Enhancing Academic Achievement And Retention In Senior Secondary School Chemistry Through Discussion And Lecture Methods: A Case Study Of Some Selected Secondary Schools In Gboko, Benue State, Nigeria

The present study was initiated to determine how academic achievement and retention in chemistry is enhanced using the two instructional methods among SSII students and ascertained the differential performance of male and female students in chemistry with a view of improving student performance in chemistry. The study adopted a non-equivalent pretest, posttest control quasi-experimental design. A total of one hundred and eighteen senior secondary school II students in intact classes were chosen from three schools in Gboko Local Government Area of Benue State using purposive random sampling. The ages of the students ranged between 16-17 years. Data were collected using a 30- item multiple choice Chemistry Achievement Test (CAT), in organic chemistry. Students were assigned to a treatment and a control group. Three hypotheses were generated and tested which were tested at 0.05  level of significance. The data obtained were analyzed using descriptive statistics, t-test, spearman’s correlation coefficient and analysis of variance (ANOVA). There was significant difference in students performance when discussion and lecture strategies were used to teach chemistry (Fcal = 4.65  > Fcrit­ = 3.85  at P < 0.05). There was significant difference in the retention ability of students exposed to discussion and   lecture  method ( rcal = 0.9786 > 0.2353 at P < 0.05). There was   significant difference in the performance of male and female students in the two groups (tcal =  3.621 > tcrit = 2.000  at P < 0.05). The overall results showed that discussion instructional strategy significantly improved students’ performance in chemistry better than the lecture instructional strategy. The study concluded that discussion enhanced better achievement and productivity than the lecture method. It was recommended that discussion method should be use to teach organic chemistry in Nigerian Senior Secondary Schools. Keywords: discussion method, organic chemistry, lecture method, achievemen

Purification of Chromate(VI) Reductase from Lichen photobiont, Trebouxia erici and its Effect on Wastewaters.

Chromate (VI) reductase (CR) was isolated and purified from soluble extracts obtained from lichen photobiont, Trebouxia erici by salt gradient and sequential chromatographic methods. The soluble extract was fractionated by ammonium sulphate precipitation, dialysed and applied onto CM-Sephadex ion-exchange column. The active fractions were pooled and chromatographed on a SephadexG-75 column .Electrophoresis on SDS-PAGE analysis of the partially purified chromate(VI) reductase revealed two bands with  molecular weights of 39 kDa and 63 kDa . The enzyme had maximum activity at pH 6 and an optimum temperature of 40oC. The enzyme was stable between pH 4 and 7. Double reciprocal plots of initial velocity data, using NADH as substrate, gave a KM value of 118 μM and Vmax of 0.173 μmol/min/mg respectively . Studies on the effect of chromium reductase on synthetic wastewater shows that chromate(VI) reductase (CR) was effective in the reduction of over 65% of Cr (VI) to Cr (III) in 4h. The bioremediation potential of chromate(VI) by lichen was discussed. Keywords: Chromate(VI) reductase, purification, bioremediation, wastewater

The Effects of Two Teachers’ Instructional Methods on Students’ Learning Outcomes in Chemistry in Selected Senior Secondary School in Kaduna Metropolis, Nigeria

The study investigated the effect of teachers’ instructional methods on students learning outcomes in selected senior secondary school in Kaduna, Nigeria   Two instructional methods (Demonstration and Lecture) were used on target population of one thousand nine  hundred and eleven (1,911) senior secondary  (S.S. II) Science Students. The sample consist  of 100 Students  randomly drawn from two co-educational senior secondary schools within Kaduna North LGA. The students were divided in to two groups: The experimental group and the control group of 50 students each based on a categorization test to ascertain the equivalence of the group. The pretest-posttest quasi-experimental control group design was adapted. The students in the experimental group were exposed to Demonstration Method, while those in the Control group were exposed to the lecture instructional strategy for a period of three weeks. The  instrument  developed and validated for data collection was Chemical Bonding Performance Test (CBPT). Four research questions were stated and four null hypotheses were tested. The data collected  were analyzed using mean, standard deviation, t-test and ANOVA at 0.05 level of significance. The major findings from the study shows that there is significant difference in  learning outcome  on students exposed to demonstration and lecture strategies used to teach chemistry (tcal = 0.774 >tcrit = 0.443 and Fcal = 0.771 > Fcrit = 0.710 at P<0.05) and there is no significant difference in the academic performance of both male and female students exposed to demonstration instruction in teaching chemistry (tcal = 0.177 < tcrit = 0.861 and Fcal = 0.728 < Fcrit = 0.781 at P<0.05) . Findings from present study suggest that Chemistry teachers should incorporate demonstration method for teaching at senior secondary school level so as to enhance academic performance and also Curriculum planners should recommend and ensure demonstration method is used  for teaching chemistry at senior secondary school among others. Keywords: Chemistry, learning outcome, gender, demonstration and lecture instructional strategie

In vitro Inhibitory Studies and Effect of Selected Plant Extracts and Cations on Elastase (EC 3.4.21.11) Activity produced by Aspergillus niger and Aspergillus flavus

Elastase is a member of the serine protease enzyme family that hydrolytically degrades elastin, a connective tissue component leading to aging and wrinkling of the skin. In this report, we investigated the in-vitro inhibitory effects of some cations and n-hexane extract of Hibiscus cannabinus, Vernonia amygdalina, Murraya koenigii, and Telfairia occidentalis on the activity of Elastase isolated from Aspergillus flavus and Aspergillus niger. Elastase was extracted, isolated and partially purified from Aspergillus flavus and Aspergillus niger. The data obtained in this study demonstrated that the activity of elastase in Aspergillus flavus was higher compared to that of Aspergillus niger after salting out. The elastase inhibition activities of Hibiscus cannabinus, Vernonia amygdalina, Murraya koenigii, and Telfairia occidentalis reveal that the leaf extract from Murraya koenigii, in Aspergillus flavus had more significant inhibition was obtained compared to that of Aspergillus niger, with inhibitory effect from 40µg/ml. While that of Hibiscus cannabinus showed similar inhibition characteristics to Murraya koenigii. Both Hibiscus cannabinus and Vernonia amygdalina had an effect at 80µg/ml; all the extracts appeared to have more effects on the enzyme obtained from Aspergillus flavus than from the Aspergillus niger. The potential of exploring these plant extract as an anti-aging recipe was discussed. Keywords: Inhibitory studies, Elastase, Aspergillus flavus, Aspergillus niger, Hibiscus cannabinus, Vernonia amygdalina, Murraya koenigii, and Telfairia occidentali

Anti-diabetic Properties and Phytochemical Studies of Ethanolic Leaf Extracts of Murraya Koenigii and Telfairia Occidentalis on Alloxan-Induced Diabetic Albino Rats

The antidiabetic properties and phytochemical studies of fractions of ethanolic leaf extract (400mg/Kgb.w) of Murraya koenigii (M. koenigii) and Telfairia occidentalis (T. occidentalis) was carried out on alloxan induced diabetic albino rats. Four and three fractions were obtained from M. koenigii and T. occidentalis extract respectively using column chromatography. Phytochemical screening of each fraction, indicate the presence of saponins, alkaloids, flavonoids, tannins and cardiac glycosides. The alloxan induced diabetic rats were treated with fractions of the extract, and fraction 1 and 2 of M. koenigii and T. occidentalis respectively which decreased blood glucose level significantly (p<0.05) by 72% and 78% respectively when compared within the group and showed no significant different when compared to normal control group. All treated groups showed no significant changes (p<0.05) in their body weight with the exception of groups treated with 3rd fractions of M. koenigii and T. occidentalis. Spectroscopic studies indicated the presence of  biological active compound in the 1st, 2nd and 3rd fractions of M. koenigii that absorbed maximally at 200-350nm and the 4th fraction showed absorption maximally at 270nm and 290nm; while the 1st fraction of T. occidentalis absorbed maximally at 320nm, 2nd fraction at 290nm and 340nm and 3rd fraction at 320nm and 350nm.  The 1st fraction of M. koenigii and 2nd fraction of T. occidentalis showed high antidiabetic properties at  λ max 320nm and 340nm respectively. Our findings certainly suggest among others the use of plants as a source of  potentially useful antidiabetic therapy for diabetics. Keywords: Diabetes mellitus, Antidiabetic components, Telfairia occidentalis and Murraya koenigi