Question

Describe how eukaryotic DNA is folded into a chromosome

Answer 1

FOLDING OF DNA INTO THE CHROMOSOMES IN EUKARYOTIC CELL:

DNA: DNA is a genetic material that determines the traits ranging from the hair colour to propensity to develop chronic disease. All the DNA is packed into chromosomes in the cells. All the eukaryotes have chromosome except bacteria.chromosomes are made up of long pieces of double stranded DNA twisted and condensed into compact package. If left uncondensed, the strands of DNA would be about 2 meters each, far too long to fit inside the cell. A person has 22 pairs of chromosomes, plus two sex chromosomes for a total of 46.

ANSWER : DNA FOLDING IN CHROMOSOMES

SPECIALIZED PROTEINS BIND TO THE DNA AND HELP FOLD IT PROPERLY SO THAT IT CONDENSES INTO THE TIGHT CONFIGURATION REQUIRED TO MAKE CHROMOSOMES WITHOUT GETTING TANGLED. THE CONDENSED DNA MUST ALSO BE CONFIGURED SO THAT ENZYMES CAN REACH EACH PART OF IT FOR REPAIR, TRANSCRIPTION AND TRANSLATION.THE BASIC DNA DOUBLE HELIX IS WOUND AROUND HISTONE PROTEINS AND THESE DNA PROTEIN COMPLEXS THEN FOLD INTO STRUTURES CALLED NUCLEOSOMES. A STRAND OF NUCLEOSOMES WINDS INTO A FIBER CALLED CHROMATIN, WHICH IS ABOUT 30 NANOMETERS IN AN ELECTRON MICROSCOPE. A CHROMOSOME IS MADE UP OF TIGHTLY PACKED CHROMATIN STRANDS.