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  • 植物类原生者分类 -- -- 高级

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    Are these really living?
    ::这些真的活下来了?

    These single-celled wheel-like structures (magnified 100x) are diatoms . Diatoms are plant-like . They are encased in a symmetrical silica-based structure. Together with various forms of seaweed , they comprise the vary diverse plant-like protists. So how are they classified?
    ::这些单细胞类轮式结构(磁化的100x)是diatoms。 Diatoms类似植物。它们被嵌入一个以硅为基的对称结构中。它们与各种形式的海藻一起,由各种不同的植物类原生体组成。它们是如何分类的呢?

    Classification of Plant-like Protists
    ::植物类原生者分类

    The of plant-like protists is about as complex as the classification of animal-like protists. Many of the members are not closely related to each other, and many are still being reclassified. Most of the simpler are either unicellular or amoeboids (“animal-like”), but there are also colonial and non-motile algae. Certain groups of algae have evolved tissue differentiation . These groups are the brown algae, the red algae, and the green algae. The Classification of Algae Table lists some of the larger groups of algae.
    ::植物类原生生物与动物类原生生物的分类一样复杂。许多成员彼此没有密切联系,许多成员仍在被重新分类。大多数较简单的成员要么是无卵类,要么是类(“类动物 ” ) , 但也有一些殖民和非流动藻类。 某些藻类已经发展成组织差异。 这些群体是棕藻类、红藻类和绿藻类。 藻类分类列出了较大的藻类类别。

    Green algae include many single-celled, motile organisms . Others are non-motile, and some (called seaweeds) are truly multicellular. Green algae are considered to be the ancestors of the higher land plants. Present-day green and red algae appear to be close relatives of other plants. The first plants on Earth evolved from shallow freshwater algae some 400 million years ago. of isolated land plant spores suggest land plants may have been around as long as 475 million years ago.
    ::绿色藻类包括许多单细胞、运动生物体,另一些则非移动性,有些(所谓的海藻)是真正的多细胞。绿色藻类被认为是较高陆地植物的祖先。今天的绿色藻类和红藻类似乎是其他植物的近亲。地球上第一批植物从大约4亿年前的浅淡水藻类中演变而来。 孤立的陆地植物颗粒表明,陆地植物可能已经存在了大约47亿年前的47亿年前。

    Algae are most prominent in bodies of but are also common on land. However, land-based (terrestrial) algae are more common in moist, regions than in dry ones. They need moist conditions because they do not have and other adaptations to live on land. Algae are also found on snow and on exposed rocks, in with to create lichen . Algae play a significant role in ecology . Microscopic algae, called phytoplankton , that live suspended in water form the food base for most . In very high densities ( algal blooms ) these algae may discolor the water and outcompete or poison other life forms. Seaweeds grow mostly in shallow marine waters. Some seaweeds are used as human food or harvested for useful substances such as fertilizer or food additives.
    ::藻类在土壤中最为突出,但在陆地上也很常见,然而,陆地(陆地)藻类在潮湿地区比在干燥地区更为常见,它们需要湿润条件,因为它们没有在陆地上生活所需的水和其他适应条件,藻类还存在于雪上和暴露的岩石上,以创造地衣;藻类在生态中起着重要作用;微型藻类,称为浮游植物,在水中悬浮,是大多数生物的食物基地。在非常高的密度(藻类繁殖)中,这些藻类可能使水变色,相互交织或毒害其他生命形式。海藻大多生长在浅水中,有些海藻被用作人类食物或收获肥料或食品添加剂等有用物质。

    Classification of Algae
    Phylum or Division Class Common Name Body Form Characteristic Features

    Division Chlorophyta
    ::氯酚司

    		  Green algae Unicellular, colonial, filamentous, multicellular chlorophyll a and b , surrounded by two membranes

    Rhodophyta
    ::罗多夫塔

    		  Red algae Multicellular chlorophylls a and d, and light-capturing molecules called phycobilins, and beta-carotene

    Euglenozoa
    ::尤格勒诺索亚语Name

    		  Euglenoids Unicellular live primarily in freshwater and have chloroplasts with three membranes
    Heterokontophyta Phaeophyceae Brown algae Multicellular  
    - Chrysophyceae Golden algae Unicellular, filamentous (?)  
    - Bacillariophyceae Diatoms Unicellular  
    Haptophyta   haptophytes Unicellular  

    Dinoflagellata
    ::迪诺佛拉拉塔

    		  Dinoflagellates Unicellular  

    Division Chlorophyta (Green Algae)
    ::氯叶司(绿色阿尔盖)

    The green algae are the large group of algae from which the higher plants emerged. There are about 8,000 of green algae. Many species live most of their lives as microscopic single , while other species form colonies or long filaments. Like land plants, green algae contain both chlorophylls a and b , and they store food as starch in their plastids . They are found in all aquatic and wet or damp environments.
    ::绿色藻类是产生较高植物的大类藻类。 绿藻类有大约8000种。 许多物种作为微型单种生存,而其他物种则形成聚居或长丝状。 像陆地植物一样,绿色藻类既含有叶绿素a和b,又将食物作为淀粉储存在其粘土中。 它们存在于所有水生和湿湿湿或潮湿环境中。

    The chloroplasts of green algae are bound by a double membrane, so presumably they were acquired by direct endosymbiosis of cyanobacteria . A few other organisms rely on green algae to carry out for them. The chloroplasts in protists such as in euglenids were probably acquired from ingested green algae. Some species of green algae can be found in symbiotic associations with fungi to form lichens. In general, the fungal species that partner in lichens cannot live on their own, while the algal species are often found living in nature without the fungus. Some green algae live attached to rocks or woody parts of trees. Members of Chlorophyta also form symbiotic relationships with , , and . Some are flagellated and have an advantage of motility .
    ::绿色藻类的叶绿板可能从摄取的绿藻类中获取。一些绿色藻类的叶绿板可能从摄取的绿藻类中获取。一些绿色藻类的种类可以在同真菌的共生关系中找到,以形成地皮。一般而言,与结为伴的真菌种无法单独生存,而藻类物种往往在没有真菌的情况下生活在大自然中。有些绿藻类与岩石或树木的木质部分相连,而绿藻类成员也与(......)和(......)绿藻类形成共生关系。有些是挂着旗状的,并具有运动的优势。

    Green algae also have an alternation of generations . Haploid algae cells (containing only one copy of their DNA) can fuse with other haploid cells to form diploid zygotes . When filamentous algae such as Spirogyra species do this, they form bridges between the two haploid cells. This process is called conjugation .
    ::绿色藻类也由几代人轮流组成。 藻类藻类细胞(只含有其DNA的复制品)可以与其他手动细胞结合,形成低脂酶。 当丝状藻类,如Spirogyra物种这样做时,它们会形成两个手动细胞之间的桥梁。 这个过程被称为共生过程。

    Volvox
    ::Volvox 伏伏

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    A colonial protist, Volvox aureus. At left, you can see what makes up this ball-shaped group of organisms. The Chlamydomonas-like flagellated protists dot the outside of the sphere (1). The flagellates are connected to each other by strands of cytoplasm, (3). The smaller “daughter” colonies (2) inside the ball will eventually be released.

    Volvox, shown in Figure , is one of the best-known and most developed chlorophytes within a group that form spherical colonies. Each Volvox is made up of numerous cells that look similar to Chlamydomona . Between 1,000 to 3,000 or more flagellates are interconnected and arranged in a gel-filled sphere. Some suggest that Volvox colonies can contain up to 50,000 cells. The cells swim in a coordinated fashion, with distinct anterior and posterior ends. Since Volvox resembles a little planet, you could call them “north” and “south” poles. The cells have eyespots, which you can see in the diagram. The eyespots are more developed near the anterior, which enables the colony to swim towards light. Volvox is considered one of the first steps in the evolution of multicellular life. 
    ::图中显示的Volvox是形成球状阵列的一组中最有名、最发达的叶绿素之一。每个Volvox由许多与Chrimydomona相似的细胞组成。1,000至3,000个或更多的旗状动物相互连接,并排列在一个凝胶填充的球体中。有人表示,Volvox聚居地可以容纳多达50,000个细胞。细胞以协调的方式游动,有不同的前额和后端。由于Volvox与一个小行星相似,你可以称之为“北”和“南”极。细胞有眼波,你可以在图表中看到。眼波更接近前端,使聚居地能够游向光。Volvox被认为是多细胞生命进化过程中的第一个步骤之一。

    Phylum Rhodophyta (Red Algae)
    ::Phylum Rhodophysta(红色阿尔盖)

    The red algae are a large group (about 5,000–10,000 species) of mostly multicellular, marine algae, including many notable seaweeds. Most species of red algae secrete calcium carbonate and play a major role in building coral reefs. Most red algae are marine seaweeds, but there about 200 species that are found in freshwater.
    ::红藻类是一个大类(约5,000—10,000种),大部分是多细胞海洋藻类,包括许多显著的海藻。 大多数红藻类碳酸钙在建设珊瑚礁方面起着主要作用。 大多数红藻类是海洋海藻,但在淡水中发现了大约200种。

    In addition to chlorophyll, the chloroplasts of red algae contain pigments called phycobilins . Phycobilins are light-capturing molecules that are also found in cyanobacteria. Phycobilins are neither found in green algae nor in higher plants.
    ::除叶绿素外,红藻的叶板中含有被称为植物胆碱的色素,而青藻和高原植物中也都找不到绿藻和高原植物中含有轻活性分子。

    The phycobilins are most efficient at absorbing red, orange, yellow, and green light, wavelengths which are not well absorbed by chlorophyll a . Organisms growing in shallow waters tend to contain phycobilins that can capture yellow and red light, while those at greater depth often contain more of the phycobilins that can capture green light, which is relatively more abundant there. The presence of phycobilins allow red algae to live at depths that green algae cannot grow. 
    ::在吸收红、橙、黄、绿光和绿光方面,这些紫绿光和波长被叶绿素吸收效率最高。 在浅水中生长的有机体往往含有能够捕捉黄和红光的氟化物,而在更深水层的有机体则往往含有能够捕捉绿光的更多的氟化物,而绿光则比较丰富。 植物绿素的存在使得红藻得以生活在绿藻无法生长的深水中。

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    Close-up of a red alga (Laurencia), a marine seaweed from Hawaii.

    Phylum Euglenozoa (Euglenids)
    ::Phylum Euglenozoa (欧洲人)

    The euglenoids are one of the best-known groups of flagellates and are commonly found in freshwater, especially when it is rich in organic materials, with a few marine and endosymbiotic members. Many euglenids have chloroplasts and produce energy through photosynthesis, but others feed by phagocytosis or strictly by .
    ::黄素是最著名的旗状物群体之一,通常在淡水中找到,特别是当它含有丰富的有机材料时,它有几个海洋生物和内生生物成员。 许多黄素有氯白,通过光合作用产生能量,但其他则通过发孔病或严格由(或)通过(或)通过(或)通过(或)通过(或)通过(或)通过)光合作用(或(或))通过(或)通过(或)通过(或)通过(或)通过(或)通过(或))通过(或(或))通过(或)通过(或))通过(或)通过(或(或))通过(或)通过)通过(或(或))通过(或(或))通过(或)通过(或)通过(或)通过(或)通过(或)通过)通过(或(或)通过)通过(或(或(或))通过(或(或(或)))通过(或(或(或)))通过)通过(或(或(或(或))))通过)通过(或(或)通过(或)通过(或(或(或(或)))通过)通过)通过(或(或(或(或(或))通过)通过(或(或(或(或)))通过)通过(或(或(或)))通过)))通过)通过)获得)获得(或(或(或(或(或(或(或))通过))))))获得(或(或(或(或(或))通过))))获得(或(或(或(或(或(或(或))通过)))))获得(或(或(或(或(或))通过))))))获得(或(或(或(或(或(或(或)通过)))))))))))))获得(或(或(或(或(或(或(或(或(或(或(或(或(或(或(或(或(或(或(或(或(或)))))))))通过))))))))))通过(或(或(或(或(或(或)

    Most euglenids with chloroplasts also have a stigma or eyespot, which is a small splotch of red pigment on one side of the flagellar pocket, as shown in  Figure . This shades a collection of light sensitive crystals near the base of the leading flagellum , so the two together act as a light-detecting eye.
    ::如图所示,大多数含氯板的悬浮物也有污名或眼水壶,这是在旗形白板口袋的一面的小红色斑点。它遮蔽着在顶尖的底部附近收集的光敏感晶体,因此两者合在一起可以作为光探测的眼睛。

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    Members of the genus Euglena contain chloroplasts and have flagella. An eyespot guides them toward light.

    Phylum Heterokontophyta
    ::希伯利亚- 希德罗诺多霍植物学组织

    The heterokonts are a major line of eukaryotes that have more than 100,000 known species. Some estimate the heterokonts as having more than 100,000 species. The heterokonts range from the giant multicellular kelp to the unicellular diatoms, which are a main component of plankton. Kelp and diatoms are autotrophic heterokonts because they have chloroplasts. Other heterokonts such as oomycetes (water molds) do not have chloroplasts and are heterotrophic.
    ::外生虫是已知物种超过10万种的主要卵巢,一些人估计其种类超过10万种。外生虫从巨型多细胞海藻到作为浮游生物主要组成部分的单细胞二原子不等。海藻和二亚原子是自发养分异族,因为它们有叶片。其他的外生虫,如水藻,没有叶片,而且具有遗传学。

    Heterokont chloroplasts are surrounded by four membranes, a feature that distinguishes them from other algae. The chloroplasts characteristically contain chlorophyll a, chlorophyll c, and usually the accessory pigment fucoxanthin, giving them a golden-brown or brownish-green color.There are a great number of heterokonts, and their classification is still debated.
    ::有机叶板环绕着四个膜,与其他藻类有区别。 叶绿板通常含有叶绿素a, 叶绿素c, 通常还有附着色素fucoxanthin, 给它们一种金色或褐色绿色的颜色。 有很多异教徒, 他们的分类仍在争论之中 。

    Division Phaeophycea (Brown Algae)
    ::Phaeophypecea分部(青藻)

    The brown algae are a large group of mostly marine multicellular algae. This division includes many seaweeds of colder Northern Hemisphere waters. About 2,000 brown seaweed species exist. They play an important role in marine environments both as food and for the habitats they form. For instance, kelps ( Laminaria ) may reach 60 meters (almost 200 feet) in length and form large underwater forests which provides shelter for and other . Another example is Sargassum , which creates unique habitats in the waters of the Sargasso Sea, a large area in the center of the Atlantic Ocean. Many brown algae such as members of the order Fucales , are commonly found along rocky seashores. Some members of the division are used as food by humans.
    ::褐藻类主要是海洋多细胞藻类,这种区分包括北半球寒冷水域的许多海藻。大约2 000个褐藻种存在。它们在海洋环境中起着重要作用,既作为食物,又作为它们构成的生境。例如,海藻(Laminaria)长达60米(近200英尺),形成大型水下森林,为它们提供栖身之所。另一个例子是Sargasum,它在大西洋中部的一个大面积地区,即Sargasso海水域中创造了独特的生境。许多棕藻类,如Fuscales成员,通常在岩石海岸一带发现。有些海藻类成员被人类用作食物。

    Most brown algae contain the pigment fucoxanthin, which gives the protists their characteristic greenish-brown color.  Fucoxanthin is a carotenoid pigment found in the chloroplasts of brown algae and most other heterokonts. Fucoxanthin absorbs light mostly in the blue-green to yellow-green part of the visible spectrum.
    ::大部分褐藻含有色素fucoxanthin, 这使原生生物具有其特有的绿色褐色特征。 Fucoxanthin是棕藻和大多数其它异族植物的叶片中发现的焦素色素。 Fucoxanthin吸收的光大部分是可见光谱中的蓝绿色至黄绿色部分。

    Brown algae are unique among heterokonts in that they have truly differentiated tissues. For example, they have specialized structures for the and release of reproductive spores. The large plant-like part of the brown algae is called the thallus , and its cells are usually haploid. The thallus of a seaweed includes the holdfast (anchor), stipe (supports the blades), and the blades (for photosynthesis).
    ::棕藻在异族动物中是独一无二的,因为它们有真正的区别组织。 比如,它们有专门的结构来培养和释放生殖螺旋。 棕藻中的大型植物类部分被称为硫柳,其细胞通常是杂交的。 海藻的味道包括持片(锚 ) 、 刀片(支撑叶片)和刀片(用于光合作用 ) 。

    Life Cycle of a Brown Algae: Laminaria
    ::布朗藻类的生命周期:拉米尼亚

    The life cycles of the different types of brown algae vary widely. The alternation of generations life cycle of Laminaria , commonly known as kelp, is made up of the diploid generation (which is the large alga that is shown in  Figure ) and a haploid generation which is smaller. The diploid form produces both male and female spores by in cells called sporangia . Male spores grow into the male gametophytes and female zoospores develop into the female gametophyte. The gametophytes are very short, branched filaments that grow on the surface of underwater rocks. The male gametophyte produce motile and the female gametophyte produce eggs . The sperm are released into the water and are attracted to the female gametophyte by chemical signals secreted by the egg. The sperm then fuses with the egg, producing a zygote. The zygote then grows into the large sporophyte form of the algae, and the lifecycle begins over again.
    ::不同种类的棕藻的生命周期差异很大,拉米纳里亚(俗称海藻)代代相传的生命周期不同,由低潮一代(图中显示的大藻)和低潮一代组成,低潮一代形成,双潮形态在叫作草原的细胞中产生男性和女性的螺旋。雄性螺旋菌生长成雄性草药,雌性动物生长到雌性植物植物中。草叶植物非常短,在水下岩石表面生长的细细丝。雄性植物产生植物,雌性植物产卵。精子释放到水中,并被卵子秘密的化学信号吸引到雌性植物。精子随后与卵结合,产生酶。随后生长到藻类的大型孔植物形式,生命周期又重新开始。

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    Two fronds of forest kelp, Laminaria digitata , washed up on the shore. This is the sporophyte, or spore-forming generation of the alga. The total length of these fronds is about 2.4 meters (8 feet). Kelp are usually found in water just below the line of lowest tides, where they usually attach to rocks with their holdfasts. The holdfast is the two thin stalks to the right of the picture. The seaweed below the kelp is another type of brown algae called wrack.

    Class: Chrysophyceae (Golden Algae)
    ::类别: 青黄藻类(金藻类)

    The golden algae , or chrysophytes, are a large group of algae, found mostly in freshwater. Originally they were thought to include all forms of algae except the diatoms and multicellular brown algae, but since then they have been divided into several different groups based on pigmentation and . They are now usually restricted to a group of closely related forms that are distinguished by the structure of the flagella in motile cells. They come in a variety of body forms, one of which is shown in Figure . Most golden algae are unicellular flagellates, with either two visible flagella or just one. Other members are non-motile. Some golden algae have a shell that covers their cell, but most of these algae do not have a cell covering. 
    ::金藻类,即晶素藻类,是一大群藻类,主要在淡水中发现,最初认为它们包括所有种类的藻类,但有的只有二头藻和多细胞棕藻类,但从那时以来,它们根据色素和色素被分为若干不同的组别。现在它们通常局限于一个密切相关的组别,由浮质细胞中的旗星体结构所区分。它们以各种各样的身体形式出现,其中之一在图中显示。大多数金藻类都是单卵状的旗状物,有两种可见的旗状物,或只有一种。其他成员是非流动的。有些金藻的外壳覆盖了它们的细胞,但大多数这些藻类没有细胞覆盖。

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    A golden algae, of the class Chrysophyceae . Some of these protists have a shell, or loricae, and grow branched colonies.

    Class: Xanthophyceae
    ::类: Xanthophyceae

    Yellow-green algae , or xanthophytes, are an important group of heterokont algae. Most live in freshwater, but some are found in marine and soil habitats. They vary from single-celled flagellates to simple colonial and filamentous forms. Unlike other heterokonts, their chloroplasts do not contain fucoxanthin, which accounts for their lighter color. They appear to be the closest relatives of the brown algae.
    ::黄绿色藻类,即三氯酚藻类,是重要的异族藻类群。大部分生活在淡水中,但有些则存在于海洋和土壤生境中。它们从单细胞旗状物到简单的殖民和丝状形态各不相同。与其他异族动物不同,它们的叶质板并不含有fucoxanthin,因为其颜色较轻。它们似乎是棕色藻类的最亲近的缘故。

    Class: Bacillariophyceae (Diatoms)
    ::等级: 白血清(Diatoms)

    Diatoms are a major group of algae and are one of the most common types of phytoplankton. Most diatoms are unicellular, although some form chains or simple colonies. There are approximately 100,000 existing species of diatoms. Diatoms are a widespread group and can be found in oceans, freshwater, soil, and on damp surfaces. Living diatoms are often found clinging in great numbers to filamentous algae or forming gelatinous masses on various submerged plants. Although usually microscopic, some species of diatoms can reach up to 2 millimetres in length.
    ::迪亚托姆是主要藻类群,是最常见的浮游植物类型之一,大多数地蛋是非冰类的,尽管是某些形式的链条或简单的聚居区,约有10万种现有的地蛋。迪亚托姆是一个广泛的群体,可在海洋、淡水、土壤和潮湿表面发现。活的地蛋往往大量粘着着丝状藻或形成各种淹没植物的凝胶质。虽然通常有微小的表面,但有些地蛋可以达到2毫米长。

    Diatoms are important , especially in the oceans, where they are estimated to contribute about 45 percent of the oceans’ primary production. Recall that primary production is the production of from inorganic compounds and energy by producers. Photosynthesis is an example of primary production.
    ::对话非常重要,特别是在海洋中,据估计,它们贡献了海洋初级生产量的45%左右。 回顾初级生产是无机化合物和生产者能源的生产。 相片合成是初级生产的一个实例。

    A characteristic feature of diatom cells is that they are encased within a unique cell wall called a test . The test is made of silicone dioxide. The diatoms secrete the silicate material that makes up the test. Diatom tests show a wide diversity of shapes; they can be very ornate, as shown in  Figure . The tests usually have two asymmetrical sides that fit together, and they appear to be cut in half. This feature gives diatoms their name, which come from the Greek terms dia ("through") and temnein ("to cut"): “to cut in half.” Fossil evidence suggests that diatoms originated about 185 million years ago.
    ::diatom 细胞的一个特征是它们被嵌入一个叫做测试的单细胞壁内。 测试由硅酮二氧化物组成。 diatom 将构成测试的硅酸盐材料分解出来。 Diatom 测试显示各种形状的多样性; 如图所示, 它们可以是非常圆形的。 测试通常有两个对称的两面, 并且它们看起来被切成两半。 这个特征给出了diatom 的名称, 名字来自希腊语“ dia ” ( “ 通过 ) ) 和 temnein ( “ 切开 ” ) :“ 切开 ” :“ 切开 一半 ” 。 化石证据表明, diastoms 起源于1.85万年前。

    The tests of diatoms are found in many ocean sediments. The many layers of silicate tests allow scientists to analyze past marine environments by taking rock samples from below the ocean floors.
    ::在许多海洋沉积物中都发现了对二原子的试验,许多层的硅酸盐试验使科学家能够分析过去海洋环境,从洋底以下采集岩石样本。

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    Scanning electron micrographs (SEM) of diatoms show some of the many shapes of their tests. (A) Biddulphia reticulata. The whole shell or frustule of a centric diatom showing valves and girdle bands (size bar = 10 micrometers). (B) (size bar = 10 micrometersres). (C) (size bar = is 20 micrometres). (D) (size bar = 10 micrometres).

    Diatoms have yellowish-brown chloroplasts with four membranes which are typical of heterokonts. Their choroplasts also contain pigments such as fucoxanthin. Mature diatoms do not have flagella, and so they are non-motile. As their dense cell walls cause them to readily sink, they usually rely on mixing of the upper layers of the water by the wind to keep them suspended in sunlit surface waters. Some species can control their buoyancy with to keep them afloat.
    ::diatoms 具有黄褐色的叶板, 上面有四色色板, 它们是异质生物的典型特征。 它们的合花板也含有色素, 如fucoxanthin。 天然的diatoms没有旗子, 所以它们没有活动。 由于它们稠密的细胞壁导致它们容易沉没, 它们通常依靠风混合水的上层, 将它们悬浮在日光化的表面水中。 有些物种可以控制它们的浮浮性, 让他们保持浮浮。

    Division: Haptophyta
    ::分区:Haptophysta

    The haptophytes are a diverse group of unicellular algae. Their chloroplasts are pigmented similar to golden algae, but the structure of the rest of the cell is very different. The cells usually have two flagella of unequal length. They also have a unique called a haptonema , from which they get their name. The haptonema looks similar to a flagellum but differs in its internal structure and in its use.
    ::机能植物是一组不同的非冰藻类。它们的叶片与金藻类相似,但细胞其余部分的结构非常不同。这些细胞通常有两种长度不相等的旗子。它们还有一个独特的叫合金藻类,从中可以找到它们的名字。 月花与旗状藻相似,但内部结构及其使用却有所不同。

    The best-known haptophytes are coccolithophores, which have a skeleton of many limestone (calcite) plates called coccoliths . Coccolithophores are some of the most common marine phytoplankton, especially in the open ocean and are extremely common microfossils. Emiliania huxleyi , a coccolithophore, is shown in  Figure . 
    ::最著名的浮游植物是coccolitophites, 其骨骼由许多石灰石(石墨)板块组成,称为coccoliths,coccolitophyors是海洋浮游植物中最常见的部分,特别是在公海上,而且是极为常见的微生物。

    In areas where of coccolithophores bloom, the water can turn an opaque turquiose color. A bloom in the English Channel, off the coast of Cornwall, England, is shown in  Figure . Scientists estimate that coccolithophores such as Emiliania huxleyi dump more than 1.5 million tons (1.4 billion kilograms) of calcite a year, making them the leading limestone producers in the ocean. Other planktonic haptophytes can form toxic marine algal blooms and blooms that can produce unpleasant foam which often accumulates on beaches.
    ::科学家估计,如Emiliania huxleyi每年倾弃超过150万吨(140亿公斤)的石灰岩,使他们成为海洋中主要的石灰石生产国。 其他浮游植物可以形成有毒的海洋藻类花朵和开花,产生不愉快的泡沫,这些泡沫通常会聚集在海滩上。

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    Under certain conditions, large numbers of the protist Emiliania huxleyi can form massive blooms which can be detected by satellite remote sensing. What look like white clouds in the water are in fact the reflected light from the coccoliths of billions of the tiny algae floating in the water-column. On the right is a SEM of E. huxleyi. The bar in the image is 2µm long.

    Phylum Dinoflagellata (Dinoflagellates)
    ::Dinoflagellata (Dinoflagellates) (迪诺佛拉拉塔)

    The dinoflagella are a large group of flagellated protists. Most make up marine plankton, but they are common in fresh water habitats too. Their populations are distributed depending on temperature, salinity, or depth of the water. Dinoflagellates make up the largest group of algae aside from the diatoms. Most dinoflagellates are unicellular and have two flagella of different lengths. The beating flagella cause the cell to move about in a whirling motion, giving them their name. The Greek term dinos means “whirling.”
    ::地诺旗子是一大批旗状的先锋。 大部分由海洋浮游生物组成,但它们在淡水生境中也很常见。 它们的人口分布取决于温度、盐度或水深。 地诺旗子是除diatolom之外最大的一群藻类。 多数地诺旗子是非冰冻的,有两面不同长度的旗子。 击打的旗子使细胞以旋转的动作移动,给它们取名。 希腊的Dinos一词的意思是“ 挥霍 ” 。

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    A photosynthetic dinoflagellate, Ceratium hirundinella. Photosynthetic dinoflagellates are important producers in the ocean.

    About half of all dinoflagellates are photosynthetic, like the dinoflagellate in  Figure . Being primary producers make them an important part of the aquatic food chain. The chloroplasts in most photosynthetic dinoflagellates are bound by three membranes and contain chlorophylls a and c . They also have either the pigments peridinin or fucoxanthin, as well as other accessory pigments.
    ::大约一半的地诺旗舰是光合体,如图中的二硝旗旗。作为主要生产商,它们成为水生食物链的重要组成部分。 大多数光合旗旗舰中的叶片都由三颗膜捆绑,并含有叶绿素a和c。 它们还有色素或紫色(fucoxanthin),以及其他附属色素。

    Other dinoflagellates are heterotrophic; they are colorless predators of other protozoa. Parasitic dinoflagellates cause disease. If you keep aquarium fish as pets, you may be familiar with some parasitic dinoflagellates. They cause the tropical fish diseases “velvet” and “ick.”
    ::其它的二氧化花旗是异氧营养;它们是其他原生动物的无色掠食者。 寄生虫的二氧化花旗引起疾病。 如果你把水族馆鱼类作为宠物,你可能会熟悉一些寄生虫的二氧化花旗。 它们会导致热带鱼类疾病“天鹅绒 ” 和“生病 ” 。

    Dinoflagellates have a complex cell covering. In some organisms, the cell is covered by overlapping cellulose plates called thecae . These come in various shapes and arrangements, depending on the species of the dinoflagellate. Some dinoflagellates have a light-sensitive organelle such as an eyespot. Some species of dinoflagellates are bioluminescent. Bioluminescence is the production of light by a living organism. It results from a chemical reaction in which chemical energy is converted to light energy. Bluish flickers visible in ocean water at night often come from large populations (blooms) of bioluminescent dinoflagellates. They emit short flashes of light when disturbed. When populations of these dinoflagellates “bloom,” there can be more than a million cells per milliliter of seawater. Figure is an example of how a bloom of bioluminescent dinoflagellates can cause waves to glow at night.
    ::Dinofolellates 具有复杂的细胞覆盖。 在有些生物中, 细胞被称为cae 的重叠纤维素板覆盖。 这些细胞的形状和安排各不相同, 取决于 dinofollowellate 的种类。 一些dinofolellites 具有对光敏感的器官, 如眼睛罐等。 一些 dinofolellates 物种是生物发光的。 生物光是活生物体产生的光源。 生物能量转化为光能的化学反应的结果。 夜间在海水中可见的模糊闪烁器往往来自生物发光的 dinofolettes 的大型人群( 闪烁) 。 当这些 dinofolellates “ 闪烁” 的人群中, 每毫升海水中可能有超过100万个细胞。 图示生物发光的花旗能如何在夜间引起波浪。

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    Bioluminescent dinoflagellates, Lingulodinium polyedrum, lighting a breaking wave at night in La Jolla, California.The blue light is a result of a luminescent enzyme called luciferase. The dinoflagellates can become so numerous that the water takes on a muddy reddish color in daylight, which gives the phenomenon its name: "Red Tide". The bioluminescence is only visible at night.

    Some dinoflagellate species that bloom produce neurotoxins. These neurotoxins can kill fish and can build up in filter feeders such as oysters and clams. People are affected by the toxins when they eat the filter feeders or fish. This phenomenon is called a red tide (shown in Figure ) because of the color the bloom gives the water.
    ::这些神经毒素可以杀死鱼类,也可以在牡蛎和蛤类等过滤饲料中积聚。人们吃过滤饲料或鱼类时会受到毒素的影响。这种现象被称为红潮(如图所示),因为盛开给水的颜色。

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    Red Tide caused by dinoflagellates off the Scripps Institution of Oceanography Pier, La Jolla California. Red tides can occur naturally or as a result of fertilizer or other pollution that add excess nutrients to the water.

    The exact cause of such large blooms is not known. In some areas, algal blooms are a seasonal occurrence resulting from coastal upwelling, a natural result of the movement of certain ocean currents. Harmful algal blooms that occur near the coast can be caused by excess nutrients in the water. The growth of marine phytoplankton is generally limited by the availability of nitrates and phosphates in the water. However, these nutrients are abundant in agricultural run-off which can cause blooms. Some colorless dinoflagellates may also form toxic blooms. Not all dinoflagellate blooms are dangerous.
    ::在某些地区,藻类开花是沿海上涌造成的季节性现象,这是某些洋流移动的自然结果。沿海的有害藻类开花可能是由于水中营养过剩造成的。海洋浮游植物的生长一般受到水中硝酸盐和磷酸盐供应的限制。然而,这些养分充斥在农业径流中,可能导致开花。一些无色的金刚花也可能形成有毒的开花。并非所有的金刚花花花花都危险。

    Summary
    ::摘要

    • Many species of chlorophytes live most of their lives as microscopic single cells, while other species form colonies or long filaments. Like land plants, green algae contain both chlorophylls a and b and store food as starch in their plastids. They are found in all aquatic and wet or damp environments.
      ::许多叶绿素物种作为微型单细胞生活着大部分生命,而其他物种则形成聚变或长丝状物,像陆地植物一样,绿藻既含有叶绿素a和b,又将食物作为颗粒储存,它们存在于所有水生和湿湿或潮湿环境中。
    • Diatoms form hard shells, called tests, to protect themselves. The tests can be very ornate.
      ::直肠形成硬壳,叫做测试,以保护自己。这些测试非常圆形。
    • Some parasitic dinoflagellates cause tropical fish diseases such as “velvet” and “ick.” Other species may seasonally grow in large number (bloom) and produce toxins that harm marine life and humans that eat affected seafood.
      ::某些寄生虫的双星旗造成热带鱼类疾病,如“天鹅绒”和“生病 ” 。 其他物种可能季节性地大量生长(膨胀),并产生伤害海洋生物和食用影响海产食品的人类的毒素。
    • A colonial protist is made up of a group of unicellular protists that have joined together. Such protists do not have tissues or specialized cells. If the colonial protist were to be broken up into its individual cells, each cell could survive. However, a truly multicellular protist has some tissue differentiation, such as sporangia and a thallus. The individual cells would not survive if they were separated from each other.
      ::殖民先质主义者由一组结为一体的单细胞先质先质分子组成,这些先质分子没有组织或专门细胞,如果将殖民先质分子分裂为单细胞,每个细胞都可以生存下来。然而,真正的多细胞先质分子在组织上有一些差异,如骨折和胸肌。如果单独细胞相互分离,它们就无法生存。

    Review
    ::回顾

    1. What feature do diatoms have that other algae do not have?
      ::其他藻类没有的 Diatom 具有什么特征?
    2. How are diatom fossils useful to geologists?
      ::地蛋化石如何对地质学家有用?
    3. Identify three features of chlorophytes.
      ::查明叶绿素的三个特征。
    4. What is the importance of Volvox?
      ::Volvox的重要性是什么?
    5. What are some advantages that red algae gain from having phycobilins?
      ::红藻类有什么好处?
    6. What distinguishes heterokonts from other algae?
      ::异教徒和其他藻类有什么区别?