问题 实验题

如图是生物兴趣小组对某家庭头发(卷发、直发)遗传特点调查后,绘制的遗传图谱,请分析回答问题.

(1)在遗传学上,人类头发的卷发和直发是一对      .小甜是直发,而妈妈是卷发,这种亲子间的差异,在遗传学上叫做     

(2)查找资料得知,卷发对直发是显性.如果控制卷发的基因是D,控制直发的基因是d,则可推测出小甜和爸爸的基因组成都是    ,爷爷、奶奶、妈妈的基因组成都是     

(3)小甜的爸爸是独生子,根据“单独二孩”政策,如果再生一个小孩,为卷发的可能性是     

答案

(1)相对性状;变异

(2)dd;Dd

(3)50%(1/2)

题目分析:(1)同种生物同一性状的不同表现形式称为相对性状;因此,人类头发的卷发和直发是一对相对性状.小甜是直发,而妈妈是卷发,这种亲子间的差异,在遗传学上叫变异.

(2)若卷发对直发是显性.如果控制卷发的基因是D,控制直发的基因是d,小甜和爸爸都是直发,则可推测出小甜和爸爸的基因组成都是dd.爸爸的基因dd一个来自爷爷,一个来自奶奶,而爷爷、奶奶都是卷发,则可推测出爷爷、奶奶的基因组成都是Dd;小甜的基因dd一个来自爸爸,一个来自妈妈,已知妈妈是卷发,则可推测出妈妈的基因组成也是Dd.

(3)小甜的爸爸是独生子,根据“单独二孩”政策,如果再生一个小孩,为卷发的可能性是50%.如图:

阅读理解

阅读理解。

     Two hours from the tall buildings of Manhattan and Philadelphia live some of the world's largest black

bears. They are in northern Pennsylvania's Pocono Mountains, a home they share with an abundance of

other wildlife.

     The streams, lakes, meadows, mountain ridges and forests that make the Poconos an ideal place for

black bears,have also attracted more people to the region. Open spaces are threatened by plans for housing

estates and important habitats are endangered by highway construction. To protect the Poconos' natural

beauty from irresponsible development, the Nature Conservancy (大自然保护协会) named the area one

of America's "Last Great Places"

     Operating out of a century-old schoolhouse in the village of Long Pond, Pennsylvania, the

conservancy's bud Cook is working with local people and business leaders to balance economic growth

with environmental protection. By forging partnerships with people like Francis Altemose, the Conservancy

has been able to protect more than 14,000 acres of environmentally important land in the area.

      Altemose's family has farmed in the Pocono area for generations. Two years ago Francis worked with

the Conservancy to include his farm in a county farmland protection program. As a result, his family's land

can be protected from development and the Altemoses will be better able to provide a secure financial future

for their 7-year-old grandson. Cook attributes the Conservancy's success in the Poconos to having a local

presence and a commitment to working with local residents

      "The key to protecting these remarkable lands is connecting with the local community," Cook said. "The

people who live there respect the land. They value quite forests, clear streams and abundant wildlife. They are

eager to help with conservation effort. For more information on how you can help The Nature Conservancy

protect the Poconos and the world's other"Last Great Places," please call 1-888-564 6864, or visit us on the

World Wide Web at www.tnc.org.

1. The purpose in naming the Poconos as one of America's " Last Great Places" is to ________.

A. gain support from the local community

B. protect it from irresponsible development

C. make it a better home for black bears

D. provide financial security for future generations

2. We learn from the passage that _______.

A. the population in the Pocono area is growing

B. wildlife in the Pocono area is dying out rapidly

C. the security of the Pocono residents is being threatened

D. farmlands in the Pocono area are shrinking fast

3. What is important in protecting the Poconos according to Cook?

A. The setting up of an environmental protection website

B. Support from organizations like The Nature Conservancy

C. Cooperation with the local residents and business leaders

D. Inclusion of farmlands in the region's protection program

4. The passage most probably is ________.

A. an official document

B. a news story

C. an advertisement

D. a research report

单项选择题 B1型题