Two units in biology

Thesis (M.A.)--Boston University, 1945. This item was digitized by the Internet Archive

Ecology of the Plankton of Lakes Wapalanne and Ocquittunk in Sussex County, New Jersey

The diversity of planktonic organisms was studied for seven months in Lake Wapalanne and Lake Ocquittunk (Stokes State Forest), Sussex County, New Jersey. Relative abundance and species diversity were studied as well as water quality including parameters: temperature, pH, dissolved oxygen, conductivity and depth of lakes. The data of seasonal changes in abundance of organisms and water quality was compared between both lakes. Three stations were set up along the straight line on Lake Wapalanne, buoyed by diatometers, which were used for diatom collection. There were also three stations located along the sides of Lake Ocquittunk arbitrary picked. Plankton samples from both lakes were collected using eighty micron plankton net which was dragged behind a row boat from one station to the next on Lake Wapalanne and collected from the sides of Lake Ocquittunk. Furthermore, water quality data were collected at each station of both lakes. The results of my study support previous findings where species composition varied throughout the seasons specially, the abundance of cladocerans, dinoflagelates and volvocines occurred during the first period of the study (June), and copepods increased in relative abundance later in the year (August and September). Representatives of Monera, Protista, Rotifera, Cladocera, Copepoda, Ostracoda, Amphipoda, Decopoda and Insecta were found in both lakes, however their species evenness and diversity varies interchangeably throughout. When taking into consideration higher taxon data, I demonstrate that the similarities of organisms in both lakes are very high; around seventy five percent with the 0.18 stress level suggesting that both sites are similar. Comparing water quality data, they are very alike in both sites

Effects in mesocosms exposed to effluents from bleached hardwood kraft pulp mill

Julkaisu sisältää myös kaksi muuta artikkelia: Part I: Effects on survival, growth, parasites and physiological status in fish exposed in mesocosms to effluents from bleached hardwood pulp production Part II: Chemical characterization and effects in mesocosms of effluents from bleached hardwood kraft pulp productionSummary: Effects in mesocosms exposed to untreated and treated total mill effluents from production of bleached hardwood kraft pulp Yhteenveto: Orgaanisen aineen vaikutuksista, kulkeutumisesta ja muuntumisesta lehtipuumassan tuotannosta aiheutuvien kokonaisjätevesien altistamassa malliekosysteemiss

Extracellular matrix of the charophycean green algae

A comprehensive knowledge of cell wallstructure and function throughout the plant kingdom is essential to understanding cell wall evolution. The fundamental understanding of the charophycean green algal cell wall is broadening. The similarities and differences that exist between land plant and algal cell walls provide opportunities to understand plant evolution. A variety of polymers previously associated with higher plants were discovered in the charophycean green algae (CGA), including homogalacturonans, cross-linking glycans, arabinogalactan protein, β-glucans, and cellulose. The cellulose content of CGA cell walls ranged from 6% to 43%, with the higher valuescomparable to that found in the primary cell wall of land plants (20-30%). (1,3)β-glucans were found in the unicellular Chlorokybus atmophyticus, Penium margaritaceum, and Cosmarium turpini, the unbranched filamentous Klebsormidium flaccidum, and the multicellular Chara corallina. The discovery of homogalacturonan in Penium margaritaceum representsthe first confirmation of land plant-type pectinsin desmids and the second rigorous characterization of a pectin polymer from the charophycean algae. Homogalacturonan was also indicated from the basal species Chlorokybus atmophyticus and Klebsormidium flaccidum. There is evidence of branched pectins in Cosmarium turpini and linkage analysis suggests the presence of type I rhamnogalacturonan (RGI). Cross-linking β-glucans are associated with cellulose microfibrils during land plant cell growth, and were found in the cell wall of CGA. The evidence of mixed-linkage glucan (MLG) in the 11 charophytesis both suprising and significant given that MLG was once thought to be specific to some grasses. The organization and structure of Cosmarium turpini and Chara corallina MLG was found to be similar to that of Equisetumspp., whereas the basal species of the CGA, Chlorokybus atmophyticus and Klebsormidium flaccidum, have unique organization of alternating of 3- and 4-linkages. The significance of this result on the evolution of the MLG synthetic pathway has yet to be determined. The extracellular matrix (ECM) of Chlorokybus atmophyticus, Klebsormidium flaccidum, and Spirogyra spp. exhibits significant biochemical diversity, ranging from distinct “land plant” polymers to polysaccharides unique to these algae. The neutral sugar composition of Chlorokybus atmophyticus hot water extract and Spirogyra extracellular polymeric substance (EPS), combined with antibody labeling results, revealed the distinct possibility of an arabinogalactan protein in these organisms. Polysaccharide analysis of Zygnematales (desmid) EPS, indicated a probable range of different EPS backbones and substitution patterns upon the core portions of the molecules. Desmid EPS is predominately composed of a complex matrix of branched, uronic acid containing polysaccharides with ester sulfate substitutions and, as such, has an almost infinite capacity for various hydrogen bonding, hydrophobic interaction and ionic cross-bridging motifs, which characterize their unique function in biofilms. My observations support the hypothesis that members of the CGA represent the phylogenetic line that gave rise to vascular plants and that the primary cell wall of vascular plants many have evolved directly from structures typical of the cell wall of filamentous green algae found in the charophycean green algae