Protista

Protista adalah makhluk hidup bersel satu atau bersel banyak dan telah memiliki membran inti (selnya bersifat eukariotik). Umumnya, protista bersifat aerobic dan menggunakan mitokondria untuk respirasi. Pada kenyataannya, ada protista yang dapat berlaku sebagai produsen. Protista tersebut dapat melakukan fotosintesis (dapat membuat makanan sendiri). Nutrisi yang diperoleh dari fotosintesis protista tersebut dapat bersifat fototropik, heterotropik, atau keduanya. Protista memiliki flagella atau cilia dalam hidupnya dan dapat berkembang secara aseksual atau seksual. Pada kondisi yang kurang menguntungkan, protista dapat membentuk kistae. Secara taksonomis, protista dibagi menjadi tiga kelompok, yaitu protista yang menyerupai jamur, protista yang menyerupai tumbuhan (ganggang atau Algae), dan protista yang menyerupai hewan (Protozoa).

Protozoans are single celled eukaryotes found worldwide with rich biodiversity. The protozoan species live in different habitats as free living or parasite having different shapes and adapted for various physiological activities. These are microscopic unicellular eukaryotes that have a relatively complex internal structure and carry out complex metabolic activities within a cell by highly specialized subcellular organelles like pseudopodia, flagella and cilia. Initially protozoans were kept in phylum Protozoa under kingdom Animalia as per classification of Linnaeus but later placed under kingdom Protista from three to six kingdom systems. In present article, author attempted to discuss the position of protozoa from two to six kingdom system of biological classification and finally concluded that protozoans are now protists, and not the animals.

KOMPETENSI DASAR:
3.6 Mengelompokkan protista berdasarkan ciri-ciri umum kelas dan mengaitkan peranannya dalam kehidupan

INDIKATOR:
3.6.1 Mendeskripsikan ciri-ciri umum Protista berdasarkan pengamatan.
3.6.2 Mengenali protista berdasarkan ciri-ciri morpologinya.

FAKULTAS PENDIDIKAN DASAR DAN MENENGAH (FAPENDASMEN) PRODI PENDIDIKAN GURU SEKOLAH DASAR (SD) UNIVERSITAS MAJALENGKA (UNMA) 2015 A. TUJUAN Tujuan praktikum kali ini agar kita dapat :  Mengidentifikasi ciri protista berdasarkan kelasnya  Untuk mengetahui bentuk dan habitat protista B. LANDASAN TEORI Kingdom Protista merupakan kingdom yang mencangkup organisme Eukariot (intinya mempunyai selaput/membran inti) yang tidak termasuk ke dalam jamur, tumbuhan, dan hewan. Protista terdiri dari organisme tingkat rendah yang pada dasarnya memiliki kesamaan struktur yang sederhana walaupun daur hidup, organisasi sel, dan pembelahan selnya berbeda-beda.

Menghayati dan mengamalkan ajaran agama yang dianutnya. Menunjukkan perilaku jujur, disiplin, tanggung jawab, peduli (gotong royong, kerja sama, toleran, damai), santun, responsif, dan pro-aktif sebagai bagian dari solusi atas berbagai permasalahan dalam berinteraksi secara efektif dengan lingkungan sosial dan alam serta menempatkan diri sebagai cerminan bangsa dalam pergaulan dunia .

Climate warming and the poleward widening of the tropical belt have induced range shifts in a variety of marine and terrestrial organisms. Among the key taxa that are rapidly expanding their latitudinal range are symbiont-bearing foraminifera of the genus Amphistegina. Analyses of foraminiferal faunas from new sites in the western Ionian Sea (Ithaka and Lefkada Islands) show that amphisteginid foraminifera continue to expand their biogeographic range, rapidly outcompete all native species and represent the most abundant taxon at almost every site colonized. The introduction and range expansion of Amphistegina puts significant pressure on local species, affects foraminiferal diversity and decreases species richness of associated biotas. Native species richness is reduced at all sites invaded by amphisteginids and correlates with the degree of infestation. Amphisteginids invasions specifically impact those species that share a similar microhabitat and include other larger symbiont-bearing foraminifera and numerous trochospiral species. The impact of Amphistegina on native biotas gradually increases from the range expansion front towards those sites where invasions commenced decades ago. High abundances may result in prolific monocultures of Amphistegina that modify the composition of sedimentary substrates and ultimately trigger changes in ecosystem functioning. Assemblage structures and patterns observed at the expansion front in recent examples resemble amphisteginid invasions recorded in Miocene foraminiferal communities from the Vienna Basin and Poland, these latter being indicative of shifts in biogeographic ranges at that time. The assemblages thus preserve environmental information that is useful in paleoecologic and paleobiogeographic interpretations to evaluate the extent and magnitude of shifts along the front of expanding species ranges.

Naturalist Christian Gottfried Ehrenberg pioneered research on living and fossil infusoria (including protists and bacteria) since the 1830s by collecting samples from all over the world, thus describing numerous microbes and discussing their effects for the planet and for humankind. This article introduces Ehrenberg as a natural historian of microbes and situates his work in the nineteenth century life sciences with respect to debates about cell theory, evolution, and concepts of disease. I argue that in spite of occurring before these major conceptual innovations of the life sciences, Ehrenberg’s work on the diversity of microbes found in earth or air is more exciting than historiography has made it appear so far, especially in light of today’s ecological microbiology.

The genus Gibbocarina has been recently established and includes only two species (G. galeata and G. gracilis) characterized by presence of a hollow keel. Morphology and morphometry of Nebela penardiana from East Herzegovina were investigated based on 47 specimens and a new combination was proposed: Gibbocarina penardiana. In addition, morphological variability of a sympatric population of G. galeata was analyzed based on 121 specimens. It is possible to distinguish these species based on morphological and morphometric data. Morphometric analysis shows that shell width is one of the best discriminating characters (95–139 µm in G. galeata versus 64–77 µm in G. penardiana). The minimal variability was observed for shell length (5.17% in G. galeata and 4.44% in G. penardiana), while the maximal variability was recorded for area of the optical section (11.31% in G. galeata and 8.50% in G. penardiana).

The genus Quadrulella comprises most species of hyalosphenid testate amoebae with quadrangular shell plates. The taxonomic status of almost all species is questionable because they are poorly studied. Quadrulella symmetrica is the type species with cosmopolitan distribution. In this paper, morphological variability of Q. symmetrica based on two populations from the central part of the Balkan Peninsula is presented. Intermediate forms between Q. symmetrica s.s. and Q. madibai were registered; therefore, taxonomic status of these two recently delimited taxa is discussed. In one studied population, a specimen covered by mixed quadrangular and circular shell plates was observed. Recently, taxonomic status of Q. longicollis has been defined as questionable. Here are present morphological and morphometric data of Q. longicollis based on 130 examined specimens from Šargan Mountain (Serbia). The present study strongly supports the opinion that this taxon is a separate species within the genus Quadrulella.

Taxonomy of hyalosphenid testate amoebae at the species level is mainly based on the shape and size of their shells. In this paper, the morphometric data for Padaungiella lageniformis (member of the family Padaungiellidae), Nebela minor and Porosia bigibbosa (members of the family Hyalospheniidae s.s.) from the Velež Lake region (East Herzegovina) are presented. The analyzed population of P. lageniformis contains specimens with shell length between 83 and 112 µm, with the arithmetic mean of 99.07 µm. These data support synonymization of P. wailesi (shell length 75-100 µm) and P. lageniformis s.s. (shell length 100-160 µm). Recently, the wide taxonomic concept of N. tincta has been proposed based on molecular and morphological analyses conducted on a small number of specimens. This concept implies synonymization of N. minor with N. tincta, but morphometric analysis of N. minor presented here does not support the wide taxonomic concept of N. tincta. In addition, morphometric analysis of P. bigibbosa has shown that it is a much more diversified taxon than previously thought. These investigations have shown that further morphometric studies of hyalosphenid testate amoebae are necessary for the clarification of their taxonomic relations.

The genus Porosia includes two species characterized by presence of two large invaginated pores. These pores are connected by internal tube as in members of the genus Certesella. In this paper, morphological variability of P. bigibbosa (Penard, 1890) Jung, 1942 based on 175 specimens from East Herzegovina is presented. Shell length ranges from 136 to 178 µm (previously noted 128-177 µm), shell width – from 86 to 118 µm (previously noted 83-123 µm), aperture width – from 40 to 51 µm (previously noted 34-49 µm), aperture-pore distance – from 45 to 62 µm (previously noted 52-70 µm), pore-pore distance – from 48 to 80 µm (previously not measured), and area of the optical section – from 9063 to 15706 µm 2 (previously not measured). The minimal variability (4.5%) was observed for shell length, while maximal variability (9.01%) was recorded for the area of the optical section. Results of size frequency distribution analysis of shell length and shell width indicate that this population possesses continuous polymorphism.

This study aims to investigate the pre-service science teachers' perceptions of protists. Within this scope, case study design was conducted. The data was collected from purposively chosen 60 third-grade pre-service science teachers from a university in Kayseri, Turkey during the spring semester of 2018-2019. The drawing-writing technique was used for data collection in the study. In the drawing test pre-service teachers were asked to choose three examples for the protists and draw them on the paper given. Moreover, they were asked to write the common features of the protists. The participants' drawings and writings that reveal their conceptual structures regarding the protists were analyzed through content analysis method. The participants' drawings and writings were analyzed based on the rubrics and grouped based on their levels. The percentages of the agreement between two experts regarding the assessment of drawings and writings were measured as 0.92 and 0.90, respectively, indicating a high reliability. In addition, Chi-square test was applied to the data in order to see whether there is a significant relationship between drawing and writing levels of the pre-service teachers. According to the findings, 11.7% of the participants had no/ irrelevant drawings and writings, 83.4% of them had partially correct drawings, and 5% of them had comprehensive drawings regarding protists. While only one participant wrote all six features for protists, 86.6% of them had partially correct writings including one to five features for protists. The findings revealed that pre-service teachers' perceptions about the protists were identified as moderate, and there is a significant relationship between the pre-service teachers' drawing and writing levels of protists. According to the (7x7) crosstabulation table, students with a high level of writing also have a high level of drawing and vice versa.