The main cloning vectors used for DNA sequencing in the Human Genome Project are _________.

Options

A. T-DNA
B. BAC and YAC
C. Expression vectors
D. pBR322 cloning vectors.

Answer

To solve the question regarding the main cloning vectors used for DNA sequencing in the Human Genome Project, we can follow these steps:

### Step 1: Understand the Human Genome Project (HGP)
The Human Genome Project was an international research initiative aimed at mapping and understanding all the genes of the human species. It involved determining the sequence of the base pairs that make up human DNA.

**Hint:** Research projects like the HGP focus on understanding complex biological systems, such as the human genome.

### Step 2: Define Cloning Vectors
Cloning vectors are small pieces of DNA that can carry foreign DNA into a host cell for replication and analysis. They are essential tools in genetic engineering and molecular biology.

**Hint:** Cloning vectors are crucial for inserting and replicating foreign DNA in host organisms.

### Step 3: Identify Common Cloning Vectors
Some common types of cloning vectors include:
- Plasmids (e.g., PBR322)
- Bacterial Artificial Chromosomes (BAC)
- Yeast Artificial Chromosomes (YAC)
- Expression vectors

**Hint:** Familiarize yourself with different types of cloning vectors and their specific applications.

### Step 4: Focus on the HGP Context
In the context of the Human Genome Project, the most suitable cloning vectors were those that could handle large fragments of DNA, which is necessary for sequencing the entire human genome.

**Hint:** Consider the size of the DNA fragments that need to be cloned when selecting appropriate vectors for a specific project.

### Step 5: Analyze the Options
- **Option A:** tDNA - not primarily used in HGP.
- **Option B:** BAC and YAC - known for their ability to clone large DNA fragments.
- **Option C:** Expression Vectors - mainly used for protein expression, not sequencing.
- **Option D:** PBR322 Cloning Vectors - suitable for smaller DNA fragments.

**Hint:** Evaluate each option based on their suitability for large DNA fragment cloning.

### Step 6: Conclusion
The main cloning vectors used for DNA sequencing in the Human Genome Project are **BAC (Bacterial Artificial Chromosomes) and YAC (Yeast Artificial Chromosomes)**.

**Final Answer:** **BAC and YAC** (Option B).