two varieties of olive plant, A and B, shown in . Under identical environmental conditions the rate of water uptake in plant A is higher than plant B. Explain why. The density of stomata is an example of a leaf adaptation to the environmental conditions. State two other adaptations of leaves for survival in a dry environment. Water lost from the leaves enters the atmosphere. Describe how water is recycled from the atmosphere back to the roots.
0610_w15_qp_33
THEORY
2015
Paper 3, Variant 3
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Questions Discovered
315