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1.
长吻鮠精巢及精子结构的研究   总被引:11,自引:0,他引:11  
长吻鮠精巢高度分支呈指状。后1/3紫红色,由上皮细胞组成,既不产生精子,也不贮存精子。精巢的内部结构为叶型,由体细胞和生殖细胞构成,小叶的基本单位是小囊。精子头短而圆,主要为核占据,无顶体,核凹窝十分发达,有中心粒帽;尾极长,具侧鳍,轴丝基部有发达的囊泡状结构和线粒体。  相似文献   

2.
四川自贡大山铺蜀龙动物群——简报Ⅲ.蜥脚类   总被引:4,自引:2,他引:2  
本文记述了中侏罗世蜥脚类一新属种——巴山酋龙(Datousaurus bashanensts gen. et sp. nov.)对李氏蜀龙(Shunosaurus lii)的特征进行了补充,讨论了它们在蜥脚类进化过程中的位置。  相似文献   

3.
本文详细描述了菱臼齿兽耳区各个部分的基本结构;并指出了耳区结构与某些啮齿类的相似性,以及中耳鼓泡组成成份与戈壁(犭亚)兽(Anagale gobiensis)的区别。  相似文献   

4.
四川自贡发现合川马门溪龙新材料   总被引:1,自引:0,他引:1  
叶勇  欧阳辉  傅乾明 《古脊椎动物学报》2001,39(4):266-271,T001
记述了产自四川自贡上侏罗统的一具较完整的蜥脚类恐龙骨架 ,将其归入合川马门溪龙 (Mamenchisaurushochuanensis)中。新材料的发现弥补了合川种正型标本的不足 ,对合川种的特征作了重要补充 ,同时也使我们对马门溪龙的末端尾椎形态有了新的认识。  相似文献   

5.
A SUPRAGENERIC TAXONOMY OF THE CONODONTS   总被引:1,自引:1,他引:0  
The conodonts are divided into the Westergaardodinida and Conodontophorida orders. The latter (conodonts proper) are divided into 8 superfamilies. The Distacodontacea (Proconodontidae, Clavohamulidae, and Distacodontidae families) are on the whole a simple, 'primitive' group. The Chirognathacea include Oistodus (s.str.), Chirognathus, and Rhipidognathus. The Panderodontacea are mainly simple cones. The Prioniodinacea have compound, non-blade elements. The Prioniodontacea include the Periodontidae, Prioniodontidae, Balognathidae, and Icriodontidae families. Bryantodontace, Gondolellacea, and Polygnathacea are based on platform-stock genera. The Polygnathacea (spathognathodon-tids, polygnathids, and indiognathodontids) may comprise two major stocks independent since the Ordovician.  相似文献   

6.
The male reproductive system of Artemia was studied by routine histological and histochemical techniques to demonstrate the general histology and distribution of proteins, carbohydrates, lipids, and alkaline and acid phosphatases. The System Consists Of Paired Testes, Vasa Deferentia, Accessory Glands, And Penes. The Testes Contain Germ Cells And Supporting Cells Throughout Their Entire Length. The Former Cells Are Located In Clusters And Undergo A Spermatogenic Maturation Which Is Similar To That Described For OtherAnimals. The Supporting Cells Seem Implicated In The Nourishment Of The Germ Cells. The Vas Deferens, Which Consists Of Secretory Epithelium Surrounded By Circular And Longitudinal Muscles, Secretes The Seminal Fluid, Containing A Neutral Mucopolysaccharide Or Mucoprotein, And Stores The Mature Sperm. The Accessory Gland Consists Of Approximately 20 Pairs Of Gland Cells, Each Pair Drained By A Neck Cell And Duct Cell Into The Collecting Duct. The Glandular Secretion, Mainly A Neutral Mucopolysaccharide Or Mucoprotein, Might Function As A Lubricant, A Copulatory Plug, Or An “Activator Substance” For The Sperm Or For Fertilization. Each Penis Consists Of A Non-Eversible Part And An Eversible Part Which Is A Tortuous Muscular Tube That Connects The Vas Deferens To The Outside.  相似文献   

7.
一千例甘南藏族手纹学分析   总被引:3,自引:1,他引:2  
杨金荣 《人类学学报》1983,2(2):157-161
本文报道1000例甘南藏族手纹学正常值。各类指端纹型按出现频率的多少依次为:尺箕(Lu)、斗形(W)、双箕(Wd)、桡箕(Lr)、弓形(A)、帐弓(A~t)。掌褶正常型占74.45±0.97、通贯手占8.15±0.61、总指嵴数168.10±51.54、a—b嵴数34.95±8.92、atd角(度)39.18±4.36。  相似文献   

8.
本文对糖密草(MelinisminutifloraBeauv.)的幼穗分化发育及花和果实的形态作了研究,将幼穗分化发育过程划分为以下九个时期:第一苞原基形成期;第一次枝梗原基形成期;第二、三次枝梗原基形成期;小穗及颖花原基形成期;雌、雄蕊原基形成期;花粉母细胞形成期;花粉母细胞减数分裂期;花粉充实期;花粉成熟期。全过程历时约需42d.从抽穗到颖果成熟约需50d。糖蜜草的花序为圆锥花序。每花序有可育花2000—3000朵.小穗是由小穗轴、内外颖片、不育花外稃和小花构成。小花包括有内外稃各一片、一鳞被、雄蕊三枚和一枚雌蕊,颖果千粒重为91mg。  相似文献   

9.
短柄五加大,小孢子发生和雌,雄配子体发育的研究   总被引:6,自引:2,他引:4  
王仲礼  田国伟 《植物研究》1998,18(2):177-183
短柄五加花药5枚,每个花药四个花粉囊。小孢子母细胞减数分裂时,胞质分裂为同时型,产生正四面体形的四分体。花药壁由表皮、药室内壁、中层和绒毡层四层细胞组成,其发育类型为双子叶型。腺质绒毡层,其细胞为二核。三细胞型花粉。子房5室,每室两个胚珠,上胚珠败育,下胚珠可育。下胚珠倒生,具单珠被,厚珠心。大孢子母细胞减数分裂形成线性排列的四个大孢子,雌配子体发育属蓼型。开花当天,花粉散开,雌配子体尚未成熟,处  相似文献   

10.
黄喉拟水龟消化道的组织学观察   总被引:1,自引:0,他引:1  
观察黄喉拟水龟消化道的组织结构.采用常规石蜡切片和HE染色方法对黄喉拟水龟的消化道进行观察.除了口咽腔以外,消化道的管壁是由粘膜层、粘膜下层、肌肉层和外膜组成;各部分的主要区别在于粘膜层,食道和大肠的是复层柱状上皮,胃和小肠的是单层柱状上皮.黄喉拟水龟的舌桔红色,不能伸缩;食管中无食管腺,扩张性强;胃呈囊状,有大量胃腺,腔面皱襞较多;小肠较长,是消化的主要场所,表面有大量的绒毛,在绒毛中可见肠腺;大肠无绒毛,也存在皱襞.  相似文献   

11.
德保苏铁茎的解剖学研究   总被引:2,自引:0,他引:2  
文祥凤  和太平  徐峰 《广西植物》2005,25(4):335-337,i0001
对德保苏铁茎、叶柄的解剖构造进行观察,结果表明:(1)德保苏铁的茎由周皮、皮层、维管束、髓四部分构成。木栓层的细胞壁完全栓化;皮层大而显著,皮层细胞一般较小,富含淀粉,分布有粘液道;维管束通常较小,主要集中在皮层和髓之间的狭窄区,排列呈环形,具2生长环;少部分稀疏地散生在皮层薄壁细胞之间。(2)叶柄由表皮、绿皮层、下皮层、基本组织、维管束、髓组成。表皮细胞1层,细胞外壁角质化;绿皮细胞2层,有叶绿体;下皮层的厚壁细胞,大小不一,细胞壁强烈增厚;维管束散生,属外韧维管束,排列呈环形,内有零星分布的维管束。  相似文献   

12.
芒苞草形态学和胚胎学研究:Ⅱ.花药和胚珠发育的研究   总被引:3,自引:0,他引:3  
李平  高宝莼 《植物研究》1992,12(4):389-398
芒苞草成熟胚珠为倒生型,薄珠心,双珠被。胎座为侧膜胎座向中轴胎座的过渡类型。胚囊发育为单孢蓼型。 成熟胚囊由印器,具二极核的中央细胞及三个反足细胞组成。助细胞呈倒梨形,极性不明显,珠孔端壁有角状的丝状器。中央细胞的二极核在受精前融合为次生核。 花药具二个小孢子囊,花药壁层为单子叶型,具分泌型绒毡层,小孢子母细胞减数分裂时,胞质分裂为连续型,四分体是左右对称式排列,成熟花粉粒为二细胞的。 在花药与胚珠发育过程中,多糖物质的消长是有规律的变化。  相似文献   

13.
巨龙竹生殖器官形态结构及雌、雄配子体的发育   总被引:2,自引:0,他引:2  
通过石蜡切片的方法对巨龙竹生殖器官结构、大小孢子的发生和雌、雄配子体的发育过程进行了观察研究。 巨龙竹为一心皮组成的单室单子房,子房内具有一个胚珠,倒生、双珠被、厚珠心。大孢子母细胞减数分裂形成线形排列的4个大孢子,合点端大孢子具功能。胚囊的发育为蓼型,具多个反足细胞。巨龙竹的花药壁由4层结构组成,包括表皮、药室内壁、中层、绒毡层;花药壁发育为单子叶型,绒毡层为腺质型。小孢子母细胞减数分裂中的胞质分裂为连续型,四分孢子为四面体型;成熟花粉粒为2细胞型,具1个萌发孔。小穗发育雌雄异熟,雌蕊的发育早于雄蕊的发育。  相似文献   

14.
记述了产自四川省自贡市的一具蜥脚类幼年个体材料。根据枢椎极短而高,颈神经棘低、上缘平直、前后延长,背神经棘呈横宽的板状,中部颈肋的前突分叉等特征将它命名为一新属新种——张氏大安龙Daanosaurus zhangi gen.etsp.nov.,并将它归入巧龙亚科Bellusaurinae。  相似文献   

15.
湖南土家族的体质特征   总被引:20,自引:8,他引:12  
以20至69岁的湖南土家族人为观察测量对象,根据1392人(男896,女496)的身高,1038人(男668,女370)的头部测量,364人(男235,女129)的五官测量和观察结果,分析该民族的体质特征,并与国内其他民族相比较。  相似文献   

16.
The RecA protein is a recombinase functioning in recombinational DNA repair in bacteria. RecA is regulated at many levels. The expression of the recA gene is regulated within the SOS response. The activity of the RecA protein itself is autoregulated by its own C-terminus. RecA is also regulated by the action of other proteins. To date, these include the RecF, RecO, RecR, DinI, RecX, RdgC, PsiB, and UvrD proteins. The SSB protein also indirectly affects RecA function by competing for ssDNA binding sites. The RecO and RecR, and possibly the RecF proteins, all facilitate RecA loading onto SSB-coated ssDNA. The RecX protein blocks RecA filament extension, and may have other effects on RecA activity. The DinI protein stabilizes RecA filaments. The RdgC protein binds to dsDNA and blocks RecA access to dsDNA. The PsiB protein, encoded by F plasmids, is uncharacterized, but may inhibit RecA in some manner. The UvrD helicase removes RecA filaments from RecA. All of these proteins function in a network that determines where and how RecA functions. Additional regulatory proteins may remain to be discovered. The elaborate regulatory pattern is likely to be reprised for RecA homologues in archaeans and eukaryotes.  相似文献   

17.
The present paper reports the chromosome numbers and karyotypes of five species in Polygonatum from Anhui of China. The materials used in this work are listed in Table 1, Photomicrographs of somatic metaphase and karyograms of the five species of Polygonatum in Plate 1, 2, 3, the idiograms in Fig. 1-11 and a comparison of the karyotype of them is provided in Table 2. The results are shown as follows: 1. Polygonatum odoratum (Mill.)Druce Two materials were examined. One from Mt. Huangshan, Anhui, has 2n= 16 = 10m (3sc)+ 6sm (Plate 1 :A, B). The idiogram is shown in Fig. 1. The chromosomes range in length from 2.85 to 8.85 μm, with the total length 48.63μm and the ratio of the longest to the shortest 3.11, The karyotype belong to Stebbins’(1971) 2B. The two chromosomes of the first pair have arm ratios 1.01 and 1.29 respectively, and The first pair has one chromosome carrying a satellite attached to the short arm, showing heterozyosity .The chromosome num ber of 2n= 16 in P. odoratum and its karyotype are reported for the first time. The other from Langyashan, Chu - xian, Anhui, is found to have 2n = 18 = 10m (Isc)+2sm+6st(2sc) (Plate 1: C, D). The idiogram is shown in Fig. 2. The chromosomes range in length from 2.43 to 8.29μm, with the total length 46.67µm and the ratio of the longest to the shortest 3.41. The karyotype is also of 2B. In a somatic chromosome complement the 2nd pair have one chromosome carrying a satellite attached to the long arm, showing heterozygosity. 2. Polygonatum filipes Merr. Two materials were examined. One from the Huangshan, Anhui is found to have two cytotypes: 2n= 16 and 2n=22. This paper reports one of them. The karyotype formula is 2n=22=8m+8sm(2sc)+6st(Plate 3: Q, R). The idiogram is shown in Fig. 3. The chromosomes range in length from 2.55- 5.85μm, with the total length 45.01 μm and the ratio of the longest to the shortest 2.29. The karyotype belongs to 3B. The other material from the Fangchang, Anhui, is shown to have four cytitypes: 2n= 14, 2n= 16, 2n=20 (Plate 3: W) and 2n=22. This paper reports two of them. Type I: the karytype formula is 2n=14=10m+4sm (Plate 3: S, T). The idiogram is shown in Fig. 5. The chromosomes range in length from 2.59 to 7.61μm, the total length 37.44μm and the ratio of the longest to the shortest is 2.94. the karyotype belongs to 2B. Type II :The karyotype formula is 2n=16=8m+4sm+4st (Plate 3: U, V). The idiogram is shown in Fig. 4. The chromosomes range in length from 2.65 to 8.21 μm, the total length 46.01 μm and the ratio of the longest to the shortest 3.10. The karyotype belongs to 2B. The chromosome numbers of 2n=20, 2n= 14 and 2n=22, and karyotype of 2n= 14 and 2n=22 in P. filipes are reported for the first time. 3. Polygonatum cytonema Hua Two materials were examined. One from the Langyashan, Chuxian, anhui, is found to have 2n = 18 = 8m (2sc)+ 6sm+ 4st (Plate 2: K, L). The idiogram is shown in Fig. 7. The chromosomes range in length from 3.41 to 9.21 μm, the total length 56.34μm and the ratio of the longest to the shortest is 2.70. The karyotype belongs to 2B. The other material from the Huangshan, Anhui, has two cytotypes: 2n=20 and 2n= 22. Type I: The karyotype formula is 2n= 20= 8m+ 6sm+ 6st (Plate 2: M, N). The idiogram is shown in Fig. 8. The chromosomes range in length from 1.75 to 5.03μm, with the total length 32. 91μm and the ratio of the longest to the shortest 2. 87. The karyotype is also of 2B. Type II: The karyotype formula is 2n=22=6m+ 8sm+4st+ 4t (Plate 2: O, P ). The idiogram is Shown in Fig. 10. The chromosomes range in length from 1.75 to 4.95 μm, with total length 35.05μm and the ratio of the longest to the shortest 2.83. The karyotype brlongs to 3B. 4. Polygonatum desoulayi kom. The material from Xuancheng, Anhui, is found to have karyotype 2n = 22 = 10m (2sc) + 6sm (lsc) + 6st ( Plate 2. I, J). The idiogram is shown in Fig. 6. The chromosomes range in length from 1.86 to 5.61μm, with the total length 41.98μm and the ratio of the longest to the shortest 3.02. The karyotype is also of 3B. The first pair has one chromosome carrying a satellite attached to the long arm, showing heterozygosity. The chromosome number and karyotype of Chinese material are reported for the first time. 5. Polygonatum verticillatum (L.) All. The material from the Langyashan, Chuxian, Anhui is found to have two cytotypes. Type 1: the karyotype formula is 2n = 18 = 2m+ 2sm+ 10st+ 2t+ 2T (Plate 1: G, H). The idiogram is shown in Fig.9. The chromosomes range in length from 1.86 to 4.03μm, with total length 28.28μm and the ratio of the longest to the shortest 2.17. The karyotype classification belongs to 3B. Type II: The karyotype formula is 2n=24=6m+4sm+12st+2T (Plate 1: E, F). The idiogram is shown in Fig. II. The chromosomes range in length from 2.01 to 5.03μm, with total length 41.36μm and the ratio of longest to shortest 2.50. The karyotype is also of 3B. The chromosome numbers and karyotypes of Chinese material are reported for the first time.  相似文献   

18.
鳗鲡肝脏、脾脏显微与超微结构   总被引:27,自引:0,他引:27  
郭琼林  卢全章 《动物学报》1994,40(2):125-130
经光镜和电镜观察发现:鳗鲡肝脏的肝小叶不规则。肝细胞胞质内富含多种细胞器及包含物。胆小管由2—4个肝细胞围成,相邻肝细胞间有连接复合体封闭胆小管。肝血窦为有孔型、孔处无隔膜,内有巨噬细胞。窦周隙明显,未见贮脂细胞。肝细胞向胆小管腔与窦周隙面伸出许多指状微绒毛。脾脏内白髓中淋巴细胞聚集成群,未见明显脾小结、淋巴鞘。红髓由脾索与脾窦组成,动脉分支末端(壁厚的毛细血管)可开放于红髓,无明显巨噬细胞中心。脾窦及脾小动脉内皮细胞通常为长杆状、沿血管纵向平行排列。脾窦为有孔型,孔处可见薄的隔膜。脾小动脉内皮外为2—5层平滑肌(多数为纵行)。  相似文献   

19.
白蜡虫阔柄跳小蜂生物学特性的研究   总被引:6,自引:0,他引:6  
焦懿  赵苹 《昆虫学报》1999,42(2):166-171
白蜡虫阔柄跳小蜂Metaphycus ericeri Xu et Jiang在昆明地区一年发生5代,以3、4、5龄幼虫和蛹在白蜡虫雌成虫体内越冬。该蜂的发育起点温度和有效积温分别为11.45℃和552.93日度。18 ℃、21℃、24℃、27℃和30℃恒温条件下的平均世代历期分别为 66.87天、42.27天、35.56天 、30.84天和27.81天。成虫需取食蜜露或白蜡虫雌虫体液作补充营养。性比为1.75~2.88:1(平均2.25:1)。产卵前期2~3天。开始产卵后的2~5天产卵量占总产卵量的62.21%。 27℃的产卵量和产卵率分别为19.31粒和89.81%。18℃时仅4.37粒和18.56%。15℃时不产卵。补充营养、性别和产卵与否对成虫寿命有显著影响。幼虫共5龄。1~4龄以寄主体液和组织为食。5龄幼虫不取食,3~4天后化蛹。  相似文献   

20.
2004~2005年,在陕西省南部米仓山黎坪国家森林公园研究了秦岭蝎蛉Panorpa qinlingensisChouetRan的年生活史和生物学习性,通过饲养,成功获得卵、幼虫、蛹等虫态。结果表明,秦岭蝎蛉在米仓山1年发生2代,以预蛹在土室里越冬,5月中旬始见越冬代成虫,5月中旬末~6月上旬为越冬代成虫羽化盛期,7月下旬~8月中旬为第1代成虫羽化盛期,成虫在室内可存活35~60 d。羽化近1周后开始交尾,交尾4~8 d后开始产卵,单雌产卵量35~180粒,卵期5~9 d;幼虫型,共4龄,历期38~50d;蛹为强颚离蛹,蛹期8~18 d。记述了主要生物学习性。  相似文献   

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