Biology For Class X - Chapter No. 8 - Biotechnology - Short Question Answers

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CHAPTER 8: BIOTECHNOLOGY
B. Short Questions Answers

Q.No.1: What kind of enzymes allows scientists to cut and paste pieces of DNA together to form recombinant DNA?
Ans: The following are the enzymes which allow scientists to cut and paste pieces of DNA together to form recombinant DNA:

1. Restriction enzymes:
   Restriction enzymes are DNA-cutting enzymes which occur naturally. They are used by bacteria as a defense to cut up DNA from Viruses. Scientists used hundreds of these restriction enzymes to snip specific gene from DNA.
   
   
2. DNA Ligase:
   DNA ligase is a DNA-joining enzyme. This enzyme is used to repair broken DNA. If two pieces of DNA have matching ends, ligase can link them to form a single, unbroken molecule of DNA. It can also be used to paste new genes into DNA.

Q.No.2: Explain how making human tissue plasminogen activator (t-PA) in Chinese hamster ovary (CHO) cells is an example of genetic engineering.
Ans: Plasminogen Activator (t-PA):
To produce t-PA for therapeutic use, researchers genetically engineered mammalian cell of Chinese hamster ovary cells. The ovary cells are grown into culture and given a segment of human DNA with the genetic instructions to make the human t-PA enzyme.
Chinese Hamster Ovary (CHO) cells:
are the most commonly used host system for the expression of high quality recombinant proteins. However, the development of stable, high-yielding CHO cell lines is a major bottleneck in the industrial manufacturing of therapeutic proteins. Therefore, different strategies such as the generation of more efficient expression vectors and establishment of genetically engineered host cells have been employed to increase the efficiency of cell line development. In order to examine the possibility of generating improved CHO host cells, cell line engineering approaches were developed making use of Biotechnology.
Result:
The results obtained in this study indicate successful development of the improved CHO host cells.
Aim:
The aim of this study was to improve the recombinant protein productivity of CHO cells. Genetic modification of the host cells has proven to be a promising strategy to eliminate or reduce the bottlenecks in recombinant protein expression.

Q.No.3: How do organisms obtain energy? How does fermentation work?
Ans: Organism Obtains Energy From ATP:
Living organisms use organic food for generation of energy. These food usually contain carbohydrates which degrade to produce CO₂, H₂O and energy. This energy is usually in the form of ATPs. Most living organisms use oxygen to make ATP from glucose.
But many living things can make ATP without oxygen as well. Some plants, fungi and many bacteria use aerobic respiration when oxygen is present but in the absence of oxygen they use anaerobic respiration.

 An important way of making ATP without oxygen is Fermentation.

FERMENTATION:
Fermentation is an alternative term for Anaerobic respiration. This term was used by W. Pasteur and he defined it as respiration in the absence of oxygen. It can be define as:

"Fermentation is the process by which living organism such as yeast or bacteria are employed to produce useful compounds or products."

Or

"An imporatnt way of making ATP without oxygen is called fermentation."

It has two major types:

1. Alcoholic (Ethanol) fermentation
2. Lactic Acid Fermentation

1. ALCOHOLIC (ETHANOL) FERMENTATION:
Each pyruvic acid molecule is converted to alcohol and carbon dioxide. It produces ethanol and NAD+. The NAD+ allows glycolysis to continue making ATP.

2. LACTIC ACID FERMENTATION:
In this fermentation pyruvic acid from glycolysis changes to lactic acid. In this process, NAD+ forms NADH. NAD+ in turn, lets glycolysis continue.

Q.No.4: What types of microorganisms cause fermentation to occur?
Ans: Microorganisms Cause Fermentation:
Fermentation occurs in the absence of oxygen (anaerobic conditions), and in the presence of beneficial microorganisms. Some beneficial micro organisms for fermentation are yeasts, molds, and bacteria that obtain their energy through fermentation. Similarly the lactic acid fermentation is carried out by the bacteria Streptococcus and Lactobacillus. They help in souring milk for yogurt and is also helpful in production of various types of cheese. The alcoholic fermentation uses Saccharomyces cerevisiae, a type of yeast to make bread and wine etc.

Q.No.5: What food and non food products are created by fermentation?
Ans: Food Products Created By Fermentation:

• Dairy products: Yogurt, cheese
• Cereal products: bread, cakes
• Fruit and vegetable products: flavorings , candy, fruit juice, silage
• Beverages: beer, wine, cider
• Pickling: pickling of beans, onions, cauliflower, cucumber, tomatoes, cabbage

Non Food Products Created By Fermentation:

• Antibiotics
• Laundry detergents
• Insulin, growth hormones
• Cellulose
• Monoclonal antibodies
• Compost
• Chemicals and
• Medicines to dissolve tumors and to clot blood

Q.No.6: What are some advantages and disadvantages of fermentation?
Ans: ADVANTAGES:

1. It is the source of ethyl alcohol in wines and beers Wines are produced by fermenting fruits like grapes, dates etc. Beers are produced by fermenting malted cereals such as Barley.
2. Yeast is used to prepare bread from wheat.
3. Milk is converted to curd (yogurt) by bacteria.
4. Preparation of cheese and other dairy products.
5. Production of lactic acid, propionic acid, and butanol.
6. Flavour of pickles is due to lactic and acetic acid.
7. Addition of lactic and acetic acids prevent foods from spoilage and also give sour flavours to yogurt and cheese.
8. Acetone is also formed as a by-product.
9. It helps restore proper bacteria balance in the intestines.
10. It improves heart health.
11. It improves the immune system.

DISADVANTAGES:

1. It is linked with the development of gastric cancer.
2. Store-bought items lose beneficial bacteria.
3. Fermentation is a slow and inefficient process. This means it carries a higher cost of production and requires more energy and resources.
4. One of the downsides of fermentation is that it products a lactic acid byproduct that can harm the cell temporarily.
5. It is vulnerable to contamination.

Q.No.7: What factors can affect the fermentation process?
Ans: Factors Effect Fermentation Process:
There are several factors which affect the process and progression of both alcoholic and lactic acid fermentation. These include:

• Fermentation time
• pH
• Presence of air
• Temperature
• Salt
• Water
• Concentration of sugar
• Contaminating organisms

Q.No.8: Define biotechnology.
Ans: BIOTECHNOLOGY:
There are several definitions for biotechnology. One simple definition is that:

"It is the commercialization of cell and molecular biology."

 According to the National Science Academy of United States:

Biotechnology is the "controlled use of biological agents like cells or cellular components for beneficial use".

It covers both classical as well as modern biotechnology.

Generally, biotechnology can be defined as:

"Biotechnology is technology that utilizes biological systems, living organisms or parts of this to develop or create different products."

OR

"Biotechnology is the branch of applied science that uses living organisms and their derivatives to produce products and processes. These products and processes feature in healthcare, medicine, biofuels, and environmental safety."

OR

"Biotechnology is the use of living organisms ,cells or cellular components for the production of compounds or precise genetic improvement of living things for the benefit of man."

Q.No.9: What is classical biotechnology?
Ans: CLASSICAL BIOTECHNOLOGY:
The second phase of evolution and development of biotechnology can be called 'Classical Biotechnology'.
Biotechnology can be considered classical when the biological systems used to obtain the given services or products, are not cellularly or molecularly manipulated or modified; hence, only their natural capacities are taken advantage of.
Scientists use classical biotechnology techniques to alter the genetic makeup (genotype) of microorganisms, plants and animals for the purpose of changing their physical characteristics (phenotype). 

 Q.No.10: What is your justification in considering biotechnology an old technology?
Ans: Biotechnology Is Considered An Old Technology:

In 1919, a Hungarian agriculture engineer called Karl Ereky coined the word Biotechnology.
There is no doubt about the fact that biotechnology is an old technology. As with the passage of time man made discoveries and developments were seen in almost every field. Food, clothes, and shelter are the most important basic needs of human beings irrespective of whether they lived in the ancient period or the modern period. The only factor that has changed is their types and origins.

Biotechnology In Old Civilization:
Biotechnology has been in practice for thousands of years, but credit goes to Indus and Indo-Aryan civilizations, which first racticed biotechnology in 5000 BC to produce fermented foods, medicines and to keep the environment clean.

Farmers Were Earliest Biotechnologist:
The earliest biotechnologists were farmers who developed, improved species of plants and animals using cross-pollination or cross-breeding techniques. The use of these techniques to manufacture products intended to improve the quality of human life.
One of the oldest examples of crossbreeding for the benefit of humans is mule. Mule is an offspring of a male donkey and a female horse. People started using mules for transportation, carrying loads, and farming, when there were no tractors or trucks.

Food Production In Early time:
Food has been an inevitable need since the existence of man as well as for continuous existence of human beings. Therefore agriculture was developed and then domestication of animals was needed. After domestication of food crops and wild animals, man moved on to other new observations like cheese, curd, etc.
The term "Biotechnology" was used before the twentieth century for traditional activities such as making dairy products like cheese and curd, as well as bread, wine, beer, etc.
Certainly, cheese can be considered as one of the first direct products (or by-product) of biotechnology, because it was prepared by adding rennet (an enzyme found in the stomach of calves) to sour milk, which is possible only by exposing milk to microbes (although this understanding was not there, at that time).
Yeast is one of the oldest microbes that have been exploited by humans for their benefit. Yeast has been widely used to make bread, vinegar production, and other fermentation products, which include production of alcoholic beverages like whiskey, wine, beer, etc. Vinegar has a significant importance because of its low pH. Vinegar is capable of preventing growth of certain microbes, and therefore, vinegar can be used successfully for food preservation.

Fermentation Process:
The discoveries and benefits of these observations led people to work on further improvement of the process. Fermentation was a powerful tool to improve their living conditions, even though they were ignorant about the principle behind it.
Based on all these facts we can consider biotechnology a very old technology.

Q.No.11: Describe the contribution of Louis Pasture toward development of classical biotechnology?
Ans: Contribution Of Louis Pasture:
Louis Pasteur is best known for inventing the process that bears his name, pasteurization. But he has other contributions as well towards biotechnology. They are as follows:

Fermentation:
In the mid-1850s, he undertook a series of studies on alcoholic fermentation. He learned about many aspects of fermentation, including the compounds that cause milk to sour. In 1857 he presented evidence that all fermentation is caused by microorganisms and that specific microorganisms cause specific kinds of fermentation.

Pasteurization:
Using his work with fermentation, Pasteur was able to devise a process, now known as pasteurization, to kill microbes and preserve certain products. Pasteurization prevents fermenting and spoilage in beer, milk, and other goods. In his work with silkworms, Pasteur developed practices that are still used today for preventing disease in silkworm eggs.

Germ theory:
Pasteur’s work with microorganisms in fermentation and pasteurization led to a much better understanding of germ theory - that certain diseases result from invasion of the body by microorganisms. Before Pasteur’s time, most people, including scientists, believed that all disease came from inside the body rather than from outside. Pasteur’s findings eventually led to improvements in sterilizing and cleaning in medical practices and antiseptic methods in surgery.

Q.No.12: What are different types of fermentation?
Ans: FERMENTATION:
Fermentation is an alternative term for Anaerobic respiration. This term was used by W. Pasteur and he defined it as respiration in the absence of oxygen. It can be define as:

"Fermentation is the process by which living organism such as yeast or bacteria are employed to produce useful compounds or products."

Or

"An important way of making ATP without oxygen is called fermentation."

TYPES OF FERMENTATION:
It has two major types:

1. Alcoholic fermentation
2. Lactic Acid Fermentation

1. ALCOHOL FERMENTATION:
Each pyruvic acid molecule is converted to alcohol and carbon dioxide . It produces ethanol and NAD⁺ from NADH. The NAD⁺ allows glycolysis to continue making ATP.
Ethanol fermentation converts two pyruvate molecules, the products of glycolysis into two molecules of ethanol and two molecules of carbon dioxide.
Cause:
This type of fermentation is carried out by yeast Saccharomyces cerevisiae and some bacteria.
Uses:

• It is used to make bread, wine, and biofuels.
• It also causes the rising of dough in breads. The yeast produces carbon dioxide gas in the dough using alcoholic fermentation. The gas forms bubbles which makes the dough rise and expand. The bubbles leave small holes in the bread after baking which makes the bread light and fluffy.

LACTIC ACID FERMENTATION:
In this fermentation pyruvic acid from glycolysis changes to lactic acid. In this process, NAD⁺ forms NADH. NAD⁺ in turn, lets glycolysis continue.
Cause:
This type of fermentation is carried out by the bacteria Streptococcus and Lactobacillu species for souring milk into yogurt and production of various types of cheese.
Uses:

• Produce yogurt and various types of cheese.
• It is also used by our own muscle cells when we work them hard and fast.

Q.No.13: What is lactic acid bacillus? Explain its role in fermentation of curd ?
Ans: LACTIC ACID BACILLUS:
Lactic acid bacillus are inactivated bacteria that are good for the gut. They prevent the growth of the other pathogenic bacteria that cause diarrhea or other bacterial infections. Thus, it helps in treating bacterial infections.

ROLE OF  LACTIC ACID BACILLUS IN FERMENTATION OF CURD:
Lactic acid bacillus is very helpful in formation of curd. When it is added to milk the bacterium uses enzymes to produce energy (ATP) from lactose. The lactic acid curdles the milk that then separates to form curds, which are used to produce cheese and whey.

Q.No.14: Name some of the fermented food products of Pakistan.
Ans: Fermented Food Products Of Pakistan
The fermented food products available in Pakistan are:

• Dairy products : Yogurt, cheese
• Cereal products: bread ,cakes
• Fruit and vegetable products: flavorings , candy, fruit juice, silage
• Beverages: beer, wine, cider
• Pickling: pickling of beans , onions, cauliflower, cucumber, tomatoes cabbage

OR

Fermentation products:
The following are the most consumed fermentation products used worldwide and in Pakistan:
1. Alcohol:
Alcohol is made as a result of the fermentation of a natural source of sugar with a catalyst, which is usually yeast. During fermentation, carbohydrates (starch and sugars) are the main source that is converted into carbon dioxide and ethyl alcohol. Alcohol is widely used in medicines.

2. Yogurt:
Yogurt is lactic acid-containing milk fermented by bacteria. Lactose present in milk is converted to lactic acid during fermentation.

3. Bread:
Wheat dough is fermented to make bread. Fermentation plays an important role in softening the bread and is also responsible for its aroma. This fermentation is mainly carried out by yeast and sometimes by bacteria.

4. Cheese:
Cheese is formed when bacteria convert milk lactose into lactic acid due to which milk proteins are also coagulated. In this way, the milk changes into cheese.

Q.No.15: Name four recombinant DNA products available on the market?
Ans: Recombinant DNA Products:
Biochemical products of recombinant DNA technology in medicine and research include:

• Human recombinant insulin
• Growth hormone
• Blood clotting factors
• Hepatitis B vaccine.