The correct answer is Cyclin D. This cyclin is expressed throughout the cell cycle, however, it directly regulates the transition from G1 to S phase. Cyclin A is also involved in the G1 to S phase transition and is expressed into the G2 phase. Cyclin E is expressed during the transition from G1 to S phase. Cyclin B is expressed during the transition from G2 to mitosis and regulates this progression. There is no Cyclin F in the cell cycle.

The correct answer is Cyclin D. This cyclin is expressed throughout the cell cycle, however, it directly regulates the transition from G1 to S phase. Cyclin A is also involved in the G1 to S phase transition and is expressed into the G2 phase. Cyclin E is expressed during the transition from G1 to S phase. Cyclin B is expressed during the transition from G2 to mitosis and regulates this progression. There is no Cyclin F in the cell cycle.

During mitosis, sister chromatids will line up in the center of the cell so that they may be pulled to opposite ends by the spindle fibers. This lining up takes place in the second phase of mitosis: metaphase.

During mitosis, sister chromatids will line up in the center of the cell so that they may be pulled to opposite ends by the spindle fibers. This lining up takes place in the second phase of mitosis: metaphase.

Meiosis results in genetically unique daughter cells due to the event of crossing over and the phenomenon of independent assortment. Crossing over takes place during prophase I when the homologous chromosomes come in contact with each other to form tetrads.

Meiosis results in genetically unique daughter cells due to the event of crossing over and the phenomenon of independent assortment. Crossing over takes place during prophase I when the homologous chromosomes come in contact with each other to form tetrads.

Cyclin proteins fluctuate in level during the different stages of the cell cycle (except for Cyclin D). For example, Cyclin E regulates the entry into S phase. The expression of the cyclin E gene increases, which leads to higher Cyclin E protein levels in the cell. After the cell passes S phase, Cyclin E protein is actively destroyed by ubiquitination.

When Cyclins are bound to Cdks, they can regulate the activity of proteins that regulate processes like replication and microtubule formation; however, of the cellular processes listed, blocking ubiquitination would be the only process that would directly interfere with cyclins' role to regulate the cell cycle as cyclin proteins need to be destroyed at the correct time to allow the cell cycle to progress.

Cyclin proteins fluctuate in level during the different stages of the cell cycle (except for Cyclin D). For example, Cyclin E regulates the entry into S phase. The expression of the cyclin E gene increases, which leads to higher Cyclin E protein levels in the cell. After the cell passes S phase, Cyclin E protein is actively destroyed by ubiquitination.

When Cyclins are bound to Cdks, they can regulate the activity of proteins that regulate processes like replication and microtubule formation; however, of the cellular processes listed, blocking ubiquitination would be the only process that would directly interfere with cyclins' role to regulate the cell cycle as cyclin proteins need to be destroyed at the correct time to allow the cell cycle to progress.

DNA ligase is an enzyme used to link DNA via the formation of a phosphodiester bond. During lagging strand synthesis, DNA ligase connects the okazaki fragments. Without this enzyme functioning properly, the lagging strand would not be completed.

DNA ligase is an enzyme used to link DNA via the formation of a phosphodiester bond. During lagging strand synthesis, DNA ligase connects the okazaki fragments. Without this enzyme functioning properly, the lagging strand would not be completed.