问题 实验题

下图是人体血液与组织细胞之间的物质交换示意图,请根据图回答下列问题:

(1)图中红细胞中的氧来自于外界空气,空气中的氧在人体肺的                 处进入血液,并与红细胞中的_____________                        结合,随血液循环到达组织细胞处,因此,红细胞具有运输氧的功能。

(2)图中血液里的营养物质主要来自于食物,食物在消化道内被消化成可以吸收的营养物质,这些物质主要在______________                         处被吸收进入血液。

(3)组织细胞产生的二氧化碳和其他废物通过毛细血管壁进入血液,血液里的这些废物主要由泌尿系统以尿的形式排出,尿液的主要成分有                   等。

(4)按图中血液流动的方向,此处毛细血管流出的血液应该是               ,原因是:                                               

答案

(1)毛细血管,血红蛋白。(2)小肠绒毛。(3)水,无机盐,尿素。(4)动脉血,含氧气和营养物质丰富

题目分析:(1)红细胞里有一种红色含铁的蛋白质,叫血红蛋白,血红蛋白的特性是在氧含量高的地方,与氧容易结合,在氧含量低的地方,又与氧容易分离,血红蛋白的这一特性,使红细胞具有运输氧的功能,外界空气中的氧气,通过吸气运动进入肺泡后扩散到血液里,与红细胞里的血红蛋白结合后,随血液循环到达组织细胞处。

(2)小肠是吸收营养物质的主要场所,这是与小肠的结构特点相适应的:小肠长约5~6 m,小肠内壁有环形皱襞,皱襞上有小肠绒毛,增大了吸收的面积,小肠绒毛内有毛细血管和毛细淋巴管,绒毛壁、毛细血管壁、毛细淋巴管壁都佷薄,只由一层上皮细胞构成的,有利于营养物质的吸收,因此食物在消化道内被消化成可以吸收的营养物质后主要在小肠处被吸收。

(3)尿的形成过程是:当血液流经肾小球时,除了血细胞和大分子的蛋白质外,血浆中的一部分水、无机盐、葡萄糖和尿素等物质,都可以经过肾小球滤过到肾小囊内,形成原尿,当原尿流经肾小管时,其中对人体有用的物质,包括大部分水、全部葡萄糖和部分无机盐,被肾小管重新吸收,并且进入包绕在肾小管外面的毛细血管中,重新回到血液里,原尿中剩下的其他废物,如尿素、一部分水和无机盐等由肾小管流出,形成尿液,因此尿液的主要成分是水、无机盐、尿素。

(4)图示中的毛细血管为组织处毛细血管,在这里,血液与组织细胞进行物质交换:将运来的营养物质和氧气供给细胞利用,将细胞产生的二氧化碳等废物带走,这样,血液就由动脉血变成了静脉血。

点评:此题涉及的知识面较广,包括了血液与组织细胞的物质交换、营养物质的吸收、红细胞的功能、尿的形成等知识,有一定的难度,解答此题的关键是掌握这些知识。

阅读理解

B

Ever since I was a small girl in school, I’ve been aware of what the school textbooks say about Indians. I am an Indian and, naturally, am interested in what the schools teach about natives of this land.

One day, I read that a delicacy(美味) of American Indian people was dried fish, which , according to the textbook, tasted “like an old shoe, or was like chewing on dried leather.” To this day I can remember my surprise, my anger and my sadness at reading these words. We called this wind-dried fish “sleet-shus”, and to us, it was our favorite delicacy and, indeed, did not  taste like shoe leather, and didn’t rot our teeth and bring about the various dietary problem that trouble Indian people in modern times. It took many hours of long and hard work to cure the fish in just this particular fashion. Early fur traders and other non-Indians must have agreed, for they often had this food as they traveled around isolated areas.

I brought the textbook home to show it to my father, leader of my tribe at that time. On this particular day, he told me in his wise and modest manner that the outside world did not understand Indian people, and that I should not let it prevent me from learning the good parts of education.

At a later time in my life, I had brought a group of Indian people to the country fairgrounds to sell Indian-made arts and crafts. My group was excited to make some money by selling Indian handicrafts. We thanked the man who showed us to our booth and told him it was nice of him to remember the people of the Indian community. The man expanded a little and remarked that he liked Indian people. “In fact,” he went on to state, “we are bringing some professional Indians to do the show!”

As we stood there in shock, listening to this uninformed outsider, I looked at my dear Indian companion, an eighty-year-old woman who could well remember the great chiefs of the tribe who once owned all the land of this country before the white man came bringing “civilization”, which included diseases and pollution. My friend said not a word, but took the hurt as Indian people have done for many years.

Of course, we all knew that the “professional Indian” were not Indians at all, but dressed in leather and dancing their own dances. And, anyway, how does one become a “professional Indian”?

45.Which of the following statements about “sleet-shus” is true?

A.It tasted like an old shoe.

B.Eating it was like chewing on dried leather.

C.It was delicious but bad for our teeth.

D.It must have brought pleasure to Indians as well as early business men.

46.What does the writer mean by saying “how does one become ‘a professional Indian’”?

A.Only the Indians know how to become professional Indians.

B.The outside civilization can help and Indian become a professional Indian.

C.An Indian is a born professional Indian.

D.The outside civilization can help white people become professional Indians.

47.After reading the passage, you don’t know __________.

A.what the writer’s profession is

B.what upset the writer and her friend at the county fair

C.why the writer went to the county fair

D.the writer’s attitude to the so-called civilization

48.This story is primarily about ___________.

A.customs of native Americans

B.how textbooks describe native Americans.

C.misunderstanding between people from different cultures

D.how an Indian becomes a “professional Indian”

单项选择题