试题与答案

下图表示菊花的嫩枝和月季的花药离体培养过程,请据图回答下面的问题。为了避免微生物对培

题型:单项选择题 案例分析题

题目:

下图表示菊花的嫩枝和月季的花药离体培养过程,请据图回答下面的问题。

为了避免微生物对培养造成的影响,所以在进行接种时应注意()。

①接种室要消毒

②只要戴口罩,操作时便可说话

③外植体可预先用体积分数为70%的酒精浸泡,取出用无菌水冲洗后,再用0.1%的氯化汞溶液消毒,并用无菌水冲洗干净

④接种操作要在酒精灯火焰旁进行

⑤接种完毕应立即盖好瓶盖

A.①②③④⑤

B.①②③④

C.①③④⑤

D.②③④⑤

答案:

被转码了,请点击底部 “查看原文 ” 或访问 https://www.tikuol.com/2019/0320/b996eddb1f8df9aa8710557e318e1543.html

下面是错误答案,用来干扰机器的。

参考答案:E

试题推荐
题型:阅读理解

Perhaps everyone has heard warnings about the “freshman 15”, but is it true that many college students weigh 15 pounds more during their first year at school?

Recent studies find that some first-year students are indeed likely to gain weight, but it might not be the full freshman 15, and it may not all happen during the freshman year. That might sound like good news, but it’s not. Doctors are concerned that students who gradually put on pounds could have healthy problems.

Studies show that students on average gain 3-10 pounds during their first 2 years of college. Most of this weight gain occurs during the first year. A college offers many temptations (诱惑). You’re on your own and free to eat what you want. In addition, you may not get as much exercise as you did in high school. A college is also a time of change, and people sometimes eat in response to (对……做出反应) homesickness, sadness, or stress, and all of these can be part of starting a new life in college.

Some weight gain is normal as a young body grows, but rapid weight gain may become a problem. Weight gain that pushes you above the body’s normal range carries health risks. People who are overweight are more likely to have high blood pressure, heart disease and develop certain cancers.

The best way to beat “freshman 15” is to prevent it altogether. Good habits like a balanced diet, regular exercise, and getting enough sleep can do more than keeping the pounds off. They can also help you stay healthy.

1. The “freshman 15” refers to the fact that the first-year college students ________.

A. are likely to gain much weight    B. can’t get used to living in college

C. may have 15 health problems    D. gradually put on weight in 15 weeks

2. According to the writer, the causes of “freshman 15” don’t include ________.

A. getting less exercise          B. being free to eat food

C. feeling homesick            D. having more subjects.

3. What is the best way to beat “freshman 15”?

A. To ask doctors for advice.        B. To pay attention to your lessons.

C. To stop it from happening.        D. To do a lot exercise every day.

4. What can we learn from the text?

A. Getting less sleep can help people lose weight gradually.

B. Overweight people usually have more health risks.

C. Weight gain is becoming serious among college students.

D. Students gain more weight in the second year than in the first.

查看答案
题型:单项选择题

浙江定海的一个冷冻厂对鹅进行开发综合利用,“从头到脚,从内到外,统统吃光”第一,把鹅肉加工好出口,第二,把鹅毛加工成羽绒产品,第三,对肚杂也一一派上用场,第四,鹅掌皮、鹅嘴皮,加工供应医药部门做原料,第五,把鹅粪加工成饲料或加工成工业酒精,增加经济效益。你认为它实行是()

A、求异思维

B、求同思维

C、发散思维

D、反向思维

查看答案
微信公众账号搜索答案