题干

飞燕草的花色多样,但缺少红花类型.科研人员以下面三种植物为材料,培育红花飞燕草.

植物种类

染色体组数

染色体数

花色

高山飞燕草

4

32

白色

深红翠雀草

2

16

朱红色

裸茎翠雀草

2

16

橙黄色

请回答问题:

(1)深红翠雀草和高山飞燕草在自然状态下无法杂交产生可育后代,这是由于两种植物间存在____ .

(2)为了获得红花飞燕草,科研人员选定的杂交方案是:用裸茎翠雀草和深红翠雀草作为亲本进行杂交获得F1,再用秋水仙素溶液处理使其____ ,获得可育的杂种植株.

(3)将上述杂种植株与高山飞燕草杂交,获得了红花飞燕草植株,该植株体细胞中每个染色体组有____ 条染色体,获得该植株的育种原理是____ 

(4)上述研究使我们认识到,保护物种多样性的重要意义在于保护生物的____ 多样性.

上一题 下一题 0.0难度 选择题 更新时间:2018-11-06 11:38:42

答案(点此获取答案解析)

生殖隔离,染色体数目加倍,8,染色体变异,基因(遗传)

同类题4

阅读理解

    As has been all too apparent in recent days at Balcombe, few issues cause greater concern than energy policy. Many village communities feel their countryside is being ruined by the power-producing machines of wind farms; yet they never take “ direct action”, even though the planning laws put them at a severe disadvantage. And the generous subsidies(财政补贴),which encourage the expansion of wind power, are not favorable to the village communities and set landowners in conflict with other residents.

    Those who disagree with the rapid expansion of wind farms state that the damage they cause is out of proportion to the benefits they bring, because their energy output cannot match that of the carbon-based power stations they are supposed to replace. Supporters insist that wind must be part of a mix of renewables, nuclear and carbon, and that the country is committed to meeting EU(European Union) targets for non-carbon energy generation.

    Against this background, the fact that there is an argument within the Government over whether to publish an official report on wind farms impact on the countryside becomes even more extraordinary. The two parties in the coalition government are in disagreement over what it should say.

    We have some advice for the two parties :publish the report ,and let the country be the judge. Even if it contains evidence that wind farms are harmful, it will hardly be a pleasant surprise to people who do not like them. Equally, supporters must argue their case by acknowledging the concerns and explaining why they are either misplaced or worthy of much attention.

    The suggestion that further negotiations are to take place to produce an “acceptable” report suggests that the politics of coalition government are doing the country harm in a certain way. Given the sensitivities involved ,all the information should be available so that people can reach their own conclusions, rather than being left with the suspicion that facts are being replaced by political beliefs.

根据短文内容,选择最佳答案,并将选定答案的字母标号填在题前括号内。