Compare and contrast the following terms:
a. cDNA and gene
b. DNA probe and gene
c. DNA polymerase and DNA ligase
d. rDNA and cDNA
e. genome and proteome

Verified step by step guidance

1. **a. cDNA and gene**: A gene is a segment of DNA that contains the necessary information to produce a functional product, typically a protein. cDNA, or complementary DNA, is synthesized from an mRNA template using the enzyme reverse transcriptase. It represents only the expressed genes of an organism, as it is derived from mRNA.
2. **b. DNA probe and gene**: A gene is a sequence of nucleotides in DNA that encodes a functional product. A DNA probe is a labeled single-stranded DNA or RNA sequence used to detect the presence of a complementary sequence by hybridization. Probes are used in various techniques to identify specific genes or sequences.
3. **c. DNA polymerase and DNA ligase**: DNA polymerase is an enzyme that synthesizes new DNA strands by adding nucleotides to a pre-existing chain during DNA replication. DNA ligase is an enzyme that joins DNA fragments together by forming phosphodiester bonds, crucial for DNA replication and repair.
4. **d. rDNA and cDNA**: rDNA, or recombinant DNA, is DNA that has been artificially created by combining DNA from different organisms. cDNA is complementary DNA synthesized from an mRNA template, representing only the expressed genes. rDNA can include cDNA as part of its sequence.
5. **e. genome and proteome**: A genome is the complete set of DNA, including all of its genes, in an organism. The proteome is the entire set of proteins that can be expressed by the genetic material of an organism. While the genome is static, the proteome can vary with time and environmental conditions.

Key Concepts

cDNA and Gene

cDNA, or complementary DNA, is synthesized from an mRNA template through reverse transcription. It represents the expressed genes in a cell, while a gene is a segment of DNA that contains the instructions for synthesizing proteins. Understanding the relationship between cDNA and genes is crucial for studying gene expression and regulation.

DNA Probe and Gene

A DNA probe is a fragment of DNA labeled with a detectable marker, used to identify the presence of complementary sequences in a sample. In contrast, a gene is a functional unit of heredity that encodes a specific protein. Probes are essential tools in molecular biology for studying gene expression and genetic variations.

DNA Polymerase and DNA Ligase

DNA polymerase is an enzyme responsible for synthesizing new DNA strands by adding nucleotides to a growing chain during DNA replication. DNA ligase, on the other hand, is an enzyme that joins Okazaki fragments on the lagging strand and seals nicks in the DNA backbone. Both enzymes play critical roles in DNA replication and repair processes.