Tài liệu miễn phí Sinh học
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Bài tập trắc nghiệm môn Sinh học lớp 12
Mời các em cùng tham khảo Bài tập trắc nghiệm môn Sinh học lớp 12 sau đây để có thêm tài liệu ôn tập, luyện tập nhằm nắm vững được những kiến thức, kĩ năng cơ bản, đồng thời vận dụng kiến thức để giải các bài tập một cách thuận lợi. Chúc các em học tập tốt và đạt kết quả cao.
4/11/2023 1:17:59 PM +00:00
A review of microalgae harvesting technology for biofuel production
Microalgae are receiving increasing attention worldwide as an alternative and renewable source for energy production. Through various conversion processes, microalgae can be used to produce many different kinds of biofuel, which include biodiesel, bio-syngas, bio-oil, bio-ethanol, and bio-hydrogen.
4/11/2023 1:12:29 PM +00:00
Khảo sát một số môi trường để sản xuất cellulose vi khuẩn từ Acetobacter xylinum
Cellulose vi khuẩn hay còn gọi là bacterial cellulose là một loại polime được tổng hợp bởi vi khuẩn Acetobacter xylinum. Bài viết trình bày việc khảo sát một số môi trường để sản xuất cellulose vi khuẩn từ Acetobacter xylinum.
4/11/2023 12:50:11 PM +00:00
Actinomycin D, Actinomycin x2, hai chất kháng sinh được phân lập dịch lên men streptomyces 21.123
Streptomyces 21.123 là chủng Streptomyces sinh tổng hợp kháng sinh được chúng tôi phân lập từ mẫu đất miền Bắc Việt Nam. Từ dịch lọc dịch lên men của chủng xạ khuẩn này, hỗn hợp kháng sinh được chiết tách tốt sang pha ethyl acetat ở pH 7,0. Sắc ký lớp mỏng cho thấy có ít nhất 4 thành phần trong trong hỗn hợp kháng sinh này.
4/11/2023 10:05:51 AM +00:00
Nghiên cứu, đánh giá đặc tính và ứng dụng trong làm sạch của Eco-enzyme từ vỏ quả họ citrus
Nghiên cứu Nghiên cứu, đánh giá đặc tính và ứng dụng trong làm sạch của Eco-enzyme từ vỏ quả họ citrus phân tích các đặc điểm của vỏ quả họ citrus (chi cam chanh) và quá trình điều chế Eco-enzyme, đánh giá sự biến đổi và ứng dụng cơ bản của loại Eco-enzyme này. Mời các bạn cùng tham khảo chi tiết nội dung!
4/11/2023 8:04:57 AM +00:00
Hydrolysis conditions of black bean and brown rice and application of the hydrolysate in trial production of plant-based milk
The main objective of the study Hydrolysis conditions of black bean and brown rice and application of the hydrolysate in trial production of plant-based milk was to evaluate the physicochemical and antioxidative properties of brown rice and black bean extracts treated with different enzymes such as Bialfa-T, Glucozyme 2x, Bialfa-T-Glucozyme 2x, Biase, Biomatasa-L andBiase-Biomatasa-L.
4/11/2023 8:03:40 AM +00:00
Evaluating the diversity of native ornamental fishes in Dong Nai biosphere reserve, Dong Nai province, Vietnam
The study Evaluating the diversity of native ornamental fishes in Dong Nai biosphere reserve, Dong Nai province, Vietnam was conducted from May 2019 to December 2020 to investigate the diversity of native ornamental fishes in Dong Nai Biosphere Reserve (DNBR). The study identified 116 fish species belonging to 11 orders and 28 families in the water bodies of the DNBR.
4/11/2023 8:03:27 AM +00:00
Morphological and molecular characterization of plant growth promoting salt-tolerant bacteria associated with halophytes in the Southeast seaside of Vietnam
In the study Morphological and molecular characterization of plant growth promoting salt-tolerant bacteria associated with halophytes in the Southeast seaside of Vietnam, halotolerant bacteria were isolated from soil and root samples of Rhizophora apiculate (R. apiculate), Avicennia officinalis (A. officinalis), Thespesia populnea (T. populnea), Acanthus ilicifolius (A. ilicifolius) and Trichophorum cespitosum (T. cespitosum), five native halophytes of southeast seaside of Vietnam.
4/11/2023 8:03:13 AM +00:00
The effects of growing media on growth and seedling quality of root cutting of Cyclea barbata Miers at nursery stage
The study The effects of growing media on growth and seedling quality of root cutting of Cyclea barbata Miers at nursery stage was conducted to evaluate the effects of different types of growing media on growth, seedling quality of root cutting of Cyclea barbata and financial efficiency at the nursery stage.
4/11/2023 8:03:06 AM +00:00
Isolation and characterization of antibacterial compounds from Euphorbia tirucalli against Xanthomonas axonopodis pv. citri
The study Isolation and characterization of antibacterial compounds from Euphorbia tirucalli against Xanthomonas axonopodis pv. citri focused on the comparison of the extraction yield and antibacterial properties of Euphorbia tirucalli against X. axonopodis pv. citri, phytochemical screening, quantification of phenolic and flavonoid contents of the fraction extract.
4/11/2023 8:03:00 AM +00:00
Phân lập, tuyển chọn các dòng vi khuẩn sinh carotenoid từ môi trường biển và xác định điều kiện ly trích sắc tố
Nghiên cứu Phân lập, tuyển chọn các dòng vi khuẩn sinh carotenoid từ môi trường biển và xác định điều kiện ly trích sắc tố nhằm hướng tới phát triển các sản phẩm carotenoid từ vi sinh vật, 14 chủng vi khuẩn sinh sắc tố vàng, đỏ và cam đã được phân lập từ 25 mẫu nước biển thu tập tại các vùng biển khác nhau. Mời các bạn cùng tham khảo chi tiết!
4/11/2023 8:02:41 AM +00:00
Sự đề kháng kháng sinh của vi khuẩn Escherichia coli phân lập từ tôm thẻ chân trắng (Litopenaeus vannamei) thương mại tại chợ đầu mối nông sản Bình Điền
Nghiên cứu Sự đề kháng kháng sinh của vi khuẩn Escherichia coli phân lập từ tôm thẻ chân trắng (Litopenaeus vannamei) thương mại tại chợ đầu mối nông sản Bình Điền nhằm đánh giá tỷ lệ kháng kháng sinh, đa kháng kháng sinh của 60 chủng E. coli phân lập từ tôm thẻ chân trắng (Litopenaeus vannamei) thương mại tại chợ đầu mối nông sản Bình Điền, TP.HCM. Mời các bạn cùng tham khảo chi tiết!
4/11/2023 8:02:34 AM +00:00
Ảnh hưởng của lipoprotein tỷ trọng thấp chiết xuất từ lòng đỏ trứng gà trong bảo quản lạnh (4°C) tinh dịch chó
Mục tiêu của nghiên cứu Ảnh hưởng của lipoprotein tỷ trọng thấp chiết xuất từ lòng đỏ trứng gà trong bảo quản lạnh (4°C) tinh dịch chó nhằm đánh giá tác động của LDL trong bảo quản lạnh tinh dịch chó. Kết quả được đánh giá qua các chỉ tiêu gồm thời gian bảo quản, hoạt lực, sức sống tuyệt đối và tính nguyên vẹn của màng acrosome tại các mức hoạt lực 0,9; 0,5 và 0,3. Mời các bạn cùng tham khảo chi tiết!
4/11/2023 8:02:28 AM +00:00
Starch recovery from turmeric powder (Curcuma longa) after ethanol curcumin extraction in comparison to the conventional method
The study Starch recovery from turmeric powder (Curcuma longa) after ethanol curcumin extraction in comparison to the conventional method aimed to recover starch from the waste generated from the curcumin extraction by using ethanol. The physicochemical properties of the isolated starch such as microscopic morphology, Fourier transform infrared spectroscopy, X-ray diffraction, total starch, iodine binding capacity of starch, curcumin content determined by highperformance liquid chromatography were compared to that of starch obtained from the conventional method of extraction from the fresh rhizome.
4/11/2023 8:02:15 AM +00:00
Influence of spray-drying conditions on the physicochemical properties of red-fleshed dragon fruit (Hylocereus polyrhizus) powder made from peel and flesh
The present study Influence of spray-drying conditions on the physicochemical properties of red-fleshed dragon fruit (Hylocereus polyrhizus) powder made from peel and flesh focused on the effects of spray-drying conditions such as coating material concentration and spray-drying temperature on the physicochemical characteristics of red-fleshed dragon fruit powder made from peel and flesh.
4/11/2023 8:02:06 AM +00:00
Accumulation and distribution of lead (Pb) in different tissues of Lucky bamboo plants (Dracaena sanderiana)
The study Accumulation and distribution of lead (Pb) in different tissues of Lucky bamboo plants (Dracaena sanderiana) has been conducted to determine the accumulation and distribution of lead in Dracaena sanderiana plants as well as the impact of Pb on changes in the anatomy structure of those tissues.
4/11/2023 8:01:59 AM +00:00
Genetic relationship analysis of Dendrobium anosmum Lindl. var. semialba based on the chloroplast matK and rbcL genes
In the study Genetic relationship analysis of Dendrobium anosmum Lindl. var. semialba based on the chloroplast matK and rbcL genes, the genetic relationship of Dendrobium anosmum Lindl. var. semialba species was determined based on the analysis of chloroplast matK, rbcL gene sequences. The matK and rbcL genes of twelve species were amplified and their DNA sequenced.chloroplast matK and rbcL genes
4/11/2023 8:01:53 AM +00:00
Quantities and antibiotic resistance of microorganisms in some microbial products for animals in Vietnam
The aims of the study Quantities and antibiotic resistance of microorganisms in some microbial products for animals in Vietnam were to look into the quantities of live beneficial microorganisms and antibiotic resistance of bacterial strains in several probiotic products used for food animals in the market.
4/11/2023 8:01:39 AM +00:00
Genetic analysis of African swine fever virus based on major genes encoding p72, p54 and p30
The study Genetic analysis of African swine fever virus based on major genes encoding p72, p54 and p30 was set out to characterize African swine fever virus genotypes from 20 farms in 10 provinces, which occurred ASF outbreaks in 2019 and 2020. The results are expected to contribute sequence data for molecular epidemiology studies and provide further understanding of ASF disease patterns in Southern Vietnam.
4/11/2023 8:01:33 AM +00:00
Relationship between the ratio of villous height:crypt depth and gut bacteria counts as well production parameters in broiler chickens
The objective of the study Relationship between the ratio of villous height:crypt depth and gut bacteria counts as well production parameters in broiler chickens was to assess the relationship between V:C ratio, gut bacteria counts and production parameters in broiler chickens.
4/11/2023 8:01:20 AM +00:00
Effects of film coating materials on the quality of postharvest ‘Sanh’ orange fruits (Citrus nobilis var. Typica) during storage
In the study Effects of film coating materials on the quality of postharvest ‘Sanh’ orange fruits (Citrus nobilis var. Typica) during storage, the oranges were stored at room temperature (30 ± 2°C) with five coating materials: polyethylene (PE), and polypropylene (PP) bags, polyvinyl chloride (PVC) film, Citra Shine preservatives and 1% chitosan and the control were used.
4/11/2023 8:00:52 AM +00:00
Factors affecting betacyanin stability in juice of LD5 Red-fleshed dragon fruit (Hylocereus polyrhizus)
In the study Factors affecting betacyanin stability in juice of LD5 Red-fleshed dragon fruit (Hylocereus polyrhizus), the processing factors possibly influencing the betacyanin stability in the red-fleshed dragon fruit juice were in turn investigated.
4/11/2023 8:00:45 AM +00:00
Total phenolic content and antioxidant activity of sesame cake aqueous extracts
The objective of the study Total phenolic content and antioxidant activity of sesame cake aqueous extracts was to investigate the efficiency of phenolic extraction and antioxidant activity from sesame cake using water extraction method and to evaluate the possibility of employing microwave irradiation to improve the extraction yield.
4/11/2023 8:00:38 AM +00:00
Seroprevalence of serotype O of foot-and-mouth disease virus in vaccinated pigs and cattle in Ho Chi Minh City
The aim of the study Seroprevalence of serotype O of foot-and-mouth disease virus in vaccinated pigs and cattle in Ho Chi Minh City was to assess the seroprevalence against serotype O FMD (foot and mouth disease) virus in vaccinated pigs and cattle in Ho Chi Minh City, as a basis to serve the prevention of FMD epidemics in these animals.
4/11/2023 8:00:31 AM +00:00
Optimization of total phenolic extraction of Chromolaena odorata leaf for antifungal activity against plant pathogens
In the study Optimization of total phenolic extraction of Chromolaena odorata leaf for antifungal activity against plant pathogens, microwave-assisted extraction (MAE) variables were optimized for the extraction of the phenolic compounds from Chromolaena odorata (C. odorata) by using a central composite design (CCD) of response surface methodology (RSM).
4/11/2023 8:00:25 AM +00:00
Effects of different extraction methods on the recovery yield of bixin from annatto seeds (Bixa orellana L.)
The extraction yield of bixin from annatto seeds using acetone, soybean oil and sodium hydroxide solution with different extraction conditions were investigated in the study Effects of different extraction methods on the recovery yield of bixin from annatto seeds (Bixa orellana L.).
4/11/2023 8:00:11 AM +00:00
Spray-drying microencapsulation of β-carotene by polysaccharide from yeast cell walls
Objective of the study Spray-drying microencapsulation of β-carotene by polysaccharide from yeast cell walls was to investigate the effects of PS concentration (20, 30, 40 and 50%) compared to MD, high pressure homogenization time (5, 10, 15, 20 min) and inlet air temperature of spray drying (130, 140, 150, 160oC) on microencapsulation yield (MEY), microencapsulation efficiency (MEE), moisture content (MC) and antioxidant capacity.
4/11/2023 7:59:58 AM +00:00
Production of seaweed snack from pangasius (Pangasius hypophthalmus) fillet by-products
In the study Production of seaweed snack from pangasius (Pangasius hypophthalmus) fillet by-products, the effects of seaweed ratio, seasoning ratio, drying and frying conditions on sensory, texture, water holding capacity and moisture of product were investigated to find the best quality of the product.
4/11/2023 7:59:51 AM +00:00
Breeding new F1 hybrids cucumber for the Southeastern market in Vietnam
The objective of the study Breeding new F1 hybrids cucumber for the Southeastern market in Vietnam was to create new F1 cucumber varieties that would meet the demands of the regional market, in term of higher yield and reasonable cost.
4/11/2023 7:59:38 AM +00:00
Effects of drying methods on color retention and chlorophyll of celery (Apium graveolens L.), spinach (Spinacia oleracea L.), Malabar spinach (Basella alba L.)
The study Effects of drying methods on color retention and chlorophyll of celery (Apium graveolens L.), spinach (Spinacia oleracea L.), Malabar spinach (Basella alba L.) aimed to evaluate the effects of three distinguish drying methods as hot-air drying, foam-mat drying and microwave drying on the color retention and chlorophyll of green vegetables powder.
4/11/2023 7:59:32 AM +00:00