The rate at which materials enter and leave through the cell membrane depends on the cell's what?
volume
What does the process of cell division result in?
two daughter cells
Sister chromatids are attached to each other at an are called what
centromere
If a cell has 12 chromosomes, how many chromosomes will each of its daughter cells have after mitosis?
12
At the beginning of cell division, a chromosome consists of what?
2 chromatids
The phase of mitosis during which chromosomes become visible and separate from one another is what?
prophase
The timing of the cell cycle in eukaryotic cells is believed to be controlled by a group of closely related proteins known as what?
cyclins
In the cell cycle, external regulators direct cells to do what?
speed up or slow down the cell cycle
What is cell division?
the process in which cells are divided
What does uncontrolled cell division result in?
cancer
How can a cell's DNA limit the cell's size?
if a cell gets too large, the cell will put a demand on its DNA. The cell will have trouble carrying nutrients across the cell membrane.
When the cell size increases, the surface area to volume...
decreases
What happens during interphase?
the cell grows bigger and replicates its DNA and centrioles.
What happens during prophase?
the chromatin condenses into chromosomes and the centrioles separate and the spindle starts to form. The nuclear envelope breaks down.
What happens during metaphase?
the chromosomes line up across the membrane attached to the spindle fibers in the centromere.
What happens during anaphase?
the sister chromatids separate into individual chromosomes and are moved apart.
What happens during telophase?
the chromosomes gather at opposite ends of the cell and lose their distinct shape. Two new nuclear envelopes will form.
What happens during cytokinesis?
the cytoplasm pinches in half. Each daughter cell has an identical set of duplicate chromosomes.
What is the cell cycle?
the series of cell stages in which cells grow and divide.
What is the M phase
when the division of mitosis and cytokinesis takes place.
What is the role of cyclin in the cell cycle?
it is a protein that regulates the timing of the cell cycle.
What is the function of internal regulators?
they proceed and then stop the cell cycle.
What is the function of external regulators?
they slow down or speed up the cell cycle.
Why is it important that cell growth in a multicellular organism is regulated so carefully?
because the consequence of uncontrolled cell growth are very severe.
How do cancer cells differ from noncancerous cells?
cancer cells divide more rapidly than noncancerous cells. Cancer cells do not respond to the signals that regulate the growth of most cells; whereas, noncancerous cells do.
In the cell cycle, the period between cell divisions is called what?
interphase
What must happen before a cell can divide?
the cell's genetic information has to be replicated.
When chromosomes are copied before cell division, what are they called?
sister chromatids
What are the three events in interphase?
G1, S, and G2.
What happens during G1?
general cell growth and the cells synthesize new proteins and organelles.
What happens during the S phase?
chromosomes are replicated and the synthesis of DNA molecules take place.
What happens during G2?
the shortest phase in which many of the organelles and molecules are required for cell division and produced.
What are the four phases of mitosis?
prophase, metaphase, anaphase, and telophase.
What does the spindle do?
helps separate the chromosomes.
The damaging of what gene may cause cancerous cells? What does the gene control?
p53. This gene halts the cell cycle until all chromosomes have properly been replicated. p53 causes cells to lose information needed to respond to signals that would normally control their growth.
What two processes take place in cell division?
mitosis and cytokinesis
How does a cell know when to stop growing?
when the cells touch each other and come in contact
What can cancer cells form when they divide uncontrollably?
tumors
What are differentiated cells?
specialized cells that have a specific function.
How are differentiated cells different than stem cells?
differentiated cells can act like stem cells by activating the genes.
What is the difference between somatic and embryotic cells?
Somatic stem cells are found in your body where cells can divide, and they can turn into a variety of cells. Embryotic cells are only found in embryos and can turn into any type of cell.
Where can you find somatic cells?
anywhere in your body.
What is regenerative medicine?
a medical practice in which doctors are producing or regenerating tissues.