English for biology students translation Lesson6-9
第六课
A Home for Life: Formation of the Solar System and Planet Earth
The story of life's origins begins with the formation of the earth. The sequence of events that gave rise to our planet began, in turn, with the cosmic explosion physicists call the Big Bang. The sun at the center of our solar system condensed from a cloud of primordial matter roughly 5 billion years ago; the planets, including the earth, condensed about 4.6 billion years ago. The earth is composed of a number of layers: a solid crust, a semisolid mantle, and a largely molten (liquid) core that has a solid center. Basic physical features of Earth that may have made the emergence of life possible include the planet's size, temperature, composition, and distance from the sun. The major current hypothesis holds that life arose spontaneously on the early earth by means of chemical evolution from nonliving substances.
生命起源于地球的形成。大爆炸是我们行星形成的开始。太阳在50亿年前生成，位于太阳系中心，行星，包括地球，在46亿年前生成。地球由多层组成：坚硬的地壳，半流体的地幔，一个很大的溶解中心中存在一个坚实的中心。地球的基本特征使生命起源成为可能，包括行星的大小，温度，组成以及离太阳的距离。当前主要假设认为，由非生命的化学物质进化过程自发产生了生命。
The Emergence of life: Organic and Biological Molecules on a Primitive Planet
Evidence for prelife stages of chemical organization comes from laboratory experiments that try to duplicate the physical environment and chemical resources of the early earth. These experiments, including the pioneering work of Miller and Urey, have successfully produced organic monomers including amino acids, simple sugars, and nucleic acid bases. The probable next step toward life was the spontaneous linking of such monomers into polymers such as proteinoids and nuclei acids. Current research suggests that likely sites for this polymerization were clay or rock surfaces.
通过创造出地球早期的自然条件和化学资源条件，科学家在实验室中已经获得了化学有机体生命前阶段的证据。这些实验包括米勒等早期所做工作，成功地产出了有机单体，包括氨基酸，单糖，核酸碱基。这些单体自发的连接成多聚体，如类蛋白和核酸，使进入生命状态成为可能。这些聚合作用可能发生在泥土或岩石表面。
Researchers have found that, when energy is available to a system, they can generate three kinds of organic molecular aggregates. The Russian Aleksandr Oparin obtained polymer-rich droplets, called coacervates from solutions of polymers. Sidney Fox generated proteinoid microspheres from mixtures of amino acids and water. A third laboratory structure is the liposome, a spherical lipid bilayer that forms from phospholipids. A structure similar to one or more of these aggregates may have been the precursor of true cells.
当一个系统获得能量时，可能发生3种有机分子的聚集。从多聚物的溶液中俄国科学家获得了富含小液滴的多聚物，即凝聚物。从氨基酸和水的混合液中Fox获得了类蛋白微球体。实验室第三个结构物质是脂质体，即由磷脂形成的球形脂双层结构。
Further steps in the appearance of cells on the earth included the development of RNA and DNA as biological information molecules. Evidence suggests that RNA, which can form spontaneously under conditions mimicking those of the early earth, was the first informational molecule. The discovery of RNA ribozymes-RNA that can act as an enzymelike catalyst suggests that such catalytic RNA also could have assembled new RNAs from early nucleotides. Certain catalytic RNAs can also carry out sexlike exchanges of pieces of RNA.
RNA可能是地球早期形成的第一个贮藏信息的物质。在实验室模拟早期地球自然条件下其可自发形成。核酶的发现说明它可以催化早期核酸形成新的RNA。对于RNA物种而言，某些催化RNA具备类似于性交换的功能。
Following the development of a lipid-protein surface layer and replicating RNA and DNA informational molecules, the events leading to the emergence of living cells would have included the origin of the genetic code; the sequestering of RNA or DNA into cell-like structures; and the development of metabolic pathways.
接下来脂蛋白表层的形成，RNA的复制,DNA信息分子的形成，最终导致活细胞的出现，包括最初的遗传密码，RNA 或DNA被包裹进细胞样的结构中；及代谢途径的建立。
The Earliest Cells
The oldest fossils that may represent living cells are found in rocks that are about 3.5 billion years old. The cells were probably anaerobic heterotrophs, with autotrophs arising much later. The first autotrophs produced their own nutrients and released O,-a metabolic by-product that had a crucial impact on later life forms. The resulting ozone layer in the earth's
atmosphere reduced the penetration of ultraviolet light. As a result, cells would survive in shallow water and on the land surface. The increasing quantity of atmospheric oxygen also permitted the evolution of aerobic cells and cellular respiration, which in turn signaled the beginning of the global carbon cycle.Although the earliest cells were all prokaryotes, by about 1.5 billion years ago eukaryotes appeared.
能说明活细胞存在的最古老化石大约有35亿年了。最早出现的细胞可能是厌氧异氧生物，自养生物很久后出现。最早的自养生物自己生产营养并释放氧气，这个新陈代谢副产品对后期生命的形成有一个深远的影响。臭氧层的出现减少了紫外线的渗透。结果，细胞就能够在浅水区和陆地上生存了。大气中氧气数量的增加使得需氧细胞进化并产生细胞呼吸，这预示着全球碳循环的开始。最早期的细胞都是原核生物，直到15亿年后，真核细胞才出现。
The Changing Face of planet Earth
Changes in land masses, the seas, and climate have greatly affected the ev olution of life on the earth. The basic parts of the planet include a light, solid crust over a hot, semisolid mantle and an inner, partially molten core. Massive segments or plates of the crust move over the mantle in the process of continental drift. Over the past 500 million years, continental drift has sculpted the earth's crusts to produce the form and distribution of present-day continents. Climatic changes that greatly affected living organisms accompanied these plate movements; the period was marked by occasional waves of mass extinctions of living creatures. Organisms were also affected by periods of glaciation that followed variations in the earth's orbit and in the output of energy by the sun.
大陆板快，海洋的改变，以及气候对地球生命的进化都有深远影响。地幔上大板快地壳的挤压形成大陆漂移。大陆漂移雕塑了地壳的外观，使现在大陆形成。伴随板块运动，气候改变对活有机体有深远影响。在特定时期的生物大量灭亡高峰是这个时期的见证。生物也受冰河期影响，在冰河期，地球轨道和太阳能的输出都发生了很大变化。Taxonomy: Categorizing the Variety of living Things
Biologists use the binomial system of nomenclature developed b y Linnaeus to categorize the varieties of life on the earth. The system assigns each type of organism to a genus and species. Organisms are then further classified into higher taxonomic categories-family, order, class, division (plants), phylum (animals), and kingdom. Evidence from many subfields of biology, such as biochemistry and comparative anatomy, helps define species and higher taxa (taxon). And whereas species were originally defined in terms of morphological traits, today biologists generally use the criterion of a reproductively isolated population.
生物学家利用林奈发展的双名法对生物分类。系统选定每个类型的生物进入属和种，然后将生物进一步分类更高级类别中，即科，目，纲，门，界。来自于生物化学和比较解剖学等亚生物学领域的证据有助于划分物种和更高级的分类单位，然而物种最初依据形态学特征进行分类的，今天生物学家大体上使用孤立多产的群体作为标准。
Taxonomy reveals a great deal about the evolutionary relationships among organisms. A clade is a taxonomic unit whose members are derived from a common ancestor.
分类学揭示了物种间进化的大量关系。进化枝中的成员来自一个共同的祖先。
The Five Kingdoms
A phylogenetic tree is a graphic representation of evolutionary relationships. Your text uses a common five-kingdom arrangement: organisms are grouped into the kingdoms Monera, Protista, Fungi, Plantae, and Animalia. Although this system is a convenient organizational tool, the kingdoms are probably no true clades.
进化系统树是进化关系的图解表现。教材中使用一个通用的5界：？，？，真菌，植物，动物。尽管这个系统是一个便利的组织工具，5界划分可能不是正确的进化枝。
第七课
Fungi: The Great Decomposers
Characteristics of Fungi
The approximately 175,000 species of fungi include some of the si mplest multicellular organisms. Fungi have a variety of lifestyles. They may be saprobes that decompose dead organic matter; they may be parasites which obtain nutrients from living hosts; or they may live in symbiotic relationships with algae or with the roots of higher plants. In spite of these variations, however, all fungi carry out extracellular digestion: they secrete enzymes that digest organic matter, and then they absorb the resulting nutrients.
包括最简单的多细胞生物在内，真菌大概有175，000种。真菌有多种生命形式。他们可能是分解无生命的腐生菌；也可能是寄生菌；或者与藻类共生，或者与高等植物共生。不管如何变化，所有真菌都是细胞外消化。他们分泌酶消化有机物，然后吸收有效的营养物质。
Most fungi have the same basic body structure consisting of a main body or thallus composed of filaments called hyphae. In most species the walls of hyphal cells contain chitin. Hyphae in certain species may become specialized to form rhizoids, which serve as rootlike anchors, or they may become the feeding structures known as haustoria. Finally, hyphae may or may not be septate-having cross walls that segregate independent cells, each with at least one nucleus. Lower fungi are coenocytic; that is, they are one mass of cytoplasm that contains multiple nuclei.
大多数真菌有同样的基本结构，即由菌丝组成的菌体。大多数真菌的细胞壁含有明角质。某些种类的菌丝可能特化形成假根，具有根样的固定作用，或者他们成为饲喂结构称吸器。菌丝或有细胞隔膜或没有细胞隔膜，但至少有一个细胞核。低级真菌是多核体的，即，一大团细胞质含有多个细胞核。
Hyphae grow and branch to form a filamentous network cal led a mycelium. Food is digested and absorbed at the tip of each hyphae; more hyphae are generated as this process continues. As a result, fungi may grow very rapidly. Growth depends on mitosis and the rapid manufacture of cytoplasm; fungal mitosis is unique in that it occurs within the nucleus. Hyphae from genetically distinct individuals may fuse to form a heterokaryon-a single cytoplasm with dissimilar nuclei.
菌丝生长形成分支，进而形成网状结构称为菌丝体。在菌丝尖端，食物被消化并吸收；这个过程能持续产生更多菌丝。结果，真菌生长很快。生长靠有丝分裂和细胞质的快速产生。真菌的有丝分裂很独特，即它只发生在细胞核里。遗传学明显不同的菌丝个体融合形成异核体——同一个细胞质中含有不同的细胞核。
As nonmotile heterotrophs, fungi must eventually be able t o find new sources of nutrients. This function is fulfilled by spores, the fungal reproductive bodies. Spores may be home on aerial hyphae, which discharge spores into the air, and depending on the species they may haploid or diploid. There are two main categories of spores: (1) dispersal spores, which are usually short-lived and are produced in large numbers during active fungal growth; and (2) survival spores, which are usually produced in smaller numbers and at a time in the life cycle when the fungus is under some kind of environmental stress.
作为不会移动的异养生物，真菌最终能够发现营养新资源的。这个过程由孢子来完成，即真菌的生殖体。孢子可能是在气生菌丝的中心，将孢子释放到空气中，依赖物种不同，可能是单倍体也可能是二倍体。有两种主要的孢子：（1）分散的孢子，通常生命期短，数量大，主要存在于活跃的菌丝生长阶段；（2）存活孢子，通常产生很少的数量，在生存压力条件下的一种生命循环。
2Classification of fungi
As with some of the other groups you have studied, it is difficult to group fungi according to actual evolutionary relationships. In general, they are classified according to morphology, methods of reproduction, and modes of spore production. On the basis of these features, the single division of the kingdom Fungi, Mycota, is divided into six principal classes.
对真菌依据实际进化关系进行分类是很困难的。总体来说，它们是依据形态学，生殖方式，孢子产生的模式来分类。基
于这些特性真菌界的门被分成6个基本纲。
The lower fungi comprise the groups Chytridiomycet es, Oomycetes, and Zygomycetes. All lack septate hyphae and are commonly coenocytic; spores are formed by asexual means. Of the six fungal classes, only the oomycetes usually have a diploid vegetative state. Oomycetes and chytrids (sometimes called water molds) produce motile, flagellated spores in sporangia. They also produce gametes in gametangia; oomycetes are distinguished by their large, immobile egg cells. In fact, both these groups have such distinctive features that some biologists prefer to classify them as protists rather than fungi. Zygomycetes resemble the other two classes in this group but have nonmotile spores. They are also completely terrestrial, and some form mycorrhizal associations with plant roots.
低级真菌包含壶菌，卵菌纲和接合菌。所有缺乏隔膜的菌丝是通用的多核细胞的；孢子通过非性方式产生。只有卵菌纲通常有二倍体的营养状态。卵菌纲和壶菌在孢子囊中产生能动的带鞭毛的孢子。在配子囊中产生配子；卵菌纲具有非寻常大的静止的卵细胞。实际上，这两大群具有不同的特征，生物学家宁愿把它们归为原生动物而不是真菌。接合菌与其它两纲相似，但它的孢子不会动。它们完全是陆生的，一些菌根与某些植物的根形成共生关系。
The higher fungi include the class Ascomycetes, the largest c lass of fungi. Most ascomycetes are either saprobes or parasites. Asexual reproduction produces spores called conidia, which develop on the tips of specialized aerial hyphae. In the ascomycete sexual cycle, hyphae of different mating strains fuse, giving rise to ascospores that form in a small, saclike ascus. Groups of asci form fruiting bodies. Ascomycetes of interest to humans include truffles, yeasts, and Penicillium species.
高级真菌包括子囊菌纲，最大的真菌纲。大多数子囊菌要么是腐生菌，要么是寄生菌。非性繁殖产生的孢子称分生孢子子实体，其依赖特化的气生菌丝尖。在子囊菌性循环过程中，不同的菌丝通过株融合进行匹配，产生的子囊菌存在于小类子囊
中。子囊群形成果实体。对人类有利的子囊菌包括块菌，酵母和产青霉素菌。
Most members of the class Basidiomycetes—the second group of higher fungi form visible fruiting bodies. A prime characteristic distinguishing basidiomycetes from ascomycetes is the dense mass of dikaryotic hyphae called the basidiocarp-the "mushroom" seen on damp lawns and the forest floor. Club-shaped basidia, each bearing four haploid basidiospores, line the surfaces of the gills on the underside of the mushroom cap. Members of this group undergo both sexual and asexual reproductive processes at different times in their life cycle, and in response to varying environmental influences.
纲中大多数菌为担子菌，第二大类高级真菌，能形成可见的果实体。担子菌与子囊菌相比，最基本不同是它具备浓密的双核菌丝，称担子果。棒形担子，每个都含有4个单倍体的担子孢子，线形地排列在蘑菇帽下的菌褶表面。大多数成员有性和非性繁殖两种，在不同生命循环中有不同形式，并依据环境变化而变化。
The class Deuteromycetes, or Fungi Imperfecti, includes a variety of fungi that lack modes of sexual reproduction. Most are known to reproduce asexually by means of conidia. Deuteromycetes important to humans include those used to ferment soybeans and rice to make soy sauce and sake respectively, and those responsible for producing citric acid and the highly dangerous aflatoxin.
半知菌纲，包括大量无性繁殖的真菌。分生孢子完成非性繁殖。对人类很重要的半知菌纲包括发酵大豆成酱油和大米发酵成清酒的菌类，它们也产生柠檬酸和有毒的黄曲霉毒素。
Lichens: The Ultimate Symbionts
Lichens are composite organisms in which about 90 percent of the lichen mass consists of one species of fungus, while the remaining 10 percent is made up of one or two species of algae. The algal portion of the lichen provides the fungal portion with essential nutrients, while the presence of the fungal component may enable the alga to exploit an otherwise unavailable ecological niche. Lichen fungi are usually ascomycetes, although the other two higher fungi are sometimes found in lichens. Lichens have a number of remarkable features, including their ability to become almost completely desiccated without drying and their ability to absorb inorganic nutrients. Reproduction in lichens is not well understood.
地衣是复合生物，大概90%的地衣团由一种地衣组成，10%含有一两种藻类。藻类为真菌提供必要的营养，真菌为藻类提供了难得的小生态环境。地衣真菌通常是子囊菌，有时在地衣中也能发现其他两类真菌。地衣有大量的显著特征，包括在几乎脱水条件下仍能吸收无机养分。地衣繁殖方式还不清楚。
Fungal Evolution
The various fungi may have arisen independently from prokaryotes, since some evidence suggests that ascomycetes and basidiomycete did not evolve from known lower forms. However, all fungi do show the same dependence on nutrients produced by plants, animals, or algae.
各种真菌可能都独立进化于原核生物，有证据表明，子囊菌和担子菌没有进化。但所有真菌都依赖由植物，动物或藻类产生的营养。
第八课
Animal Development
Production of Sperm and Eggs
In sexually reproducing organisms males and females produce sex cells, known as gametes. These are swimming sperm in males and ova (eggs) in females.
在性繁殖过程中，生物的雄性和雌性产生性细胞，称配子。雄性是能够游动的精子，雌性是卵子。
The process of sperm production, spermatogenesis, takes place in testes. The sperm originate in gonial cells (spermatogonia) in the walls of seminiferous tubules. Spermatocytes produced by mitosis in spermatogonia divide meiotically to generate haploid spermatids. The mature sperm has a tail, a nucleus containing haploid chromosomes, and a front end with an acrosome, the storage site for enzymes that will aid fertilization.
精子产生过程，即精子发生在睾丸中。精子产生于输精管壁的性母细胞（精原细胞）。精原细胞经有丝分裂再减数分裂产生单倍体精子细胞，即精母细胞。成熟精子有尾部，单倍体染色体组，头部有顶体，内部储存酶类，有助于受精。
Ova, which are produced during oogenesis, are generated in gonial cells (oogonia) of the female's ovaries. Oocytes then enter a stage of arrest in early meiosis. At a species-specific later point, a final ripening (ovulation) and the first meiotic division occur. A second meiotic division, followed by development of the embryo, takes place if the egg is fertilized.
在卵子发生过程中，由卵巢中的性母细胞产生。卵母细胞进入减数分裂的抑制阶段。第一次减数分裂产生一个成熟卵。如果卵受精，那么第二次减数分裂伴随胚胎的发育。
Eggs vary greatly in size from species to species and have complex structures. Virtually all developing animal ova are
surrounded by helper cells, either follicle cells or nurse cells. Depending on the species, eggs also store varying amounts of yolk, a reservoir of nutrients produced by digestive-gland cells in the mother's body. Finally, follicle cells or cells of the maternal oviduct provide protective coatings for the egg, including albumen (egg white) and various types of outer membranes and shells.
品种间卵的大小变化很大，并且有复杂的结构。实际上，所有发育过程中的卵都辅助细胞环绕，要么是滤泡细胞，要么是抚育细胞。依赖物种的不同而不同，卵黄贮备也不同，即由母体消化腺细胞产生的营养储备。最后，滤泡或母体输卵管细胞产生保护性的卵膜，包括清蛋白和各种外部膜及壳。
Frog oocytes have served as model systems for studies of oocyte development. During maturation they produce huge numbers of ribosomes through gene amplification. Large quantities of mRNA may also be made and stored.
蛙卵母细胞作为卵母细胞发育的研究系统模型。在成熟过程中，通过基因扩增产生大量的核糖体。同时也产生和储备了大量的mRNA。
Fertilization: Initiating Development
Fertilization unites male and female gametes and initiates development. In so me species fertilization is external; in others (including most terrestrial animals) it takes place internally. The first contact of the sperm head with the egg's jelly coat triggers the acrosome reaction, in which enzymes are released to digest a hole through the egg's protective layers, and the plasma membrane of the sperm is brought into position to bind to the ovum's surface. After fusion of the egg and sperm plasma membranes, the haploid male nucleus with its chromosomes moves into the egg cytoplasm. Fusion also triggers the egg's final meiotic reduction divisions. When sperm and egg nuclei unite, the two sets of chromosomes mingle to create a diploid set. The fertilized egg is now a zygote.
雌雄配子结合作用称受精作用，发育开始。某些物种中，是外部受孕；另一些物种，包括大部分陆生动物，是内部受孕。当精子和卵子的胶状膜发生接触时，触发了顶体反应。释放多种酶而将卵保护膜消化出一个洞。精子的原生质膜与卵子的表面连接起来。精卵原生质膜融合后，单倍体雄性核进入卵细胞质。融合也触发了最后的减数分裂。当精卵核结合时，两套染色体混合产生一二倍体，即受精卵。
T he egg's cortical reaction serves as a barrier to the entry of more than one sperm.Initially, there is a temporary change in the egg's electrical state, and the egg cell is activated. The final stage of the reaction, the rapid elevation of the fertilization membrane, prevents further sperm penetration.
卵皮层阻止其他的精子进入，充当壁垒作用。开始时，卵电位发生暂时变化，卵细胞被激活。反应最后阶段，受精卵的膜快速隆起，阻止更多精子进入。
In some species fertilization is not necessary. Instead, parthenogenesis takes place: the egg is spontaneously activated and proceeds to normal embryonic development.
对某些物种而言，受精不是必须的。孤雌生殖，即卵自发地被激活并进入正常的胚胎发育过程中。
Cleavage: An Increase in Cell Number
Cleavage, the major developmental event immediately following fertilization, is a special form of cell division (mitosis). Cleavage produces a blastula, a sheet of cells rounded into a sphere that in most species surrounds a cavity. In the process, the single-celled zygote is divided into many small cells, and yolk, mRNA, ribosomes, and other materials arc distributed to each cell in precise ways. The cells of the blastula, called blastomeres, also each receive a full diploid set of chromosomes.
受精后，立即发生卵裂，细胞有丝分裂的特殊过程。卵裂产生一个囊胚，形成的细胞壁球形排列形成一个空腔。在这个过程中，单细胞的受精卵分裂成许多小细胞，卵黄，mRNA，核糖体和其他物质被精确分配到每个细胞中。这些囊胚细胞，称卵裂球，每个细胞都有一套二倍体染色体组。
T here are different patterns of cleavage in different species.The amount of yolk present in the egg is a major factor in determining the pattern: in species having little yolk (such as mammals) the zygote cleaves completely through, forming cells that are roughly equivalent in size. In frogs, in which the egg has somewhat more yolk, cleavage proceeds more rapidly in regions of the embryo having less yolk. In bird eggs the yolk is so massive that cleavage divisions are restricted to a tiny area of cytoplasm.
不同物种，卵裂方式不同。决定因素主要取决于卵黄的含量。含有少量卵黄的物种（例如哺乳动物），合子分裂得很彻底，子细胞大致平均分裂。蛙卵，卵黄稍微多点，在胚胎的卵黄较少区域发育更快些。鸟卵卵黄很大，卵裂被限制在细胞质很小区域内。
In many species the precise distribution to blastomeres of molecular determinants in the cytoplasm is crucial to proper development of different cell types in the embryo. In mammal and bird species the fate of cells is determined by the position
of a cell late in cleavage.
细胞质中分子遗传因素精确分配到卵裂球中，对许多物种而言，是发育成胚中不同类型细胞关键所在。对哺乳动物和鸟类而言，细胞的命运最终由细胞分裂后所处的位置决定的。
Gastrulation: Rearrangement of Cells（原肠胚：细胞重排列）
T he rearrangement of the blastula into a three-dimensional orga nism with inner, middle, and outer layers occurs during gastrulation. The resulting gastrula consists of an outer ectoderm, an inner endoderm, and a mesoderm layer positioned between them.
在原肠胚形成过程中，囊胚重新排列，形成包括内层，中层，外层的三围组织。最终原肠胚由一个外肠胚，内肠胚，和一个中肠胚构成。
E ach layer gives rise to specific tissues during em bryonic development. A variation in gastrulation, involving the movement of cells into endodermal and mesodermal positions through the thickened primitive streak, arose in reptiles and can still be seen in bird and mammalian embryos, lending support to the theory that birds and mammals evolved from reptiles.
每个胚层产生特殊的胚胎组织。密实的原肠胚通过细胞运动进入内胚层和中胚层，爬虫，鸟，哺乳动物的胚胎都如此。因此提出这样的理论，鸟类和哺乳动物是由爬虫进化而来的。
Organogenesis: Formation of Functional Tissues and Organs
The organs and tissues of the embryo arise during organogenesis as cells inside the embryo and on its surface become specialized. Organogenesis actually includes two closely linked processes, morphogenesis and differentiation. During morphogenesis cells and cell populations change shape: an example is neurulation in vertebrate embryos, in which the edges of the flat neural plate fold upward and fuse, forming the beginnings of the hollow brain and spinal cord. During differentiation cells mature so that they may perform separate functions. This maturation may include taking on a function-related shape, such as the long, spindly shape of skeletal-muscle cells. Cell differentiation also results in responsiveness-the ability of a cell to be regulated within the organism through the action of hormones, neurons, and other signals.
胚经过内部细胞和表面细胞特化后，器官形成，发育成器官和组织。器官形成实质上包括两个联系紧密的过程，即形态发生和分化。在形态发生期间，细胞和细胞群体形状发生改变：例如，脊椎动物的神经胚，扁平神经板的边缘向上折叠并融合，是中空大脑和脊髓神经形成的开端。在分化期间，细胞成熟，执行各自功能。成熟包括功能相关的成型过程。例如，细长的骨骼肌肉细胞。细胞分化也产生应答能力，即细胞受生物体内激素，神经和其他信号的调控过程。
Embryonic Coverings and Membranes
The embryos of land vertebrates are enclosed within four extraembryonic membranes that afford protection while still permitting the exchange of gases, nutrients, and other materials.
脊椎动物的胚胎被4层膜包被，起保护作用，但仍能交换气体，营养和其他物质。
Growth: Increase in Size
Growth in embryos is largely due to an increase in the number of cells rather than to an increase in the size of individual cells. In many species the extent of embryonic growth is limite d by the availability of food (yolk). In animals that develop entirely free of the maternal body, such as frogs and insects, the embryo give rise to a larval stage that can feed itself and later undergo metamorphosis to attain the adult stage. In many species the most spectacular growth phase takes place during the juvenile and adolescent phases of the life cycle. Actual growth generally stops once the organism reaches its typical adolescent phases of the life cycle. Actual growth generally stops once the organism reaches its typical adult size, although replacement of dead cells may continue.
胚的生长很大程度取决于细胞数量的增加而不是单个细胞大小的改变。在大多数物种中，胚的生长是受卵黄的量限制的。在动物细胞中，完全依赖于母体，例如蛙和昆虫，胚产生幼虫状态，后来经历变态而进入成年状态。在许多物种中，在少年和青春期，发生特别显著的生长。一旦细胞进入成年状态和成年大小，生长就停止了，尽管死细胞的替代不断发生。
A special type of growth, regeneration of lost body parts, can take place in adults of some species. Prior to such regeneration cells in stump tissue undergo dedifferentiation. They lose their functional phenotype, divide rapidly, and generate a population of cells that will regenerate the lost part. Compensatory hypertrophy is a different, temporary growth response in which residual tissue increases in mass and cell number: cells undergo mitosis but do not dedifferentiate.
一个特殊类型的生长，再生失去的部分躯体，发生在某些物种的成体中。在再生之前，残肢组织细胞经历了去分化过程。他们失去功能表型，快速分裂，产生细胞群来再生失去的部分。代偿式肥大是一个不同的，暂时的生长应答过程，残余组织在体积和细胞数量上增加：细胞经历了减数分裂，但没有去分化过程。
Aging and Death: Final Developmental Processes
Aging is an ongoing, time-dependent developmental process in which body parts deteriorate. Proposed causes include the degeneration of collagen (the fibrous proteins of the connective tissues) and limits on the number of times cells can divide. Other theories focus on a decline of the immune system or on the accumulation of lipofuscins (aging pigments).
老化是一个持续过程，随时间发育，身体部分恶化。可能原因包括胶质的退化（纤维蛋白）和能分裂活细胞的限制。另外理论认为，免疫系统的免疫下降或脂褐素的堆积造成的。
第九课
How Biologists Define a Species
Modern biology generally define a species as group of actually or potentially interbreeding populations that is reproductively isolated from the such groups. Members of a species can interbreed with each other, but they cannot breed with organisms belonging to another species. One advantage of the standard of reproductive isolation is that it is very precise. Notice, however, that it can only be applied to organisms that reproduce sexually. Asexual reproducers, including most prokaryotes, many plants, and some animals, must be classified into species on the basis of physical (biochemical or morphological) traits.
现代生物学大体将物种定义为实际上的一群或潜在的杂交群体，即从这个群体隔离繁殖的后代。种族中个体可以互相交配，但种间不能。这种繁殖隔离的一个优势是很精确。但仅适用于性繁殖的生物。非性繁殖，包括大多数原核生物，许多植物，某些动物，需要通过自然特征进行归类。
Preventing Gene Exchange
Two general types of mechanisms operate to block the exchange of genes between individuals of related groups. The first general type is made up of prezygotic isolating mechanisms that prevent the formation of zygotes. Prezygotic isolation falls into two categories: ecological and behavioral. In the first case, two related group may become adapted to slightly different environments-perhaps varying soil types or food sources. Over time, these genetic differences become so great that successful cross-fertilization can no longer take place. In behavioral isolation, related groups evolve differing behaviors such as specific mating rituals-that restrict the exchange of genes to members of the same group.
两种基因型机制阻碍了相关群体中个体的基因交换。第一种基因型由前合子机械隔离机制阻止合子的生成。前合子隔离分两类：生态学的和行为学的。第一种情况，两个相关群体可能分别适应稍微不同的环境，如土壤类型或食物来源的变化。长时间，这些遗传差异变得很大而很难异体受精。而行为学隔离，相关的群组进化成不同的行为方式，例如，结婚仪式，从而限制了同群成员基因交流。
Sometimes the differences that produce prezygotic isolation involve mechanical isolation. That is, mating is physically impossible between members of different species because genitals of males and females are structurally incompatible or because molecules on the surfaces of sperm and egg fail to bind. A final type of prezygotic mechanism is temporal isolation, in which time-related environmental cues that trigger reproductive processes are different for related species.
有时，产生前合子隔离的差异涉及了隔离机制。即，由于生殖器结构不匹配或精卵分子表面不结合而使不同种群成员间不能自然结合。最后一类前合子机制是暂时隔离，与时间有关的环境因素触发了相关物种的不同繁殖过程。
In postzygotic isolating mechanisms mating occur, but the resulting hybrid organism is inviable or sterile. In a special case of hybrid sterility termed hybrid breakdown, the second and subsequent generations after a cross show reduced reproductive success. Contrast this fact with the very different outcome of crossbreeding between two genetically distant members of the same species, where the result is often heterozygote advantage (hybrid vigor).
在合子后隔离机制中，匹配可以进行，但或不产生杂种或杂种不育。杂种不育在某些特殊情况下，是指第二代或以后几代显示出杂交繁殖能力的降低。正是同种远基因成员间的杂交产生不同的结果，而产生杂种优势。
Populations of a species that are spread out over a broad geographical range are often arrayed in a cline-a gradual change in one or more characteristics as each population evolves adaptations to its own local environment. Along a cline, subspecies with distinct characteristics may arise. Often, individuals at either end of a cline are reproductively isolated.
地域上分布很广的种的群体中，经常存在变异群，因为适应当地的环境，每个群体逐渐产生一个或多个与众不同的特点。在变异群中，带有明显特征的亚群可能产生。通常，在两个变异群中的个体是繁殖隔离的。
Becoming a Species: How Gene Pools Become Isolated
Ernst Mayr's model of allopatric speciation proposes that species can originate in a two-stage process. In the first stage, populations of existing species are separated by a physical or geographical barrier. As a result, over time genetic differences leading to pre- or postzygotic isolation arise between the two groups. In the second stage, the diverged populations may again come into contact. If this happens, speciation becomes complete through the action of natural selection.
异地物种形成模型认为，物种可能起源于两个阶段。第一阶段，已经存在的物种群体可能由于自然或地理屏障被隔离。结果，长时间后，在两个群体间遗传差异导致前合子或后合子隔离的产生。第二阶段，这些趋异群体可能再次接触，物种发生可能通过自然选择发生。
The Genetic Bases of speciation
The extent of differences between populations that are diverging into separate species or between species that have already diverged is represented by a statistic called genetic identity-the relative proportion of the same structural genes present in members of groups being compared. In general, biologists believe that the genetic events leading to speciation take place gradually. Once a new species has arisen, it tends to diverge genetically from related species at a more rapid pace. In some cases, such as the primate order, major differences in body form are not reflected by corresponding divergences in structural genes. This has led Biologists to hypothesize that small changes in regulatory genes may account for many of the large-scale changes responsible for sepciation and the origin of higher taxonomic groups.
能够趋异的群体或已经趋异的物种，他们之间差异的扩大，由一个稳定的遗传识别代表。即在可比群体成员中相同基因所占相关比例。大体而言，生物学家相信，遗传导致的物种形成是逐渐发生的。在某些情况下，身体主要差别并不能反映结构基因的趋异，生物学家因此提出，调控基因很少的改变可能导致很大规模物种改变和更高分类学上群体的产生。
One mechanism that may rapidly split populations genetically is polyploidization—the sudden multiplication of an entire complement of chromosomes. This can result in sympatric speciation, in which new species arise even though no geographical isolation has taken place. A phenomenon similar to polyploidization involving the rearrangement of chromosomes has been proposed to explain the evolutionary origin of giant pandas. Clearly, species can originate in a variety of ways.
遗传学上可以快速分离群体的一个机制是多倍体，一个完全互补染色体组的突然倍增。结果导致同域物种形成，即使没有地理隔离也会产生新的物种。与多倍体相似的一个现象是染色体重排，可以解释巨大熊猫的进化起源。显然，物种可以以多种方式进化。
Explaining Macroevolution: Higher-order Changes
The changes that generate species are sometimes termed microevolution; those that produce the major phenotypic differences that separate genera, classes, orders, and so on are termed macroevolution. Some lines of descent can be traced by studying the fossil record. In other cases relationships must be inferred by comparison of related living organisms. When lines of descent over evolutionary time are constructed, the result is a phylogeny.
遗传物种的改变有时称微进化；那些产生很大差异用来区分属，纲，目的表型变化称大幅进化。某些品系的后代可以通过化石追根溯源。而其他相关性可以通过现存活体的比较来推论。当品系后代以进化钟构建时，形成系统发育树。The rationale for building a phylogeny is simple: it assumes that similarities in body structure, biochemistry, reproductive strategies, and other features of organisms can be used to trace lines of common descent. The process is complex because evolution proceeds in different patterns. In cases of parallel evolution, two or more lineages evolve along similar lines. In convergent evolution, very distantly related lineages become more alike as similar adaptations take hold in response to demands of the environment. Thus similar structures in different organisms may reflect homology (derivation from a common ancestor) or analogy (independent origin of structures used for similar purposes).
建立系统发育树的基本理论很简单：把身体结构，生物化学，繁殖策略以及其他特征相似的生物划分进同一个品系。这个过程很复杂，因为进化经历不同模式。就平行进化而言，两个或更多的血统沿相似品系进化。在相似生存条件下，亲源关系很远的血统也可能更相似。不同生物间的相似结构可能说明它们具有同源性。
One of the most common evolutionary patterns that can be constructed from the fossil record is divergent evolution or radiation. It is represented by the branching and rebranching of a single line. Another common feature of evolution is extinction-the complete loss of a species or group of species. Mass extinctions have occurred at least five times in the earth's history.
从化石证据构建的最普通进化模式是趋异进化。由分支和次级分支的简单线条代替。另一个进化的共同特征是灭绝。地球历史中至少发生过5次大规模的灭绝。
Gaps in the fossil record have led some paleontologists to propose the punctuated equilibrium theory of evolution. The theory holds that evolution proceeds by spurts-radical changes over short (in geological time) periods of time-with intervening periods of equilibrium. The theory is controversial and tends not to be supported when an abundant fossil record is available.
化石证据上的断代使古生物学家们提出间断平衡进化理论。这个理论认为进化在短期内经历了根本突变，中间又介入均衡阶段。这个理论很有争议，一旦发现丰富的化石证据，理论就难支撑了。
The Role of microevolution in Macroevolution
Biologists have no certain answers to a number of questions about large-scale evolutionary changes. These questions range from whether novel higher taxa result from as-yet undescribed radical genetic processes, to whether known processes such as genetic drift and small gene changes can plausibly account for the evolution of new genera, families, and orders. Investigators are exploring these areas using traditional methods as well as the newer techniques of molecular biology.
生物学家还无法回答关于大规模进化的许多问题。许多问题是新类别的物种可能起源于还不确定的遗传过程，或者知道遗传过程，例如，遗传漂移和少量基因的改变可能是新属，科，目产生的原因。科研工作者不但利用传统方法对这些领域进行研究，还利用分子生物学新科技。
Lesson6
Big Bang大爆炸
Binomial system ofnomenclature双名法
clade进化枝，分化单位
kingdom界
division门（植物）
phylum（复phylum）门（动物）
class纲
order目
family科
genus属
species种，物种
coacervate团聚体，凝聚层
continental drift大陆漂移
core核心
crust地壳
lipsome脂质体
mantle地幔，外套部
ozone臭氧层
proteinoid类蛋白
taxon分类单位，分类群
taxonomy分类学
Lesson7
ascomycetes子囊菌
ascus（复asci）子囊
basidiocarp单子果
basidiomycetes担子菌纲
basidium担子
conidium（复conidia）分生孢子子实体fungiimperfecti(deuteromycetes)半知菌类，半知菌亚门gametangium(复gametangia)配子囊
haustorium(复haustoria)吸器
heterokaryon异核体
hyphae（单hypha）菌丝
lichen地衣
mycelium（复mycelia）菌丝体
rhizoid假根
saprode腐生菌
septate有隔膜的，分隔的
sporangium(复sporangia)孢子囊，孢子果
Lesson8
acrosome reaction顶体反应
blastomere卵裂球blastula囊胚，囊胚泡
cleavage卵裂
compensatoryhypertrophy代偿性肥大
dedifferentiatation去分化
differentiatation分化，鉴别
ectoderm外胚层
mesoderm中胚层
endoderm内胚层
fertilization受精
gastrula原肠胚
gastrulation原肠胚形成
gene amplification基因扩增
metamorphsis变态
morphogenesis形态建成，形态发生
neurulation神经肽形成
oogenesis卵子形成
organogenesis器官形成
ovaries卵巢，子房
oviduct输卵管
ovum(复ova)卵，卵子
parthenogenesis孤雌生殖
primitive streak原条（原肠胚）
regeneration再生
sperm精子，精液
spermatogenesis精子发生
yolk卵黄，蛋黄
zygote合子，受精卵
Lesson9
allopatricspeciation异域物种形成
analogy相似，同功
cline梯度变异，变异群
convergentevolution趋同进化
divergentevolution趋异进化
extinction灭绝，熄灭，消失
homology同源性，同种性，同系性
hybrid sterility杂种不育性
macroevolution宏观进化，种外进化
microevolution微进化，种内进化
parallel evolution平行进化
phylogeny种系发生，系统发生，系统发育punctuatedequilibrium间断平衡
sympatricspeciation同域物种形成，同地物种形成，分布区重叠物种形成
一、表示数量的词素 1. haplo,mono,uni ：单，一，独haploid 单倍体monoxide一氧化碳monoatomic单原子的 2. bi,di,dipl,twi,du :：二，双，两，偶biocolor 双色,dichromatic 双色的,diplobacillus 双杆菌dikaryon 双核体 twin ：孪生dual 双重的 3. tri :三，丙triangle三角triacylglycerol三酰甘油tricarboxylic acid cycle 三羧酸循环 4. quadri,quadru,quart,tetr,tetra：四quadrilateral四边的quadrivalent四价的quadruped 四足动物tetrode四极管tetracycline四环素 5. pent,penta,quique五pentose戊糖pentagon五角形pentane戊烷quintuple 五倍的pentose戊糖pentomer五邻粒 6. hex,hexa,sex 六hexose已糖hexapod六足动物hexapoda昆虫纲hexamer六聚体 7. hepta,sept 七heptane 庚烷heptose 庚糖heptoglobin七珠蛋白 8. oct八octpus 章鱼octagon八角形octane 辛烷octase 辛糖 9. enne,nona九nonapeptide 九肽enneahedron 九面体 10. deca,deka 十:decapod 十足目动物decahedron 十面体decagram 十克 11. hecto, 百hectometer百米hectoliter百升hectowatt 百瓦 12. kilo,千kilodalton (KD) 千道尔顿kilobase 千碱基kiloelectron volt 千电子伏特 13. deci,十分之一，分decimeter 分米decigram 十分之一克 14. centi,百分之一 15. milli,千分之一，毫millimole 毫摩（尔）milliliter 毫升 16. micro,百万分之一，微，微小，微量microgram微克microogranism微生物microecology 微生态学micropipet微量移液器 17. nano十亿分之一，毫微，纳nanosecond十亿分之一秒nanometer纳米 18. demi,hemi,semi半demibariel 半桶hemicerebrum 大脑半球semiopaque半透明semi-allel半等位基因semi-conductor半导体 19. holo 全，整体，完全holoenzyme 全酶holoprotein全蛋白holocrine全（质分）泌 20. mega巨大，兆，百万megaspore大孢子，megabasse兆碱基megakaryocyte巨核细胞megavolt兆伏megalopolitan特大城市 21. macro 大，巨大，多macrophage巨噬细胞macrogamete大配子macroelement常量元素macromolecular大分子 22. poly,multi,mult 多，复合polyacrylate聚丙烯酸酯polymerase 聚合酶multichain多链的multinucleate 多核的multicistronic mRNA多顺反子mRNA multicopy多拷贝 二、表示颜色的词素 1 chrom颜色 chromophore生色团chromosome染色体chromatography色谱法 2 melan,melano,nigr 黑 melanoma黑素瘤melanin黑色素melanophore黑色素细胞 3 xantho,flavo,fla,flavi,lute黄 xanthophyl叶黄素xanthous黄色的，黄色人种xathine黄嘌呤flavin黄素flavone黄酮letein黄体素，叶黄素flavin adenine dinucleotide(FAD)黄素腺嘌呤二核苷酸 4 erythro, rub, rubrm, ruf,红 erythrocyte红细胞erythromycin红霉素erythropoitin(EPO)促红细胞生成素 5 chloro,chlor绿，氯
Inside the Living Cell: Structure and Function of Internal Cell Parts Cytoplasm: The Dynamic, Mobile Factory 细胞质：动力工厂 Most of the properties we associate with life are properties of the cytoplasm. Much of the mass of a cell consists of this semifluid substance, which is bounded on the outside by the plasma membrane. Organelles are suspended within it, supported by the filamentous network of the cytoskeleton. Dissolved in the cytoplasmic fluid are nutrients, ions, soluble proteins, and other materials needed for cell functioning. 生命的大部分特征表现在细胞质的特征上。细胞质大部分由半流体物质组成，并由细胞膜（原生质膜）包被。细胞器悬浮在其中，并由丝状的细胞骨架支撑。细胞质中溶解了大量的营养物质，离子，可溶蛋白以及维持细胞生理需求的其它物质。 The Nucleus: Information Central（细胞核：信息中心） The eukaryotic cell nucleus is the largest organelle and houses the genetic material (DNA) on chromosomes. (In prokaryotes the hereditary material is found in the nucleoid.) The nucleus also contains one or two organelles-the nucleoli-that play a role in cell division. A pore-perforated sac called the nuclear envelope separates the nucleus and its contents from the cytoplasm. Small molecules can pass through the nuclear envelope, but larger molecules such as mRNA and ribosomes must enter and exit via the pores. 真核细胞的细胞核是最大的细胞器，细胞核对染色体组有保护作用（原核细胞的遗传物质存在于拟核中）。细胞核含有一或二个核仁，核仁促进细胞分裂。核膜贯穿许多小孔，小分子可以自由通过核膜，而象mRNA 和核糖体等大分子必须通过核孔运输。 Organelles: Specialized Work Units（细胞器：特殊的功能单位） All eukaryotic cells contain most of the various kinds of organelles, and each organelle performs a specialized function in the cell. Organelles described in this section include ribosomes, the endoplasmic reticulum, the Golgi complex, vacuoles, lysosomes, mitochondria, and the plastids of plant cells. 所有的真核细胞都含有多种细胞器，每个细胞器都有其特定功能。本节主要介绍核糖体，内质网，高尔基体系，液泡，溶酶体，线粒体和植物细胞中的质体。 The number of ribosomes within a cell may range from a few hundred to many thousands. This quantity reflects the fact that, ribosomes are the sites at which amino acids are assembled into proteins for export or for use in cell processes. A complete ribosome is composed of one larger and one smaller subunit. During protein synthesis the two subunits move along a strand of mRNA, "reading" the genetic sequence coded in it and
生物专业英语词汇——词素（词根）部分 一、表示数量的词素 1. haplo,mono,uni ：单，一，独haploid 单倍体monoxide一氧化碳monoatomi c单原子的 2. bi,di,dipl,twi,du :：二，双，两，偶biocolor 双色,dichromatic 双色的,diplobacillus 双杆菌dikaryon 双核体 twin ：孪生dual 双重的 3. tri :三，丙triangle三角triacylglycerol三酰甘油tricarboxylic acid cycle 三羧酸循环 4. quadri,quadru,quart,tetr,tetra：四quadrilateral四边的quadrivalent四价的quadruped四足动物tetrode四极管tetracycline四环素 5. pent,penta,quique五pentose戊糖pentagon五角形pentane戊烷quintuple 五倍的pentose 戊糖pentomer五邻粒 6. hex,hexa,sex 六hexose已糖hexapod六足动物hexapoda昆虫纲hexamer六聚体 7. hepta,sept(i) 七heptane 庚烷heptose 庚糖heptoglobin七珠蛋白 8. oct八octpus 章鱼octagon八角形octane 辛烷octase 辛糖 9. enne,nona九nonapeptide 九肽enneahedron 九面体 10. deca,deka 十:decapod 十足目动物decahedron 十面体decagram 十克 11. hecto, 百hectometer百米hectoliter百升hectowatt 百瓦 12. kilo,千kilodalton (KD) 千道尔顿kilobase 千碱基kiloelectron volt 千电子伏特 13. deci,十分之一，分decimeter 分米decigram 十分之一克 14. centi,百分之一 15. milli,千分之一，毫millimole 毫摩（尔）milliliter 毫升 16. micro,百万分之一，微，微小，微量microgram微克microogranism微生物microecology 微生态学micropipet微量移液器 17. nano十亿分之一，毫微，纳nanosecond十亿分之一秒nanometer纳米 18. demi,hemi,semi半demibariel 半桶hemicerebrum 大脑半球semiopaque半透明semi-allel 半等位基因semi-conductor半导体 19. holo 全，整体，完全holoenzyme 全酶holoprotein全蛋白holocrine全（质分）泌 20. mega巨大，兆，百万megaspore大孢子，megabasse兆碱基megakaryocyte巨核细胞megavolt兆伏megalopolitan特大城市 21. macro 大，巨大，多macrophage巨噬细胞macrogamete大配子macroelement常量元素macromolecular大分子 22. poly,multi,mult 多，复合polyacrylate聚丙烯酸酯polymerase 聚合酶multichain多链的multinucleate 多核的multicistronic mRNA多顺反子mRNA multicopy多拷贝 二、表示颜色的词素 1 chrom颜色chromophore生色团chromosome染色体chromatography色谱法 2 melan,melano,nigr 黑melanoma黑素瘤melanin黑色素melanophore黑色素细胞 3 xantho,flavo,fla,flavi,lute黄xanthophyl叶黄素xanthous黄色的，黄色人种xathine黄嘌呤flavin(e)黄素flav one黄酮letein黄体素，叶黄素flavin adenine dinucleotide(FAD)黄素腺嘌呤二核苷酸 4 erythro, rub, rubrm, ruf,红erythrocyte红细胞erythromycin红霉素erythropoitin(EPO)促红细胞生成素 5 chloro,chlor绿，氯chlorophyll叶绿素chloride氯化物chloramphenicol氯霉素 6 cyan,cyano 蓝，青紫色，氰cyanophyceae 蓝藻纲cyanobacteria蓝细菌cyanide氰化物 7 aur,glid,chrys金色aureomycin金霉素chrysose 金藻淀粉chrysanthemum菊花glidstone 金
教学内容： Cytoplasm: The Dynamic, Mobile Factory 细胞质：动力工厂 Most of the properties we associate with life are properties of the cytoplasm. Much of the mass of a cell consists of this semifluid substance, which is bounded on the outside by the plasma membrane. Organelles are suspended within it, supported by the filamentous network of the cytoskeleton. Dissolved in the cytoplasmic fluid are nutrients, ions, soluble proteins, and other materials needed for cell functioning. 生命的大部分特征表现在细胞质的特征上。细胞质大部分由半流体物质组成，并由细胞膜（原生质膜）包被。细胞器悬浮在其中，并由丝状的细胞骨架支撑。细胞质中溶解了大量 的营养物质，离子，可溶蛋白以及维持细胞生理需求的其它物质。 The Nucleus: Information Central（细胞核：信息中心） The eukaryotic cell nucleus is the largest organelle and houses the genetic material (DNA) on chromosomes. (In prokaryotes the hereditary material is found in the nucleoid.) The nucleus also contains one or two organelles-the nucleoli-that play a role in cell division. A pore-perforated sac called the nuclear envelope separates the nucleus and its contents from the cytoplasm. Small molecules can pass through the nuclear envelope, but larger molecules such as mRNA and ribosomes must enter and exit via the pores. 真核细胞的细胞核是最大的细胞器，细胞核对染色体组有保护作用（原核细胞的遗传物质 存在于拟核中）。细胞核含有一或二个核仁，核仁促进细胞分裂。核膜贯穿许多小孔，小 分子可以自由通过核膜，而象mRNA和核糖体等大分子必须通过核孔运输。 Organelles: Specialized Work Units（细胞器：特殊的功能单位） All eukaryotic cells contain most of the various kinds of organelles, and each organelle performs a specialized function in the cell. Organelles described in this section include ribosomes, the endoplasmic reticulum, the Golgi complex, vacuoles, lysosomes, mitochondria, and the plastids of plant cells. 所有的真核细胞都含有多种细胞器，每个细胞器都有其特定功能。本节主要介绍核糖体， 内质网，高尔基体系，液泡，溶酶体，线粒体和植物细胞中的质体。 The number of ribosomes within a cell may range from a few hundred to many thousands. This quantity reflects the fact that, ribosomes are the sites at which amino acids are assembled into proteins for export or for use in cell processes. A complete ribosome is composed of one larger and one smaller subunit. During protein synthesis the two subunits move along a strand of mRNA, "reading" the genetic sequence coded in it and translating that sequence into protein. Several ribosomes may become attached to a single mRNA strand; such a combination is called a polysome. Most cellular proteins are manufactured on ribosomes in the cytoplasm. Exportable proteins and membrane proteins are usually made in association with the endoplasmic reticulum. 核糖体的数量变化从几百到几千，核糖体是氨基酸组装成蛋白质的重要场所。完整的核 糖体由大亚基和小亚基组成。核糖体沿着mRNA移动并阅读遗传密码，翻译成蛋白质。一条mRNA上可能有多个核糖体，称多聚核糖体。大多数细胞蛋白是由细胞质中核糖体生产。输出蛋白和膜蛋白通常与内质网有关。 The endoplasmic reticulum, a lacy array of membranous sacs, tubules, and vesicles, may be either rough (RER) or smooth (SER). Both types play roles in the synthesis and transport of proteins. The RER, which is studded with polysomes, also seems to be the source of the
生物专业英语第七课：Fungi: The great decomposers characteristics [,k?r?kt?'ristiks]n. 特性，特征；特色（characteristic的复数）approximately [?'pr?ksim?tli] adv. 大约，近似地；近于 saprobe ['s?pr?ub]腐生菌，腐生生物，污水生物 decompose [di:k?m'p?uz]vt. 分解；腐烂；使腐烂 parasite['p?r?sait]n. [基医] 寄生虫；[生物] 寄生生物（parasite的复数）symbiotic [simbai'?tik]adj. [生态] 共生的；共栖的 algae ['?ld?i:]n. [植] 藻类；[植] 海藻 digestion [dai'd?est?(?)n; di-]消化，消化作用，消化吸收 secrete [si'kri:t]vt. 藏匿；分泌 thallus ['θ?l?s]n. 菌体，[植] 叶状体；叶状植物 hyphae ['haifi:]n. 菌丝（hypha的复数形式）hypha ['haif?] hyphal ['haif?l]adj. 菌丝的 chitin ['kaitin]n. 壳质；几丁质；明角质 rhizoid ['raiz?id]n. 假根adj. 根状的；假根的 anchor ['??k?]锚，锚点，安佳 haustoria [h?:'st?:ri?]n. 吸器 septate ['septeit]adj. 有隔膜的；被隔膜分开的 segregate ['segrigeit]vt. 使隔离；使分离；在实行种族隔离 coenocytic [si:n?'sitik]adj. 多核细胞的；多核体的；合胞体的 mycelium [mai'si:li?m]n. 菌丝；菌丝体 genetically [d?e'netik?li]adv. 从遗传学角度；从基因方面；由基因决定的 distinct [di'sti?(k)t]adj. 明显的；独特的；清楚的；有区别的 fuse [fju:z]vt. 使融合；使熔化，使熔融 heterokaryon [het?r?u'k?ri?n]n. [植] 异核体 nonmotile ['n?n'm?utail]adj. 无运动的；不动的 heterotrophs ['het?r?utr?f]n. [生物] 异养生物（helerotroph的复数形式） fulfilled [ful'fild]v. 实现（fulfill的过去分词）；履行；满足 spore [sp?:]n. 孢子 aerial [['e?ri?l]]adj. 空中的，空气的；空想的 discharge [dis't?a:d?]vi. 排放；卸货；流出 dispersal [di'sp?:sl]n. 分散；传播；散布；疏散；消失 classification [,kl?sifi'kei?(?)n]n. 分类；类别；等级；分级 feature ['fi:t??]n. 特色，特征；容貌；特写或专题节目 Mycota ['maik?uta:]n. 真菌界；真菌门 principal ['prins?p(?)l]adj. 主要的；基本的；资本的 comprise [k?m'praiz]vt. 包含；由组成；构成 chytridiomycetes [,kaitridi?'maisi:tiz]壶菌纲；壶菌门 oomycetes [,?u?'maisi:t]n. [微] 卵菌（一类真菌）；卵菌纲 zygomycetes [,zaig?u'maisi:tiz, ,zi-]n. 接合菌；接合菌目；接合菌纲；结合菌亚纲vegetative ['ved?it?tiv; -teitiv]adj. 植物的；营养的；促使植物生长的；有生长力的mold [m?uld]n. 霉菌；模子 flagellated ['fl?d??leitid]adj. [生物] 生有鞭毛的；生有匍匐茎的
生物专业英语试题及答案 一、将下列英文术语或缩写译为合乎学术规范的中文术语： 1、Odorant receptor 气味受体（气味感受器、嗅觉受体、嗅觉感受器也得1分；仅答受体或感受器，则得0.5分）。 2、Differentially expressed gene 差异化表达基因（答为“不同表达基因”，仅得0.5分）。 3、MOE 主要嗅（觉）上皮[答为“嗅（觉）上皮”也得1分；若写出其英文术语全称“Main olfactory epithelium”，也得 分]。 4、VNO4 犁鼻器（答为“信息素外周感受器”也得1分；若写出其英文术语全称“Vomeronasal organ”，也得分）。 5、Social behavior 社会行为（答为“社群行为、社交行为”也得1分）。 6、Monogamy 一夫一妻制（答为“一雄一雌制、单配制”也得1分） 7、Vasopressin 加压素（答为“抗利尿素”仅得0.5分）。 8、Oxytocin 催产素。 9、Kin recognition 亲属识别。 10、Autism
自闭症/孤独症。 11、NIH (美国)国家(立)卫生研究院(所)(若写出其英文术语全称NIH = National Institutes of Health 也得分)。 12、HHMI 霍华德·休斯医学研究所(若写出其英文术语全称HHMI = Howard Hughes Medical Institute 也得分；或者译为Howard Hughes 医学研究所，也得全分)。 13、Nanotechnology 纳米技术（纳米科技、奈米技术、奈米科技）。阳光大学生网 14、Renewable energy 可再生能源（量）（答为“可更新能源、再生能源”，或意思相近者，也得1分）。 15、Biomechanical energy 生物机械能（答为“生物力能、生物力学能”也得1分，而“生物化学能、生物能”，则得0.5分） 16、Nanogenerator 纳米发电机（答为“纳米发动机、纳米电机、纳米发生器、纳米生产器”，也得1分）。 17、Systems biology 系统生物学。 18、DNA sequencer DNA测序仪[答为“DNA测序（器、机）、DNA序列仪（器）”也得1分，答为DNA序列，仅得0.5分]。 19、Neurodegenerative diseases 神经退行性病（若答为“神经系统退行性疾病”或者“神经系统退化性疾病”，也得1）。 20、Amygdala 杏仁核（答为“杏仁体”，也得1分）。
生物专业英语词汇—词素（词根）部分 一、表示数量的词素 1. haplo,mono,uni 单，一，独haploid 单倍体 monoxide一氧化碳 monoatomic单原子的 2. bi,di,dipl,twi,du：二，双，两，偶 biocolor 双色, dichromatic 双色的, diplobacillus 双杆菌 dikaryon 双核体 twin 孪生 dual 双重的 3. tri 三，丙 Triple 三倍的 triangle三角 triacylglycerol三酰甘油 tricarboxylic acid cycle 三羧酸循环 4. quadri,quadru,quart,tetr,tetra：四 Quadruple 四倍的 quadrilateral四边的 quadrivalent四价的 quadruped四足动物 tetrode四极管 tetracycline四环素 5. pent, penta, quique五 pentose戊糖 pentagon五角形 pentane戊烷 quintuple 五倍的 pentose戊糖 pentomer五邻粒 6. hex,hexa,sex 六 hexose已糖 hexapod六足动物 hexapoda昆虫纲 hexamer六聚体 7. hepta,sept(i) 七 heptane 庚烷 heptose 庚糖 heptoglobin七珠蛋白8. oct八 octpus 章鱼 octagon八角形 octane 辛烷 octase 辛糖 9. enne, nona九 nonapeptide 九肽 enneahedron 九面体 10. deca, deka :十 decapod 十足目动物 decahedron 十面体 decagram 十克 11. hecto, 百 hectometer百米 hectoliter百升 hectowatt 百瓦 12. kilo,千 kilodalton (KD) 千道尔顿 kilobase 千碱基 kiloelectron volt 千电子伏特 13. deci,十分之一，分 decimeter 分米 decigram 十分之一克 14. centi,百分之一 15. milli,千分之一，毫 millimole 毫摩（尔） milliliter 毫升 16. micro,百万分之一，微，微小， 微量 microgram微克 microogranism微生物 microecology微生态学 micropipet微量移液器 17. nano十亿分之一，毫微，纳 nanosecond十亿分之一秒 nanometer纳米 18. demi,hemi,semi半 hemicerebrum 大脑半球 [hemi'seribr?m] semiopaque半透明： ['semi?u'peik] semi-allel半等位基因 semi-conductor半导体 19. holo 全，整体，完全 holoenzyme 全酶 holoprotein全蛋白 holocrine全（质分）泌 20. mega巨大，兆，百万 megaspore大孢子， ['meg?sp?:] megabasse兆碱基 megakaryocyte巨核细胞 megavolt兆伏 megalopolitan特大城市 [.meg?'l?p?lis] 21. macro 大，巨大，多 macrophage巨噬细胞 macrogamete大配子 macroelement常量元素 macromolecular大分子 22. poly,multi,mult 多，复合 polyacrylate聚丙烯酸酯 polymerase 聚合酶 multichain多链的 multinucleate 多核的 multicistronic mRNA多顺反子 mRNA multicopy多拷贝 二、表示颜色的词素 1. chrom颜色 chromophore生色团['kr?um?f?:] chromosome染色体 chromatography色谱法 [kr?um? 't?gr?fi] 2. melan,melano,nigr 黑 melanoma黑素瘤 melanin黑色素 melanophore黑色素细胞 3. xantho,flavo,fla,flavi,lute黄 xanthophyl叶黄素 xanthous黄色的，黄色人种 xathine黄嘌呤 flavin(e)黄素 flavone黄酮 letein黄体素，叶黄素 flavin adenine dinucleotide(FAD)黄素腺嘌呤二核 苷酸 4. erythro, rub, rubrm, ruf,红 erythrocyte红细胞 [i'riθr ?.sait]
Lesson One（4学时） Inside the Living Cell: Structure and Function of Internal Cell Parts Cytoplasm: The Dynamic, Mobile Factory细胞质：动力工厂 生命的大部分特征表现在细胞质的特征上。细胞质大部分由半流体物质组成，并由细胞膜（原生质膜）包被。细胞器悬浮在其中，并由丝状的细胞骨架支撑。细胞质中溶解了大量的营养物质，离子，可溶蛋白以及维持细胞生理需求的其它物质。 The Nucleus: Information Central（细胞核：信息中心） 真核细胞的细胞核是最大的细胞器，细胞核对染色体组有保护作用（原核细胞的遗传物质存在于拟核中）。细胞核含有一或二个核仁，核仁促进细胞分裂。核膜贯穿许多小孔，小分子可以自由通过核膜，而象mRNA和核糖体等大分子必须通过核孔运输。 Organelles: Specialized Work Units（细胞器：特殊的功能单位） 所有的真核细胞都含有多种细胞器，每个细胞器都有其特定功能。本节主要介绍核糖体，内质网，高尔基体系，液泡，溶酶体，线粒体和植物细胞中的质体。 核糖体的数量变化从几百到几千，核糖体是氨基酸组装成蛋白质的重要场所。完整的核糖体由大亚基和小亚基组成。核糖体沿着mRNA移动并阅读遗传密码，翻译成蛋白质。一条mRNA上可能有多个核糖体，称多聚核糖体。大多数细胞蛋白是由细胞质中核糖体生产。输出蛋白和膜蛋白通常与内质网有关。 内质网，带有花边的生物囊，有管状，泡状之分，以及光滑和粗糙面区别。两种都与蛋白质的合成和运输有关。粗糙内质网上分布许多核糖体，也可能提供细胞分裂后所需的细胞膜。光滑内质网上无核糖体，主要作用是脂肪和类固醇的合成以及细胞内有毒物质的氧化。两种内质网合成的产物在其中进行分流或运输到细胞外。 运输小泡能够将可运输分子从内质网运输到高尔基复合体上。在高尔基复合体中修饰，包装后输出细胞或传递到细胞质中的其他场所。 细胞中的液泡好象是中空的，但实际上充满了液体和可溶分子。最典型的液泡存在于植物细胞中，储备水，糖以及其它分子。动物中的液泡起吞噬和胞饮作用。 溶酶体是液泡亚单位，含有消化酶，降解大部分生物大分子。消化食物微粒和降解损伤的细胞残片。 线粒体是细胞中化学产能的场所。另外，植物细胞中的质体在光合作用中利用光能产生碳水化合物，线粒体内嵴上提供了很大的表面积并分布着产ATP酶。线粒体自我复制，并且可能是自由生活的原核生物在进化中形成的后代。 质体有两种类型：白色体，缺乏色素，是淀粉，蛋白质和油的储备场所；色质体，含有色素。叶绿体是最重要的色质体，含有与光合作用有关的叶绿素。叶绿体的内部结构是由多层膜形成的叶绿体基粒，其中包埋在基质中的基粒称子座。 The Cytoskeleton（细胞骨架） 所有的细胞都有细胞骨架，网络结构的纤丝充满了它所能触及的全部空间并且对细胞器提供支持作用。细胞骨架大部分由微丝组成，微丝主要由可收缩的肌动蛋白组成。动植物细胞的许多种类型细胞内运动与肌动蛋白有关。第二类蛋白是肌球蛋白，它与肌肉细胞的收缩有关。细胞骨架的另一个主要结构成分是微管，由球状的微管蛋白组成，象脚手架一般维持细胞的稳定形态。细胞骨架的中间丝提供了细胞质伸缩动力。机械酶，例如，肌球蛋白，动力蛋白，驱动蛋白与微丝，微管相互作用产生动力而引起细胞运动。 Cellular Movements（细胞运动 尽管细胞骨架提供了细胞的某些稳定性，微丝，微管及相关蛋白能使细胞爬行或滑动。这种运动需要固体基质依托并通过表面几何形状的改变而运动。某些细胞具备趋药性，即趋向或
A band A带 A chromosome A染色体[二倍体染色体组中的正常染色体（不同于B染色体）] A site[核糖体]A部位 ABA脱落酸abasic site脱碱基位点，无碱基位点 abaxial远轴的 abequose阿比可糖，beta脱氧岩藻糖 aberrant splicing异常剪接 aberration象差；畸变；失常 abiogenesis自然发生论，无生源论 ablastin抑殖素（抑制微生物细胞分裂或生殖的一种抗体） abnormal distrbution非正态分布 abnormality异常，失常；畸形，畸变 ABO blood group systemABO血型系统 aboriginal mouse原生鼠 abortin流产素 abortion流产，败育 abortive egg败育卵 abortive infection流产（性）感染 abortive transduction流产（性）转导 ABP肌动蛋白结合蛋白 abrin相思豆毒蛋白 abscisic acid脱落酸 abscission脱落 absolute绝对的 absolute configuration绝对构型 absolute counting绝对测量 absolute deviation绝对偏差 absolute error绝对误差 absorbance吸收，吸光度 absorbed dose吸收剂量 absorbent吸收剂 absorptiometer吸光计 absorptiometry吸光测定法 absorption吸收 absorption band吸收谱带 absorption cell吸收池 absorption coefficient吸收系数 absorption spectroscopy吸收光谱法 absorption spectrum吸收光谱；吸收谱 absorptive endocytosi s吸收（型）胞吞（作用） absorptive pinocytosis吸收（型）胞饮（作用） absorptivity吸光系数；吸收性 abundance丰度 abundant丰富的，高丰度的
个人整理 free electron laser 自由电子激光器 optical klystron 光学速调管 α-1,3-GalT α-1,3-glactsyltransferase α－1，3半乳糖苷转移酶 6-DMAP 6-Dimethyaminopurine 6－二氨基甲基嘌呤 AFS Simultaneous activation and fusion 融合同时激活 AI Artificial insemination 人工授精 BSA Bovine serum albumin 牛血清白蛋白 CB Cytochalasin B 细胞松弛素B CHX Cyclohexmide 放线菌酮 COCs Cumulus oocytes complexes 卵丘－卵母细胞复合体 DC Direct crruent 直流电 DMSO dimethylsulfoxide 二甲基亚砜 DNMT DNA methyltransferase DNA甲基转移酶 DPBS Dulbecco's phosphate buffered saline 杜氏磷酸盐缓冲液EAA Essential amino acid 必需氨基酸 ECG Equine chorionic gonadotropin 马绒毛膜促性腺激素 EGF Epidermal growth factor 表皮生长因子 ESC Embryo stem cell 胚胎干细胞 带 A chromosome A染色体[二倍体染色体组中的正常染色体（不同于B染色体）] A site [核糖体]A部位 ABA 脱落酸 abasic site 脱碱基位点，无碱基位点 abaxial 远轴的 abequose 阿比可糖，beta脱氧岩藻糖 aberrant splicing 异常剪接 aberration 象差；畸变；失常 abiogenesis 自然发生论，无生源论 ablastin 抑殖素（抑制微生物细胞分裂或生殖的一种抗体） abnormal distrbution 非正态分布 abnormality 异常，失常；畸形，畸变 ABO blood group system ABO血型系统 aboriginal mouse 原生鼠 abortin 流产素 abortion 流产，败育 abortive egg 败育卵 abortive infection 流产（性）感染 abortive transduction 流产（性）转导
蒋悟生《生物专业英语》教/学案 Lesson One（4学时）Inside the Living Cell: Structure and Function of Internal Cell Parts Lesson One（4学时） Inside the Living Cell: Structure and Function of Internal Cell Parts 教学目的：使学生掌握细胞的组成结构（各种细胞器以及它们在细胞中的位置），以及结构与功能之间的关系。各细胞器及功能相关英语词汇以及主要用法。 教学重点：各细胞器的概念和功能，及相关英语词汇的掌握 教学难点：专业英语词汇的记忆 讲授方法：以学生翻译为主，老师讲解相关专业知识辅助学生理解 授课时间：3月22日；3月29日 教学内容： Cytoplasm: The Dynamic, Mobile Factory 细胞质：动力工厂 Most of the properties we associate with life are properties of the cytoplasm. Much of the mass of a cell consists of this semifluid substance, which is bounded on the outside by the plasma membrane. Organelles are suspended within it, supported by the filamentous network of the cytoskeleton. Dissolved in the cytoplasmic fluid are nutrients, ions, soluble proteins, and other materials needed for cell functioning. 生命的大部分特征表现在细胞质的特征上。细胞质大部分由半流体物质组成，并由细胞膜（原生质膜）包被。细胞器悬浮在其中，并由丝状的细胞骨架支撑。细胞质中溶解了大量的营养物质，离子，可溶蛋白以及维持细胞生理需求的其它物质。 The Nucleus: Information Central（细胞核：信息中心） The eukaryotic cell nucleus is the largest organelle and houses the genetic material (DNA) on chromosomes. (In prokaryotes the hereditary material is found in the nucleoid.) The nucleus also contains one or two organelles-the nucleoli-that play a role in cell division. A pore-perforated sac called the nuclear envelope separates the nucleus and its contents from the cytoplasm. Small molecules can pass through the nuclear envelope, but larger molecules such as mRNA and ribosomes must enter and exit via the pores. 真核细胞的细胞核是最大的细胞器，细胞核对染色体组有保护作用（原核细胞的遗传物质存在于拟核中）。细胞核含有一或二个核仁，核仁促进细胞分裂。核膜贯穿许多小孔，小分子可以自由通过核膜，而象mRNA 和核糖体等大分子必须通过核孔运输。 Organelles: Specialized Work Units（细胞器：特殊的功能单位） All eukaryotic cells contain most of the various kinds of organelles, and each organelle performs a specialized function in the cell. Organelles described in this section include ribosomes, the endoplasmic reticulum, the Golgi complex, vacuoles, lysosomes, mitochondria, and the plastids of plant cells. 所有的真核细胞都含有多种细胞器，每个细胞器都有其特定功能。本节主要介绍核糖体，内质网，高尔基体系，液泡，溶酶体，线粒体和植物细胞中的质体。