首页
外语
计算机
考研
公务员
职业资格
财经
工程
司法
医学
专升本
自考
实用职业技能
登录
考研
Women’s fertility is determined in large part at birth. They are born with their total number of reproductive cells, which norma
Women’s fertility is determined in large part at birth. They are born with their total number of reproductive cells, which norma
admin
2015-07-13
871
问题
Women’s fertility is determined in large part at birth. They are born with their total number of reproductive cells, which normally influences the age at which menopause—the shutting down of female reproductive system—begins. But in the 1990s, researchers proposed that if a child’s energy is depleted by malnutrition, disease, or other factors, he or she would be less fertile as an adult. Byusing the natural experiment of migration, researchers demonstrated how differences during childhood do alter the course of reproduction in adult women.
Biological anthropologist Gillian Bentley of Durham University in the UK and colleagues compared levels of reproductive hormones in 250 Bangladeshi women, including women who migrated from Sylhet, Bangladesh to London; women who stayed in Sylhet; and Bangladeshi women born in London. In the first stage of their study, they found that women who migrated from Bangladesh as children had higher levels of reproductive hormones in their saliva than women who lived in Sylhet, but less than women born in London. This had a direct effect on fertility: Migrant women in London had an 11% higher rate of ovulation—discharging of mature ovum—during their lives than did women in Sylhet, the team reported in 2007.
The team has now studied 900 women between the ages of 35 and 60 to see if the beginning of menopause varies between migrants and women in Sylhet. Bentley presented preliminary results from their measurement of hormones that regulate the maturation of reproductive cells and are indirect indices of how many ova they can still produce. Her team found that migrants enter menopause later than did women who stayed in Bangladesh but earlier than did those born in London. "The adult migrants seem to be sensitive to improved conditions," says Bentley.
The group is trying to find out which environmental factors in Bangladesh lower growing girls’ fertility. All the Bangladeshi women in the study came from middle-class, land-owning families, who grew up with adequate calories. However, girls growing up in Bangladesh were probably exposed to more infectious diseases during crucial developmental years. So, they may have had to make tradeoffs among using energy to grow, to maintain their bodies, or to maximize their reproductive potential as adults. Bentley plans to test that idea next year when her team returns to Bangladesh to see if girls there suffer from more diseases than do those in London. "In other words," says Bentley, "where you spend your childhood influences adult reproductive function."
According to the text, which of the following factor in childhood will probably cause an adult to be less fertile?
选项
A、Menopause period.
B、Infectious disease.
C、Vigorous exercise.
D、Reproductive hormones.
答案
B
解析
推理判断题。根据第一段第三句话可得知使妇女生育能力下降的因素包括因营养不良、疾病或其他因素,B项包括在内,故选。
转载请注明原文地址:https://jikaoti.com/ti/09FRFFFM
0
考研英语一
相关试题推荐
Shoppinghasalwaysbeensomethingofanimpulsiveactivity,inwhichobjectsthatcatchourfancywhilestrollingareimmediate
Inthelate1960’s,manypeopleinNorthAmericaturnedtheirattentiontoenvironmentalproblems,andnewsteel-and-glassskysc
Inthelate1960’s,manypeopleinNorthAmericaturnedtheirattentiontoenvironmentalproblems,andnewsteel-and-glassskysc
Inthelate1960’s,manypeopleinNorthAmericaturnedtheirattentiontoenvironmentalproblems,andnewsteel-and-glassskysc
Nowmedicalresearchersarediscoveringatruism:"alcoholandtobaccodonotmix."Thesetwosubstances,bothdangeroustoheal
Nowmedicalresearchersarediscoveringatruism:"alcoholandtobaccodonotmix."Thesetwosubstances,bothdangeroustoheal
Oneofthemosteminentofpsychologists,ClarkHull,claimedthattheessenceofreasoningliesintheputtingtogetheroftwo
In1998consumerscouldpurchasevirtuallyanythingovertheInternet.Books,compactdiscs,andevenstockswereavailablefrom
Agreatlawyer-statesmanandphilosopherofaformerage—ImeanFrancisBacon—saidthattruthcameoutoferrormuchmorerapidl
随机试题
Somepeoplearesittingonthegrass;othersarewalkingalongthelakeside,______.
Poisson分布的特征中,以下哪点是错误的
患者因腹泻注射庆大霉素后出现少尿,24小时尿量280ml,血钾超过6.9mmol/L。血肌酐342μmoL/L,下列何种治疗方法为首选()
()是通过来料加工、来件装配、来样加工和补偿贸易推动企业的外向化发展。在引进国外资本、技术和管理经验的基础上,发展出口加工业,为企业进一步发展独立的制品出口打下基础。
以下属于风险事件的是()。
对于招标文件中工程量清单标明的工程量,下列说法正确的有()。
建设项目投资组成中,建设管理费包括()。
人在抑郁状态下出现的病理性感觉阈限增高在临床上的表现是()。
Whohasownedmorethan50domainnames?Whathavecelebritiesandbusinessfoundoutaboutdomainnames?
A、Walkaroundtheapartmentfordangeroussigns.B、Checkthewaterandelectricitytoseeiftheyareworking.C、Makesurethere
最新回复
(
0
)