Wednesday, March 18, 2015

INTRODUCTION TO GENETICS

Genetics

Introduction to Genetics:

A persons eye can be blue, brown, green, gray, or hazel; a person’s hair can be different shades of brown, red, blond, or black; a parakeet’s feathers can be green, blue, or yellow, with black or gray markings. What causes these biological spectra of colours? We can frame the question in more general terms: What is genetic basis of variation among a populations individuals? Or, what principles account for the transmission of these variations from parents to offspring?

One possible explanation of heredity is a “blending hypothesis”, the idea that genetic material contributed by two parents mixes in a manner analogous to the way blue and yellow paints blend to make green. The hypothesis predicts that mating a blue parakeet with a yellow one would result in green offspring, and once blended, the hereditary material of the two parents would be as inspirable as the colours of mixed paint. If the blended hypothesis were correct, over many generations a freely mating population of blue and yellow parakeets would give rise to a uniform population of green birds. The actual results of parakeet breeding, however, contradict such a prediction. The blending hypothesis also fails to explain other phenomenon of inheritance, such as traits skipping a generation.

An alternative to the blending model is a "particulate model" of Inheritance: the gene idea. According to this model, parents pass on discrete heritable units – genes – that retain their separate identities in offspring. An organisms collection of genes is more like a bucket of marbles than a pail of paint. Like marbles, genes can be sorted and passed along, generation after generation, in undiluted form.


The first scientific advance in the study of inheritance was made by the Austrian monk Gregor Mendelwho published a paper in 1866 which laid the foundations for the present-day science of genetics. He demonstrated that characteristics do not blend but pass from parents to offspring as discrete units. These units, which appear in the offspring in pairs, remain discrete and are passed on to subsequent generations by the male and female gametes which each contain a single unit. The Danish botanist Johannsen called these units GENES in 1990 and the American geneticist Morgan in 1912 demonstrated that they are carried on the chromosomes. Since the early 1900s the study of genetics has made great advances in explaining the nature of inheritance at both the level of the organism and at the level of gene.

Definition of Genetics:

Genetics is the study of genes, heredity, and variation in living organisms. 

A Chromosome

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Why is sea water salty and Why cant humans drink salt water

The water of the oceans is salty because the rivers dissolve salt minerals from the mountains and bring them into the sea.
When the water evaporates at the surface the salt remains.
Over millions of years, the amount of salt reached such a scale that the sea water has become undrinkable.

What is salinity?

The salt content in seawater, expressed in grams, is called salinity. The average ocean salinity is 35ppt, which means that in every kilogram (1000 grams) of seawater, 35 grams are salt.
The ocean water in estuaries is a mix of fresh and ocean water, so the salinity there is less than the open ocean. Also, bottom water almost always contains more salt than surface waters.

Why cant humans drink salt water?

The ocean animals have same salinity inside their bodies as the water outside, because the water likes a balance. If for example salt water animal is placed in fresh water, the fresh water will enter into the animal through its skin. Also, if fresh water animal found is placed into salty water, the water inside of it will rush out.  This process in which water flows from an area of high concentration (lots of water, little salt) to an area of low concentration (little water, lots of salt) is called osmosis.
This is the main reason why humans can’t drink salt water. 
When extra salts enter the body, it will try to expel them as quickly as possible. The kidneys will try to flush the salts out in the urine, and in the process, it will pump out large amount of water - more than taken.
This leads to dehydration, and the cells and organs will not be able to function properly.

The Dead Sea is the saltiest sea in the world, six times saltier from the water in the oceans!

The Dead Sea water has so many minerals, that the head and shoulders of the swimmers are always out.  

The Dead Sea is actually a large, narrow salt lake, which lies between the River Jordan and the State of Israel. It, has the lowest elevation in the world, about 400 meters below the surface of the Mediterranean Sea.


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Jet lag What is Jet Lag – Symptoms Treatment How to Avoid Jet Lag

Jet lag is the disorientation in the normal biological circadian rhythm, which is experienced by a person traveling from one time zone to another with more than four hours difference.
The greater the time difference, the greater the degree of disorientation.

Jet lag symptoms

During the time the traveler needs for his or her body to adjust to new eating and sleeping patterns, he or she may feel disoriented, tired, and “out of sync” with the new schedule, that is, sleepy during the day, awake at night, and hungry at inconvenient hours.
The body temperature may also no longer be synchronized with day and night requirements.

How to avoid jet lag

The symptoms of jet lag are often made worse by overeating and by a high consumption of alcohol during the flight, which is known to cause dehydration.
It is, therefore, advisable to drink plenty of nonalcoholic fluids during a long flight.
Some people believe that jet lag may be completely avoided by abstaining totally from alcohol and eating as lightly as possible during the flight, preferably on the schedule of mealtimes in the destination time zone.
Additionally, a diet developed by some researches is thought by some travelers to help adjust the circadian rhythms prior to flying by altering the intake of food and caffeine for several days before travel. There is no medical evidence to support this; people are advised to check with their physician before following the diet, since it could have detrimental effects on certain health conditions, such as diabetes.

Jet Lag Treatment

The body may take a long time to adjust to a new circadian rhythm, possibly as long as 10 days.
If the stay in the new time zone is to be brief, it is often advisable not to try to adapt, but rather to retain the familiar rhythm, even at the expense of unusual hours.
On a business trip this generally means that at least some working hours fall within commercial times.
A longer stay in the new time zone requires adaptation.
A mild sedative, prescribed by a physician, may help to ensure proper sleep for a few nights after arrival. The body will adjust its eating habits to conform with the new sleeping pattern.
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SIMPLE RECIPE TO THINK THROUGH CONSTRAINTS



    Whenever you get into a situation of confusion, remember a journey of travel you have undertaken in the past

    e.g going to coimbatore or bangalore from chennai …

  1. All that you do is to decide the destination and target date
  2. Then look for buying ticket..if class of your choice not available, you will book the next best. If train not available you will try bus, if not air..BUT NEVER DEVIATE from the goal of reaching the destination on that date.
  3. Again once ticket is booked you plan everything else, like what to take, whom to inform etc., try to reach station before the departure time. HERE IF THERE ARE ANY CONSTRAINTS ON THE WAY, OR LAPSES ON YOUR PART you will not worry and abandon the trip. You try to find a means and methods to rectify or overcome the constraints and MOVE ahead.
  4. Next on board also, in your many journeys you must have experienced lot of discomfitures, difficulties, constraints, set backs during journey like e.g no proper food, no water in compartment or unclean areas, may be cockroaches etc.. But you overlook, overcome them and KEEPING FOCUS on the GOAL and try to reach the destination..
  5. You can think of AIR travel too similarly.
  6. IT IS SUCH A SMALL AND SIMPLE PRINCIPLE ONE CAN FOLLOW IN LIFE TOO.





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Furosemide What is Furosemide



Furosemide is powerful diuretic available in tablet and injection form. Furosemide (trade name – Lasix), is used to treat edema, a retention of fluid that accompanies disorders such as heart failure, kidney disease, and cirrhosis of the liver.
Furosemide may also be prescribed in the treatment of high blood pressure and sometimes is used in the treatment of overdoses of certain drugs, such as barbiturates, because it increases the flow of urine.

Furosemide Side Effects

Furosemide may cause nausea and diarrhea, and it may, in rare cases, result in deafness.
The use of furosemide may also cause a de crease in the levels of sodium, calcium, and potassium in the blood. For this reason, potassium supplements should be prescribed when furosemide is taken for a long period of time.
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Shooting Gallery Game for Kids Homemade Shooting Gallery

This interesting toy, with its funny animal targets, and a harmless pistol with which to shoot at them, will provide an endless amount of fun for a winters evening or stormy afternoon.

Fig. 212.—The Completed Toy Shooting Gallery.
Figure 212 shows the completed toy, and Fig. 213 the box that forms

The Framework. The targets can be arranged to suit the form of box that you find, and the number may be increased or decreased to suit the space.
Fig. 213.—The Box Framework.

The right position for the box is upon its side so its open top forms the front of the target box (Fig. 213). The horizontal piece A (Fig. 213) is fastened between the ends of the box, to support targets. It is held in place by nails driven through the box ends into its ends. If your box is much larger than the one shown in the illustration, you can provide two crosspiece supports for targets, instead of one.

The Circular Target should be drawn upon a piece of cardboard with a compass, or, by marking around a cup or small saucer to make the outer circle, marking around a can cover for the second circle, and a coin for the center circle. Blacken the outside and center rings with ink, or by rubbing with a soft pencil.

Figs. 214-215.—Details of Targets.

Figure 214 shows how the target should be hinged in place to the horizontal strip A. Tack or glue the lower edge of the piece of cardboard to a block of wood B. Then cut a hinge-strip out of a piece of dress lining, and either tack or glue one-half of it to block B and the other half to the target support A.

The Animal Targets are made with pictures cut from magazines and newspapers. The pictures should be colored with crayons or water-colors, to make them as nearly like their right colors as possible.

After cutting out the pictures, paste them upon cardboard, mount the pieces of cardboard upon blocks of wood, as shown at B and C (Figs. 214 and 215), and hinge the blocks to the target supports with cloth strips. B shows the method of hinging the targets to strip A, and to the lower side of the box, and C shows the method of hinging the targets to the ends of the box. The former targets fall backwards when struck; the latter targets swing sideways when struck.
Fig. 216.—The Card-shooting Pistol.

Figure 216 shows
The Card-shooting Pistol, and Figs. 217, 218, and 219 show the details for making it. Cut block A about 8 inches long, and block B about 3 inches long. Nail A to B as shown. Then take two rubber-bands, loop them together end to end, as shown in Fig. 218, and fasten one end of the looped bands to the end of block A by means of a nail driven into the block and bent over as shown in Fig. 217. Cut a piece of cardboard about I inch square, notch the center of two opposite edges (Fig. 219), and fit [Pg 144] the loop of the free end of the rubber-bands over the piece of cardboard and into the notches, as shown in Figs. 217 and 218. This completes the pistol.

The toy pistol shoots small squares of cardboard, placed in it as shown in Figs. 216 and 218, with one corner slipped beneath the rubber-band loop.
Figs. 217-219.—Detail of Card-shooting Pistol.

Number the Targets as shown in Fig. 212, marking the circular target "25," four of the animal targets "10," and the remaining four "5." Each number represents the score of that particular target.

When Shooting, stand 3 or 4 feet away from the target box. Aim at the circular target, because that one counts the most. If you miss it, there is the chance, of course, of hitting one of the other targets below or to one side of it and making a smaller score.

HOME-MADE TOYS FOR GIRLS AND BOYS
BOOKS BY A. NEELY HALL
LOTHROP, LEE & SHEPARD CO., BOSTON
Published, August, 1915
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Tuesday, March 17, 2015

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Brain Human Anatomy Picture Function Parts Conditions More


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