BIO.B.1 Cell Growth and Reproduction
Topic Summary for DNA Replication:
Each strand of the double helix has all the information needed to reconstruct the other half by the mechanism of base pairing. Because each strand can be used to make the other strand, the strands are said to be complementary. DNA copies itself through the process of replication:
The two strands of the double helix unzip, forming replication forks.
New bases are added, following the rules of base pairing (A with T and G with C).
Each new DNA molecule has one original strand and one new strand.
DNA polymerase is an enzyme that joins individual nucleotides to produce a new strand of DNA.
During replication, DNA may be lost from the tips of chromosomes, which are called telomeres.
The cells of most prokaryotes have a single, circular DNA molecule in the cytoplasm. Eukaryotic cells have much more DNA. Nearly all of it is contained in chromosomes, which are in the nucleus.
Replication in most prokaryotic cells starts from a single point and proceeds in two directions until the entire chromosome is copied.
In eukaryotic cells, replication may begin at dozens or even hundreds of places on the DNA molecule, proceeding in both directions until each chromosome is completely copied.
Topic Summary for DNA Replication:
Each strand of the double helix has all the information needed to reconstruct the other half by the mechanism of base pairing. Because each strand can be used to make the other strand, the strands are said to be complementary. DNA copies itself through the process of replication:
The two strands of the double helix unzip, forming replication forks.
New bases are added, following the rules of base pairing (A with T and G with C).
Each new DNA molecule has one original strand and one new strand.
DNA polymerase is an enzyme that joins individual nucleotides to produce a new strand of DNA.
During replication, DNA may be lost from the tips of chromosomes, which are called telomeres.
The cells of most prokaryotes have a single, circular DNA molecule in the cytoplasm. Eukaryotic cells have much more DNA. Nearly all of it is contained in chromosomes, which are in the nucleus.
Replication in most prokaryotic cells starts from a single point and proceeds in two directions until the entire chromosome is copied.
In eukaryotic cells, replication may begin at dozens or even hundreds of places on the DNA molecule, proceeding in both directions until each chromosome is completely copied.