2006-07-20 03:05:25 · 7 answers · asked by mariz s 2 in Science & Mathematics ➔ Biology
DNA is not confined just to the nucleus, it is present in other organelles like chloroplast and mitochondria too. However the nuclear DNA is in majority.
Anyway, DNA is confined to a membrane bound organelle in order to prevent its degradation by DNAses present in the cytoplasm. These are enzymes that denature DNA.
2006-07-20 03:12:00 · answer #1 · answered by Anonymous · 14⤊ 3⤋
It depends on the level of complexity of the organism.
Prokaryotes are unicellular organisms which don't have a nucleus-the DNA is in the cytosol in the form of a complex with various proteins and in some cases it is believed to be attached to the plasma membrane.
In eukaryotic cells the majority of the DNA is within the nucleus, while there is also mitochondrial DNA (and DNA in chloroplasts in plant cells). Such organelles are thought to have evolved from the engulfment of prokaryotic cells and their symbiosis with an ancestor of the eukaryotic cell.
The nuclear membrane itself might have also evolved from a deep invagination of the plasma mebrane in a prokaryotic ancestor which is in agreement with the fact that the inside of the nucleus is topologically equivalent to the cytosol, while the space between the inner and outer side ot the nuclear mebrane is topologicaly equivalent to extracellular space.
Compartmentalization helps a lot: in increasing local concentration of molecules, controlling which reactions will occur, applying more levels of regulating gene expression etc
Of course it helps to protect the fragile DNA better from oxidation and other chemical damages but it is not 100% efficient and it is not the only reason for the evolution of the nucleus.
2006-07-20 04:13:31 · answer #2 · answered by bellerophon 6 · 0⤊ 0⤋
the dna is the most vital molecule to your survival. it encodes all the necessary information to keep you alive and kicking. so to have swimming in the cytoplasm with billions of other molecules would be quite silly wont it? so the dna is safely and neatly wound up with the help of proteins and histones and kept safe and sound in the nucleus
2006-07-20 03:10:20 · answer #3 · answered by sandeepan88 1 · 0⤊ 0⤋
It's not true. There is also DNA in the mitochondria, which are in the cytoplasm.
2006-07-20 03:09:20 · answer #4 · answered by Zelda Hunter 7 · 0⤊ 0⤋
It is in a prokeriatic cell. This allows, in the eukariotic cell, which is what makes up our bodies to have a more designed form. And allowing mor efficenntcy when it comes to what ever the job at that cell will be.
2006-07-20 03:09:10 · answer #5 · answered by cosmo5847060 3 · 0⤊ 0⤋
compartmentation leads to efficiency and fidelity. but there is DNA in other organelles such as the mitochondria
2006-07-20 03:09:20 · answer #6 · answered by ngonde 2 · 0⤊ 0⤋
Geekgal, you are so cool. I concur!
2006-07-20 03:46:07 · answer #7 · answered by Paul 3 · 0⤊ 0⤋