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Protist unicellular, or multicellular without specialized tissues

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Presentation on theme: "Protist unicellular, or multicellular without specialized tissues"— Presentation transcript:

1 Protist unicellular, or multicellular without specialized tissues
"plant-like"  "animal-like"  "fungus-like"

2 Algae simple, typically autotrophic organisms, ranging from unicellular to multicellular forms Most are photosynthetic like plants, but they lack the many distinct cell and organ types found in land plants All true algae have a nucleus enclosed within a membrane  (左)Diatom - 矽藻 (右)kelp-昆布

3 Classification Rhodophyta Heteromontophyta Chlorophyta Diatomaceae
Cyanophyte is a phylum of bacteria not Algae

4 Rhodophyta cells without flagella and centrioles
with phycobiliproteins as accessory pigments (giving them red color) sexual reproduction Most rhodophytes are marine, generally prefer clean, running water

5 Heteromontophyta contain the pigment fucoxanthin, which is responsible for the greenish-brown color sexual or asexual reproduction adapted to a wide variety of marine ecological niches including the rock pools, the whole intertidal zone and relatively deep near shore waters.

6 Chlorophyta most with two flagella per cell
almost all forms have chloroplasts contain chlorophylls a and b, giving them a bright green color (as well as the accessory pigments beta carotene and xanthophylls) green algae are eukaryotic organisms that follow a reproduction cycle called alternation of generations.

7 Alternation of generations

8 Diatomaceae most diatoms are unicellular
the most common types of phytoplankton diatom cell wall made of silica (hydrated silicon dioxide) widespread in the oceans, freshwater, soils and damp surfaces Their yellowish-brown chloroplasts are containing pigments such as the carotenoid fucoxanthin. asexual binary division

9 Protozoa

10 Protozoa are a diverse group of unicellular eukaryotic organisms, many of which are motile. Originally, protozoa had been defined as unicellular protists with animal-like behavior, e.g., movement. Protozoa were regarded as the partner group of protists to protophyta, which have plant-like behaviour, e.g., photosynthesis.

11 Classification Protozoa were previously often grouped in the kingdom of Protista, together with the plant- like algae and fungus-like slime molds. As a result of 21st-century systematics, protozoa, along with ciliates, mastigophorans, and apicomplexans, are arranged as animal-like protists. With the possible exception of Myxozoa, protozoa are not categorized as Metazoa.Protozoa are unicellular organisms and are often called the animal-like protists because they subsist entirely on other organisms for food. Most protozoa can move about on their own.Amoebas, paramecia, and trypanosomes are all examples of animal-like protists.

12 characteristics Protozoa commonly range from 10 to 52 micrometers, but can grow as large as 1 mm, and are seen easily by microscope. They were considered formerly to be part of the protista family. Protozoa exist throughout aqueous environments and soil, occupying a range of trophic levels.

13 Ecological role As components of the micro- and meiofauna, protozoa are an important food source for microinvertebrates. Thus, the ecological role of protozoa in the transfer of bacterial and algal production to successive trophic levels is important. As predators, they prey upon unicellular or filamentous algae, bacteria, and microfungi. Protozoa are both herbivores and consumers in the decomposer link of the food chain. They also control bacteria populations and biomass to some extent. Protozoa such as the malaria parasites (Plasmodium spp.),trypanosomes and leishmania, are also important disease causing agents in humans.

14 Motility and disgestion
Tulodens are 2 of the slow-moving form of protozoa. They move around with whip-like tails called flagella, hair-like structures called cilia, or foot-like structures calledpseudopodia. Others do not move at all. Protozoa may absorb food via their cell membranes, some, e.g., amoebas, surround food and engulf it, and yet others have openings or "mouth pores" into which they sweep food,and that engulfing of food is said to be phagocytosis. All protozoa digest their food in stomach-like compartments called vacuoles.

15 paramoecium

16

17 原生菌物 以分解食物獲得能量 演化為菌物界

18 吞噬有機物或分泌酵素,分解並吸收有機分子的異 營營養方式。
黏菌 (slime molds) 和水黴菌 (water molds),他 們的外表特徵與真菌界的成員相似。

19 原生菌類---黏菌 slime molds 有細胞壁,無葉綠體,以分解食 物獲得養分,是分解者;

20 黏菌又分為 --原生質體黏菌 (plasmodial slime molds) --細胞性黏菌(cellular slime molds)

21

22 原生菌類---水黴菌 water molds
水黴又分為 --單鞭毛可動細胞 (uniflagellate motile cells) --雙鞭毛可動細胞 (biflagellate motile cells) 。

23 原生菌類---水黴菌 water molds
生長於淡水中 是重要的分解者

24 他們與真菌界的成員的關係並不密切。 具 Zoospores,具鞭毛; 行變形蟲運動 ; 水黴會儲藏一種碳水化合物--mycolaminarin


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