ㅤㅤ

Chapter 11: Enhancement of Food Production [ Exercise,Solutions,Notes ]

Chapter 11: Enhancement of Food Production [ Exercise,Solutions,Notes ]

Chapter 11: Enhancement of Food Production [ Exercise,Solutions,Notes ]

Multiple Choice Question

Exercise | Q 1.1 | Page 270
Antibiotic Chloromycetin is obtained from ____________.
Streptomyces erythreus
Penicillium chrysogenum
Streptomyces venezuelae
Streptomyces griseus
Solution:
Antibiotic Chloromycetin is obtained from Streptomyces venezuelae.

Exercise | Q 1.2 | Page 270
Removal of large pieces of floating debris, oily substances, etc. during sewage treatment is called _______________.
primary treatment
secondary treatment
final treatment
amplification
Solution:
Removal of large pieces of floating debris, oily substances, etc. during sewage treatment is called primary treatment.

Exercise | Q 1.3 | Page 270
Which one of the following is a free-living bacterial biofertilizer?
Azotobacter
Rhizobium
Nostoc
Bacillus thuringiensis
Solution:
Azotobacter

Exercise | Q 1.4 | Page 270
Most commonly used substrate for industrial production of beer is ___________.
barley
wheat
corn
sugarcane molasses
Solution:
The most commonly used substrate for industrial production of beer is barley.

Exercise | Q 1.5 | Page 270
Ethanol is commercially produced through a particular species of _____________.
Aspergillus
Saccharomyces
Clostridium
Trichoderma
Solution:
Ethanol is commercially produced through a particular species of Saccharomyces.

Exercise | Q 1.6 | Page 270
One of the free-living anaerobic nitrogen-fixer is _________.
Azotobacter
Beijerinckia
Rhodospirillum
Rhizobium
Solution:
One of the free-living anaerobic nitrogen-fixer is Rhodospirillum.

Exercise | Q 1.7 | Page 270
Microorganisms also help in production of food like ______________.
bread
alcoholic beverages
vegetables
pulses
Solution:
Microorganisms also help in the production of food like bread.

Exercise | Q 1.8 | Page 270
MOET technique is used for _____________.
production of hybrids
inbreeding
outbreeding
outcrossing
Solution:
MOET technique is used for the production of hybrids.

Exercise | Q 1.9 | Page 270
Mule is the outcome of __________________.
inbreeding
artificial insemination
interspecific hybridization
outbreeding
Solution:
Mule is the outcome of interspecific hybridization.


Very Short Answer Question

Exercise | Q 2.1 | Page 270
What does make idlies puffy?
Solution:
The bubbles of CO2 trapped in dough during fermentation make idlies puffy.

Exercise | Q 2.2 | Page 270
Name any two bacterial biofertilizers.
Solution:
Bacterial biofertilizers are :

a. Rhizobium:
  • Rhizobia are rod-shaped, motile, aerobic, gram-negative, non-spore-forming, nitrogen-fixing bacteria containing Nod genes and Nif genes.
  • They form symbiotic associations with the roots of leguminous plants.
  • They bring about nodule formation on the roots and multiply inside the nodule.
  • They fix atmospheric nitrogen into organic forms, which can be used by plants as nutrients.
  • For e.g. R. leguminosarum is specific to pea and R. phaseoli to beans.
b. Azotobacter:

It is the important and well-known free-living, nitrogen-fixing, aerobic, non-photosynthetic, non-nodule forming bacterium, intimately associated with roots of grasses and certain plants.
It is used as a bio-fertilizer for all non-leguminous plants especially rice, cotton, vegetables, etc.

c. Azospirillum:

It is a free-living, aerobic nitrogen-fixing bacterium associated with roots of corn, wheat, and jowar.
It fixes the considerable quantity of nitrogen (20-40kg N/ha) in non–leguminous plants such as cereals, millets, cotton, oilseed, etc.

Exercise | Q 2.3 | Page 270
What is the microbial source of vitamin B12?
Solution:
The microbial source of Vitamin B12 is Pseudomonas denitrificans.

Exercise | Q 2.4 | Page 270
What is the microbial source of enzyme Invertase?
Solution:
The microbial source of enzyme Invertase is Saccharomyces cerevisiae

Exercise | Q 2.5 | Page 270
Milk starts to coagulate when Lactic Acid Bacteria (LAB) is added to warm milk as a starter. Mention any two other benefits of LAB.
Solution:
Production of dairy products:
i. Curd: Indian curd is prepared by inoculating milk with Lactobacillus acidophilus. It also checks the growth of disease-causing microbes.
ii. Yogurt (yogurt): It is produced by curdling milk with the help of Streptococcus thermophilus and Lactobacillus bulgaricus.
iii. Butter Milk: The acidulated liquid left after churning of butter from curd, is called buttermilk.

iv. Cheese:
The milk is coagulated with lactic acid bacteria and the curd formed is filtered to separate whey.
The solid mass is then ripened with the growth of mold that develops flavor in it.
Different varieties of cheese are known by their characteristic texture, flavor, and taste which are developed by different specific microbes.
The ‘Roquefort and Camembert cheese’ are ripened by Bluegreen molds Penicillium roqueforti and P. camemberti respectively.
The large holes in Swiss cheese are developed due to the production of a large amount of CO2 by a bacterium known as Propionibacterium shermanii.

Exercise | Q 2.6 | Page 270
Name the enzyme produced by Streptococcus bacterium? Explain its importance in medical Science?
Solution:
The enzyme produced by streptococcus bacterium is the streptokinase enzyme (TPA). It is a bioactive molecule. It is used as a 'clot buster' for removing clots from the blood vessels of patients who have undergone myocardial infractions leading to a heart attack.

Exercise | Q 2.7 | Page 270
What is the breed?
Solution:
A group of animals related by descent and similar in most characters like general appearance, features, size, configuration, etc., are said to belong to a breed.

Exercise | Q 2.8 | Page 270
Define estuary.
Solution:
Estuaries are places where rivers meet the sea and may be defined as areas where saltwater is measurably diluted with freshwater.

Exercise | Q 2.9 | Page 270
What is shellac?
Solution:
Shellac is a pure form of lac obtained by washing and filtering.

Short Answer Question

Exercise | Q 3.1 | Page 270
Many microbes are used at home during the preparation of food items. Comment on such useful ones with examples.
Solution:
Many household preparations involve the use of microbes. e.g. idli, dhokla, jalebi, dosa, etc.
Microbes such as Leuconostoc and Streptococcus help in the fermentation of batter of idli and dosa.
Microbes like Lactobacilli help in the preparation of jalebi and nan.
Milk is fermented to make curd, yogurt, and cheese using lactobacilli.
Saccharomyces cerevisiae (yeast) is commonly used for making bread.

Exercise | Q 3.2 | Page 270
What is biogas?
Solution:
Biogas is a non-conventional and renewable source of energy and is obtained by microbial fermentation.

Exercise | Q 3.2 | Page 270
Write in brief about the Biogas production process.
Solution:
Process of biogas production:

Anaerobic digestion involves three processes:
a. Hydrolysis or solubilization:

In the initial stage, the raw material (cattle dung) is mixed with water in equal proportion to make a slurry which is then fed into the digester.
Here anaerobic hydrolytic bacteria (e.g. Clostridium, Pseudomonas) hydrolyse carbohydrates into simple sugars, proteins into amino acids, and lipids into fatty acids.
b. Acidogenesis: In this stage, facultatively anaerobic, acidogenic bacteria and obligate anaerobic organisms, convert simple organic material into acids like formic acid, acetic acid, H2, and CO2.

c. Methanogenesis: This is the last stage in which anaerobic Methanogenic bacteria like Methanobacterium, Methanococcus convert acetate, H2, and CO2 into Methane, CO2 and H2O, and other products.


Exercise | Q 3.3 | Page 270
Write a note on biocontrol agents.
Solution:
i. The agents which are employed for biological control are called biocontrol agents.

ii. Microbes like bacteria, fungi, viruses, and protozoans act as biocontrol agents. They act in three ways, either they cause the disease to the pest or compete or kill them.
Example:
i. Bacillus thuringiensis
It is used to get rid of the butterfly, caterpillars where dried spores of Bacillus thuringiensis are mixed with water and sprayed onto vulnerable plants such as Brassica and fruit trees.
These spores are then eaten by insect larvae.
In the gut of the larvae, the toxin (cry protein) is released and the larvae get killed eventually.

ii. Trichoderma
Trichoderma species are free-living fungi found in the root ecosystem (rhizosphere).
These are effective as biocontrol agents of several soil-borne fungal plant pathogens.
The fungus produces substances like viridin, gliotoxin, gliovirin, etc. that inhibit the other soil-borne pathogens attacking root, rhizomes, etc. causing rot disease.

Exercise | Q 3.4 | Page 270
Name any two enzymes and antibiotics with their microbial source.
Solution:
No.EnzymeMicrobial Source
i.InvertaseSaccharomyces cerevisiae
ii.PectinaseSclerotiana libertine, Aspergillus niger
iii.LipaseCandida lipolytica
iv.Cellulase

Trichoderma koningi

No.Antibiotic

Microbial source

i.ChloromycetinStreptomyces venezuelae
ii.ErythromycinStreptomyces erythreus
iii.PenicillinPenicillium chrysogenum
iv.StreptomycinStreptomyces griseus
v.GriseofulvinPenicillium griseofulvum
vi.BacitracinBacillus licheniformis
vii.Oxytetracycline/ Terramycin

Streptomyces aureofaciens


Exercise | Q 3.5 | Page 270
Write the principles of farm management.
Solution:
  1. Principles of farm management include the following points:
  2. Selection of high-yielding breeds.
  3. Understanding the feed requirements of farm animals.
  4. Supply of adequate nutritional sources for the animals.
  5. Maintaining the cleanliness of the environment.
  6. Maintenance of health with the help of veterinary supervision.
  7. Undertaking vaccination of programs.
  8. Development of high-yielding cross-bred varieties.
  9. Making various products and their preservation.
  10. Distribution and marketing of the farm produce.

Exercise | Q 3.6 | Page 270
Give the economic importance of fishery.
Solution:
Economic importance of fishes:
  1. Fishes are caught, processed, raised, and marketed under fisheries. It provides good job opportunities and self-employment.
  2. Culturing fishes on a large scale in ponds, lakes, and reservoirs boost the productivity and economy of the nation.
  3. Fishes are a source of nutritious food as they are rich in proteins, vitamins (A, D, and K), carbohydrates, fats, and minerals.
  4. They also yield a number of by-products that hold commercial value.
  5. The by-products obtained from fishes include fish oil, fish meal, fertilizers, fish guano, fish glue, and isinglass, which are widely used in paints, soaps, oils, and medicines.
  6. Prawns and lobsters have a market value all over the world.

Exercise | Q 3.7 | Page 270
Enlist the species of honey bee mentioning their specific uses.
Solution:
  1. Apiculture or beekeeping deals with an artificial rearing of honey bees to obtain bee products like honey, wax, pollen, bee venom, propolis (bee glue), and royal jelly as well as pollinating agents for crop plants.
  2. The four species of honey bees commonly found in India are
  3. Apis dorsata (rock bee or wild bee),
  4. Apis florea (little bee),
  5. Apis mellifera (European bee), and
  6. Apis indica (Indian bee).
  7. For beekeeping, Apis mellifera and Apis indica are suitable species and are known as domesticated species.

Exercise | Q 3.8 | Page 271
What are A, B, C, and D in the table given below :

Types of microbeNameCommercial product
FungusAPenicillin
BacteriumAcetobacter aceti

B

CAspergillus nigerCitric acid
YeastDEthanol

Solution:
Types of microbeNameCommercial product
FungusPenicillium chrysogenum

Penicillin

BacteriumAcetobacter acetiAcetic acid (vinegar)
FungusAspergillus nigerCitric acid
YeastSaccharomyces cerevisiae

Ethanol


Long Answer Question

Exercise | Q 4.1 | Page 271
Explain the process of sewage water treatment before it can be discharged into natural water bodies.
Solution:
  1. The sewage treatment plants process is carried out in two ways:
  2. Primary treatment: It involves the physical removal of particles from sewage through filtration and sedimentation. Floating debris is removed by filtration and grit is removed by sedimentation. Thus, all solids which settle from the primary sludge and the supernatant forms the effluent.

Secondary treatment: 
  1. The effluent from primary treatment is passed to aeration tanks where the air is pumped into it. This allows the growth of useful aerobic microbes into flocs (masses of bacteria associated with fungal filaments) and microbes consume the major part of the organic matter in the effluent. 
  2. This reduces the BOD (biological oxygen demand) of the effluent. The effluent is then passed into the settling tank where bacterial flocs are allowed to sediment. This sediment is called activated sludge. 
  3. The small portion of this activated sludge is again passed to the aeration tank to serve as inocula. The remaining major part of this sludge is pumped into large anaerobic sludge digesters. 
  4. Here, anaerobic bacteria digest bacteria and fungi in the sludge. During this digestion, bacteria produce a mixture of gases such as methane, H2S, and CO2.
  5.  This treatment is essential as the sewage or municipal waste discharged into rivers, streams and other water bodies contains human excreta, organic wastes, and several pathogenic microbes.

Exercise | Q 4.1 | Page 271
Why is this sewage water treatment essential?
Solution:
Importance of sewage water treatment:
The sewage water contains pathogenic microorganisms like bacteria, viruses, protozoa, and parasitic worms, which can spread a variety of diseases.
Also, it contains harmful chemicals that may cause toxicity if mixed with the natural resources of water. Therefore, sewage water treatment is essential before it can be discharged into natural bodies.

Exercise | Q 4.2 | Page 271
Write a short note on ‘lac culture’.
Solution:
a. Lac is a pink coloured resin which hardens on coming in contact with air forming lac.
b. Tacchardia lacca is most commonly used for lac culture.
c. Lac insects feed on succulent twigs of certain plants like Ber, peeple, palas, kusum, babool, etc.
d. Natural lac is always contaminated, so washing and filtering is needed to obtain shellac in pure form.
e. India contributes upto 85% of total lac production in world.
f. Lac is the byproduct of lac culture which is used in bangles, toys, woodwork, polish inks, silvering mirrors etc.

Exercise | Q 4.3 | Page 271
Describe various methods of fish preservation.
Solution:
After catching the fishes, fish spoilage is prevented by different preservation methods like:
Chilling with ice: It is a method of refrigeration. Due to the lowering of temperature, putrefaction is prevented and the quality of fish is maintained.

Freezing: Freezing of fishes helps to retain the natural appearance of fishes.
Freeze drying: Fishes are frozen and dried.
Smoke drying: This removes the moisture and prevents the growth of bacteria.
Sun-drying: Fishes are dried in sun to remove moisture.
Salting: By adding salt, dehydration takes place by osmosis.
Canning: Fishes are preserved in cans with salt or other artificial preservatives.

Exercise | Q 4.4 | Page 271
Give an account of poultry diseases.
Solution:
  1. Following are the different types of poultry diseases:
  2. Viral diseases like Ranikhet, Bronchitis, Avian influenza (bird flu), etc.
  3. Bacterial diseases mainly include Pullorum, Cholera, Typhoid, TB, CRD (chronic respiratory disease), Enteritis, etc.
  4. Fungal diseases are Aspergillosis, Favus, and Thrush.
  5. Parasitic diseases include lice infection, roundworm, caecal worm infections, etc.
  6. Protozoan diseases e.g. Coccidiosis is a protozoan disease.

Exercise | Q 4.5 | Page 271
Give an account of mutation breeding with examples.
Solution:
  1. The mutation is a sudden heritable change in the genotype. In mutation breeding, desirable mutations are induced in crop plants with the use of physical or chemical mutagens.
  2. Natural (physical) mutagens are High temperature, high concentration of CO2, X rays, UV rays.
  3. Chemical mutagens are Nitrous acid, EMS (Ethyl- Methyl- Sulphonate), Mustard gas, Colchicine, etc.
  4. Seedlings or seeds are irradiated by CO-60, exposed to UV bulbs, X-ray machines, etc.
  5. Mutagens cause gene mutations and chromosomal aberrations.
  6. The treated seedlings are then screened for resistance to diseases/ pests, high yield, etc. e.g. Jagannath variety of rice, NP 836 variety of wheat (rust-resistant), Indore-2 variety of cotton (resistant to bollworm), Regina-II variety of cabbage (resistant to bacterial rot), etc.

Exercise | Q 4.6 | Page 271
Describe briefly various steps of plant breeding methods.
Solution:
Hybridization involves the following steps:

1. Collection of variability:

Wild species and relatives of the cultivated species having desired traits are collected and preserved.
The entire collection having all the diverse alleles (i.e. variations) for all genes in a given crop is called germplasm collection.
Variations are useful in the selection. Germplasm conservation can be done in the following ways.
a. In situ conservation: It can be done with the help of forests and natural reserves.

b. Ex-situ conservation: It is done through botanical gardens, seed banks, etc.

2. Evaluation and selection of parents:

The collected germplasm is evaluated (screened) to identify plants with desirable characters.
The selected parents must be healthy, vigorous, and should show desirable but complementary features.
The selected parents are selfed for three to four generations to make them pure or homozygous.
It is made sure that only pure lines are selected, multiplied, and used in the hybridization.

3. Hybridization:
  1. The variety showing maximum desirable features is selected as a female (recurrent) parent and the other one as a male parent (donor) which lacks good characters found in a recurrent parent.
  2. The pollen grains from anthers of male parents are collected and then artificially dusted over stigmas of emasculated flowers of the female parents.
  3. Pollination is followed by seed and fruit formation in due course.
  4. The seed thus obtained represents the hybrid generation.
  5. The hybrid F1 progeny is selected and evaluated for the desired combinations of characters.

4. Selection and testing of superior recombinants:
  1. The F1 hybrid plants showing superiority over both the parents and having high hybrid vigour are selected.
  2. Such hybrids are then selfed for a few generations to make them homozygous for the said desirable characters till there is a state of uniformity so that the characters will not segregate further.

5. Testing, release, and commercialization of new cultivars:
  1. The newly selected lines are evaluated for productivity and other features like disease resistance, pest resistance, quality, etc.
  2. Initially, these plants are grown under controlled conditions of water, fertilizers, etc. and their performance is recorded.
  3. The selected lines are then grown for three generations at least in the natural field, in different agroclimatic zones.
  4. Finally, variety is released as a new variety for use by the farmers.

enhancement of food production notes

 Improvement In Food Production : Food is one of the basic needs as it gives us energy for everything. It keeps us alive, strong and healthy. It can be defined as any thing solid or liquid, which when swallowed, digested and assimilated in the body, keeping us well. It is organic, energy rich, non-poisonous, edible and nourishing substance. Green plants synthesize their own food through photosynthesis. But animals including humans can not synthesize their food on their own, hence are dependent on plants directly. 

The famine is responsible for dearth of food, besides the rapid and dramatic increase in world population over the time. To meet the increasing demand for food, there is need for improvement of food production, both quantity wise and quality wise (nutritive). Plant breeding and animal breeding help us to increase the food production.

Plant breeding : The improvement or purposeful manipulation in the heredity of crops and the production of new superior varieties of existing crop plants, constitute what is called plant breeding. It is, therefore, an applied branch of botany. It is infact an art and the science of changing and improving the heredity of plants. Plant breeding can be carried out by using the applications of principles of genetics, taxonomy, physiology, pathology, agriculture, rDNA technology, etc.

Plant breeding is a method of altering the genetic pattern of plants to increase their value and utility for human welfare. The plant breeding is done to increase crop yield, improve quality, increase tolerance to environmental stresses, make the plants resistant to pathogens and increase tolerance to insect pest. Green Revolution was the result of a sequence of scientific breakthroughs and developmental activities that successfully fought hunger by increasing food production. 

Seeds with superior quality, use of chemicals - pesticides and fertilizers, and multiple cropping system supported by the use of modern farm machinery and proper irrigation system, helped for the development of high-yielding and disease resistant varieties in wheat, rice, maize, etc. In fact, plant breeding dates back to about 10,000 years ago. The present day crops are the result of domestication and acclimatization.

Hybridization and its technique : It is the cheif method that offers greater possibilities in the crop improvement than other methods. The use of this method is the only effective means of combining together the desirable characters of two or more varieties. By this method, one can create new genetic combinations of already existing characters and new genetic variations. It also exploits and utilizes hybrid-vigour.

Hybridization can be intravarietal, intervarietal (between two varieties of the same species), interspecific (between two species of the same genus) and intergeneric (between two genera of the same family). As parental plants are distantly related, such crosses are also called wide/ distant crosses. Interspecific and intergeneric hybrids are seldom to occur in the nature. The main steps of the plant breeding program (Hybridization) are as follows 

1. Collection of Variability : Wild species and relatives of the cultivated species having desired traits, should be collected and preserved. The entire collection having all the diverse alleles (i.e. variations) for all genes in a given crop, is called germplasm collection. Variations are useful in the selection. Germplasm conservation can be done in following ways-

• In situ conservation : It can be done with the help of forests and Natural Reserves. 
• Ex situ conservation : It is done through botanical gardens, seed banks, etc.
 
Evaluation and Selection of Parents : It is an important and essential step. The collected germplasm is evaluated (screened) to identify plants with desirable characters. The selected parents must be healthy, vigorous and should show desirable but complementary features. The selected parents are selfed for three to four generations to make them pure or homozygous. It is made sure that only pure lines are selected, multiplied and used in the hybridization.

Hybridization : The variety showing maximum desirable features is selected as female (recurrent) parent and the other one as male parent (donor) which lacks good characters found in recurrent parent. The pollen grains from anthers of male parent are collected and then artificially dusted over stigmas of emasculated flowers of female parent. Pollination is followed by seed and fruit formation in due course. The seed, thus obtained represents the hybrid generation. The hybrid F1 progeny is selected and evaluated forthe desired combinations of characters. 

Selection and Testing of Superior Recombinants : The F1 hybrid plants showing superiority over both the parents and having high hybridvigour, are selected. Such hybrids are then selfed for few generations to make them homozygous for the said desirable characters till there is a state of uniformity, so that the characters will not segeregate further.

Testing, Release and Commercialization of New Cultivars : The newly selected lines are evaluated for the productivity and other features like disease resistance, pest resistance, quality, etc. Initially, these plants are grown under controlled conditions of water, fertilizers, etc. and their

 performance is recorded. The selected lines are then grown for three generations at least in natural field, in different agroclimatic zones. Finally variety is released as new variety for use by the farmers. Many high yielding, hybrid varieties of rice, wheat, sugarcane, millets, developed through hybridization, have helped farmer community to attain record agricultural production in India since 1961. This is called green revolution

Biofertilizer microorganisms:

1. Rhizobium: Rhizobia are rod shaped, motile, aerobic, gram negative, non spore forming, nitrogen-fixing bacteria containing Nod genes and Nif genes. They form symbiotic association with roots of leguminous plants. They bring about nodule formation on the roots and multiply inside the nodule. They fix atmospheric nitrogen into organic forms, which can be used by plants as nutrients. For eg. R. leguminosarum is specific to pea. and R. phaseoli to beans. 

 2. Azotobacter: It is the important and well known free living, nitrogen fixing, aerobic, non-photosynthetic, non-nodule forming, bacterium, intimately associated with roots of grasses and certain plants. It is used as a Bio-fertilizer for all non-leguminous plants especially rice, cotton, vegetables, etc.

3. Azospirillum: It is free living, aerobic nitrogen fixing bacterium associated with roots of corn, wheat and jowar. It fixes the considerable quantity of nitrogen (20-40kg N/ha) in non – leguminous plants such as cereals, millets, cotton, oilseed, etc.


4. Anabaena : It is a genus of multicellular, filamentous cyanobacteria that exits as plankton. It has ability to fix nitrogen and also forms symbiotic relationships with certain plants, such as the coralloid roots of Cycas and Anthoceros thallus. It has some specialized and colourless cells, called Heterocysts which are the sites for nitrogen fixation.

5. Azolla: Azolla is a free-floating water fern. Azolla plant consist of a floating rhizome (stem) with small overlapping bi-lobed leaves and roots. The leaf shows dorsal and ventral lobe. 
 

Maharashtra Board Solutions Class 12 Biology: Chapter 11

Balbharati solutions for Biology 12th Standard HSC for Maharashtra State Board
Chapter 1: Reproduction in Lower and Higher Plants
Chapter 2: Reproduction in Lower and Higher Animals
Chapter 3: Inheritance and Variation
Chapter 4: Molecular Basis of Inheritance
Chapter 5: Origin and Evolution of Life
Chapter 6: Plant Water Relation
Chapter 7: Plant Growth and Mineral Nutrition
Chapter 8: Respiration and Circulation
Chapter 9: Control and Co-ordination
Chapter 10: Human Health and Diseases
Chapter 11: Enhancement of Food Production
Chapter 12: Biotechnology
Chapter 13: Organisms and Populations
Chapter 14: Ecosystems and Energy Flow
Chapter 15: Biodiversity, Conservation and Environmental Issues

Post a Comment

Thanks for Comment

Previous Post Next Post