1. DNA replicates to ensure that each new cell receives a complete and identical copy of the genetic material during cell division, allowing for the transmission of genetic information from one generation of cells to the next.
2. DNA replication is described as semi-conservative because each of the two resulting DNA molecules consists of one original (parental) strand and one newly synthesized strand. This was demonstrated by the Meselson-Stahl experiment.
3. Two key enzymes used during DNA replication are helicase and DNA polymerase. Helicase unwinds the double-stranded DNA by breaking the hydrogen bonds between complementary base pairs, creating a replication fork. DNA polymerase synthesizes the new DNA strand by adding nucleotides complementary to the template strand in the 5’ to 3’ direction.
4. DNA replication occurs during the S phase (Synthesis phase) of the cell cycle, which takes place between the G1 and G2 phases, before mitosis begins.
5. In eukaryotic cells, DNA replication occurs in the nucleus. In prokaryotic cells, which lack a nucleus, it occurs in the cytoplasm, typically at a region called the nucleoid.
True/False — If the statement is false, correct the statement.
F - Cytosine, guanine, thymine and adenine are referred to as nitrogen bases.
T - DNA is in the shape of a helix.
F - A nucleotide is made up of a sugar, phosphate and one nitrogen base.
T - Replication is performed prior to cell division.
F - Adenine always pairs with thymine.
F - Complementary base pairing matches up complementary nitrogen bases.
F - The sides of the DNA molecule are made up of repeating phosphates and sugars.
F - The letters that make up the DNA molecule code for amino acids.
T - Replication results in two strands of DNA, each of which has half of the original strand.
F - Hydrogen bonds hold nitrogen bases together, forming the rungs of the DNA ladder.
Sentence Arrange — Put the steps of DNA replication in order by writing a number in the space before each statement.
5 — Two new molecules of DNA are created.
4 — DNA polymerase attach the free-floating nucleotides to the exposed nitrogen bases.
2 — Helicase begins to break the hydrogen bonds between nitrogen bases.
1 — Cell starts into the mitosis phase of the cell cycle.
3 — Free floating nucleotides pair up with exposed nitrogen bases.
Complete the statement
Adenine, guanine, cytosine, and thymine are the four nitrogen bases. In DNA, cytosine always forms hydrogen bonds with guanine. The sequence of nitrogen bases carries the genetic information of an organism. The process of DNA replication produces a new copy of an organism's genetic information. The double coiled shape of DNA is called a double helix.
Parent Tip: Review the logic above to help your child master the concept of dna rna and replication worksheet.
