Yeast is a single-celled, microscopic fungus which uses sugar as food. Ethanol fermentation is a biological process of converting sugars to alcohol and carbon dioxide. It is performed by yeasts in the absence of oxygen. 

Yeast reproduces rapidly and produces carbon dioxide during respiration. Bubbles of the gas fill the dough and increase its volume.

Fermentation is the process which is carried by anaerobic respiration of microorganism which leads to the production of lactic acid or alcohol with the release of carbon dioxide. When the yeast is added to the dough of the bread it converts the sugar to ethanol and carbon dioxide which forms bubbles. Yeast has a lot of economical value to the mankind. It is used in the production of bread, wine, curd etc.

Streptococcus lactis is an important bacteria responsible for manufacturing of  dairy product, curd. It converts milk into curd by the process of fermentation. It breaks the sugar present in the milk and produces lactic acid. This lactic acid results in the curdling of the milk proteins and produces curd with a tangy taste.

• In the production of bread one of the step is fermentation which is done with the help of the yeast or better know as baker's yeast ie Saccharomyces cerevisiae 
• At the time of making dough for the bread yeast is added along with other ingredients and is left to rest for sometime which gives yeast time for the fermentation process where it converts the sugar present in the  flour to carbon dioxide and alcohol.
• When the dough is baked the release of carbon dioxide at the time of baking leaves holes in the bread which gives the bread its sponginess
• So, the correct answer is 'Evolution of CO22 makes the bread spongy'
  

• Saccharomyces cerevisiae also know as Baker's yeast is used in bread making and in production of many other bakery products.
• It is used for the act of fermentation which is done by the yeast on the sugar/starch that is present in the flour. The starch is converted into alcohol and carbon dioxide by the act of fermentation.
• The carbon dioxide in the dough makes the bread dough to rise and also provides the bread with softness and makes it fluffy after it is cooked.
• So, the correct answer is 'Saccharomyces cerevisiae'
  

Yeast is a fungal species that converts carbohydrates to carbon dioxide and alcohols. Saccharomyces cerevisiae is responsible for the production of ethyl alcohol.

The yeast most commonly used for leavening bread is Saccharomyces cerevisiae, the same species used for brewing alcoholic beverages. This yeast ferments some of the carbohydrates in the flour, including any sugar, producing carbon dioxide. 

Bread is prepared from the dough, which is fermented using baker's yeast ( Saccharomyces cerevisiae ). The puffed-up appearance of dough is due to the production of carbon dioxide during fermentation. Carbon dioxide gas along with ethyl alcohol evaporate during baking, making bread porous and soft. 

In the making of bread both carbon dioxide and alcohol are trapped by the dough and both are expelled from the dough by the heat of baking. So, the bread tastes semi-sweet.

• Yeast is used as a leavening agent in bread making. Yeast converts sugars present in the dough to carbon dioxide.

The productivity of plants as biofuel or biomaterial crops is established by both the yield of plant biomass per unit area of land and the efficiency of conversion of the biomass to biofuel. Genomics approaches support genetic selection strategies to deliver significant genetic improvement of plants as sources of biomass for biofuel manufacture. Genetic modification of plants provides a further range of options for improving the composition of biomass and for plant modifications to assist the fabrication of biofuels. The relative carbohydrate and lignin content influences the deconstruction of plant cell walls to biofuels. Key options for facilitating the deconstruction leading to higher monomeric sugar release from plants include increasing cellulose content, reducing cellulose crystallinity, and/or altering the amount or composition of noncellulosic polysaccharides or lignin. Modification of chemical linkages within and between these biomass components may improve the ease of deconstruction. Expression of enzymes in the plant may provide a cost-effective option for biochemical conversion to biofuel.

A mold or mold is a fungus that grows in the form of multicellular or unicellular filaments called hyphae. So the above-selected option is correct 

(A)Ascomycota is a class commonly known as sac fungi with asexual spore ascus.

Mould is a fungus that grows on the bread when kept outside for long, molds feed on the carbohydrate present on the bread. Fungi ahs saprophytic mode of nutrition.

Mould is a fungus that grows on the bread when kept outside for long, molds feed on the carbohydrate present on the bread. Fungi have the saprophytic mode of nutrition. Fungi is further classified into fungi imperfecti called Hyphomycetes.

(A)Bacteria grows in the form of colonies.

Beewax is the natural secretion of the worker bees and is poured out in thin delicate flakes. It is made of:(i) even numbered alcohols. (ii) even numbered fatty acids and (iii)  odd numbered normal paraffins.

About $34\%$ of sunlight is reflected back out of the total amount of sunlight falling on earth. $10\%$ is absorbed by ozone and out of remaining $56\%$ only $0.02\%$ is used for photosynthesis.

Curing of tea leaves is accomplished by bacteria. Leaves of tea and tobacco are cured off their bitterness with the help of certain bacteria, e.g., Bacillus megatherium. Beans of coffee and cocoa are similarly cured.

Organic compounds like plant and animal residues are present in the soil. These organic compounds are broken down by a large number of bacteria, fungi, larger organisms. Bacteria like Pseudomonas lives in the soil and decomposes organic compounds and releases carbon dioxide, energy, water and other plant nutrients.

Ranikhet disease, also known as new castle disease, is found in young birds. Its symptoms include sneezing, gasping and often  droopiness. The affected birds are depressed with ruffled feathers. Control of Ranikhet disease can be done by sanitary and vaccination measures.

• Nitrogen fixation is a process by which atmospheric nitrogen is converted into ammonium compounds and made available for plants. Examples include Rhizobium, Azotobacter.
• Many bacteria are also involved in the sewage disposal process. Mostly saprophytic aerobic bacteria are used in treatment plants.
• During the process of ripening of cream, Lactic acid bacteria are used. These bacteria convert lactose into acid and results in the curdling of cream.
  

Grazing is a method of feeding in which an animal feeds on plants such as grasses. The animals are called grazing animals. They are also called as Ruminants. Examples include cattle, sheep, goats, deer. They are capable of digesting cellulose present in the plants. The cellulose is digested by intestinal bacteria present in them. These bacteria possess the necessary enzymes to digest cellulose in the GI tract.

• Escherichia coli, also known as E. coli, is a Gram-negative, facultatively anaerobic, rod-shaped, coliform bacterium of the genus Escherichia that is commonly found in the lower intestine of warm-blooded organisms.
• Escherichia coli (E. coli) bacteria normally live in the intestines(colon) of Humans and animals.
  
• E.coli  is nonpathogenic bacteria of the colon because it is present in the colon but do not cause any disease.
• So, the correct answer is 'E.coli'.

Clostridium butylicum is used to produce butyric acid. Lactic acid is produced by Acetobacter.