Indicate whether each of the following occurs mainly in G1 phase (G), S phase (S), or G2 phase (H) of the cell cycle. Your answer would be a four-letter string composed of letters G, S, and H only, e. g. HGSS. DNA helicase activation DNA helicase deposition on DNA at the replication origins ORC phosphorylation ()Licensing of replication origins (1 point) SGGH ? a. GGSG b. GGSH c. SHSG d. SGSG

Correct choice should be:

"SGSG"

Explanation:

The cell cycle consists of G1, S, G2 and M phase. The former three phases include the interphase and M phase is the dividing phase of cell . G1 prepares cell for DNA synthesis. S phase is the phase where DNA replication takes place. G2 phase prepares cell for cell division or M phase.

G1 phase preceeds replication or S phase and G1 phase licences DNA replication.

During other phases of cell cycle, ORC complex masks origin of replication. ORC phosphorylation takes place at S phase, which removes this omplex and unmasks origin of repication site so that replication machinery can bind to it.

DNA helicase activation: S phase

DNA helicase deposition on DNA at the replication origins: G phase (actually G1)

ORC phosphorylation: S phase

Licensing of replication origins : G phase (actually G1)

Hence correct choice should be:

SGSG

hydroxyl -oh

alcohols, always polar, can form hydrogen bonds with h2o molecules

carboxyl -cooh  

cargoxylic acids, has acidic properties which is a source of hydrogen ions, found in cells in ionized for with a charge of oh-1

carbonyl > co

ketone if within skeleton, aldehyde if group is at the end of skeleton, k & a may be structural isomers, it determines 2 sugars (ketose & aldose)

amino -nh2

amines, acts as a base, it can pick up h+ ions from surrounding solution, ionized with charge of 1+

methyl ch2

addition to rna/dna affects and gene expression

phosphate -opo3 ²⁻

organic phosphates, contributes to negative charge to, molecule that it is a part of, and potential to react with h20

sulfhydryl -sh

thiols, cross-linking stabilize the protein, and it is structure