AP Bio Unit 6 Part 2 Vocab

Transformation

The direct introduction of DNA sequences into prokaryotic cells, “naked” DNA fragments enter into the cells.

Transduction

Bacteriophage (virus) infects bacterial cell, injects its own DNA, and by mistake encapsulates the bacterial DNA. The bacteriophage infects other bacterial cells with the bacterial DNA (no DNA to make the bacteriophage shell), resulting in a mutated strain of bacteria.

Conjugation

Sex pilus of bacterial cell forms a mating bridge that allows a plasmid to pass between the two bacterial cells. Relaxosome cuts the plasmid at the origin of transfer, makes a single strand of DNA, each bacterial cell completes the complement of the single strand.

Transposition

Transposons/retrotransposons

Transposons

Transposons cut and paste genomes, moving and pasting genomes to a different site

Retrotransposons

Copy and paste, leaving a copy of the genome behind, producing RNA transcribed by reverse transcriptase into DNA that is then inserted into a new site. Can move entire exons.

Evo-Devo

Evolutionary Developmental biology: the study of how developmental processes have changed over time, and how they modify an organism’s features.

Internal Signals

internal signals present inside of cells that control gene expression. ex: Hox/Homeotic gene products

Hox/homeotic gene products

Homeobox, nucleotide sequence found within all homeotic genes, widely conserved in organisms, fungi, animals, plants. Genes code for morphology/development of animal limb segments. Suggests common ancestor.

Viruses

Intracellular parasites, not considered alive. Infects and replicates inside of host cell.

Viruses have…

Nucleic acids, a protein coat, and lipid envelope (in eukaryotic viruses)

(+)ssRNA

Virus’s mRNA that can be translated into protein in the host cell.

(-)ssRNA

Complementary to mRNA, must be transcribed first before being translated into a protein. Usually carries mRNA replicase enzyme

Infection

First virus stage, specific virus receptors allow it to infect specific kinds of host cells, transfers its genetic information.

Replication

Second virus stage, viral genome (and polymerases) use the host cell to manufacture viral proteins and replicate virus genome.

Self-assembly

Third virus stagel new virus components are assembled to make more of the virus.

Release

Fourth virus stage, viral particles produced by the host cell are released to infect more cells.

Lytic Cycle

Cycle of viral replication, virus replicates until it causes the host cell to lyse (die), releasing more virus particles.

Virulent phages

Phages that only replicate through the lytic cycle.

Lysogenic Cycle

Virus replication where the virus genome is integrated into the host cell’s genome, virus genome is replicated/translated with the host genome.

Prophage

Phages that replicate using the lysogenic cycle

Temperate phages

Phages that replicate using both the lytic and lysogenic cycle.

Anti-viral Drugs

Drugs that interfere with the virus life cycle. Can prevent virus from attaching to host cell, or preventing the virus genome from integrating to host cell genome. Ex. used for HIV patients.

RNA Interference

Cells are careful to choose which genes to synthesize into proteins to prevent disease and viral infection.

Viral RNA Processing

Viruses can express genetic information in non-dogmatic modes, ex: reverse transcriptase, making DNA from RNA, DNA then integrated into host cell genome.

Virus evolution

Viruses evolve very rapidly because their RNA polymerases make more mistakes than eukaryotic cells do, many changes = many mutations, more evolution.

Viral Recombination

Two separate viral strains infect a cell at the same time, DNA/genetic information of each viral strain is mixed, creates a new strain.