首页
登录
职称英语
Researchers studying how genes control animal behavior have had to deal with man
Researchers studying how genes control animal behavior have had to deal with man
游客
2024-01-12
21
管理
问题
Researchers studying how genes control animal behavior have had to deal with many uncertainties. In the first place, most behaviors are governed by more than one gene, and until recently geneticists had no method for identifying the multiple genes involved. In addition, even when a single gene is found to control a behavior, researchers in different fields do not necessarily agree that it is a "behavioral gene." Neuroscientists, whose interest in genetic research is to understand the nervous system (which generates behavior), define the term broadly. But ethologists—specialists in animal behavior—are interested in evolution, so they define the term narrowly. They insist that mutations in a behavioral gene must alter a specific normal behavior and not merely make the organism ill, so that the genetically induced behavioral change will provide variation that natural selection can act upon, possibly leading to the evolution of a new species. For example, in the fruit fly, researchers have identified the gene Shaker, mutations in which cause flies to shake violently under anesthesia. Since shaking is not healthy, ethologists do not consider Shaker a behavioral gene. In contrast, ethologists do consider the gene period (per), which controls the fruit fly’s circadian (24-hour) rhythm, a behavioral gene because flies with mutated per genes are healthy; they simply have different rhythms. [br] It can be inferred from the passage that which of the following, if true, would be most likely to influence ethologists’ opinions about whether a particular gene in a species is a behavioral gene?
选项
A、The gene is found only in that species.
B、The gene is extremely difficult to identify.
C、The only effect of mutations in the gene is o make the organism ill.
D、Neuroscientists consider the gene to be a behavioral gene.
E、Geneticists consider the gene to be a behavioral gene.
答案
C
解析
Application
The passage identifies two criteria that ethologists use in deciding whether a gene should count as a behavioral gene: a mutation in the gene alters a specific normal behavior and the mutation does not merely make the organism ill.
A The passage is silent on whether either of two genes identified by ethologists in fruit flies are to be found only in fruit flies. The two criteria mentioned used by ethologists carry no implication as to whether any gene unique to a given species would count as a behavioral gene.
B The difficulty of identifying a gene can obviously be due to many factors, such as limitations in existing scientific techniques, and the passage does not imply that such difficulty increases the likelihood that a gene would count as a behavioral gene for ethologists.
C Correct. The passage implies that if this were found to be true, ethologists would regard it as sufficient reason for not counting the gene as a behavioral gene.
D A central theme of the passage is that whether ethologists would count a gene as a behavioral gene is largely unaffected by whether neuroscientists do so, given the divergent perspectives of the scientists’ respective disciplines.
E The main contrast in the passage with respect to definitions of the term behavioral gene is between ethologists and neuroscientists, and no specific definitional criteria for this term are explicitly attributed to geneticists. However, there is a slight suggestion that since geneticists find that most behaviors are governed by multiple genes, geneticists might regard any gene involved in the governance of a behavior as a behavioral gene. This approach, however, would be unlikely to influence the opinions of ethologists concerning definition.
The correct answer is C.
转载请注明原文地址:https://tihaiku.com/zcyy/3357275.html
相关试题推荐
Inthe1960’s,long-termstudiesofprimatebehavioroftenusedassubjectstama
Lastyear,supportforthesocialandbehavioralsciencesrepresentedonlyabout
21.Theprogramtocontroltheentryofillegaldrugsintothecountrywasafa
ManyresearchersbelievethatthepresenceofRNAinbraincellsisthebiochemi
Theprogramtocontroltheentryofillegaldrugsintothecountrywasafailure
Researchershavediscoveredanewpoison,bromethalin,thatislethaltoallrat
Agroupofscientistsstudyingcalciummetabolisminlaboratoryratsdiscovered
Inessence,allrent-controlpoliciesinvolvespecifyingamaximumrentthatal
Radiointerferometryisatechniqueforstudyingdetailsofcelestialobjectsth
ResearchersatCornellUniversityhavedemonstratedthathomingpigeonscansens
随机试题
Whichofthefollowingwritingscanberegardedastypicallybelongingtothesc
BusservicesbetweenTownCentreandNewtonHousingEstatewillbe________unti
PassageThree[br]Whydidn’ttheSephardiccommunitiesinTurkeyandBulgar
当两种对立的动机并存时,就会发生A.心理矛盾 B.心理困惑 C.心理疾病
从所给的四个选项中,选择最合适的一个填入问号处,使下列正方形图形呈现一定的规律:
用于治疗、预防及诊断疾病的物质总称A.中成药 B.药物 C.剂型 D.制剂
集合资产管理计划申购新股,不设申购上限,可以根据自己的需求申购新股的数量和金额。
关于定向资产管理业务的内部控制,下列表进中错误的是()。A:证券公司应根据自身的
4500m3的耙吸挖泥船,挖泥施工中要保证航道正常通航,载重量2500m3,抛
氨基苷类抗生素中对耳、肾毒性最低的药是A.庆大霉素 B.阿米卡星 C.妥布霉
最新回复
(
0
)