问题 单项选择题

下面关于胚芽鞘弯向光源的原理叙述有错误的是()

A.感受光刺激的部位在胚芽鞘尖端

B.向光弯曲的部位在尖端下面一段

C.向光一侧生长素分布的多,生长慢

D.生长素在尖端产生并向下输送

答案

参考答案:C

解析:尖端是胚芽鞘感受光刺激的部位;向光弯曲的部位在尖端下面一段;单侧光使胚芽鞘尖端的生长素发生横向运输,由向光侧运输到背光侧,所以背光一侧生长素分布的多,生长快;生长素在尖端产生并向下输送到作用部位,促进生长。故选C

阅读理解

  Not long ago, people thought babies were not able to learn things until they were five or six months old. Yet doctors in the United States say babies begin learning on their first day of life.

Scientists note that babies are strongly influenced by their environment. They say a baby will smile if her mother does something the baby likes. A baby learns to get the best care possible by smiling to please her mother or other caregivers. This is how babies learn to connect and communicate with other human beings.

One study shows that babies can learn before they are born. The researchers placed a tape recorder on the stomach of a pregnant woman. Then, they played a recording of a short story. On the day the baby was born, the researchers attempted to find if he knew the sounds of the story repeated while in his mother. They did this by placing a device in the mouth of the newborn baby.

The baby would hear the story if he moved his mouth one way. If the baby moved his mouth the other way, he would hear a different story. The researchers say the baby clearly liked the story he heard before he was born. They say the baby would move his mouth so he could hear the story again and again.

Another study shows how mothers can strongly influence social development and language skills in their children.

Researchers studied the children from the age of one month to three years. The researchers attempted to measure the sensitivity of the mothers. The women were considered sensitive if they supported their children’s activities and did not interfere (干涉) unnecessarily. They tested the children for thinking and language development when they were three years old. Also, the researchers observed the women for signs of depression (消沉).

The children of depressed women did not do as well in tests as the children of women who did not suffer from depression. The children of depressed women did poorly in tests of language skills and understanding what they hear.

These children also were less cooperative and had more problems dealing with other people. The researchers noted that the sensitivity of the mothers was important to the intelligence development of their children. Children did better when their mothers were caring, even when they suffered from depression.

小题1: According to the passage, which of the following is NOT the factor that influences intelligence development in babies?

A.The environment.

B.Mother’s sensitivity.

C.Education before birth.

D.Their peers (同龄人)小题2: What is the purpose of the experiment in which newborn babies heard the stories?

A.To prove that babies can learn on the first day they are born.

B.To prove that babies can learn before they are born.

C.To show mothers can strongly influence intelligence development in their babies.

D.To indicate early education has a deep effect on the babies’ language skills.小题3: Which group of children did the worst in tests of language skills?

A.The children of women who did not suffer from depression.

B.The children of depressed but caring mothers.

C.The children of depressed mothers who cared little for their children.

D.The children with high communication abilities.小题4: What is the main idea of the passage?

A.Scientific findings about how intelligence develops in babies.

B.Scientific findings about how the environment has an effect on babies’ intelligence.

C.A study shows babies are not able to learn things until they are five or six months old.

D.Scientific findings about how babies develop before birth.

单项选择题