2021AP生物Free response怎么答 先来看看官网的样本例题解析吧

很多同学在回答AP生物Free respons时毫无头绪，马上就要迎来了新一年的AP生物考试了，同学们想知道改革之后的2021AP生物Free response怎么答吗？先来一起看看官网的sample例题怎么回答吧！

解析：从题干来看，题目的背景是比较结合生活实际的，是疟疾的传播通过蚊虫叮咬，然后科学家希望能用化学物质（pyrethroids，除虫菊酯）来除掉蚊子。

To investigate pyrethroid resistance, mosquitoes were collected four times over a two-year period from the following two regions.

Region A: a southern vegetable-growing region where large amounts of insecticide are applied for crop protection

Region B: a northern rice-growing region where very little insecticide is applied for rice protection

Scientists exposed the collected mosquitoes to filter papers soaked in two different pyrethroid insecticides, deltamethrin and permethrin, and the percent mortality of the mosquitoes was determined after 24 hours (Figure 2).

解析：在题目中看到表格图表什么的，及时去分析，这样可以化被动为主动。接着出题以一种实验探究的方式来看蚊子抗性的原因。从上述图表中，我们可以看到，deltamethrin对于两个地区的蚊子，效果都很好，蚊子死亡率高。permethrin对区域A的效果较差，对区域B的效果依旧较好。

The scientists simultaneously determined whether leucine or phenylalanine was encoded at position 1014 by each of the two copies of the sodium channel gene (Table 1).

解析：同样的，依旧是及时分析。从表格中可以看出，A区域在1014位点上主要是苯丙氨酸，B区域的在1014位点上主要是亮氨酸，随着时间的进行，杂合子的比例在增加。

(a) Describe the most likely cause of the amino acid substitution in the sodium channel protein.

(b) Explain how the substitution of a single amino acid in the channel protein could cause pyrethroid resistance in mosquitoes.

(c) Identify the dependent variable in the experiment whose data are graphed in Figure 2.

(d) Identify the positive control in the experiment.

(e) Justify exposing some mosquitoes to untreated filter paper each time the experiment was performed.

(f) Based on the data in Figure 2, describe whether mosquitoes from region A or from region B are more likely to exhibit greater evolutionary fitness if exposed to permethrin in their native environment over the time period of the experiment.

(g) Based on the data in Figure 2, describe any significant change in the susceptibility of mosquitoes from region B to each of the two insecticides over the two-year period.

(h) Use the data in Table 1 to calculate the frequency of the allele coding for phenylalanine in each population of mosquitoes in October 2008. Round your answers to two decimal places.

解析：从题目中，可以看出，考察的不仅是实验数据的分析，还有变异的来源、实验设计的原则、膜蛋白的功能、生物进化中的适应现象、基因频率的计算等，是非常综合的考察。总体难度不大，但考的灵活。

本文对AP生物Free respons的回答建议就到这里。AP生物不管对学员AP生物知识点的掌握程度还是分析结果能力都有很高的要求，因此考生一定将所有的AP生物知识点烂熟于心，同时培养一定的科学分析能力。

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