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Flashcards in Cell cycle Deck (19):

What is Interphase

When the nucleus is visible, nuclear membrane is intact, the longest period of the cell cycle


What are the three phases of Interphase

The G1 phase- cell growth. size of cell increases, more organelles and proteins are made
The S-phase- DNA replication -new DNA synthesized when chromosomes are replicated .by the end of the S-phase the cell contains twice as much DNA as before
The G2 phase- preparing for cell division. many organelles and molecules required for division are produced


One of the four stages of mitosis

Prophase, metaphase, anaphase, and telophase


Describe prophase

-The genetic material inside the nucleus condenses and the chromatin condenses into chromosomes
-nuclear membrane breaks down
-spindle fibers begin to form
-The duplicated chromosomes are visible


Describe metaphase

-The chromosomes attach to the spindle
-The centromeres of the duplicated chromosomes line up in the center of the cell


Describe Anaphase

Sister chromatids separate and begin to move the opposite ends of the cell


Describe telophase

-The chromosomes reach the end of the cell
-spindles disappear
-nuclear membrane and nucleus reappear
-The chromosomes begin to spread into a tangle of chromatin


Define cytokinesis

During cytokinesis the cytoplasm divides into two sister cells completing the process of cell division


What is the difference between cytokinesis in animal cells and plant cell

Animal- The cell membrane is drawn inward and the cytoplasm is pinched into two equal parts
Plant- The cell membrane is not flexible enough to draw inward so a cell plate forms halfway between the divided nuclei


What happens when cells come in contact with one another

They stop growing and dividing. This is called contact inhibition


What are cyclins

They are proteins that regulate the cell cycle


What happens when a cell becomes cancerous

It stops responding to the signals that regulate the growth and division of the cell


What are the two types of factors that help regulate the cell cycle

Internal regulatory proteins and external regulatory proteins


What is the relationship between mitosis and cytokinesis

Mitosis is what triggers the cytokinesis to begin


Explain how the cell cycle is regulated

Proteins inside and outside the cell regulate cell division. They only allow the cell to proceed into the cycle when certain events have occurred inside the cell. External regulators respond to events outside the cell.


What is apoptosis

The process of a programmed death


Define stem cells and explain their importance

Stem cells are fertilized eggs that are able to develop into any type of cell in the body. They are important because they allow for the process of differentiation.


As a cell becomes larger how does its volume and surface area change? Which parameter changes more quickly?

Both the volume and surface area get larger. The volume changes more quickly


Explain the difference between chromatids and chromatin

Chromatin is a complex of chromosomes and proteins. Chromatids identical parts of a replicated chromosome.