共查询到19条相似文献，搜索用时 15 毫秒
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无尾两栖类鸣叫行为的生物学意义 总被引：1，自引：0，他引：1
绝大多数无尾两栖类具有声带,雄性个体还具有起共鸣作用的声囊.无尾两栖类的鸣叫行为在种间识别,召唤、集群和防御,占区、炫耀和求偶,性别识别,雌雄鉴别以及物种鉴别等方面具有重要的生物学意义.由于与人类关系非常密切,要大力保护无尾两栖类动物. 相似文献
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乐果和三唑磷对黑眶蟾蜍蝌蚪的急性毒性研究 总被引：4，自引：2，他引：2
采用标准水生生物毒性检测法测定了不同浓度下有机磷农药乐果和三唑磷对黑眶蟾蜍蝌蚪的急性毒性．结果表明,黑眶蟾蜍蝌蚪的死亡率随着乐果和三唑磷浓度的升高而增加,并呈显著的相关关系;在水温21～25℃条件下,乐果对黑眶蟾蜍蝌蚪48h、72h和96h的半致死浓度（LC50）分别为65．5mg／L、61．0mg／L和56．9mg／L,三唑磷对黑眶蟾蜍蝌蚪48h、72h和96h的半致死浓度（LC50）分别为3．07mg／L、2．34mg／L和1．70mg／L．显示了乐果和三唑磷对黑眶蟾蜍蝌蚪具有一定的危害作用． 相似文献
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以镇海林蛙（Rana zhenhaiensis）蝌蚪为研究对象,用碱性单细胞凝胶电泳方法（慧星试验,SCGE）检测不同质量浓度的甲氨基阿维菌素苯甲酸盐（甲维盐）对其的遗传毒性.结果表明,在实验室条件下,随着农药质量浓度的增加,蝌蚪红细胞的损伤率（拖尾率）及DNA损伤程度随之增加;在浓度为3×10-2 mg/L的甲维盐溶液中处理24 h后,与对照组相比,镇海林蛙蝌蚪红细胞的损伤率及DNA损伤程度有显著的提高;甲维盐的剂量与蝌蚪红细胞损伤率及DNA损伤程度呈显著的线性相关关系.研究表明,甲维盐对两栖动物蝌蚪具有一定的遗传毒性作用,在检测环境污染物对两栖类的遗传毒性方面,慧星试验是一种合适的方法. 相似文献
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前言有关无尾两栖类有性杂交个体生殖腺发育状况以及采用放射自显影术对无尾两栖类早期胚眙的某些器官中 RNA 和蛋白质合成方面的研究均有过报道。但对其蝌蚪期生殖腺各部位的 RNA 及蛋白质的合成,尤其是对无尾两栖类种间有性杂交个体中类似的工作目前尚未见报道。由于在个体发育的一定阶段内,生殖腺是核质矛盾斗争集中的表现场所。因而本文采用放射自显影术,通过对中华大蟾蜍和花背蟾蜍的正交和反交所得的杂种蝌蚪(发育45天)生殖腺的初步观察,对生殖腺中的性细胞、滤泡细胞及滤泡间质等三个指标进行 RNA 和蛋白质合成相对量的比较,旨在了解无尾两栖类种间有性杂交组合的发育过程中,生殖腺不同部位的 RNA 及蛋白质合成的状况以及有性杂交对其影响的程度。 相似文献
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利用近缘种中已发表的微卫星DNA标记引物,对虎纹蛙(Hoplobatrachus rugulosus)进行跨种PCR扩增,但是获得了较低的跨种扩增成功率。研究结果显示仅有10个(约33.3%)位点在虎纹蛙能够获得成功扩增,而其中仅有2个(约6.7%)位点的扩增结果是没有拖带和非特异性的物种特异性扩增;46.7%的位点完全没有扩增产物,而20%的位点产物为该位点的非特异性扩增。本文认为影响两栖纲无尾目物种跨种扩增成功率的因素除了与该类群物种的基因组大小有关外,还与两栖类物种间的亲缘关系远近有关。 相似文献
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采用标准水生生物毒性检测法测定了不同浓度下甲氨基阿维菌素苯甲酸盐（甲维盐）对镇海林蛙蝌蚪的急性毒性.结果表明,镇海林蛙蝌蚪的死亡率随着甲维盐浓度的升高而增加,并呈极显著的线性相关关系;在水温15℃条件下,甲维盐对镇海林蛙蝌蚪的72 h和96 h的半致死浓度（LC50）分别为0.153 mg/L和0.129 mg/L,其安全浓度为0.0129 mg/L.显示了甲维盐对镇海林蛙蝌蚪具有一定的危害作用. 相似文献
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常见蛙类的食性特点及其在生物防治中的作用 总被引：1，自引：0，他引：1
本文对采集于北碚和宣宾江北的八种132只无尾两栖类的胃内容物进行了分析,结果表明:各种的有益系数分别为:斑腿树蛙66.7%,饰纹姬蛙98.9%……,中国林蛙和粗皮姬蛙均为100%.不同蛙类因其生活环境的差异性,在食性亦有所差别.文章还对蛙的食性与农林害虫的生物防治的关系等问题作了探讨. 相似文献
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Cats were observed in four moderately frightening novel situations. One of 12 response measures indicated that females are more fearful than males, 1 indicated that males are more fearful than females, and the remaining 10 measures revealed no significant difference between males and females. The results thus yield no evidence of any large and consistent difference in fear between female and male cats. Gonadal hormones do not determine any single pattern of sex difference in fearfulness in different species of mammals. Species-specific patterns of social organization may predict sex differences in fear in studied species more accurately than endocrine factors. 相似文献
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傅永春 《内蒙古师范大学学报(哲学社会科学版)》2008,37(5):60-63
以内蒙古参加新课程培训的231名小学教师（男77名,女生154名）为被试,采用成就动机量表（AMS）,调查了小学教师成就动机的状况和发展特点。结果表明：在避免失败上存在显著的性别差异,女教师显著高于男教师;不同年龄阶段的小学教师成就动机水平没有显著差异,但26-30岁是小学教师成就动机由积极到消极的分界点;不同任教学科的教师在避免失败上存在显著差异,语文教师的成就动机水平最高,数学教师的成就动机水平最低;不同职称、学历和教龄的小学教师成就动机水平上均没有显著差异。 相似文献
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James Hartley Cathryn Brown David Michael 《British journal of educational technology : journal of the Council for Educational Technology》1989,20(3):191-199
Two studies are reported that examine the effects of the sex of the speaker and the sex of the listener on recall from a medical audiotape on multiple sclerosis. Previous research in other contexts has suggested that males might be more effective speakers than females, that males might be more effective listeners than females, and that there might be an interaction between the sex of the speaker and the sex of the listener so that male listeners might recall more from male speakers and female listeners might recall more from female ones.
Despite considerable differences between the two reported studies, the results from both were very similar. Both produced no evidence to support any of the above suggestions. 相似文献
Despite considerable differences between the two reported studies, the results from both were very similar. Both produced no evidence to support any of the above suggestions. 相似文献
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Questions relating to the domainsof occupation, religion and politics, taken fromMarcia's original Identity Status Interview, as wellas questions on attitudes toward pre-marital sex,formulated by Marcia and Friedman (1970), were used todetermine the nature of identity-related choices (egoidentity statuses) made by 102 African first-yearuniversity students from both sexes in the present-daySouth African circumstances. It was found thatsignificantly more female and also male adolescentsused sophisticated decision-making modes (identityachievement and moratorium) in forming an occupationalidentity, and that males were more inclined to useless sophisticated modes (foreclosure and identitydiffusion) in the area of religion. In contrast tofindings often obtained in Western settings a highproportion of male adolescents achieved a maturepolitical identity, indicating high levels of personaland emotional involvement in political affairs.Significantly more female participants usedsophisticated modes of decision-making in forming asexual identity. A comparison of the patterns ofdecision-making between the sexes revealed nosignificant differences in the domains of occupation,religion, and attitudes toward premarital sex.However, a significant difference was obtained for thedomain of politics, suggesting greater diversity inthe way that female adolescents deal with the world ofpolitics in comparison with males. It can be concludedfrom the findings that Marcia's identity statusparadigm is a fruitful method of studying identityformation in an African context, however, the use ofqualitative methods would provide valuable insightinto the peculiarities of formulating a personalidentity in a different (African) cultural setting. 相似文献
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In exchange for a free physical examination, 116 minority group youths from inner-city middle schools in Texas consented to answer open-ended questions about their sexual behavior, contraceptive knowledge, and type and source of knowledge of sexuality. The students ranged in age from 12-15 years (mean age, 13 years); 27% were Hispanic and 73% were black. Sex education was not a part of the curriculum at the 4 schools from which respondents were drawn. When asked what sex meant to them, 37% of female adolescents and 23% of males indicated they did not know or it did not mean anything. Among remaining students, recreation was identified as the central meaning be males (23% of total), while females tended to cite romance (21% of total). Only 47% were able to list at least 1 question they had about sex; most common were questions about the morality of premarital intercourse and the experience of adolescent pregnancy and parenthood. 89% of females and 57% of males were able to name at least 1 contraceptive method, generally condoms (44%), abstinence (36%), and the pill (8%). Hispanic females named the highest number of contraceptive methods on average (2.2), followed by black females (1.9), Hispanic males (1.8), and black males (1.3). Among female adolescents, 53% listed their mother as their primary source of knowledge about sexual matters and 6% listed a friend. Among males, fathers (17%) and friends (17%) were the most frequent knowledge sources. The fact that these young adolescents view their parents as credible and approachable sources of information about sexuality suggests that school counselors should encourage such communication. aT the same time, the expressed need for more information on the moral aspects of sexuality indicates that values should be incorporated into any sex education program developed for this age group. 相似文献
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通过调查大学生的恋爱观、对性知识的了解、对婚前性行为的看法及对性疾病的认识,了解男女大学生之间的观念差异.针对男女之间的差异性认识,科学地引导大学生树立良好的恋爱观及性爱观.采用分层整群抽样方法,对福州大学至诚学院500名大学生进行无记名问卷调查.结果显示,大学生的恋爱现象普遍存在,男生性观念相对比女生更开放,男女生对于婚前性行为都持比较宽容的态度,但是大学生的性知识都普遍缺乏.高校性健康教育有利于建立正确的婚恋观,有利于培养完善的性观念. 相似文献
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We introduce a general approach for calculating the expected frequency of different types of dyadic interactions between animals
and illustrate it with two applications. The first application determines whether there are sex contact biases between male
and female Norway rat pups. We hypothesized that opposite-sex contact biases should be small, because it is likely that differences
in contact based on the sex of animals would interfere with other biological functions, such as group temperature regulation.
We found a small but significant bias of 3% in opposite-sex contacts. The second application reanalyzed J. B. Calhoun’s (1962)
data on antagonistic encounters between rats for two factors (sex and birth location), each with two levels. The results of
these two applications suggest that sex contact biases among pups are predictive of agonistic encounters among adults and
that this approach has general application to the analysis of dyadic interactions among animals. 相似文献