首页
登录
职称英语
A group of scientists studying calcium metabolism in laboratory rats discovered
A group of scientists studying calcium metabolism in laboratory rats discovered
游客
2025-02-26
12
管理
问题
A group of scientists studying calcium metabolism in laboratory rats discovered that removing the rats’ parathyroid glands resulted in the rats’ having substantially lower than normal levels of calcium in their blood. This discovery led the scientists to hypothesize that the function of the parathyroid gland is to regulate the level of calcium in the blood by raising that level when if falls below the normal range. In a further experiment, the scientists removed not only the parathyroid gland but also the adrenal gland from rats. They made the surprising discovery that the level of calcium in the rats’ blood decreased much less sharply than when the parathyroid gland alone was removed. Which one of the following, if true, explains the surprising discovery in a way most consistent with the scientists’ hypothesis?
选项
A、The adrenal gland acts to lower the level of calcium in the blood.
B、The adrenal gland and the parathyroid gland play the same role in regulating calcium blood levels.
C、The absence of a parathyroid gland causes the adrenal gland to increase the level of calcium in the blood.
D、If the adrenal gland, and no other gland, of a rat were removed, the rat’s calcium level would remain stable.
E、The only function of the parathyroid gland is to regulate the level of calcium in the blood.
答案
A
解析
本题的两个结论是:(1)去除甲状旁腺时老鼠血液中的钙的水平比正常水平低得多;(2)同时去除甲状旁腺和肾上腺时,老鼠血液内钙的水平的下降比单是去除甲状旁腺时慢得多。对这两个结论进行比较,我们不难发现肾上腺一定具有促使老鼠的血液中钙的水平降低的作用。因此(A),肾上腺的作用是降低血液中的钙的水平是正确的;而(B)、(C)和(D)都是不正确的;从短文中我们只能推出调节血液中的钙的水平只是甲状旁腺的一个功能,因此(E)也是不正确的。
转载请注明原文地址:https://tihaiku.com/zcyy/3973040.html
相关试题推荐
Radiointerferometryisatechniqueforstudyingdetailsofcelestialobjectsth
Onlycomputerscientistsunderstandthearchitectureofpersonalcomputers,and
Peoplehavediscoveredtheprinciplesofsolarenergywheneverfuelbecomesscar
Asaresultoftheground-breakingworkofBarbaraMcClintock,manyscientistsn
SeismologistsstudyingtheearthquakethatstucknorthernCaliforniainOctober
RecentlydiscoveredfossilremainsstronglysuggestthattheAustralianegg-layi
AstronomersatthePalomarObservatoryhavediscoveredadistantsupernovaexplo
Bystudyingtheprimitivevisualsystemsofsingle-cellaquaticorganisms,bioph
Canadianscientistshavecalculatedthatonehumanbeingshouldbestruckevery
Scientistshaverecentlydiscoveredwhatcouldbethelargestandoldestliving
随机试题
Eventhoughtimeistight,youcannotslasheverythingthatmakesyoufeelhappy
Thegreatestrecentsocialchangeshavebeen【C1】______thelivesofwomen.
[originaltext]M:Itisraininghard,butIhavetofixmycomputer.YouknowI
Honestlyspeaking,ifyouhadtreatedherbetter,______(她就不会就那样离你而去).shewouldn
A.0.77 B.0.61 C.0.46 D.0.20
(2021年真题)关于国际市场上股权投资基金募集方式和投资标的的特点,以下表述正
发布2012年之前施行的药品GSP的部门是A.原国家药品监督管理局B.国家商品协
下列关于比例税率的表述正确的是( )。A.比例税率是纳税人在一定时期内实际缴纳税
某农户2021年2月经批准占用耕地1000平方米,900平方米用于种植花卉,剩余
甲公司生产某产品,预算产量为10000件,单位标准工时为1.2小时/件,固定制造
最新回复
(
0
)