Architecture of the nucleosome core particle:

• There are not 8 different types of histones; core histones consist of four conserved families.
• histone types (H1, H2A, H2B, H3, H4) exist in total chromatin, but H1 is a linker histone that sits outside the octamer core.
• 6 types of histones is biologically incorrect.
• The nucleosome core histone octamer consists of exactly 8 histone protein subunits belonging to four distinct core histone classes: an $(\text{H3}_2\text{--H4}_2)$ tetramer and two $(\text{H2A--H2B})$ dimers (two copies each of H2A, H2B, H3, and H4).

Bacteriophage developmental life cycles:

• The lysogenic cycle involves integration of phage DNA into the bacterial genome where it replicates passively without killing the host cell.
• The lytic cycle (virulent infection) involves active phage genome replication, transcription, structural protein synthesis, virion packaging, and eventual synthesis of endolysins and holins that cause enzymatic lysis and physical bursting (destruction) of the host cell wall to release progeny virions.
• prophage is the latent, quiescent viral genome integrated into the host chromosome during lysogeny.
• Temperate phase refers to phages capable of adopting the dormant lysogenic pathway without destroying the host.

Structural classification of viral particles:

• Primitive virus is an evolutionary term, not a structural classification.
• Virion denotes any complete, infectious extracellular viral particle (which may be either enveloped or non-enveloped).
• Viruses that consist solely of a nucleic acid genome (DNA or RNA) enclosed by a protein shell (capsid) without an outer surrounding lipid bilayer membrane (envelope) are specifically termed naked viruses (non-enveloped viruses, such as picornaviruses, adenoviruses, and reoviruses).
• Capsovirion is a non-standard artificial term.