Other scientists have argued that human beings originated in Africa before moving to other regions 150,000 to 200,000 years ago. Homo sapiens discovered in Middle Awash, Ethiopia, from 160,000 years ago were believed to be the oldest 'modern' human beings.Other remains previously found in Israeli caves are thought to have been more recent and 80,000 to 100,000 years old.ther scientists have argued that human beings originated in Africa before moving to other regions 150,000 to 200,000 years ago. Homo sapiens discovered in Middle Awash, Ethiopia, from 160,000 years ago were believed to be the oldest 'modern' human beings.
The structure of DNA lends itself easily to DNA replication. Each side of the double helix runs in opposite (anti-parallel) directions. The beauty of this structure is that it can unzip down the middle and each side can serve as a pattern or template for the other side (called semi-conservative replication).However, DNA does not unzip entirely.It unzips in a small area called a replication fork, which then moves down the entire length of the molecule. Let's look at the details: 1  An enzyme called DNA gyrase makes a nick in the double helix and each side separates. 2  An enzyme called helicase unwinds the double-stranded DNA.NA Replication. Â­DNA carries the information for making all of the cell's proteins. These proÂ­teins implement all of the functions of a living organism and determine the organism'Â­s characteristics. When the cell reproduces, it has to pass all of this information on to the daughter cells.
Transcription. 1. Transcription: The DNA unwinds and unzips in the area of the gene. A promoter is needed in order to start. Enzymes match RNA nucleotides to the unzipped nitrogen bases of the gene, forming a single strand of mRNA. 2. The strand of mRNA detaches from the gene and goes out of the nucleus through one of the pores in the nuclear envelope. The DNA zips back together and winds back up. 3. The mRNA finds a ribosome where protein synthesis will happen.