皮皮学，免费搜题
登录
logo - 刷刷题
搜题
【简答题】
在“观察洋葱根尖分生组织细胞的有丝分裂”实验之后，不同班级的同学在一起进行交流，某同学发现，上午第一节课做实验的同学极少能观察到分裂期的细胞，而上午第三节课做实验的同学则大多数能观察到分裂期的细胞，他推测洋葱根尖细胞在一天中的某些分裂比较活跃，并就此展开下面的探究活动。 (1)准备：资料检索表明：25℃时洋葱根尖细胞周期为18小时，其中分裂期为1.5小时。所以，要准确掌握洋葱根尖分生区细胞在不同的分裂状况，每次取样的时间间隔不应超过______小时。 (2)培养洋葱幼根，装片制作。装片制作的正确步骤是：______、 ______、______、制片。 (3)观察装片。 (4)记录观察结果。请将下列记录表中①～⑤的内容补充完整。 (5)结果统计与分析。数据显示根尖分生区细胞大多数处于分裂间期，出现这种现象的原因是_________。
手机使用
分享
复制链接
新浪微博
分享QQ
微信扫一扫
微信内点击右上角“…”即可分享
反馈
参考答案：
举一反三
【简答题】A few days ago, I went to school with lots of books，hoping to get a locker (锁柜). Suddenly, it started raining heavily. I hurried to pay for my locker, but I was disappointed when they informed me they...
查看完整题目与答案
【多选题】根据皮亚杰的认知发展阶段理论，下列举例中不符合前运算阶段特征的是（ ）。
A.
将容量相等的两杯水分别倒入矮而粗的杯子和高而细的杯子让儿童辨别哪个杯子中的水多，一部分儿童认为矮而粗的杯子的水多，而另一部分认为高而细的杯子的水多
B.
向儿童提出这样的问题：假定A>B，B>C，问A和C哪个大，他们难以回答。若换一种 说法：“张老师比李老师高，李老师比王老师高，问张老师和王老师哪个高?”他们可以回答
C.
对于一个白色的长方形的玩具，儿童既可以把它归入“白色物体”一类，也可以把它归人“长方形”物体
D.
将一大杯中的水倒人小杯时，儿童能够考虑水从大杯倒人小杯，而且还能设想水从小杯倒回大杯，并恢复原状
E.
问一名儿童：“你有兄弟吗?”他回答“有”。“兄弟叫什么名字?”他回答道：“吉姆”。但反过来问：“吉姆有兄弟吗?”他回答：“没有。”
查看完整题目与答案
【单选题】下列有关皮亚杰的认知发展阶段理论的说法，正确的是（ ）
A.
儿童的认知发展可以分为前运算、具体运算和形式运算三个阶段
B.
2-7 岁的儿童处于前运算阶段，表现出知觉的集中倾向性、不可逆性、自我中心主义等特点
C.
认知发展的每一个阶段都有独特的认知结构，其出现的顺序因人而异
D.
认知发展的每个阶段都是独立、毫无关联的
查看完整题目与答案
【单选题】It's _______ these days. There are lots of yellow leaves on the streets. [     ]
A.
cloudy
B.
sunny
C.
windy
查看完整题目与答案
【单选题】听力原文： In some countries, taking lots of days off work sick would get you fired and the idea of offering prizes for good attendance would be little more than a joke. But absenteeism has become a big pr...
A.
is now a big problem
B.
could lead to dismiss of the staff
C.
is not so serious as before
D.
is protected by the employment laws
查看完整题目与答案
【简答题】The Arts Cinema is open 7 days a week, showing lots of American and foreign films. Next week，it will show an Australian film called “Midnight Meeting”. It is set in Sydney in the 1960s. You can see th...
查看完整题目与答案
【单选题】听力原文： In some countries, taking lots of days off work sick would get you fired and the idea of offering prizes for good attendance would be little more than a joke. But absenteeism has become a big pr...
A.
is now a big problem
B.
could lead to dismiss of the staff
C.
is not so serious as before
D.
is protected by the employment laws
查看完整题目与答案
【单选题】These days lots of young Japanese do omiai, literally, 'meet and look. ' Many of them do so willingly. In today's prosperous and increasingly conservative Japan, the traditional omiai kekkon , or arra...
A.
a traditional arranged marriage
B.
a new type of arranged marriage
C.
a Western love marriage
D.
a more Westernized love marriage
查看完整题目与答案
【简答题】A few days ago，I went to school with lots of books，hoping to get a locker (锁柜)．Suddenly，it started raining heavily. I hurried to pay for my locker，but I was disappointed when they informed me they onl...
查看完整题目与答案
【单选题】瑞士心理学家皮亚杰认为,人从出生到成人伴随认知结构的不断重构,形成几个按不变顺序相继出现的时期或阶段。当儿童凭借形象在头脑中进行“表象性思维”时,其认知发展到了
A.
感知运动阶段
B.
前运算阶段
C.
具体运算阶段
D.
形式运算阶段
查看完整题目与答案
相关题目：
【简答题】A few days ago, I went to school with lots of books，hoping to get a locker (锁柜). Suddenly, it started raining heavily. I hurried to pay for my locker, but I was disappointed when they informed me they...
查看完整题目与答案
【多选题】根据皮亚杰的认知发展阶段理论，下列举例中不符合前运算阶段特征的是（ ）。
A.
将容量相等的两杯水分别倒入矮而粗的杯子和高而细的杯子让儿童辨别哪个杯子中的水多，一部分儿童认为矮而粗的杯子的水多，而另一部分认为高而细的杯子的水多
B.
向儿童提出这样的问题：假定A>B，B>C，问A和C哪个大，他们难以回答。若换一种 说法：“张老师比李老师高，李老师比王老师高，问张老师和王老师哪个高?”他们可以回答
C.
对于一个白色的长方形的玩具，儿童既可以把它归入“白色物体”一类，也可以把它归人“长方形”物体
D.
将一大杯中的水倒人小杯时，儿童能够考虑水从大杯倒人小杯，而且还能设想水从小杯倒回大杯，并恢复原状
E.
问一名儿童：“你有兄弟吗?”他回答“有”。“兄弟叫什么名字?”他回答道：“吉姆”。但反过来问：“吉姆有兄弟吗?”他回答：“没有。”
查看完整题目与答案
【单选题】下列有关皮亚杰的认知发展阶段理论的说法，正确的是（ ）
A.
儿童的认知发展可以分为前运算、具体运算和形式运算三个阶段
B.
2-7 岁的儿童处于前运算阶段，表现出知觉的集中倾向性、不可逆性、自我中心主义等特点
C.
认知发展的每一个阶段都有独特的认知结构，其出现的顺序因人而异
D.
认知发展的每个阶段都是独立、毫无关联的
查看完整题目与答案
【单选题】It's _______ these days. There are lots of yellow leaves on the streets. [     ]
A.
cloudy
B.
sunny
C.
windy
查看完整题目与答案
【单选题】听力原文： In some countries, taking lots of days off work sick would get you fired and the idea of offering prizes for good attendance would be little more than a joke. But absenteeism has become a big pr...
A.
is now a big problem
B.
could lead to dismiss of the staff
C.
is not so serious as before
D.
is protected by the employment laws
查看完整题目与答案
【简答题】The Arts Cinema is open 7 days a week, showing lots of American and foreign films. Next week，it will show an Australian film called “Midnight Meeting”. It is set in Sydney in the 1960s. You can see th...
查看完整题目与答案
【单选题】听力原文： In some countries, taking lots of days off work sick would get you fired and the idea of offering prizes for good attendance would be little more than a joke. But absenteeism has become a big pr...
A.
is now a big problem
B.
could lead to dismiss of the staff
C.
is not so serious as before
D.
is protected by the employment laws
查看完整题目与答案
【单选题】These days lots of young Japanese do omiai, literally, 'meet and look. ' Many of them do so willingly. In today's prosperous and increasingly conservative Japan, the traditional omiai kekkon , or arra...
A.
a traditional arranged marriage
B.
a new type of arranged marriage
C.
a Western love marriage
D.
a more Westernized love marriage
查看完整题目与答案
【简答题】A few days ago，I went to school with lots of books，hoping to get a locker (锁柜)．Suddenly，it started raining heavily. I hurried to pay for my locker，but I was disappointed when they informed me they onl...
查看完整题目与答案
【单选题】瑞士心理学家皮亚杰认为,人从出生到成人伴随认知结构的不断重构,形成几个按不变顺序相继出现的时期或阶段。当儿童凭借形象在头脑中进行“表象性思维”时,其认知发展到了
A.
感知运动阶段
B.
前运算阶段
C.
具体运算阶段
D.
形式运算阶段
查看完整题目与答案
参考解析：
知识点：
题目纠错 0
发布
创建自己的小题库 - 刷刷题