Steps of DNA replication process with a table demonstrating complementary base pairing between original and new DNA strands.

Let's go through each part of your DNA replication task step by step.

---

1. Number the steps of DNA replication in the correct order (1, 2, 3):

We are given three steps:

- ____ Daughter strands are formed using complementary base pairing.
- ____ DNA unwinds
- ____ The DNA of the daughter strands winds together with its parent strand.

Correct Order:

1. DNA unwinds
→ Helicase breaks hydrogen bonds between the two strands, separating them into two single strands.

2. Daughter strands are formed using complementary base pairing
→ DNA polymerase adds nucleotides to each template strand, following base-pairing rules (A-T, G-C).

3. The DNA of the daughter strands winds together with its parent strand
→ Each new double helix consists of one original (parent) strand and one newly synthesized strand.

✔ So the numbered order is:

- 2 Daughter strands are formed using complementary base pairing.
- 1 DNA unwinds
- 3 The DNA of the daughter strands winds together with its parent strand.

---

2. Why is DNA replication called "semi-conservative"?

Answer:
DNA replication is called semi-conservative because each new DNA molecule consists of one original (parental) strand and one newly synthesized strand. This means that half of the DNA is conserved from the original molecule, while the other half is new.

> 🔍 *This was demonstrated by the Meselson-Stahl experiment using nitrogen isotopes.*

---

3. What enzyme unwinds and unzips the parent strand?

Answer:
Helicase is the enzyme that unwinds and unzips the parent DNA strand by breaking the hydrogen bonds between the complementary bases.

---

4. What enzyme connects the new bases to the old bases in the DNA template?

Answer:
DNA polymerase is the enzyme that adds new nucleotides to the growing DNA strand, using the original (template) strand as a guide. It forms phosphodiester bonds between nucleotides.

> ⚠️ Note: This question asks about connecting new bases to old ones — this is done by DNA polymerase, which reads the template and adds complementary nucleotides.

---

5. What enzyme connects the new nucleotides together and proofreads them?

Answer:
DNA polymerase also performs both functions:
- It connects new nucleotides together via phosphodiester bonds.
- It proofreads the newly added nucleotides by checking for correct base pairing and correcting mismatches using its 3'→5' exonuclease activity.

So the answer is: DNA polymerase

---

6. Show the complementary base pairing that would occur in the replication...

We are given a short DNA sequence and asked to show what happens during replication. We need to:

- Copy the original strands.
- Add the newly synthesized complementary strands.
- Use two different colors (or symbols) to distinguish:
- Original strands (e.g., black)
- New strands (e.g., red)

Since I can't use colored pencils here, I’ll indicate:
- Original strands: Bold
- New strands: Italic

Also, remember:
- A pairs with T
- T pairs with A
- G pairs with C
- C pairs with G

Each row shows a segment of the original DNA. We'll replicate it by adding the complementary strand to each original strand.

Let’s fill in the table:

| Original DNA Strand 1 | Original DNA Strand 2 | → | Original DNA Strand 1 (copy from left) | New DNA Strand | + | New DNA Strand | Original DNA Strand 2 (copy from left) |
|------------------------|------------------------|----|----------------------------------------|----------------|---|----------------|----------------------------------------|
| A – T | C – G | → | A – T | *T – A* | + | *C – G* | C – G |
| C – G | T – A | → | C – G | *G – C* | + | *A – T* | T – A |
| T – A | T – A | → | T – A | *A – T* | + | *A – T* | T – A |
| T – A | A – T | → | T – A | *A – T* | + | *T – A* | A – T |
| A – T | C – G | → | A – T | *T – A* | + | *G – C* | C – G |
| C – G | G – C | → | C – G | *G – C* | + | *C – G* | G – C |
| G – C | C – G | → | G – C | *C – G* | + | *G – C* | C – G |
| C – G | G – C | → | C – G | *G – C* | + | *C – G* | G – C |
| G – C | A – T | → | G – C | *C – G* | + | *T – A* | A – T |
| A – T | T – A | → | A – T | *T – A* | + | *A – T* | T – A |

---

✔ Explanation of the Table:

For each row:
- The original strand 1 is copied exactly (in bold).
- The new strand is the complement of strand 1.
- The new strand opposite strand 2 is the complement of strand 2.
- The original strand 2 is copied exactly (in bold).

> 💡 Example:
> Original: A–T and C–G
> → New strand paired with A–T is T–A
> → New strand paired with C–G is G–C

So after replication:
- One daughter molecule: A–T (original) + T–A (new)
- Other daughter molecule: C–G (original) + G–C (new)

Each daughter DNA molecule has one old and one new strand → semi-conservative!

---

✔ Final Summary:

1. Order:
1. DNA unwinds
2. Daughter strands are formed
3. DNA winds together

2. Semi-conservative: Each new DNA molecule has one old and one new strand.

3. Unwinding enzyme: Helicase

4. Connects new bases to template: DNA polymerase

5. Connects & proofreads: DNA polymerase

6. Complementary base pairing shown in table above.

Let me know if you'd like this formatted as a printable version or want visual annotations!