Can You Answer These Questions from Biology Flashcards

1. Small circular DNA molecules in some bacteria (can have 1+ plasmids)
2. Carry nonessential bacterial genes but that may aid in reproduction/growth
3. plasmids able to replicate independently, can integrate themselves into bacterial chromosomes

OriV: Origin of replication on the plasmid
OriT: Origin of replication for episome transfer, involved in conjugation (F+) where DNA replication begins in rolling circle
OriC: in circular bacterial chromosome

1. H- transfer of genetic material from organism to organism without reproductionEx. conjugation, endosymbiotic, lobaccia example (lives inside insect cells.)
2. Parent to offspring, reproductive

Conjugation is the transfer of genetic material between cells by a bridge-like connection between two cells or by direct cell-to-cell contact. The two cells have to physically contact each other for an exchange to occur.
Unlike conjugation, transduction and transformation are not hindered by the need for physical contact.
Transduction is the process of having the genetic material of one bacterium inserted into another by use of a virus.
Transformation is the intake of a piece of DNA from the bacterial cell’s environment.

1. Relaxosome recognizes fertility factor, associates with origin of transfer, cuts 1 strand, frees up 3' end hydroxyl group
2. Transferosome forms "hole" between cells, connects the two cells with sex pili, pulls ssDNA into recipient cell

1. High Frequency recombinant, F factor is integrated into the bacterial chromosome (not on plasmid)
•recombination occurs between homologous chromosome DNA, crossing over occurs (recombination of alleles)•DOES account for Lederberg and Tatum's observations•F factor rarely integrates into bacterial cell

2. F⁺ has the F factor separate from the bacterial chromosome, does NOT account for L and T's observations, whole F plasmid goes into F- cell and makes it an F+ cell

F+/F-: donor->recipient•separate circular DNA plasmid with F factor

Hfr/F-: donor->recipient•leads to recombination in recipient cell•doesn't turn into an F+ cell

1. F' cells: made from Hfr cell•F factor removes host DNA during excision•Contain an F factor w/ SOME bacterial genes•partially diploid cells produced
2. F' can conjugate with F- cells and transfer in SOME bacterial cells with the plasmid

1. replicating structure made up of nucleic acid surrounded by protein coat
2. virus that infects bacteria•Lytic cycle: kills host•Lysogenic cycle: incorporates viral DNA into host
3. Temperate phage: undergoes either lytic or lysogenic, can be incorporated into the genome of hostVirulent phage: ONLY lytic (always kills host)

Generalized transduction: ANY GENE can be transferred
Specialized transduction: only some GENES NEAR INSERTION SITE can be transferred

Chloroplast DNA and Mitochondrial DNA (provide energy)
Wolbachia in insects (influences sexual differentiation and viral resistance)

RNA virus: Influenza•uundergoes something similar to lytic cycle.•Not always completely lytic, but important that it carries with it within viral captin•carries enzyme that's RNA dependent: RNA polymerase (Has to transcribe RNA so it canbe translated into DNA, has to replicate its genome)•Does not integrate itself into genome (keeps infecting more hosts)•Polymerase: makes RNA, dependent on RNA asa template
Retro virus: HIV•intergrates itself into genome, has to convert RNA into DNA (reverse transcriptase)•in order for it to be intergrated= 2 enzymes, 1)reverse transcriptase: uses RNA as atemplate to make complementary strand to make it dbl stranded2) Integrase: intergrates it into genome. More lysogenic.

Levels of DNA compactionfrom linear helical molecule1st: association w/ nucleosomes (histones) •Nucleosomes are the fundamental repeating units of chromatin! •histones: small, + charged proteins (5 types), most abundant proteins in chromatin •contain positively charged lysine residues in C-terminus tail2nd: formations of solenoids & association loops (H1 mediates solenoid assembly) •solenoid: helical fiber of interacting nucleosomes3rd: addition of scaffold proteins (Lampbrush chromosome part of scaffold)4th: further interaction of scaffold loops

1. Tertiary structure; DNA helix is subjected to strain by being overwound or underwound. A partial solution to the cell's DNA packing problem b/c occupies less space. Takes place within associated scaffold loops
2. •positive supercoiling: DNA is overrotated •negative supercoiling: underrotated

1. Enymes that add or remove rotations from the DNA helix
2. Break nucleotide bonds, rotate one strand, and rejoining the broken ends; can induce and relieve supercoiling (most DNA is negatively supercoiled)