• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

mitosis. Interphase is made up of phases: G1, S phase, and G2. The G1 and G2 phases are checkpoints for the cell

Extracts from this document...

Introduction

The Cell Cycle The cell cycle is a process that is subject to control at multiple points along the pathway. These control points include both the G1/S and G2/M transitions of interphase as well as anaphase of mitosis. These checkpoints are critical in ensuring genome is preserved. Interphase is made up of phases: G1, S phase, and G2. The G1 and G2 phases are checkpoints for the cell to make sure that it is ready to proceed in the cell cycle.. S phase involves the replication of chromosomes. All three stages of interphase involve continued cell growth and an increase in the concentration of proteins found in the cell. * G1, S, and G2 are collectively called interphase. * G1 stands for gap 1, or presynthesis; S for synthesis; G2 for gap 2, or postsynthesis. ...read more.

Middle

PROMETAPHASE When the microtubules attach to chromosomes, they attach to a specialized structure called the kinetochore is fromed on the centromeres called microtubules. The microtubules enter the nuclear region. Centrosomes complete migration to opposite poles Metaphase: The chromosomes align at the equitorial plate and are held in place by microtubules attached to the mitotic spindle and to part of the centromere. Then the Chromosomes are lined up single file in the center of the cell. spindle fibers extend from one side of the cell to the other. Anaphase: the duplicated centromeres of each pair of sister chromatids separate, and the now-daughter chromosomes begin moving toward opposite poles of the cell due to the action of the spindle. Movement is generated by motor proteins using ATP. Motor protein 1 is in the kinetochore, as the chromosome moves tubulin units are lost. ...read more.

Conclusion

or twice (successive type). 4. Involves division of chromosomes. Involves separation of homologous chromosomes in M-I and division of chromosomes in M-II. 5. Dividing cells can be haploid or diploid. Dividing cells are diploid. 6. Does not involve either pairing of homologous chromosomes or crossing over. Pairing of homologous chromosomes and crossing over occur during Prophase-I. 7. Two daughter cells are formed. Four daughter cells are formed. 8. Number of chromosomes present in the mother cell is maintained in both the daughter cells. Therefore it is an equational division. Diploid number of chromosomes is reduced to haploid in each daughter cell. this is a reduction division. 9. Original characters of the chromosomes are maintained in the daughter cells. Chromosomal characters are altered due to "crossing over" causing recombination of genes. 10. Daughter cells are similar to each other and also to the original mother cell. Daughter cells differ from each other as well as from the original mother cell. 11. Helps in growth and body repairs. ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our AS and A Level Molecules & Cells section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month
  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work