Chromosomes Karyotype picture of a cells chromosomes arranged

Chromosomes… • Karyotype – picture of a cell’s chromosomes arranged in order from largest to smallest • Homologous pairs (from mom and dad) next to each other

GENES

GENES • Pieces of DNA that code for specific proteins • Encompassed in the chromosome and make up the genetic information. • There are thousands of genes – Ex. gene for eye colour – gene for colour vision – Gene for diseases (like hemophilia)

DNA • Strands of information • Double helix structure • (twisted ladder) • Nitrogen bases make up the rungs • Sugar and phosphate backbone

LOOKING INTO A NITROGENOUS BASE

NUCLEOTIDES FORM IN 2 STRANDS SO BASES CAN PAIR UP

THINK OF IT THIS WAY

3 letter code for a specific AMINO ACID A string of hundreds of amino acids makes a PROTEIN, which gives us our characteristics

RECAP…

A DNA T G C DNA is the code in which ALL information necessary to make a complete organism is stored. C GA T G C T A C G A T T A DNA Helix G C C G T 1 n. M =. 000001 M Everything that can make this complete organism, human in this instance, is contained within the nucleus of each and every cell! A 2 n. M

A T G C Packaging DNA C GA T G C T A C G A T T A DNA Helix G C C G T 2 nm A DNA is “packed”, “coiled”, “wrapped” inside structures called Cromosomes.

A T G C Packaging DNA C GA T G C T A C G A T T A DNA Helix G C C G T A 2 nm

A T G C Packaging DNA C GA T G C T A C G A Protein spheres T T A DNA Helix G C C G T A 2 nm

Packaging DNA G C T A C G A T T A G C C G T A

Packaging DNA G C T A C G A T T A G C C G T A

A Packaging DNA C G A T T A G C C G T A

Packaging DNA One Chromosome T G C A

If all The DNA wrapped in each of the Chromosomes in one cell were unwrapped, it would be enough to stretch to the Moon and back in 6000 times!

WHY ALL CELLS HAVE THE SAME AMOUNT OF INFORMATION • Sperm and egg zygote (makes a somatic cell) • (23 + 23) 46 chromosomes • Haploid cells • Somatic cells are DIPLOID and have 2 n chromosomes.