问题 单项选择题

用组织培养技术可以在生物反应器中通过培养紫草细胞生产紫草素,下图记录了生物反应器中紫草细胞产量、紫草素产量随培养时间发生的变化。下列说法错误的是()

A.从图中可以看出反应器中紫草细胞的生长呈现S型增长规律

B.从图中可以看出反应器中影响紫草素产量的因素是细胞数量和细胞所处的生长期

C.在生产前,需先加入紫草细胞作为反应器中的“种子”,这些“种子”是紫草叶肉细胞经过脱分化和再分化而获得的

D.在培养过程中,可以通过继代培养得到更多的紫草细胞

答案

参考答案:C

解析:

从图中可以看出反应器中紫草细胞的数量呈“S”型增长,原因是开始生长较慢,要经过适应期,然后进入生长较快的对数期,随细胞数目的增多,食物、空间等生活条件成为限制因素,此时进入稳定期,细胞的数目相对稳定。因为紫草素是从大量培养的紫草愈伤组织细胞中提取的,所以生产前必须要加入离体的紫草细胞进行脱分化培养,以获得大量的紫草愈伤组织细胞(“种子”)。在这个时期紫草细胞要产生大量的次级代谢产物——紫草素,所以说紫草素产量的高低与紫草愈伤组织细胞的数目和生长期有关。在培养过程中,可以通过继代培养得到更多的紫草细胞。故选C

考点:本题考查植物组织培养和细胞培养的相关知识。

填空题



The Commission is expected to propose allowing people to choose which (36) they would come under, based on their (37) or their residency. But the proposal is set to (38) because of the very different laws on divorce that apply across the EU. The Commission wants to (39) problems over which law to apply when, for example, a married couple from one member state is resident in another member state or when the couple is of different ELI nationalities.
The (40) of member states are said to be (41) the idea and responded positively to a (42) which followed the (43) of a Commission Green Paper. With 15% of German divorces each year involving couples of different nationalities, the government of Berlin (44) see resolved the issue of which laws should apply.
But some member states are expected to resist the (45) which would involve allowing different divorce laws to be applied in their countries. For example, Malta does not allow divorce. The proposal would mean that although Maltese nationals could not divorce in Malta, a couple of different EU nationality (46) in Malta could apply to the Maltese court for a divorce under their country’s laws. Similarly in Ireland where the divorce law states a couple must have been separated for four years, establish that their marriage has broken down and be offered (47) a couple from Sweden could apply to an Irish court to allow them to divorce under Swedish law, where divorce can be (48) quickly. The Irish government’s submission to the Commission on the Green Paper stated: "reland is not in favor of allowing (49) to choose the applicable law, as this could be open to abuse ... such abuse would be likely to (50) most on divorce regimes, such as that of Ireland, which require a relatively long separation period."
Ireland, like the UK, however, is allowed to choose whether to "opt-in" to such a proposal under rules agreed in the Amsterdam treaty. Malta has no such (51) but could (52) the proposal in the Council of Ministers since (53) approval will be required. "It is going to lead to (54) said Geoffrey Shannon, Irish expert on the Commission on European Family Law, which examines the (55) of EU family law. The proposal would also mean that judges would have to be trained in the divorce law of all 25 member states.
The Commission is expected to propose allowing people to choose which (36) they would come under, based on their (37) or their residency. But the proposal is set to (38) because of the very different laws on divorce that apply across the EU. The Commission wants to (39) problems over which law to apply when, for example, a married couple from one member state is resident in another member state or when the couple is of different ELI nationalities.
The (40) of member states are said to be (41) the idea and responded positively to a (42) which followed the (43) of a Commission Green Paper. With 15% of German divorces each year involving couples of different nationalities, the government of Berlin (44) see resolved the issue of which laws should apply.
But some member states are expected to resist the (45) which would involve allowing different divorce laws to be applied in their countries. For example, Malta does not allow divorce. The proposal would mean that although Maltese nationals could not divorce in Malta, a couple of different EU nationality (46) in Malta could apply to the Maltese court for a divorce under their country’s laws. Similarly in Ireland where the divorce law states a couple must have been separated for four years, establish that their marriage has broken down and be offered (47) a couple from Sweden could apply to an Irish court to allow them to divorce under Swedish law, where divorce can be (48) quickly. The Irish government’s submission to the Commission on the Green Paper stated: "reland is not in favor of allowing (49) to choose the applicable law, as this could be open to abuse ... such abuse would be likely to (50) most on divorce regimes, such as that of Ireland, which require a relatively long separation period."
Ireland, like the UK, however, is allowed to choose whether to "opt-in" to such a proposal under rules agreed in the Amsterdam treaty. Malta has no such (51) but could (52) the proposal in the Council of Ministers since (53) approval will be required. "It is going to lead to (54) said Geoffrey Shannon, Irish expert on the Commission on European Family Law, which examines the (55) of EU family law. The proposal would also mean that judges would have to be trained in the divorce law of all 25 member states.

单项选择题