Cell Cycle/ Chapter 8 Test Flashcards
What is the longest phase of mitosis?
Prophase
What are the 2 major stages of cell division?
Mitosis and cytokinesis
What does a chromosome consist of?
2 identical chromatids
How is a pair of chromatids attached to each other?
With a centromere
What is interphase?
The period of cell growth that occurs between cell divisions
Summarize the cell cycle in 3 sentences/bullet points
The cell grows.
It prepares for division.
Divides to form 2 daughter cells, each of which begins the cycle again.
What are the 4 phases of the cell cycle?
G1 (First Gap Phase)
S Phase
G2 (Second Gap Phase)
M Phase (mitosis)
What happens during G1?
The cell increases in size and synthesizes new proteins and organelles
What happens during the S phase?
Chromosomes and key proteins are replicated and DNA synthesis takes place
Where is the point of no return?
At the beginning of the S phase when chromosomes begin being replicated
What happens in G2?
The organelles and molecules required for cell division are produced
What are the phases of mitosis in order?
Prophase, Metaphase, Anaphase, and Telophase
What happens during prophase?
The centrioles separate and take up positions on opposite sides of the nucleus
The centrosome helps organize the spindle, a fanlike microtubule structure that helps separate the chromosomes
What makes up a centrosome?
2 centrioles (and microtubules)
What happens during metaphase?
The chromosomes line up across the center of the cell and
microtubules connect the centromere of each chromosome to the poles of the spindle
What happens during anaphase?
The sister chromatids separate into individual chromosomes. The chromosomes continue to move until they have separated into 2 groups
What happens during telophase?
Chromosomes gather at opposite ends of the cell and lose their distinct shape. The cell looks kind of like an 8.
What happens during cytokinesis?
During cytokinesis, the cytoplasm pinches in half. Also, each daughter cell has an identical set of duplicate chromosomes
How many chromosomes does a cell in the human body have?
46 chromosomes
What is the order of the cell cycle?
G1 (First Gap Phase) S Phase G2 (Second Gap Phase) Prophase Metaphase Anaphase Telophase Cytokinesis
When does the nuclear envelope form?
During Telophase
What’s inside the nuclear envelope during Interphase + Cytokinesis?
Chromatin
When do cells stop reproducing and growing?
When they run out of space/ come in contact with other cells
What regulates the cell cycle?
A protein called cyclin
What changes amount of cyclin in the cell?
The amount of cyclin changes throughout the stages cell cycle
What does cyclin do?
It regulates the timing of the cell cycle in eukaryotic cells
What is contact inhibition?
A fancy word for the the fact that cells stop reproducing and growing when there’s no more room left
What does an internal regulator do?
Internal regulators allow the cell cycle to proceed (into mitosis) only when certain processes have happened inside the cell
What is an external regulator and what does it do?
They’re proteins that respond to events outside the cell. External regulators direct cells to speed up or slow down the cell cycle.
What is cancer?
Cancer is a disorder in which some of the body’s own cells lose the ability to control growth
What makes cancer so dangerous?
Cancer cells divide uncontrollably and form masses of cells called tumors that can damage the surrounding tissues
What can cancer cells do when they break away from the main tumor? What does it cause?
Cancer cells may break loose from tumors and spread throughout the body, disrupting normal activities and causing serious medical problems or even death
