background image

14

15

Red blocks represent 

the base guanine.

1x

1x

2x

Содержание 1953

Страница 1: ...1953 ...

Страница 2: ...s way they learn about the function of different genes the units of information in DNA and how the traits relate to the genetic make up of individuals What can we learn by studying DNA Chemists first identified DNA in the late 19th century In the early 20th century scientists showed that it is essential for the transmission of hereditary traits from one generation to the next LMB scientists in Cam...

Страница 3: ...1 2 Blue blocks represent adenine base 1x 1x 2x ...

Страница 4: ...sent Hydrogen Bonds between the bases These weak bonds hold our DNA strands together Green thymine pairs with blue adenine When DNA is copied these base pairs are melted Note that adenine is a larger base than thymine 2x 1x ...

Страница 5: ...5 6 7 Grey Blocks represent the sugar deoxyribose one unit of sugar and the nucleobase combined is called a nucleoside 2x 2x 1x ...

Страница 6: ...8 9 1x 2x 1x ...

Страница 7: ...10 11 2x 2x ...

Страница 8: ...The black blocks represent the phosphate groups of the backbone You ve completed a full nucleotide base pair now start building the next tier 12 13 2x 2x ...

Страница 9: ...14 15 Red blocks represent the base guanine 1x 1x 2x ...

Страница 10: ...16 17 Yellow bricks show cytosine which pairs with guanine notice the difference between the sizes 2x 1x ...

Страница 11: ...18 19 20 2x 2x 1x ...

Страница 12: ...21 23 22 24 2x 2x 2x 1x 2x ...

Страница 13: ...25 Add this base pair red yellow to the base blue green to make the first turn of your double helix ...

Страница 14: ...26 27 Repeat steps 14 24 Repeat steps 1 8 10 13 ...

Страница 15: ...28 1x 26 1x 27 Add nucleotide base pairs to start forming the helix ...

Страница 16: ...4x 26 3x 27 29 ...

Страница 17: ...is the information stored and how could you access it 1 1 100 000 000 1 Sugar Phosphate backbone Adenine Guanine Thymine Cytosine 2 nm 20 cm 3 4 nm 34Å 34 cm One strand of DNA measures about 2 nanometers in diameter It would take about 12 500 strands of DNA to equal the diameter of a human hair G C A T ...

Страница 18: ...ines eye colour called OLA2 340 457 base pairs would reach over 10 km The model contains 11 base pairs in a human cell there are 6 billion base pairs If you unravelled all the DNA from one human cell it would measure 2 metres At the scale of the Lego model that would reach more than half way to the moon ...

Страница 19: ...more than 250 times How can all this DNA fit DNA has to be packaged A chromosome is a single piece of coiled DNA which is packaged up with proteins Humans have 46 chromosomes receiving 23 from each parent Humans are 99 8 genetically identical so just a 0 2 difference provides all the diversity and variation seen in the human population ...

Страница 20: ...Lego kits were designed by John Schollar at the National Centre for Biotechnology Education Images were supplied by The Wellcome Library LMB Visual Aids ...

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