09. Applied biology Flashcards
What are aquatic organisms?
Fish
Molluscs
Crustaceans
Aquatic Plants
What are some importances of aquaculture
Farming edible aquatic organisms is accepted as one of the best solutions for feeding the ever increasing human population.
A healthy diet, high in protein is necessary to ensure that growing population doesn’t succumb to sicknesses and diseases due to the lack of essential nutrients, Harvests from wild sources of fish, crustaceans and other aquatic species cannot keep up with the demand presented by the growing human population.
Trying to match the demand through commercial fishing would eventually result in over-fishing and the loss of those species entirely. It is accepted that while aquaculture is essential to meet the human demand for fish and fishery products, it also relieves the strain on wild species and allow them to continue to be a significant source of food for humans.
What are the general characteristics of species that could be cultured?
Selected species should withstand the climate of the region in which it is cultured.
It should grow well (have a fast growth) in prevailing physical and chemical parameters of water in the area.
It should be easy to breed (breeding techniques should be available) so that sufficient number of fertilized eggs/early fry could be obtained easily.
Techniques of incubation of fertilized eggs and rearing techniques of hatchlings/ early fry should be available so that the production of sufficient number of young organisms (seed) would be easy under culture conditions
If the eggs. larvae, fry, fingerlings, juveniles and adults of the species are hardy it is easier for the hatchery manager/farmer (handling hardy species is easy)
Food and feeding habits of each developmental stage of the species should be known (easy to provide nutritionally balanced diet for each developmental stage)
It should not reproduce in grow-out ponds/tanks
If it reaches sexual maturation relatively late, it is advantageous
It should accept formulated food and grow well.
It should be an efficient converter of economical foodstuffs.
If it is accidentally released to natural water bodies there shouldn’t be adverse environmental impacts.
It should tolerate high population density and grow well
Having resistance to common diseases is advantageous
It should satisfy consumers by the taste, nutritive value, texture of flesh or appearance/body color/color patterns
How did ornamental fishes lure and draw a great attention worldwide?
Through their attractive colouration
shapes
sizes of body and fins
Swimming behaviors
Ability to live under captive conditions and adaptability to live in little spaces
Why do people keep fish in their homes?
Decoration
Children’s education
Enjoyment
Relaxation of elderly or health affected individuals
Prosperity and fortune of home occupants
To collect rare species and even to propagate them
What are the species of fish commonly used in freshwater ornamental fish culture of SL
Guppy (Poecilia reticulata)
Black molly (Poecilia mexicana)
Swordtail (Xiphophorous helleri)
Platy (Xiphophorous maculatus)
Angelfish (Pterophyllum scalarae)
Discus (Symhysodon discus)
Siamese fighting fish (Betta splendens)
Kissing gourami (Helostoma temmincki)
Goldfish (Carassius auratus)
Koi Carp (Cyprinus carpio)
How do aquaria vary?
In size, shape and design ranging from a simple bottle containing some water (ex: an empty jam bottle used to keep a Siamese fighting fish) to a multimillion liters commercial exhibit tanks
How often must the maintenance of a home aquarium be carried out?
Daily, weekly, fortnightly and monthly
Why must a home aquarium be maintained?
in order to maintain environmental conditions (water quality parameters) within the optimum ranges for the fish kept in an aquarium
What activities must be performed to maintain a home aquarium?
Provision of correct nutrition
Maintenance of water quality within the optimum ranges contribute for the well-being
Health management of fish kept in an aquarium
What must be performed daily to maintain a home aquarium?
- feed the fish with a nutritionally balanced diet following a correct feeding regime (suitable daily ration should be offered in 2 or 3 meals)
- Check on the status of health while feeding and remove the affected individuals for treating in another tank/basin
- Allowing fish to adapt for the changing intensity of light (to prevent unnecessary stress on fish)
This is done by switching on the light of the aquarium several minutes after the room lights have been on or after the day break
Switch off the light of the aquarium several minutes before the room lights are switched off or shortly before natural lights fade
What must be performed weekly to maintain a home aquarium?
- fish shouldn’t be fed one day per week (not applicable for brood fish, fry and fingerlings)
What must be performed fortnightly to maintain a home aquarium?
- Switch off aeration
- Rake or stir up gently the surface of the rooting medium (under-gravel filter medium)
- Scrape excess algal growth
- Allow debris to settle
- Siphon off the debris along with 20-25% of the aquarium water
- Replace the volume siphoned out with freshwater in which temperature, pH and hardness watch with conditions of the water in the aquarium
- Switch on aeration
What must be performed monthly to maintain a home aquarium?
- Take out some water from the aquarium into a basin/another tank/bucket
- Collect the fish carefully using a hand net and introduce them into the basin/tank/bucket and arrange aeration to it
- Rinse rooting medium (under-gravel filter medium)
- Remove the aeration tube the air lift, scrape off any deposit (algal or calcite) from the opening and clean/scrape off air diffuser stones
- Introduce the siphoning tube under the filter plates and suck out the accumulated organic debris
- Check the terminals of light source
- Remove dead and dying leaves from plants
- Prune, thin out and tidy the plants and replace poorly grown plants
- Rearrange the filter plates and the filter medium
- Arrange the aeration and fill the aquarium halfway with clean freshwater/aged aerated tap water
- reintroduce the fish with the water and then fill the aquarium to the original level of water using aged clean freshwater.
What can go wrong in a aquarium from time to time?
Equipment failure
Excessive algal growth
Poor water quality
Occurrence of diseases
What are the indications of the aquarium receiving too much light?
Water turning green frequently
Green algae growing on plants on aquarium décor and on the side glasses of the aquarium
How can you prevent the aquarium receiving too much light?
Reduction of intensity and/or duration of light followed by partial water exchange
What are the indications of insufficient illumination in an aquarium?
Growth of brown algae as brown encrustations on plants on aquarium décor and on the side glasses of the aquarium
What are the indications of an aquarium of having high level of oranic pollution?
Blue-green algal mats on plants on aquarium décor and on the side glasses of the aquarium
What must be done to prevent the further accumulation of organic pollution in an aquarium?
Physical removal of algal mats followed by partial water exchange
A review of the maintenance routine with a view to prevent further accumulation of organic pollutants
Why might organic pollutants be accumulated in an aquarium ?
Too much food being offered to fish
Inadequate filtration or aeration
Overstocking
What may lead to the development of infectious diseases in ornamental fish?
Invasion of fish tissues by a disease causing agent (a pathogenic virus, bacterium, fungus or an obligatory/opportunistic parasite)
Multiplication of it in/on fish tissues and increasing its population
What can be done to present infectious diseases in ornamental fish?
Better management practices (BMPS such as maintenance of water quality, correct stocking density of compatible fish with compatible plants, correct feeding regime) to keep the immunity of fish at a higher level
Through correct bi-security measures (to present contamination by pathogens) by quarantining new fish, plants and other aquarium décor
What group causes bacterial fin rot and gill rot?
Bacteria
What group causes hemorrhagic septicemia?
Bacteria
What group causes columnaris disease?
Bacteria
What group causes external mycosis?
Fungi
What group causes fish spot disease (ich disease)
A unicellular, external, obligatory parasite
What group causes trichodinosis?
A unicellular, external, opportunistic parasite
What group of disease causes gill and skin infestation?
obligatory/opportunistic, gill flukes and skin flukes
What are the benefits of ornamental fish culture?
Species conservation
Production of species that are difficult to obtain from the wild
90% of freshwater ornamental fish traded globally are done under captive conditions, there is some environmental benefits or elimination of environmental damage via those breeding programs
The golden arrowana and tiger barb (puntius tetrazona) are two species conserved via ornamental fish production
Sale of fish to hobbyists
Fish can be reintroduced to habitats in which they have been eliminated
What are two species conserved via ornamental fish production?
The golden arrowana
tiger barb (puntius tetrazona)
What are the harmful impacts of ornamental fish culture?
Invasive ornamental fishes/aquatic plants that are accidentally escaped to natural environment could affect a wide range of native organisms from zooplankton to mammals across multiple levels of biological organizations ranging from the genome to the ecosystem
With imported live fish non-indigenous disease causing agents may also come in to a country.
Haphazard use of broad-spectrum antibiotic and other chemicals as preventive/therapeutic treatments and release of treated water (containing those medications) in to the natural environment may cause antibiotic resistance/resistance to chemicals used on pathogenic microorganisms including human pathogenic bacteria
Where can plant propagation and nursery management be done?
In fields, orchids, forests or in protected environments such as greenhouses, polytunnels or tissue culture laboratories
What is the main requirement of a nursery?
Providing optimum/favorable conditions for germination and seedling growth which provides healthy, vigorous, evenly grown plants leading to best transplants
What issues to growers face when they manage plant nurseries?
The optimum capacity of a crop could be obtained only by providing optimum environmental conditions to the nursery plants
Some issues in nursery management practices (like management of light, soil management (soil type, properties of soil and maintenances of soil) pest and disease control, water management (water quality and quantity) nursery structures and environmental controls (protected cultivation versus open air cultivation)
+ Lack of access to modern technology
+ Lack of financial incentives to further improve the nursery and cultivation facilities
+ Shortage of quality planting/propagating materials
+ Inadequate knowledge on suitable techniques and growth conditions that can be used to grow crops
what are some issues in nursery management practices ?
management of light
soil management (soil type, properties of soil and maintenances of soil)
pest and disease control
water management (water quality and quantity)
nursery structures and environmental controls (protected cultivation versus open air cultivation)
Why is the management of light a critical factor?
For rooting cuttings
Seed germination
Seedling growth as in tissue culture facilities
How can light be manipulated in nursery management?
By controlling quality (wave length) and duration (day length, photoperiod)
What factors influence soil condition?
Soil texture
Structure
Organic matter content
How can soil condition be improved?
Via application of fertilizer or manure into soil
Why is pest and disease control vital?
To get a quality product and to maintain plant health
How is pest and disease control achieved?
via biological, cultural, physical, chemical or combination of these as integrated pest management
What factors govern the rooting of cuttings and regulation of plant growth?
Water management and humidity control
What does the type of irrigation used depend on?
Natural conditions of the area
Soil type
Slope of the land
Water availability
The crop to be irrigated
Adequate supply of good quality water
What is the advantage of growing horticultural crops in various types of plant growing structures?
These structures provide a more favorable environment for plants than the open air/outdoor cultivation. In simple terms protected cultivation is growing crops under controlled environmental conditions
Protected cultivation of horticultural crops will tremendously benefit in terms of enhanced productivity
What is protected cultivation technology used for?
Its used to protect plants from adverse climatic conditions (wind, heavy rain, mist, etc.) by providing optimum conditions to achieve maximum yield and the best quality
How must protected cultivation be done?
In green houses (depends on the covering materials different structures are used such as polytunnels)
What is protected cultivation mainly utilized for?
To grow perishable horticultural produce such as fruits, vegetables and ornamental plants
What is a simple form of green house?
A structure where it is covered with material that allows light to penetrate inside and reach plants
How are green houses made with advanced technology?
Sophisticated modern green houses are constructed in horticulture industry, where the plants microenvironment in more precisely controlled.
What are the plants grown in green houses including polytunnels?
- Vegetables such as bell pepper, tomato, salad cucumber, cauliflower and lettuce
- Fruits - strawberries
- Ornamental plants - carnations, roses, orchids
Tissue culture is the ability to….
establish plant tissues (cells, callus and protoplasts) plant organs (embryos, shoots, roots) is aseptic, in vitro culture.
What is the most common benefit of tissue culture?
Cloning or mass production of genetically identical organisms
What is the main concept behind plant tissue culture?
Totipotent ( a single cell has the genetic programme to grow into an entire new plant )
Who introduced the concept of totipotent?
Matthias Schledien and Theodor Schwann who postulated the cell theory in 1838
What does a tissue culture medium generally consist of?
Inorganic salts
Organic substances
Water and gelling agent
How is the inorganic salt component in the tissue culture medium made?
Macro and micronutrients in appropriate ratios make the organic salt component
Name some organic substances in a tissue culture medium
Carbon energy source (usually sucrose)
Plant growth regulators (cytokinins and auxins)
vitamins
miscellaneous compounds
What substance is incorporated as the gelling agent?
Agar
What is the function of agar in the tissue culture medium?
Provides physical support for the explant and increase the aeration of the medium
What are the commercial media available for tissue culture?
Murashige and Skoog or MS medium
What are the importance of tissue culture techniques?
Rapid multiplication of clones
Mass propagation of specific clones
Genetic uniformity
Genotype modifications
Ability to produce plants in large numbers in a small space
Production of pathogen-free plants
All year around production of plants
Ability to produce plants which do not produce viable seeds
What are examples for tissue-cultured plants?
Anthurium ( Anthurium andreanum)
Banan
Pineapple
Dragon fruit
What is the most common and widely used propagation method for plants?
Seeds
What is a prime importance in the horticulture sector?
Producing high quality seeds
What kind of seeds do growers wish to have?
High quality seeds with higher percentage of germination and higher viability and free of diseases and pest damage
For a seed to initiate germination what conditions must be completed?
The seeds must be viable
The seed must be subjected to suitable environmental conditions
Dormancies existing should be overcome
What plants can be produced using seed propagation methods ( at present tissue culture is culture methods)
Anthurium and Orchid
How are new plants in vegetatively propagated plants?
The new plants are nearly always genetically identical to the parent
What are the various methods of vegetative propagation?
Separation and division
Cuttings
Layering
Grafting
What structures are used in the separation process in the separation and division of plants?
Separation is a process where naturally detachable structures (ex: Rhizomes, bulbs and corms) are used.
What occurs during division process in the separation and division of plants?
During division, the plant is cut or divided into sections with both roots and stems (ex: stolons and rooted runners)
Give examples for corms
Alocassia/Colocasia
Gladiolus
Give examples for runners
Spider plant / chlorophytum comosum
Give examples for stolons
Cyanodon grass species
Mentha (mint)
Stachys
What is one of the most important clonal regeneration techniques used in horticulture industry for ornamnetal plants and fruit trees?
Cutting propagation
What is a prerequisite of the cutting propagation process?
Adventitious root formation
What are adventitious roots?
A piece of plant from the stem, leaf root or leafy bud can generate into a fully developed plant. The roots arising from stem, lead or bud tissues are adventitious roots
Give examples for adventitious roots
Roses
Ficus
Dracaena s African violets
Croton
What is the difference between stem and leaf-bud cuttings and root and leaf cuttings?
Although stem and leaf-bud cuttings need only a new adventitious root system to be formed, for root and leaf cuttings both the new shoot and root systems need to be formed
Give examples for the propagation of via leaf cuttings
Begonia
African violet
Snake plant (sansvieria)
What happens in layering?
It is a method of vegetative propagation where stems are rooted while attached to the parent plant
What are the natural tendencies naturally self-layering plants have?
They have the tendency to regenerate by self-layering, forming adventitious roots from the stem where they touch the soil (ex: Strawberry and Cynodon sp.)
What is the advantage of layering?
Layering technique is a good way of getting a small number of plants with relative certainty because the new plant is nourished by its parent plant until roots are formed and rooted
Give examples for layered plants
Rose
Hibiscus
What occurs in grafting
Grafting involves joining two separate plants so that they later function as one healthy plant that has the best characteristics of two parent plants. A root system is provided by one plant (known as root stock or understock) and the desired top part by the other plant (known as scion)
ex: roses
During a graft union it’s vital that the cambium of the scion is placed in close contact with the rootstock cambium. Initially a callus (mass of undifferentiated parenchyma cells) bridge is formed between the scion and restock in a successful graft. These callus cells originate from the scion and the rootstock.
What do floricultural practices found in SL include?
Cut flowers and ornamental foliage plants
Give examples for cut flowers
Anthurium
Orchids
Give examples for ornamnetal foliage plants?
Rose
Dracinia
Begonia
What is the function of food preservation?
Food preservation ensures that food can be preserved for a particular period. and protects the food that is available for human consumption reducing the “food loss”
prevent unnecessary wastage and contribute greatly to meet food requirement of growing human population
When is food preserved?
Food is preserved during some seasons over production of certain food occurs and the excess production could be preserved (using suitable methods) and stored to be used later.
How can food be preserved before undergoing spoilage using suitable techniques?
- eliminating avoidable losses
- making more nutritive food items from low grade raw commodity using proper processing and fortification
- diverting a portion of food materials presently being fed to animals for human consumption by way of processing
- fortifying low grade food and organic wastes and by-products into nutritive animal feed
How must the contamination of harvested food from damaging agents be done?
Hygienic handling
Transportation
Storage
What are the three basic principles of food preservation?
Preservation of entry of microorganisms into food (aseptic)
Prevention of the growth and activity of microorganisms in food
Remove or killing microorganisms in food
What do food preservation methods aim to do?
Prevent contamination in the first place
To remove/reduce the numbers of contaminants
How is the preservation of food achieved?
By the application of physical, chemical, and/or biological methods. The techniques may be applied separately or in combination
What factors do microorganisms need to grow?
A source of food
Water
A suitable pH
A suitable temperature
What must be removed by the food preservation technique?
One or several of the living conditions needed for the growth of microorganisms have to be removed by the food preservation technique
What is one of the oldest method of food preservation?
drying
How is drying performed?
Food is mostly dried in the sun and drying reduces the water activity of the food sufficiently to prevent or delay microbial growth allowing food to be kept for weeks.
What kinds of food are dried?
Most types of grains are dried to increase shelf life
Wheat, corn, oats, rice, rye, and barley are eft to dry to prevent spoilage
Hams are meats preserved through drying in ovens
What food is dried to increase shelf life?
Most grains
What food is left to dry to prevent spoilage?
Wheat, corn, oats, rice, rye, and barley are left to dry to prevent spoilage
What is an example for meat preserved through drying in ovens?
Hams
Why is heating food an effective way of preservation?
Because the great majority of harmful pathogens are killed at temperatures close to the boiling point of water
What method of food preservation is the preliminary step in many other forms of food preservation?
Especially in forms that make use of packaging, is to heat the food to temperatures sufficiently high enough to destroy pathogens. In many cases, food is actually cooked prior to their being packaged and stored.
What is the most common of all modern food preservation methods both commercially and domestically?
Freezing
How is commercial freezing done?
Its done in different types of freezers under extremely fast freezing or fast freezing (bringing the temperature of fish/meat down to a value between -18 to -30c within 15 minutes to 2 hours) to preserve the quality until distributed in order to prevent the growth and spreading of spoilage of microorganisms (the extreme cold prevents microbial growth)
Storage of food (fruits, fruit juices, vegetables, fish, meat, etc) in refrigerators at low temperatures (chilling at 4=7c) reduces the growth and activities of spoilage microorganisms, preserving food for a short period (for 10 to 14 days)
Name a older form of preserving raw foods?
Salting
Why is salting an effective way of food preservation?
Salt has an ability to suck the moisture out of food through the process of osmosis. When the food is totally dry from salting, growth of microorganisms are inhibited
What food is commonly preserved through salting?
Meat
How is dried fish prepared?
(anchovy, tuna, etc.) are first salted and then dried in the sun.
How is dried fish prepared?
(anchovy, tuna, etc.) are first salted and then dried in the sun.
Why is salt added in the salting and drying of dried fish?
Addition of salt makes the removal of water fast and the salt inhibits microbial growth on fish even though some moisture is still remaining in flesh
What foods is sugaring used in?
Sugar is used in syrup form to preserve fruits and in crystallized form to preserve food items like ginger and orange peel.
Why are some fruits glazed with a sugar syrup?
For the fruits to get a superficial, protective coating
Why are some fresh fruits cooked with sugar and then dried?
High sucrose concentration produces osmotic stress on microorganisms and protects the food from microbial spoilage
What are examples for fresh fruits that are cooked with sugar and dried?
Jam
Sugared toffees made made with ash pumpkin
What is smoking?
Smoking is the process that cooks, flavors, and preserves food exposing it to the smoke from burning wood.