Cell Cylce

Cell Cycle

Brief Overview

The cell cycle is a repeating cycle of cellular growth and division- it occurs during the entire life of an organism, from birth until death.

Multiple Choice

The cell cycle is a repeating cycle of cellular growth and division- it occurs during the entire life of an organism, from birth until death.

• True

• False

The cell cycle is typically a four-phase process followed by cytokinesis. An individual cell spends about 90% of its time in the first three phases of the cycle, which collectively is called interphase.

Multiple Choice

The phases of the cell cycle are as follows:

• G2, G1, S, Mitosis, Cytokinesis

• Cytokinesis, Mitosis, S, G1, G2

• G1, S, G2, Mitosis, Cytokinesis

A cell will enter the last phase of the cell cycle called, mitosis, only if it is about to divide.

Open Ended

A cell will enter the last phase of the cell cycle only if it is about to divide. This phase is called______.

Poll

The cell cycle is typically a four-phase process followed

by __________.

• cytokinesis

• mitotic spindles

• chromatid sisters

The phases of the cell cycle are as follows:

First growth phase (G1): During this phase the cell grows rapidly and carries on routine functions. For most organisms, this phase occupies the major portion of a cell’s life.

Open Ended

Explain what happens during G1 phase of interphase.

Synthesis phase (S): A cell’s DNA is replicated (copied) during this phase. The DNA transforms from chromatin (one copy; shapeless) to sister chromatids (two copies; “X” shaped).

Open Ended

Explain what happens during the S phase of interphase.

Second growth phase (G2): In the G2 phase, preparations are made for the nucleus to divide (mitosis). Cell organelles, such as mitochondria, replicate to prepare for two cells. Hollow protein fibers called microtubules are assembled.

Open Ended

Explain what happens during G2 phase of interphase.

Mitosis + Cytokinesis

The process of one nucleus dividing into two nuclei is known as mitosis.

mitosis phases

Each nucleus ends up with an equal amount of chromosomes. During mitosis,

microtubules are used to help move chromosomes to opposite ends of the cell.

The process of the cytoplasm dividing is known as cytokinesis.

Once the cytoplasm has divided, two new cells are formed. They are called daughter cells.

Open Ended

Explain cytokinesis.

Mitosis and cytokinesis are alike in that they are both crucial parts of the cell cycle AND they are both making two of something.

Mitosis is the process in which two nuclei are formed, and cytokinesis is the splitting of the cytoplasm, which leads to two cells.

Poll

Rate your understanding of the cell cycle.

• I get it and could explain it to another.

• I get it.

• I need visuals to explain it, but it is starting to make sense to me.

• I need another lesson for my understanding of it.