What stage is it when chromosomes are attached to microtubules?
In prophase, which is the first stage of mitosis.
What is the synthesis stage?
The cell cycle is divided into what stages?
The three main stages are interphase, mitosis, and cytokinesis.
Why is diffusion over large distances so slow and inefficient?
It is so slow and ineffiecient because the diffusion relies on random movement of molecules and ions. (pg.245)
In plant cells, what does cytokinesis begin with?
A cell plate is formed between the two daughter nuclei. (pg.252)
Where are embryonic stem cells found?
They are the cells of the newly fertilized egg. (pg.256)
What happens in prophase in a plant cell?
The nuclear membrane disintegrates, the nucleolus disappears, chromosomes condense, and the spindle apparatus begins to form between the poles. (pg.249)
What happens at the end of prophase?
At the end of prophase the nuclear envelope seems to disappear. The spindle fibers attach to the sister chromatids on both sides of the centromere and then attach to oppostie poles of the cell. This arrangement ensures that each new cell receives one complete copy of the DNA. (pg.250)
Know the 4 phases of mitosis and what happens in each.
Prophase- nuclear membrane disintegrates, the nucleolus disappears, chromosomes condense, and the spindle apparatus begins to form between the poles.
Metaphase- chromosomes attach to the spindle apparatus and align along the equator of the cell
Anaphase- microtubules shorten, moving chromosomes to opposite poles
Telophase- chromosomes reach poles of the cell, nuclear envelope re-forms, nucleolus reappears, chromosomes decondense (pg.249)
If a cell has 20 chromosomes, how many chromosomes will each daughter cell have?
What regulates the cell cycle?
Why can cancer cells reproduce rapidly?
Cancer cells spend less time in interphase, therefore the cell cycle is much quicker.
What causes cancer?
Substances and agents, such as the sun's UV rays, radiation from x-rays, or tobacco products, that are known to cause cancer are called carcinogens. Also often the genetic change or damage that occurs is repaired by various repair systems. But if the repair system fails,cancer can result. (pg.254-255)
What is asexual reproduction and what is the result?
Asexual reproduction is reproduction by only one parent. During asexual reproduction, the organism inherits all it's chromosomes from the one single parent, so basically it is a clone of the parent. (pg.276)
When does DNA replication occur?
DNA replication occurs in the substage "S" of interphase. It does this in preparation for cell division. (pg.247)
Which is the shortest phase of mitosis?
The shortest phase of mitosis is in the substage metaphase (when chromosomes attach to the spindle apparatus and align along the equator of the cell). (pg.250)
What are the potential medical uses of stem cells?
Potential medical uses of stem cells include the stem cells being able to develop into different kinds of cells, providing new treatments for many diseases and conditions. (pg.257)