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Biology

CAIE2023

/arbitrary units (au)

Question

Biology

CAIE2023

(b) Explain how processes such as ethanol fermentation and lactate fermentation allow cells to continue to function in the absence of oxygen. ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ............................................................................................................................................. [3] (c) The cereal crop rice, Oryza sativa, grows in fields that are flooded with water. The roots of the rice plants are submerged in water that contains very little oxygen. Describe and explain how rice plants are adapted to grow in flooded fields. ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ............................................................................................................................................. [3] [Total: 9] © UCLES 2023 9700/42/O/N/23 [Turn over PMT

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Biology

CAIE2023

aα aα lack of nutrients aα an ascus - a sac containing 4 four spores

Question

Biology

CAIE2023

Research suggests that selective breeding began about 10 000 years ago. Selective breeding has been important in satisfying the global demand for food. (a) The introduction of disease resistance to varieties of wheat is an example of selective breeding. Outline the steps involved in the introduction of disease resistance to varieties of wheat. ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ............................................................................................................................................. [5] (b) Suggest two possible disadvantages of selective breeding. ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ............................................................................................................................................. [2] [Total: 7] © UCLES 2023 9700/42/O/N/23 [Turn over PMT

Question

Biology

CAIE2023

7.815 11.345 16.266

Question

Biology

CAIE2023

When neurone X and neurone Y are stimulated at the same time, an action potential will not occur in the postsynaptic neurone. Explain whether or not you agree with these statements. ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ............................................................................................................................................. [3] © UCLES 2023 9700/42/O/N/23 PMT

Question

Biology

CAIE2016

(i) With reference to Fig. 8.1 and Fig. 8.2, justify the statement that the rise in glyphosate-resistant weeds has resulted from the introduction of genetically modifi ed crops. ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ...................................................................................................................................... [2] (ii) Give one piece of evidence from Fig. 8.2 to support the idea that the development of weeds resistant to herbicides is not due to horizontal gene transfer from genetically modifi ed crops. ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ...................................................................................................................................... [1] (iii) Outline how herbicide resistance in weeds arises and spreads without horizontal gene transfer. ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ...................................................................................................................................... [4] © UCLES 2014 9700/04/SP/16 PPMMTT

Question

Biology

CAIE2016

(ii) Name a vector suitable for genetically modifying plant cells. ...................................................................................................................................... [1] (iii) The HT crops received two new genes that gave resistance to glyphosate herbicide and also a marker gene called GUS. The parts of the plant that express the GUS gene turn blue when dipped into a colourless chemical substrate. Explain why the GUS gene was also transferred to the genetically modifi ed crops. ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ...................................................................................................................................... [2] (b) Fig. 8.2 shows the increase in the number of weed species resistant to glyphosate herbicide and triazine herbicides since 1970. Crops have not been genetically modi fi ed to resist triazine herbicides.

Question

Biology

CAIE2016

glyphosate

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