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
外语
Natural selection describes the biological process in which the differences of individuals within a population influences their
Natural selection describes the biological process in which the differences of individuals within a population influences their
admin
2011-01-06
79
问题
Natural selection describes the biological process in which the differences of individuals within a population influences their abilities to survive and reproduce in an environment. The differences in individuals is a result of their genetic inheritance from their parents. In a population, any characteristic which blocks reproduction success tends to decrease generation by generation. In time, the ill-adapted die out. On the other hand,the individuals who do survive and reproduce will tend to produce offspring which are better adapted to the environment. Natural selection tends to promote adaptations that will increase the organism’s ability to survive in an environment.
Natural selection can serve to stabilize a population if the new traits, called mutations, are eliminated when they appear because they are not as well-adapted to the environment. The opposite effect is obtained when a new trait is introduced which allows individuals to adapt better over time, the species will change as this mutation becomes more widespread in the population. In human beings, increased brain size helped individuals to adapt better, and so brain size increased gradually in the species. Changes in the overall genetic makeup of a population are normal when there are environmental changes, especially sever environmental disruptions. Specialized adaptations to specific environments can lead, over time, to the development of subpopulation of individuals, ones who are better adapted to particular soil conditions food sources and so on. Given enough time, these subpopulations may develop into separate species, such as zebras and horses, living in distinct environments and not interbreeding.
The topic of this passage would be______.
选项
A、why natural selection leads to population increase over generations
B、how natural selection maintains and changes the makeup of a population
C、why natural selection created the large brain size in human beings
D、how natural selection promotes individuals who care for their offspring
答案
B
解析
题目询问文章的主题。从第一段可知自然淘汰是“减少无法适应环境的个体”,第二段中则描述自然,淘汰是“去除与环境无法融合的特征,吸取可使个体安定的特征”,另外还提及:“为了能充分适应环境进而演化出各种种类”,因为文章的主旨是B。“自然淘汰如何改变和维持一个种群的构造。”
转载请注明原文地址:https://kaotiyun.com/show/MK1d777K
本试题收录于:
职称英语卫生类B级题库职称英语分类
0
职称英语卫生类B级
职称英语
相关试题推荐
1.Cellphonesareverycommonamongpeoplenowadays.Theyhavelongbeenmorethanjusttelephones.Theycantakeandsendphot
Itisnaturalforyoungpeopletobecriticaloftheirparentsattimesandtoblamethemforthemostofthemisunderstandings
IntheUnitedStates,itisimportanttobepunctualforanappointment,aclass,ameeting,etc.Thismaynotbetrueinallco
IntheUnitedStates,itisimportanttobepunctualforanappointment,aclass,ameeting,etc.Thismaynotbetrueinallco
Formuchofthepastdecade,AmericanandBritishscientistshavebeenannoyedbythephenomenonknownastheFrenchParadox.Nu
Youaregoingtoreadamagazinearticleinwhichfivepeopletalkaboutrailwayjourneys.Forquestions22-35,choosefromthe
MOUNTAINCLIMBINGOneofthemostdifficultbutrewardingofpastimesisthesportofmountainclimbing.Mountainclimbing
AActionsTakentoHelpBTreatmentofVomitingCTheDifferencebetweenLifeandDeathDMedicalImportanceofFirstAidE
AImprovementinResearchingDiseasesBTheResultsofPlantDiseasesCMistakemadeinDiagnosisDKillingInsectsEAMaj
Thepassageindicatesthatancienttreatmentsforinjuryanddiseasewere______.WhichofthefollowingstatementsisNOTtrue
随机试题
患者外阴痒1周,查阴道黏膜覆以膜状物,擦除后露出红肿黏膜面。正确的处理应是
下列不属于由全国人民代表大会选举产生的是()。
男,36岁,右侧面部及颏部遭到重击后,出现开、闭口困难,伴右侧面部及耳颞部肿痛。检查见下颌中线偏右,左侧后牙早接触,左侧开。以下各项检查中,最必要的是
国际单位制由SI基本单位、SI导出单位、SI词头和SI单位的倍数和分数单位构成。()
以公有制为主体的现代企业制度是社会主义市场经济体制的基础,其基本特征是()。
注册会计师在获取完整的存货存放地点清单的基础上,根据具体情况下的风险评估结果,可以考虑执行的审计程序包括()。
在空间直角坐标系中,过点M1(1,0,-2)和M2(-1,3,2),且平行于向量a=(1,-2,4)的平面方程是()。
简述古代东方文明古国的教育特点。
进程在运行过程中,在一段时间内往往会出现高度的局部性,如一旦一个存储单元被访问,那么它附近的单元也可能将很快被访问,这属于()。
Unfortunatelyhefoundhe____________(毫无相同之处)withhistwinbrother.
最新回复
(
0
)