Molecular Genetics

Option (2) is the correct answer.

A sigma factor (σ factor) is a protein needed only for initiation of RNA synthesis. It is a bacterial transcription initiation factor that enables specific binding of RNA polymerase to gene promoters. 

In the CATH protein structure classification system, T stands for Topology. CATH is a hierarchical classification: Class, Architecture, Topology (arrangement of secondary structures), and Homologous superfamily. Topology describes the overall shape and connectivity of secondary structure elements.

The Human Genome Project (HGP) reported approximately 2.1 million single nucleotide polymorphisms (SNPs) in the human genome. This number represented the initial catalog of genetic variations discovered during the project. The larger numbers (3.3 billion and 4.2 billion) are closer to the total number of base pairs in the human genome, not SNP counts.

 The synthesis of DNA from an RNA template, via reverse transcription, produces complementary DNA (cDNA). Reverse transcriptases (RTs) use an RNA template and a short primer complementary to the 3' end of the RNA to direct the synthesis of the first strand cDNA, which can be used directly as a template for the Polymerase Chain Reaction (PCR).

 During transcription holoenzyme RNA polymerase binds to a DNA sequence and the DNA assumes a saddle like structure at that point. This sequence is called TATA box. It is a type of promoter sequence, which specifies to other molecules where transcription begins.

 Telomerase, also called telomere terminal transferase,is a ribonucleoprotein that adds the polynucleotide "TTAGGG" to the 3' end of telomeres, which are found at the ends of eukaryotic chromosomes.

The key difference is that RER (Rough Endoplasmic Reticulum) has ribosomes attached to its surface, which is why it appears rough under a microscope. SER (Smooth Endoplasmic Reticulum) lacks ribosomes and has different functions like lipid synthesis. Neither contains DNA.

RNA, specifically messenger RNA (mRNA), carries genetic information from DNA in the nucleus to ribosomes in the cytoplasm where protein synthesis occurs. DNA remains in the nucleus, the nucleus is the organelle containing DNA, and the nucleolus produces ribosomal RNA.

The 8;14 translocation activates the myc oncogene, which is a transcription factor.

Nucleolus participates in protein synthesis by forming and storing RNA. 

The genetic material in viruses can be either DNA or RNA.

Viroids consist of a single-strand RNA molecule and lack a protective protein coat. They were discovered in the late 1960s.

Introns are DNA bases, which are found between exons, but are not transcribed. The DNA sequence of the intron does not encode protein and is not highly conserved.

Small nuclear ribonucleic acid (snRNA) is a small RNA molecules that are found within the nucleus of eukaryotic cells. snRNA (small nuclear RNA) is a component of the splicosome.