问题 解答题

阅读下列资料,回答问题:

资料一:在江苏省农科院的桃资源圃中目前已收集保存了来自国内外的桃种资源600份,涉及普通桃、山桃和甘肃桃等.这些不同品种的桃具有抗逆性、抗病性等优良基因,专家们通过复杂和漫长的育种工作,培育出了水蜜桃、黄桃、蟠桃和油桃等28个桃品种.

资料二:近年来园艺师精心选育,将油桃和蟠桃进行杂交,培育出油蟠桃的种子,将其播种后,长出的植株上结出的桃子有着蟠桃的“脸”,油桃的“皮肤”,果实扁平,表皮光滑,肉质厚、甜度高.为了快速繁殖推广该新品种,研究人员一般用山桃作砧木,油蟠桃作接穗来快速繁育油蟠桃.

(1)资料一体现桃的育种利用生物的______多样性.

(2)资料二中利用播种繁殖油蟠桃植株的生殖类型属于______生殖.油蟠桃的食用部分是由______发育而来的.

(3)要提高嫁接植株的成活率,其操作的关键是______.

答案

(1)、生物多样性通常有三个层次的含义,即生物种类的多样性、基因(遗传)的多样性和生态系统的多样性.杂交育种是利用了基因的多样性.

(2)、生物的生殖保护有性生殖和无性生殖,有性生殖过程中有两性生殖细胞的结合,无性生殖无两性生殖细胞的结合,可见利用种子繁殖,在形成种子时有传粉和受精过程,属于有性生殖.传粉和受精之后,只有子房继续发育,子房壁发育出果实的果皮,即可食用部分由子房壁发育而来.

(3)、嫁接成功的关键是接穗和砧木的形成层紧密结合,因为形成层属于分生组织,能不断分裂产生新的细胞,使得接穗和砧木能生长在一起,利于嫁接的成活效率.

故答案为:(1)基因的

(2)有性;子房壁

(3)使接穗和砧木的形成层紧密结合

阅读理解

根据短文内容,从短文后的选项中选出能填入空白处的最佳选项,选项中有两项为多余选项。

Four Habits t0,Help You Succeed

We all want to succeed,whether it’s in losing weight or learning the guitar.For those who hay e tried and failed,success seems difficult to understand.Why does one person succeed while another person fails?       1   

1.Identify your core values.   

Finding your core values is in line with creating inner motivation.  2     Pick a handful of things and actually write them down.Remind yourself of your values every day,and reflect on whether you are honoring those values through your work.

2.Pick a goal and focus on it.

Choose one goal to start something large enough that will give you a sense of accomplishment,while adjusting well to your core values.Focus is key here.    3     If you perform many tasks at。a time,you might never complete your projects because they will take far too lon9.

3.Set a deadline for success.

Set a date for success.Identify when you hope to achieve your goal.    4     By setting a time limit,you are making the process more real.

4.     5       .Failure can’t be avoided when you take risks, By its very definition,the desire to succeedmeans you are risking failure。Many people tend to give up far too early.Don’t fall into this trap! Remember your mindset earlier.Know it will happen.A failure is merely you working out the details,and learning what works and what doesn’t.Use failure.Treat it as a good thin9,and march on!

A.The more focused you are on one goal,the higher chance you have of Success.

B.Make the right decision.

C.I’ve made a list of four habits to help you set goals and achieve them.

D.Stick to your goal.E.Keep it realistic,while not giving you too mu ch time.

F.Sit and reflect on what you value most.

G.Push yourself to be courageous,and take that next step.

单项选择题