Show:
Introduction
Checkpoints and Interphase
Mitosis and Cytokinesis
Meiosis
Replication and Relationships
100
What is cell division used for?
Growth and development
100
What might happen in the cell cycle occurred without regulation?
Cells might go from one phase to the next before they are ready
100
What divides in mitosis and how many times?
Nucleus, once
100
What divides in meiosis and how many times?
Nucleus, twice
100
What are the three steps of replication?
1) DNA molecule separates 2) Each original strand serves as a template for free-floating nucleotides to fill in the other side 3) Two identical strands of DNA are created
200
How do most prokaryotic cells divide?
Binary Fission
200
What controls the cell cycle by signalling the cell to either start or delay the next phase of the cycle?
Regulatory proteins called cyclins
200
Summarize what happens in prophase?
Chromosomes condense and become visible, the nuclear membrane breaks down, and the spindle apparatus forms at opposite poles of the cell
200
What is the difference between prophase I and prophase II?
Prophase I is when synapsis (forming of homologous pairs) and crossing over take place XX Prophase II begins with chromsomes composed of two sister chromatids X
200
After replication, how is each new molecule of DNA related to the original molecule?
It is an identical copy, and contains half of the original DNA strand
300
True or false: The cell cycle occurs only once in a cell and then it will never go through the cycle again.
False, the cell cycle is a repeating series of events that include growth, DNA synthesis, and cell division
300
What are the three key checkpoints?
Cell growth checkpoint, DNA synthesis checkpoint, and mitosis checkpoint
300
Summarize what happens in metaphase?
Chromosomes are aligned along the metaphase plate
300
What is the difference between metaphase I and metaphase II?
Metaphase I begins with the homologous pairs lining up in the middle Metaphase II begins with chromosomes, composed of two sister chromatids, lining up in the middle
300
What does it mean that DNA replication is semiconservative?
Since each new strand contains half of the original DNA, it is being reused and conserved.
400
What are the three major steps in which the cell divides?
Interphase, Mitosis/Meiosis, and Cytokinesis
400
What occurs during interphase?
The cell grows and copies its DNA
400
Summarize what happens in anaphase?
Chromosomes move to opposite ends of the cell
400
What is the difference between anaphase I and anaphase II?
Anaphase I is when the homologous pairs separate so that one chromosome, composed of two sister chromatids, are pulled towards the two poles of the cell Anaphase II is when chromosomes, composed of two sister chromatids, seperate so that one chromosome, composed of one chromatid, are pulled towards the two poles of the cell
400
How are base-pairs, DNA, chromatin, and chromosomes related?
The combination of base-pairs carry the genetic information in the DNA, uncoiled DNA is chromatin, tightly coiled DNA is chromosomes
500
What are the three steps of binary fission?
1) DNA replication 2) chromosome segregation 3) seperation
500
What are the three main parts of interphase?
1) Gap 1 (G1) - increase in size and number of organelles 2) Synthesis (S) - copies DNA 3) Gap 2 (G2) - additional growth
500
Summarize what happens in telophase and cytokinesis?
Telophase: Two daughter nuclei form and the chromosomes become less condensed Cytokinesis: The cytoplasm divides and results in two new cells
500
What is the difference between telophase I/cytokinesis and telophase II/cytokinesis?
Telophase I/cytokinesis results in two cells with chromosomes, composed of two sister chromatids, in each cell Telophase II/cytokinesis results in four cells with chromosomes, composed of one chromatid, in each cell
500
How are genes and alleles related?
Genes are segments of DNA that code for a trait, and alleles are different forms of genes that code of a particular version of that trait For instance, if the gene codes for hair color, the alleles could code for blonde, brunette, red, or black hair.