16.3. Sexual reproduction in plants
A subsection of Biology, 0610, through 16. Reproduction
Listing 10 of 316 questions
Acid rain has negative effects on many ecosystems. Describe the negative effects of acid rain on freshwater ecosystems, such as streams, rivers and lakes. Two groups of students were asked to investigate the effects of acid rain on the germination of pine tree seeds. Both groups of students decided to use sulfuric acid rather than hydrochloric acid to represent acid rain in their investigation. Suggest why. State how the students could have measured the pH of the sulfuric acid. The students provided the environmental conditions that seeds need to germinate. State two of these environmental conditions. One group of students recorded the change in temperature as the seeds germinated in five insulated flasks, labelled A to E. Suggest why germinating seeds increase in temperature. The students sterilised the seeds before their investigation. Their teacher told them to use a sterilising solution to wash the seeds because steam would kill the seeds and prevent the seeds from germinating. Explain why steam sterilisation would prevent seed germination. The results from this group of students are shown in Table 5.1. Table 5.1 flask pH group 1 temperature of seeds after 72 hours / °C A 2.0 20.6 B 3.5 20.3 C 4.0 21.2 D 5.5 34.1 E 7.0 46.2 Describe the results obtained by group 1. The second group of students placed 100 seeds in each of five Petri dishes, labelled 1 to 5. Group 2 used the same range of pH values as group 1. They recorded the percentage of seeds that had germinated after 72 hours. Their results are shown in Table 5.2. Table 5.2 Petri dish pH group 2 percentage of seeds germinated after 72 hours 2.0 3.5 4.0 5.5 7.0 The teacher thought that group 2 had forgotten to add the sulfuric acid to one of their Petri dishes. Suggest which Petri dish was not set up correctly.
0610_s17_qp_42
THEORY
2017
Paper 4, Variant 2
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A student investigated the conditions needed for germination of seeds. shows the apparatus and conditions used. A B light seeds wet soil dark C D light seeds dry soil dark box to exclude light The seeds in test-tubes A and B germinated but the seeds in test-tubes C and D did not germinate. Use the information in to state one condition required for germination. Use the information in to state one condition not required for germination. The investigation was repeated with seeds that had been boiled for 10 minutes and then cooled. Predict and explain the effect of boiling on the results. Photosynthesis and germination have different requirements. State the word equation for photosynthesis. State the name of one condition needed for both photosynthesis and germination.
0610_s21_qp_31
THEORY
2021
Paper 3, Variant 1
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A student investigated plant growth responses. A seedling was attached to a support stand and placed under a lamp. Complete by drawing the expected position of the root and shoot after seven days of growth. root shoot support stand direction of light State the type of growth response plants show in response to the direction of light. State the type of nuclear division that is used for growth. Seeds need certain factors for germination. Circle three factors that are needed for germination. carbon dioxide iron nitrogen oxygen suitable temperature water vitamin C Complete the sentences. Seeds contain proteins for the of developing shoots and roots. Proteins contain the elements , oxygen, and nitrogen. The new leaves of a seedling need the mineral ion to make the green pigment . This green pigment is needed to carry out the process of , in the presence of light.
0610_s22_qp_32
THEORY
2022
Paper 3, Variant 2
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A student investigated the conditions needed for the germination of cress seeds. shows the apparatus, conditions used and the results of the investigation. damp cotton wool 4 °C A dry cotton wool 20 °C B damp cotton wool 20 °C C damp cotton wool 20 °C D damp cotton wool 20 °C E cress seeds box that excludes light germinating seedlings substance that removes oxygen bung Identify the letters of the two test‑tubes in that show that oxygen is needed for germination. and A gardener wanted to store some cress seeds for a long time before using them. Use the information in to identify the ideal conditions to prevent germination. Tick two boxes. cold dry light low carbon dioxide concentration low pH Tropic responses were investigated in two plants, X and Y. The plants were placed in separate boxes for 5 days. shows plants X and Y at the start of the investigation. Both boxes had a hole on one side that let light in. Plant X was kept in the same position. Plant Y was placed on a platform that was continually rotated. light plant Y rotating platform light plant X fixed platform Predict and explain how the shape of plant Y will differ from the shape of plant X after 5 days of growth. State the name of the tropic response that would be seen in plant X in after 5 days. Suggest and explain the advantage to a plant of tropic responses in shoots. State the position plants occupy in a food chain.
0610_s24_qp_31
THEORY
2024
Paper 3, Variant 1
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Questions Discovered
316