Skills 4-6: Mitosis
Skill 4: Which kind of cells use mitosis to divide?
Skill 5: In mitosis, are the daughter cells identical to or different from the original cell?
Skill 6: What are the stages of the cell cycle, in order, and what happens to the DNA in each stage?
Mitosis is the type of cell division which makes somatic, or body cells, like muscle and skin. All cells use this process for cell division, except sex cells.
Mitosis is the type of cell division which makes somatic, or body cells, like muscle and skin. All cells use this process for cell division, except sex cells.
Diploid cells
Diploid cells
Each somatic, or body, cell contains two copies of each chromosome. One was inherited from your mother and the other from your father. Di = two, so diploid cells have two of each chromosome. In humans, the diploid body cells each have 46 chromosomes in their nucleus, 23 from Mom and 23 from Dad. Other organisms have different numbers. Record your definition of "diploid" in the vocabulary section of your packet.
Each somatic, or body, cell contains two copies of each chromosome. One was inherited from your mother and the other from your father. Di = two, so diploid cells have two of each chromosome. In humans, the diploid body cells each have 46 chromosomes in their nucleus, 23 from Mom and 23 from Dad. Other organisms have different numbers. Record your definition of "diploid" in the vocabulary section of your packet.
Skill 6: What are the stages of the cell cycle, in order, and what happens to the DNA in each stage?
Skill 6: What are the stages of the cell cycle, in order, and what happens to the DNA in each stage?
Work through the 13 slides below.
Work through the 13 slides below.
Audio recording to go with the Skill 6 slideshow below. You can listen while you scroll through the slides below. Note: I made two mistakes in the audio recording. Once on question 5, I make a reference to the spindle fibers coming from the centromere. I meant to say that spindle fibers come from the centriole. I made the same mistake again on question 6.
Audio recording to go with the Skill 6 slideshow below. You can listen while you scroll through the slides below. Note: I made two mistakes in the audio recording. Once on question 5, I make a reference to the spindle fibers coming from the centromere. I meant to say that spindle fibers come from the centriole. I made the same mistake again on question 6.
Centromere = center of the chromosome, where the two sister chromatids attach. This is also where spindle fibers attach.
Centromere = center of the chromosome, where the two sister chromatids attach. This is also where spindle fibers attach.
Centriole = pair of organelles which move to opposite poles of the cell during prophase. They release the spindle fibers which reach out and attach to the chromosomes to move them around during mitosis. The centrioles are like Spiderman's wrists, shooting out fibers to attach to things.
Centriole = pair of organelles which move to opposite poles of the cell during prophase. They release the spindle fibers which reach out and attach to the chromosomes to move them around during mitosis. The centrioles are like Spiderman's wrists, shooting out fibers to attach to things.
Look at the human karyotype:
Look at the human karyotype:
See the first 22 homologous pairs? One from each pair came from your Mom and the other from your Dad.
See the first 22 homologous pairs? One from each pair came from your Mom and the other from your Dad.
The 23rd pair determines your sex, whether you are biologically male or female.
The 23rd pair determines your sex, whether you are biologically male or female.
Typical females have 2 'X' chromosomes in the 23rd pair.
Typical females have 2 'X' chromosomes in the 23rd pair.
Typical males have an 'X' and a 'Y.' 'Y' is 'guy stuff,' or what makes a guy different from a girl.
Typical males have an 'X' and a 'Y.' 'Y' is 'guy stuff,' or what makes a guy different from a girl.
When we study genetics, you will see that there are other possibilities, besides 'XX' or 'XY.'
When we study genetics, you will see that there are other possibilities, besides 'XX' or 'XY.'
This karyotype shows both 'XX' and 'XY.' A real karyotype would show 'XX' OR 'XY'.'
This karyotype shows both 'XX' and 'XY.' A real karyotype would show 'XX' OR 'XY'.'
Thinking challenge: Can you use the karyotype above to prove that the father determines the gender of the baby? Explain it to me when you figure it out.
Thinking challenge: Can you use the karyotype above to prove that the father determines the gender of the baby? Explain it to me when you figure it out.
Plant versus animal mitosis
Plant versus animal mitosis
Mitosis looks a little different in plants than animals. Check out the differences below. (Expand to full screen.) What is the main difference in cytokinesis between plant and animal cells?
Mitosis looks a little different in plants than animals. Check out the differences below. (Expand to full screen.) What is the main difference in cytokinesis between plant and animal cells?
