Question

1. put the steps of dna replication in order by writing a number (1 through 5) in the space before each statement.

______ two new molecules of dna are created.
______ dna polymerase attaches the free - floating nucleotides to the exposed nitrogen bases.
______ helicase begins to break the hydrogen bonds between nitrogen bases.
______ cell starts into the mitosis phase of the cell cycle.
______ primase adds an rna primer to the dna strand

1. fill in the complementary base pairs for the following strand of dna:
2. describe the process of dna replication in a cell. in your answer be sure to

a. explain why it is necessary for dna to replicate.
b. identify the location in the cell where dna replication occurs.
c. describe why dna replication is considered semi - conservative.

Explanation:

2. Step - by - Step Format

Step 1: Start of the process

The cell cycle's mitosis phase is preceded by DNA replication. So, the first step is "Cell starts into the mitosis phase of the cell cycle" (1).

Step 2: Unzipping the DNA

Helicase breaks the hydrogen bonds between nitrogen bases to unwind the DNA double - helix. So, "Helicase begins to break the hydrogen bonds between nitrogen bases" (2).

Step 3: Priming

Primase adds an RNA primer to the DNA strand as a starting point for DNA synthesis. So, "Primase adds an RNA primer to the DNA strand" (3).

Step 4: Nucleotide addition

DNA polymerase attaches free - floating nucleotides to the exposed nitrogen bases. So, "DNA polymerase attaches the free - floating nucleotides to the exposed nitrogen bases" (4).

Step 5: End result

Two new molecules of DNA are created. So, "Two new molecules of DNA are created" (5).

a.

DNA replication is necessary for cell division. When a cell divides (either through mitosis or meiosis), each new cell needs a complete set of genetic information. DNA replication ensures that each daughter cell receives an identical copy of the DNA.

b.

In eukaryotic cells, DNA replication occurs in the nucleus. Prokaryotic cells (which lack a nucleus) have their DNA in the cytoplasm, and replication occurs in the cytoplasm.

c.

DNA replication is semi - conservative because each new DNA molecule consists of one original (parent) strand and one newly synthesized (daughter) strand. The original strand serves as a template for the synthesis of the new strand.

Answer:

1. Cell starts into the mitosis phase of the cell cycle
2. Helicase begins to break the hydrogen bonds between nitrogen bases
3. Primase adds an RNA primer to the DNA strand
4. DNA polymerase attaches the free - floating nucleotides to the exposed nitrogen bases
5. Two new molecules of DNA are created

3. Step - by - Step Format

Step 1: Recall base - pairing rules

In DNA, adenine (A) pairs with thymine (T), and cytosine (C) pairs with guanine (G).

Step 2: Complement each base

For the given strand \(A - C - T - G - C - C - G - A - G - T - C - T - G - G - A - A - C - T\), we apply the base - pairing rules:

• \(A\) pairs with \(T\)
• \(C\) pairs with \(G\)
• \(T\) pairs with \(A\)
• \(G\) pairs with \(C\)