搜题
问题详情
在进化的过程中，鸟嘴形成了各种不同的形状，下面是鹦鹉、鹭鸶、老鹰、金丝雀的头部画像，鹭鸶是哪一个？（）
相关热点： 金丝雀
未搜索到的试题可在搜索页快速提交，您可在会员中心"提交的题"快速查看答案。
收藏该题
查看答案
搜题
相关问题推荐
鸟嘴的形状，下图是鹦鹉、鹭鹭、老鹰、金丝雀头部的画像，从嘴型看，金丝雀应当是()
ABCD
ABCD
下面是某位教师进行“生长素的发现”一节教学时，关于达尔文实验的教学片段。
“生长素的发现——达尔文实验”的教学片段师：植物的向光性是一个普遍存在的生物学现象。最早对这个实验现象进行研究的人是达尔文，他以金丝雀籙草的胚芽鞘作为实验材料进行了实验（展示实验过程示意图）。在这个实验中，变量是什么？生：光照。师：自变量是单侧光。谁来描述一下实验现象？生：黑暗条件下，胚芽鞘竖直向上生长；而单侧光照下，胚芽鞘向光弯曲生长。师：通过这个实验，能得到什么结论呢？生：胚芽鞘的生长与单侧光是有关系的。……在该教学片段中，教学的主要意图是（）。A.帮助学生理解科学研究是植根于特定文化背景的B.帮助学生理解科学研究的基本设计思路和分析方法C.帮助学生理解科学知识具有暂定性，是不断发展的D.帮助学生理解科学是众多科学家长期共同研究的成果
阅读下文。完成73～76题。
美国科学家近期对山雀的行为进行研究，发现这些田鼠般大小的鸟，能把为过冬而贮藏种子的地方牢记心里，不管是5处10处，甚至更多的地方，它们均能找到这些秘密的仓库。在对燕雀、金丝雀的研究中，科学家们听到它们每年春天唱的歌，“曲目”同往年完全不同，既新鲜又动听。这说明，鸟类的大脑有特殊的学习记忆能力。’
对42只山雀的脑部进行解剖，观察到海马回的细胞每年都在更新。冬季来临之前，更新量最大，每年约有2%的神经元被新生长的神经细胞取代。燕雀的海马回也有类似的情况。科学家于是得出结论：。
以往的研究认为，神经突触是记忆单元，大脑的学习能力在于大脑皮层细胞之间相连网络的增加。尽管神经细胞不再生，但突触能不断长出，使树型思维结构不断分叉，而保持较好的记忆能力。而现在的研究则认为，记忆单元是整个神经元，神经细胞能再生，至少山雀是这样的。
为了产生良好的、长达数月或数年的记忆，需要整个神经元参加，而不是几个突触。这是部分脑科学家最新研究得出的结论。但是，鸟类的此种学习系统能否适用于人类，还有待进一步的实验研究。现在已有证据确认，人、猴、啮齿类动物记忆的衰退，与海马回受损有关。实际，传统的突触网络记忆说——不断强化、产生深刻记忆的观点，有说服力的证据也不多。神经元更新学习记忆，为揭开大脑之谜指示了新的研究方向。
第73题第2段段末横线上填入的句子最确切的一项是（）。
A．山雀、燕雀都有学习记忆能力
B．鸟类的大脑有特殊的学习记忆能力
C．鸟类的学习记忆能力同神经元的更新相关
D．研究鸟类的学习记忆能力，要对脑部进行解剖
鸟嘴的形状，下图是鹦鹉、鹭鹭、老鹰、金丝雀头部的画像，从嘴型看，金丝雀应当是( )
A.A
B.B
C.C
D.D
A.A
B.B
C.C
D.D
共用题干第二篇
Where Have All the Frogs Gone?
In the 1980s,scientists around the world began to notice something strange:Frogs
were disappearing. More recent research has shown that many kinds of amphibians（两栖
动物）are declining or have become extinct. They have been around for a long time一over
350 million years.Why are they dying out now?
Scientists are seriously concerned about this question.First of all,amphibians are an
important source of scientific and medical knowledge.By studying amphibians,scientists
have learned about new substances that could be very useful for treating human diseases.
Further research could lead to many more discoveries,but that will be impossible if the
amphibians disappear.
The most serious aspect of amphibian loss,however,goes beyond the amphibians
themselves.Scientists are beginning to think about what amphibian decline means for the
planet as a whole.If the earth is becoming unlivable for amphibians,is it also becoming
unlivable for other kinds of animals and human beings as well?
Scientists now believe that amphibian decline is due to several environmental factors.
One of these factors is the destruction of habitat,the natural area where an animal lives.
Amphibians are very sensitive to changes in their habitat.If they cannot find the right
conditions,they will not lay their eggs一These days,as wild areas are covered with
houses,roads,farms,or factories,many kinds of amphibians are no longer laying eggs.
For example,the arroyo toad（蟾蜍）of southern California will only lay its eggs on the
sandy bottom of a slow-moving stream.There are very few streams left in southern
California,and those streams are often muddy because of building projects. Not
surprisingily,the arrovo toad is now in danaer of extinction.
There are a number of other factors in amphibian decline.Pollution is one of them.In
many industrial areas,air pollution has poisoned the rain,which then falls on ponds and
kills the frogs and toads that live there,In farming areas,the heavy use of chemicals on
crops has also killed off arrtphibians.Another factor is that air pollution has led to increased
levels of ultraviolet (UV) light. This endangers amphibians, which seem to be especially
sensitive to UV light. And finally, scientists have discovered a new disease that seems to
be killing many species of arnpttibians in different parts of the world.
All these reasons for the disappearance of amphibians are also good reasons for more
general concern. The destrriction of land, the pollcition of the air and the water, the
changes in our atmosphere, the spread of diseases-these factors affect human beings,
too. Amphibians are especially sensitive to environmental change. Perhaps they are like
the canary （金丝雀）bird that coal miners once used to take down into the mines to detect
poisonous gases. When the canary became ill or died,the miners knew that dangerous
gases were near and their own lives were in danger. Scientists think that the decline of amphibians couldA:cause environmental change.B:cause a decline in other kinds of animals.C:be a warning signal for human beings.D:be a good sign for human beings.
Where Have All the Frogs Gone?
In the 1980s,scientists around the world began to notice something strange:Frogs
were disappearing. More recent research has shown that many kinds of amphibians（两栖
动物）are declining or have become extinct. They have been around for a long time一over
350 million years.Why are they dying out now?
Scientists are seriously concerned about this question.First of all,amphibians are an
important source of scientific and medical knowledge.By studying amphibians,scientists
have learned about new substances that could be very useful for treating human diseases.
Further research could lead to many more discoveries,but that will be impossible if the
amphibians disappear.
The most serious aspect of amphibian loss,however,goes beyond the amphibians
themselves.Scientists are beginning to think about what amphibian decline means for the
planet as a whole.If the earth is becoming unlivable for amphibians,is it also becoming
unlivable for other kinds of animals and human beings as well?
Scientists now believe that amphibian decline is due to several environmental factors.
One of these factors is the destruction of habitat,the natural area where an animal lives.
Amphibians are very sensitive to changes in their habitat.If they cannot find the right
conditions,they will not lay their eggs一These days,as wild areas are covered with
houses,roads,farms,or factories,many kinds of amphibians are no longer laying eggs.
For example,the arroyo toad（蟾蜍）of southern California will only lay its eggs on the
sandy bottom of a slow-moving stream.There are very few streams left in southern
California,and those streams are often muddy because of building projects. Not
surprisingily,the arrovo toad is now in danaer of extinction.
There are a number of other factors in amphibian decline.Pollution is one of them.In
many industrial areas,air pollution has poisoned the rain,which then falls on ponds and
kills the frogs and toads that live there,In farming areas,the heavy use of chemicals on
crops has also killed off arrtphibians.Another factor is that air pollution has led to increased
levels of ultraviolet (UV) light. This endangers amphibians, which seem to be especially
sensitive to UV light. And finally, scientists have discovered a new disease that seems to
be killing many species of arnpttibians in different parts of the world.
All these reasons for the disappearance of amphibians are also good reasons for more
general concern. The destrriction of land, the pollcition of the air and the water, the
changes in our atmosphere, the spread of diseases-these factors affect human beings,
too. Amphibians are especially sensitive to environmental change. Perhaps they are like
the canary （金丝雀）bird that coal miners once used to take down into the mines to detect
poisonous gases. When the canary became ill or died,the miners knew that dangerous
gases were near and their own lives were in danger. Scientists think that the decline of amphibians couldA:cause environmental change.B:cause a decline in other kinds of animals.C:be a warning signal for human beings.D:be a good sign for human beings.