Journey through the studies of Mitosis and Meiosis

1. Journey through the studies of Mitosis and Meiosis

2. What is mitosis? When a cell splits it becomes two, many stages start within the nucleus. One of these stages involves the splitting of chromosomes.   There are five separate and distinct stages.

3. What are the stages of mitosis? • In prophase, duplicated chromosomes become more visible • In metaphase, chromosomes align themselves in the middle of the cell • In anaphase, there is a separation - half of the chromosomes are pulled to one side of the cell • In telophase, cytoplasm divides and 2 separate cells are formed • In interphase, chromosomes (DNA) duplicate, cell division repeats all over again

4. What happens when mitosis goes wrong? • If one daughter receives both of the sister chromosomes and the other will receive none. This results in three chromosomes having the same genes.  • Many times chromosomes may become damaged. An arm of the chromosome may be broken and the fragment lost, causing mutation. • The failure of chromosome pairs to separate properly. When they fail to complete cell division in one cell, it results in containing two nuclei.

5. What is meiosis? • Meiosis is a process of cell division that produces the egg and sperm • The purpose of meiosis is to reduce 2 copies of each chromosome • The cells duplicate their DNA but follow this by two rounds of division, instead of one like mitosis.

6. What are the stages of meiosis? • Interphase I is the same in both mitosis and meiosis, but in meiosis, it is followed by two cell divisions • In prophase I, chromosomes come together and match up in pairs • In metaphase I, pairs of chromosomes move to the middle of the cell • In anaphase I, the chromosomes separate, and one of each pair travels to each of the two poles of the cell • Telophase I two daughter cells immediately go into the second cell division • Meiosis II  is pretty much like mitosis the sister cells are separating which results in four daughter cells

7. What is the difference between meiosis and mitosis? Meiosis Mitosis • Meiosis takes place within the reproductive system forming the sex cells. • Two divisions of the parent cell result in four different daughter cells. • Reduced number of chromosomes in contrast to the number of chromosomes in the parent cell. • There is at least one crossing-over or DNA exchange per homologous pair of chromosomes. • Mitosis takes place within the body cells. • One single division of the parent cell results in two IDENTICAL daughter cells. • The number of chromosomes per nucleus remains the same after division. • There is no exchange of DNA between chromosomes.

8. What happens if meiosis goes wrong? • When mitosis or meiosis go wrong in humans, serious health problems can result. • In the case of meiosis, things can go wrong when the chromosome pairs don’t split apart. • If meiosis goes wrong it can result in three copies, rather than the normal two.

9. What happens to the offspring when it receives less than or more than the amount of chromosomes? Less than the amount of chromosomes More than the amount of chromosomes Turner’s syndrome • It only affects females • Missing part of X chromosome • Turner’s syndrome has almost fourteen symptoms (kidney problems, heart problems, overweight, learning difficulties…) • Affects growth and development Down syndrome • Causes you to have a life long retardation • Development delays • Common genetic cause of learning disabilities • Extra copy of 21st chromosome