Matric Notes Biology Class 10th Ch 17 Bio-Technology Short Questions
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Q1: Write about any four products developed through fermentation?
Ans: The process in which there is incomplete oxidation-reduction of glucose is called fermentation.
Fermentation products: Traditionally only food and beverages products were produced by fermentation but now many other products like industrial chemicals are also being produces. This can be categorized as:
b) industrial products.
Fermented foods: Fermentation often makes the food more nutritious, more digestible and tastier. It also tends to preserve the food, lowering the need for refrigeration. The following groups are included in fermented foods.
Cereal products: Bread is the commonest type of fermented cereal product. Wheat dough is fermented by S.cerevisiae along with some lactic acid bacteria.
Dairy products: Cheese and yogurt are important fermentation products.
Cheese formation: Cheese is formed when a milk protein is coagulated. This happens when the acid produced by lactic acid bacteria react with milk protein.
Yogurt formation: Yogurt is made from milk by different lactic acid bacteria.
Fruit and vegetable products: Fermentation is usually used, along with salt and acid to preserve pickle, fruits and vegetables.
Beverages products: Beer is produced from cereal grains which have been malted, dried and ground into fine powder. Fermentation of the powder is done by yeast. This process breaks the glucose present in powder into pyruvic acid and then into ethanol. Grapes can be directly fermented by yeast to wine.
Q2: Name any four microorganisms used in biotechnology. Also name the process in which they are used.
| Products | Microorganism used | Some uses |
|---|---|---|
| Formic acid | Aspergillus | Textile dying, leather treatment, electroplating, rubber manufacture |
| Ethanol | Saccharomyces | Used as solvent, production of vinegar, production of beverages. |
| Glycerol | Saccharomyces | Used as solvent, production of plastics, production of cosmetics, production of soaps, used in printing, used as sweetener |
| Acrylic Acid | Bacillus | Used in production of plastics. |
| - | - | - |
Q3: Why are vectors used in genetic engineering?
Ans: Vectors are used in genetic engineering. In molecular cloning, a vector is a DNA molecule used as a vehicle to artificially carry foreign genetic material into another cell, where it can be replicated and/or expressed (e.g.- plasmid, cosmid, Lambda phages). A vector containing foreign DNA is termed as recombinant DNA.
Reason: Genetic vectors are vehicles for delivering foreign DNA into recipient cells. Vectors can replicate autonomously and typically include features to facilitate the manipulation of DNA as well as a genetic marker for their selective recognition.
Example: The most common vectors are DNA plasmids, viruses and artificial chromosomes.
Q4: Write any five advantages of biotechnology in the field of agriculture.
Ans: Advantages in the field of agriculture: Biotechnology has also revolutionized research activities in the area of agriculture.
1. Vitamin A enriched rice: Genetically modified crops have enhanced nutritional value.
Example: Vitamin A enriched rice.
2. More tolerant: Genetically modified crops are more tolerant to stresses such as drought, cold, heat etc.
3. Resistance against herbicides: Herbicides resistance genes have been incorporated into many crops of soybean, corn, and cotton. Therefore, herbicides can be used around these plants to kill weeds without harming the crops.
4. Resistance against viruses: Virus resistance trait have been introduced into many crops, including squashes, tomatoes, potatoes, tobacco etc. These plants are not affected by viruses and survive viral attacks.
5. Resistance against insects: Widespread use of insecticides, fungicides and pesticides for crop production has damaging effects on environment. It is important to improve the control of pest by genetic mean. Genetic engineers have introduced pest resistance genes into several crops , including tomato and cotton. Such modified plants show resistance against pests.
Q5: How is yogurt produced through the use of biotechnology?
Ans: The bacteria convert the lactose (milk sugar) to lactic acid, which thickens the milk and gives it the tangy taste characteristic of yogurt. The yogurt is then cooled and can be flavoured with fruit, sugar, other sweeteners or flavourings. Stabilizers, such as gelatin, may also be added. Method of yogurt production: The main (starter) cultures in yogurt are Lactobacillus bulgaricus and Streptococcus thermophilus. The function of the starter cultures is to ferment lactose (milk sugar) to produce lactic acid. The increase in lactic acid decreases pH and causes the milk to clot, or form the soft gel that is characteristic of yogurt.
Q6: The following diagram shows how a gene is transferred to bacterial cell. Identify the structures labelled as 1 to 5?
Ans:
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