Answer to Question #281118 in Cell Biology for OWaruhanga

Question

Learning Journal

• Briefly summarize the processes of mitosis and meiosis indicating where the similarities lie and in which aspects they differ. Don't forget to mention the primary reason for each type of cell division by indicating the roles that mitosis and meiosis play in human reproduction and development.
•  Explain what is meant by the term ‘linked genes’ with respect to homologous recombination. For example, if an organism is heterozygous at two genetic loci on the same chromosome, in what way does the position of these alleles with respect to each other affect how they are transmitted to gametes during meiosis?

 

Answer 1

Mitosis

- is a process of cell division in which a single cell divides to two identical daughter cells.

-The stages of mitosis are interphase, prophase, metaphase, anaphase and telophase

-Primary purposes of Mitosis are;

• Asexual Reproduction. -In a single-celled organism, such as an amoeba,...
• Growth- As plants and animals age, most also grow in size.
• Tissue Repair- When an organism is injured, mitosis occurs to replace the damaged cells.

Meiosis

-is a special type of cell division in sexually-reproducing organisms where a single cell divides twice to produce four cells containing half the original amount of genetic information.

-Primary purposes of meiosis are, it allows sexual reproduction of diploid organisms, it enables genetic diversity, and it aids the repair of genetic defects.

Similarities

1. Both begins with diploid parent cell
2. Both consists of interphase, prophase, metaphase, anaphase and telophase
3. For both in metaphase individual chromosomes (pairs of chromatids) line up along the equator.
4. For both during anaphase the sister chromatids are separated to opposite poles.
5. Both ends with cytokinesis.

Differences

Mitosis.

1. It involves one cell division.
2. Will results in two daughter cells
3. will results in diploid daughter cells (chromosome number remains the same as parent cell)
4. Daughter cells are genetically identical
5. Occurs in all organisms except viruses
6. Creates all body cells apart from the germ cells ie eggs and sperms
7. No recombination/crossing over occurs in prophase.
8. prophase, metaphase, anaphase and telophase occur once.
9. In mitosis, cytokinesis does not always occur, some cells divide and are multinucleate, like muscle cells.

Meiosis,

1. It involves two successive cell divisions
2. will results in four daughter cells
3. will results in haploid daughter cells (chromosome number is halved from the parent cell)
4. the daughter cells are genetically different
5. It occurs only in animals, plants and fungi
6. It creates germ cells (eggs and sperm) only
7. Involves recombination/crossing over of chromosomes in prophase I 
8. prophase, metaphase, anaphase and telophase occur twice.
9. In meiosis, cytokinesis must occur twice: once after telophase I and again, after telophase II.

Mitosis involves one cell division while meiosis involves two cell divisions. Mitosis results in two daughter cells while meiosis results in four daughter cells. Mitosis results in diploid daughter cells while meiosis results in haploid daughter cells. The interphase, prophase, metaphase, anaphase, and telophase stages occur once in mitosis while in meiosis they occur twice.

Linked genes are genes that are inherited together.

The alleles for the genes will segregate together during meiosis