Plant growth occurs in a fairly narrow range - 60 - 100 degrees F
Hydrogen is also essential since it helps in the generation of sugars and thus contributes in the growth of the plant.
Light Quality in Plant Growth and Development
Let us see now how protists and other little animals of ponds react to alteration to theirenvironment.
1 - Some microscopic algae, like the euglena, search out light (phototaxis) and to do thisthey use an organelle sensible to the light, named stigma. With a dark paper, cover thebottom part of a test tube holding a culture of euglena. The part of the test tube exposedto light should become green, rich with algae. Make the same experiment with othermicroscopic algae and with protozoa.
2 - Add two or three drop of distilled water to a little water drop collected in a pondand watch what happens to the protists. Very probably you will see them inflate and thenexplode. This occurs because of the different saline concentration inside and outside theprotists and the osmotic pressure which is produced inside their cells.
3 - Protists are sensitive to most chemicals and generally they react by running away; insome cases instead they approach them (chemotaxis). Prepare some microscope slides withprotists and observe through the microscope their behavior when you add acidic substances(i.e.: vinegar), basic substances (i.e.: backing soda), glucose, salt, sparkling water(rich of CO2), broth, milk, tiny grain of cheese, dyes, etc. At thebeginning use very low amounts of these substances, then increase their concentration.
4 - From a pond or an aquarium, collect a hydra and place it on a microscope slide with apair of water drops. Observing this tiny polyp through the microscope, probably you willsee some sucker shaped microorganisms (trichodina) moving on its body. Watch what happensafter adding a little drop of vinegar to their water! Trichodina will escape from thehydra and probably die. Hydra itself will have launched many of its harmful paralyzingdarts.
5 - Submit protists to different stimulus such as light, temperature, electric field(about 5 V in DC). In this last case, some protists will gather on the cathode (thenegative - pole). Also amebas are inclined to move towards the cathode. Change thepolarity of the current and observe the behavior of the protists.
Internet Keyword: phototaxis chemotaxis protists.
Industrial societies manufacture huge quantities of goods. Once used, these products arecast away. Hence, on one hand we substract great amounts of resources from nature, on theother hand we make enormous heaps of garbage which pollute the environment. If you thinkof it, a lot of materials which are discarded could be reused. In fact, metals, plasticand glass can be used in manufacturing new items. Paper and fabric can be turned back intopulp and fibers, and reassembled into new products. Organic wastes of kitchen, usuallymade of vegetable and animal substances, and garden material, can be composted and used asfertilizer. Wood can be burned, yielding electrical energy, heat and carbon dioxide whichwill be used by other plants to produce more wood. Recycling of waste materials has thedouble advantage of reducing the need for raw materials, and the amount of rubbish.
Every day for a month, separate the different kinds of scrap of your home, weight them andwrite out a list. At the end, estimate the amount of materials which can be recycled,evaluate the recycling and waste management program of your community. Highlight theproblem areas of the system. Assess the problems created by not easily recyclable things,and by the polluting ones: paint cans, batteries, oils, detergents, medicines, etc. Bringout the difficulties and the questions facing particular problems in the recovery ofwastes. Ask the authorities of your city. Write a guide for families on how treat wastesin the right manner. Show this guide and the report of your research to your teacher.
Environmental Defense, Recycling
Recycling - At School
Recycling Obscure Materials
Global Recycling Network
The Internet Consumer Recycling Guide
Internet keywords: recycling.
How does photosynthesis affect algae growth
Until the end of the 17th century, people believed that little animals like flies andworms could spontaneously be born from substances in decomposition or from mud. FrancescoRedi, Lazzaro Spallanzani and Louis Pasteur made experiments which proved the idea of thespontaneous generation was wrong. At your home or in your school you can made suchexperiments too.
1 - Take two glass jars with a screw top. Put in each a little piece of cooked apple and aspoon of vinegar. For a night, leave one of these jars opened so it can be visited byvinegar (fruit) flies. Close the other jar with the lid and sterilize it by placing it inboiling water in a pressure cooker for a half an hour. After removing it from the cooker,let it cool, leaving it closed. The morning after, let the possible bugs present into thefirst jar leave and then close it with a fine gauze or a plastic sheet on which you willmake some pinholes to allow oxygen to enter. After a few days, you should see some bugs inthe first jar, and none in the second one. What has happened in the first jar which hasnot happened in the second? Some vinegar flies laid eggs in the first jar and from themsome new flies are born. In the second jar, even if there had been eggs, these are deadbecause of high temperature in the pressure cooker. More eggs were not laid because thejar was kept closed. With experiments like this one, you can realize that living beingscannot born from nothing, but they are born from other organisms like them. Fall is themore suited season to do this experiment because vinegar flies are particularly active.
2 - Anyway you can try to adapt this experiment to organisms present at other times of theyear. For example, if you place some dry grass in a water glass, in few days a deal ofprotists will appear. If instead you will put the same material in a close glass pot andif you boil it, nothing will be born. Only some rare thermoresistant microorganisms,bacteria which resist the high temperature of boiling water.
... Uhm, and still there is something which is not working: if any living being comes fromanother living being, from where has come the first living being from which all others arederived? Can we consider completely falsified the theory of the spontaneous generationwith these experiments? Is it possible to assert that, even if the spontaneous generationis not the usual way with which living creatures are born, at least at one time duringbillions of years it has happened on the Earth or another place in the Universe? It is noaccident that there are scientists who study how life began in the first place.
Internet keywords: spontaneous generation.
If placed in a suitable nutrient environment, cells and tissues of many organisms are ableto reproduce and form new plants or animals. Now, we will deal with vegetable tissues,whose culture is simpler than that of animal cellules and tissues. It is necessary toprepare a nutritive and sterilized culture medium for the piece of plant tissue. Keep theculture in the suitable conditions of light and temperature and which vary from plant toplant. Over many days, you will observe the growth of a callus or roots or shoots. In thisway you can obtain even whole plants (cloning). These experiments show that special cellskeep all the information necessary to generate the whole plant.
As we have mentioned, it is necessary avoid bacteria and moulds in the cultures. For thisyou will need sterilize tools, vials, tubes, and nutrient medium. Place each in anautoclave for a ten minutes or, lacking an autoclave, a pressure cooker. The tissues aswell have to be free from microorganisms and they have to be sterilized with bleach (40%solution for 15 min) or with alcohol.
The transfer of the tissues into the test tubes has to be made in aseptic conditions,using a sterile box. Lacking that, make your first trials in a quiet place, as devoid ofwind and dust as possible. The culture medium should contain water, vitamins (particularlythose of the B-complex. For this, use yeast extract), sugars, mineral salts. To enrich thewater with mineral salts, boil some water with a handful of soil, then let settle andfilter it. Usually, people also insert 0.5-0.8% of agar-agar to "solidify" themedium. As culture medium, coconut milk has been used. It contains mineral salts, sugars,vitamins and growth hormones.
1 - For yours first tests of micropropagation, use strawberries tissues.
2 - If this simple experiment interests you, you can continue on the way of the invitro culture of vegetable tissues. In fact you can propagate a lot of plants in thisway. Plants easy to culture are the following: tomato, potato, strawberry, chrysanthemum,geranium, sunflower, tobacco, carrot and onion. You can use tissues obtained from seeds,such as the embryo, but you can use also tissues taken from adult plants, such as tissuesof roots, stems, apical buds, shoots, leaves, even single cells. Each plant and tissue hasits own needs. They are different from each other. You can try the influence of thevegetable hormones, special nutrients, etc.
This field is very broad and complex so, if you are interested in continuing with theseexperiments, you can buy special books and you should build a sterile box.
Plant Tissue Culture for the Gardener
Basic Principle in Plant Tissue Culture Technique
Plant Tissue Culture Kit Manual
Plant Micropropagation Using African Violet Leaves
Plant Tissue Culture (links)
Internet keywords: in vitro culture plant tissue micropropagation.
Range plant growth and development are controlled by ..
Hydroponics is a method of growing plants without soil. Plants are simply placed in water with the necessary chemicals. As plants are deprived of support from the ground, they will fall down. To support the plants, an inert material like expanded clay pebbles is used in a pot in the tank (figure 5). Before inserting a plant in a hydroponic system, you must carefully remove all soil from the roots otherwise bacteria will putrefy them.
For many houseplants you can use tap water. Though, particularly for vegetables, it is advised to add appropriate nutrients. This cultivation method has the advantages of both requiring less frequent waterings and using very little water. With this system you can grow nearly any houseplant or vegetable. Hydroponics is useful also to show what nutrition plants need.
1 - Place some houseplants in hydroponics.
2 - Try hydroponics with vegetables and find the suitable nutrients.
Hydroponics in the Classroom
Growing plants without soil
To teach orphaned children how to grow their own food with hydroponics (gardening that uses very little water).
Organic Greenhouse Vegetable Production
Internet keywords: hydroponics classroom.
Making an aquarium or a terrarium is not a complicated thing. Learning to build them isvery useful for those who are fond of breeding animals, observing them, taking picturesand movies. You can use an aquarium to breed fish, amphibians, protists, algae, artemia,shrimps, etc. You can use a terrarium to breed many species of animals, but avoid raisingspecies which suffer in captivity. Aquaria and terrariums can be used also to take picturesof animals temporarily taken from their environment.
In their simpler form, acquaria and terrariums are simple glass boxes enclosed on 5 sidesand which can be provided with a lid. This simple container is suitable to breedamphibians and as a terrarium. Aquaria for fish require a compartment for a filter, a pumpfor water circulation, another pump for air, a thermostat, lighting, etc. We'll deal ofthe simplest aquaria.
How you can build an aquarium? In first you have to make a drawing. The bottom glass hasto be surrounded by the other four walls and it has to be the thickest. The thickness ofthe plates has to be proportioned to the size of the aquarium. Avoid building too wide,and more importantly, too high an aquarium. The pressure of the water increases and couldunglue the plates. After having drawn the acquarium you have to cut the glass plates bymeans of a glasscutter. To do this keep the glasscutter vertical and push down with forcewhile you move it along a ruler. This operation require practice, so use some scrap piecesuntil you have the necessary manual ability. It is important you use a sharp glasscutter,kept in oil to avoid rust. Before gluing the slabs, you have to round off the edges withsandpaper in order to remove their sharp edges. With some acetone, clean the slabs wherethe silicone rubber will be deposited. As the acetone is toxic, work outdoor or in a wellventilate piece. Use high quality transparent silicone. To keep the internal walls free ofexcessive glue, on the slabs and near the gluing positions, place stripes of sticking tape(figure 6). When the silicone is cured, remove these stripes and the excess glue.
: handling and cutting glass is a dangerousoperation which has to be made only by adult people wearing gloves and a heavy apron. Away to elegantly solve this problem is to order plates. A hardware or building supplystore can help. Never move aquaria and terrariums containing water or stones, move them onlywhen they are empty. Do not place aquaria in positions where a water leak could damagesomething below them, for example over electrical devices or sockets, and books. Onlyadults should handle glass-made aquaria or terrariums. Give children transparent plastictanks. Do not keep dangerous or rare organisms. Do not breed and most important, do notfree species which do not belong to your environment! Do not free sick animals or plants.
Reef Aquarium Guide
CyberAqua (list of links)
Internet keywords: aquarium glass homemade.
Hydrofarm - A Review of Factors Affecting Plant Growth
A Review of Factors Affecting Plant Growth
Factors Affecting Plant Growth
on plant growth and development ..
Light quality is an important environmental factor for plant growth and development
then used by the plant for its own growth and ..
We can conclude that minerals are also important for healthy plant growth and development.
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