什么是组织培养
一种生物学研究方法,将取自动物或植物体的小块组织转移到该组织能在其中继续生存并发挥功能的人工环境中,而被培养的组织可为单个细胞、一群细胞或器官的一部分或整个器官。这种方法常用於研究正常和反常的细胞结构;生物化学、遗传和生殖活动;代谢、功能和老化及康复过程;对物理、化学及生物作用(如药品、病毒)的反应等。一个微小的组织样体细胞能在生物原料制成的培养基(如血清和组织提取物)、合成化合物组成的培养基,或两者混合而成的培养基上生长。培养基必须含有待研究细胞所必需的营养物质,酸硷值和温度也必须适宜。培养的结果可用显微镜观察,有时可透过部分处理(如着色)来提高特定观察部位的亮度。一些病毒也会在组织培养中生长。组织培养技术在鉴定感染、缺陷、染色体异常、分类脑肿瘤,以及配制、测验药物和疫苗方面已发挥很大作用。
tissue culture
Biological research method in which tissue fragments (a cell, a population of cells, or all or part of an organ) are sustained in an artificial environment for examination and manipulation of cell behavior. It has been used to study normal and abnormal cell structure; biochemical, genetic, and reproductive activity; metabolism, functions, and aging and healing processes; and reactions to physical, chemical, and biological agents (e.g., drugs, viruses). A tiny sample of the tissue is spread on or in a culture medium of biological (e.g., blood serum or tissue extract), synthetic, or mixed origin having the appropriate nutrients, temperature, and pH for the cells being incubated. The results are observed with a microscope, sometimes after treatment (e.g., staining) to highlight particular features. Some viruses also grow in tissue cultures. Work with tissue cultures has helped identify infections, enzyme deficiencies, and chromosomal abnormalities; classify brain tumors; and formulate and test drugs and vaccines.
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什么是月岩和月壤
从月球采回的岩石和表土样品大致分为3类:(1)结晶质火成岩,细粒多孔状(颗粒直径<1毫米)至中粒等粒状(颗粒直径>1毫米)岩石,主要由岩浆结晶形成,少数是晶质化的冲击熔岩(见陨石坑)。(2)角砾岩,显微角砾状岩石。碎屑直径约0.1~1.0厘米。由火成岩碎屑、矿物碎屑、玻璃质和月壤机械混...
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什么是毛霉科
毛霉目中最大、最重要的1科。孢囊梗自菌丝上发生,简单不分枝至分枝多次,单生或成束。在孢囊梗或其分枝的顶端形成孢子囊,全部为大型孢子囊,孢子囊内一般都有发达的囊轴。少数的属在孢子囊下面还有孢囊下泡或楔形的囊托。孢子囊成熟时消解或破裂,释放出孢囊孢子。本...
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什么是ÓêÑàÄ¿
Äñ¸ÙµÄ1ĿСÐÍÅÊÇÝ¡£×ìÐζÌÀ«¶øƽ±â£¬»òϸ³¤³É¹Ü×´£»Á½³á¼â³¤£»Î²´ó¶¼³Ê²æ×´£»õÆÛ•¶Ì£¬´ó¶¼±»Óð£¬×ã´ó¶à³ÊÇ°ÖºÐÍ¡£´ÆÐÛÏàËÆ¡£±¾Ä...
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什么是蛇岛蝮
蛇目蝰科蝮亚科蝮属的1种。仅见于中国辽宁省的蛇岛。估计现存2万条。全长可达800毫米(见图)。体型粗壮,头略呈三角形,有颊窝,眼后斜向口角有一细窄的黑褐色眉纹,其下缘镶有一极细的灰白色线纹;躯尾背面灰褐色,有一列暗褐色的“X“形斑。躯干中段背鳞23行,腹鳞150~164,尾下...