Amazing DNA facts

Amazing DNA facts

DNA stands for Deoxy-ribo-Nucleic Acid. 
1. On February 28, 1953, Francis Crick and James Watson figured out the structure of deoxyribonucleic acid (DNA).  That structure, a 'double helix', can "unzip" (separate into two long strands) to make copies of itself.  This discovery confirmed suspicions that DNA carried an organism's hereditary information.

2. DNA molecules are linked, one after another, like pearls on a very long string.

3. DNA molecules are the "software" that direct cellular activity and determine everything about an organism - from what it looks like to how long it is likely to live. Genes are pieces of this DNA, and are the fundamental units of heredity.

4. The complete human genome consists of approximately 3 billion DNA molecules.

5. On average, each chromosome has about 65 million DNA molecules.

6. A gene is a stretch of DNA molecules (ranging in length from thousands to tens of thousands of DNA molecules, in some cases they may be even larger).

7. Between genes, along the length of a chromosome, there may be long stretches of DNA, which have no known function.

8. A chromosome contains about 1000 genes.

9. Humans have approximately 30,000 different genes spread out over the 46 chromosomes.

10. Humans get one complete set of genes from each parent.

11. In April 2003, the National Human Genome Research Institute (NHGRI) celebrates the completion of the human genome sequence and the 50th anniversary of the description of the DNA double helix.

12. The nucleus, or control centre, of a cell, is where the DNA is coiled up into chromosomes. With the exception of reproductive cells, every cell has 46 chromosomes. Twenty-two pairs of the chromosomes are similar in terms of size, shape and genetic content. The twenty-third pair determines the sex of the individual, and is composed of either two x chromosomes (female) or an x and a y chromosome (male).

13. DNA molecules are incredibly long. If all of the DNA from all of your cells was stretched out into a single thread, it would extend to the moon and back about one million times!

14. DNA is found inside every cell in our body (apart from red blood cells).

15. Each cell contains roughly 2 metres of DNA.

16. Humans have roughly 100,000,000,000,000 (100 trillion cells).

17. If you unravelled all of your DNA from all of your cells and laid out the DNA end to end, the strand would stretch from the Earth to the Sun hundreds of times (the sun is approximately 98 million miles away from Earth).

18. You could fit 25,000 strands of DNA side by side in the width of a single adult hair.

19. The DNA is tightly coiled up and structured into 46 chromosomes.

20. Our chromosomes are arranged in pairs. We inherit one copy of the pair from our Mum and one from our Dad.

21. When chromosomes are stained they can be quite easily recognised by their distinctive stripy patterns. This is used to check whether people have the right number of chromosomes and check for any rearrangements.

22. There are approximately 3 billion (3,000,000,000) chemical letters (otherwise known as bases) in the DNA code in every cell in your body.

23. This is a massive amount of information. It would fill 200 yellow pages in small type font.

24. If you tried typing the whole genetic code out (typing at 200 letters per minute) it would take 29 years (without taking any breaks!).

25. The DNA is made up of 4 building blocks (an alphabet of 4 letters spelling out the instructions to help us grow, develop and function).

26. The four letters in the DNA alphabet- A, C, G and T -are used to carry the instructions for making all organisms. The sequence of these letters holds the code - just like the order of letters that makes words mean something. Each set of three letters corresponds to a single amino acid.

27. Sections of DNA that code for proteins are called genes. The complete set of genetic information for an organism is called the genome. The latest estimate is that there are between 20,000 and 25,000 genes in the human genome.

28. We share a lot of DNA with other animals, plants and microorganisms.

29.  Every cell in your body has 46 chromosomes except for egg and sperm cells.

30. Women’s chromosomes are described as 46,XX; men’s as 46,XY.

Women have
46 chromosomes (44 autosomes plus two copies of the X chromosome) in their body cells and are described as 46,XX. 23 chromosomes (22 autosomes plus an X chromosome) in their egg cells.

Men have  
46 chromosomes (44 autosomes plus an X and a Y chromosome) in their body cells and are described as 46,XY. 23 chromosomes (22 autosomes plus an X or Y chromosome) in their sperm cells.

AMAZING FACTS ABOUT HUMAN BODY

AMAZING FACTS ABOUT HUMAN BODY

1. A human being loses an average of 40 to 100 strands of hair a day.

2. A cough releases an explosive charge of air that moves at speeds up to 60 mph.

3. Every time you lick a stamp, you consume 1/10 of a calorie.

4. A fetus acquires fingerprints at the age of three months.

5. A sneeze can exceed the speed of 100 mph.

6. Every person has a unique tongue print.

7. According to German researchers, the risk of heart attack is higher on Monday than any other day of the week.

8. After spending hours working at a computer display, look at a blank piece of white paper. It will probably appear pink.

9. An average human drinks about 16,000 gallons of water in a lifetime.

10. A fingernail or toenail takes about 6 months to grow from base to tip.

11. An average human scalp has 100,000 hairs.

12. It takes 17 muscles to smile and 43 to frown.

13. Babies are born with 300 bones, but by adulthood, we only have 206 in our bodies.

14. Beards are the fastest growing hairs on the human body. If the average man never trimmed his beard, it would grow to nearly 30 feet long in his lifetime.

15. By age sixty, most people have lost half of their taste buds.

16. By the time you turn 70, your heart will have beat some two-and-a-half billion times (figuring on an average of 70 beats per minute).

17. Each square inch of human skin consists of twenty feet of blood vessels.

18. Every human spent half an hour as a single cell.

19. Every square inch of the human body has an average of 32 million bacteria on it.

20. Fingernails grow faster than toenails.

21. Humans shed about 600,000 particles of skin every hour about 1.5 pounds a year. By 70 years of age, an average person will have lost 105 pounds of skin.

22. At rest, a person breathes about 14 to 16 times per minute. After exercise it could increase o over 60 times per minute.

23. New babies at rest breathe between 40 and 50 times per minute. By age five it decreases to around 25 times per minute.

24. The total surface area of the alveoli (tiny air sacs in the lungs) is the size of a tennis court.

25. The lungs are the only organ in the body that can float on water.

26. The lungs produce a detergent-like substance which reduces the surface tension of the fluid lining, allowing air in.

27. Your heart is about the same size as your fist.

28. An average adult body contains about five quarts of blood.

29. All the blood vessels in the body joined end to end would stretch 62,000 miles or two and a half times around the earth.

30. The heart circulates the body's blood supply about 1,000 times each day.


31. The right lung is slightly larger than the left.

32. Hairs in the nose help to clean the air we breathe as well as warming it.

33. The capillaries in the lungs would extend 1,600 kilometres if placed end to end.

34. We get two sets of teeth. Our 20 'Baby Teeth’ are replaced starting at around 6-7 years of age with our 32 ‘Adult Teeth’.

35. 1.5 litres of saliva are produced each day.

36. The oesophagus is approximately 25cm long.

37. Tears and mucus contain an enzyme (lysozyme) that breaks down the cell wall of many bacteria.

38. The brain looks like a giant, wrinkled walnut.

39. Unlike other body cells, brain cells can not regenerate. Once brain cells are damaged they are not replaced.

40. The brain and spinal cord are surrounded and protected by cerebrospinal fluid.

41. The longest muscle in the body is the sartorius, from the outside of the hip, down and across to the inside of the knee. It rotates the thigh outwards and bends the knee.

42. The smallest muscle in the body is the stapedius, deep in the ear. It is only 5mm long and thinner than cotton thread. It is involved in hearing.

43. The biggest muscle in the body is the gluteus maximus, in the buttock. It pulls the leg backwards powerfully for walking, running and climbing steps.

44. The largest bone is the pelvis, or hip bone. In fact it is made of six bones joined firmly together.

45. The longest bone is the 'femur', in the thigh. It makes up almost one quarter of the body's total height.

46. The smallest bone is the 'stirrup', deep in the ear. It is hardly larger than a grain of rice.

47. The ears and end of the nose do not have bones inside them. Their inner supports are cartilage or'gristle', which is lighter and more flexible than bone. This is why the nose and ears can be bent.

48. After death, cartilage rots faster than bone. This is why the skulls of skeletons have no nose or ears.