38. Mitosis and meiosis are two different ways cells divide. They both share common characteristics and processes, but differ in some very important ways.
a. What are the end products of the two processes? How do they differ from the original or "parent" cell, if at all?
My answer:
In the end of mitosis, each nucleus ends up with the same number and kinds of chromosomes as the original cell. In the end of meiosis, a nuclear envelope forms around each set of chromosomes. The spindle breaks down, and the cell undergoes cytokinesis. The result of meiosis is four haploid cells.
b. Explain the major differences between the two processes that result in the different end products. In which process does chromosomal exchange occur?
My answer:
During mitosis, spindle fibers drag the chromatids to opposite poles of the cell. A nuclear envelope forms. Each resulting nucleus contains a copy of the original cell's chromosomes. On the other hand, during meiosis I, homologous chromosomes separate. During meiosis II, the two chromatids of each chromosome separate. As a result of meiosis, 4 haploid cells are produced from one diploid cell. Chromosomal exchange occurs during meiosis.
Are my answers OK?
Thanks
-MC
Exactly right for diploids. Some day grab a genetics book and look up the processes for tripolids (mainly salamanders, and trout) and quadraploids (mainly occuring in tobacco, inbred plants, a species of rats in China, and in "seedless" fruits.
Thanks(:
-MC
Your answers are generally correct, but here are a few suggestions to improve the clarity and accuracy of your responses:
a. What are the end products of the two processes? How do they differ from the original or "parent" cell, if at all?
Mitosis results in two identical daughter cells, each with the same number and types of chromosomes as the original cell. In other words, the daughter cells are genetically identical to the parent cell.
Meiosis, on the other hand, results in four daughter cells, each with half the number of chromosomes as the parent cell. These daughter cells are called haploid cells and are genetically different from the parent cell. This is because meiosis involves two divisions, meiosis I and meiosis II, which lead to a reduction in chromosome number and genetic recombination.
b. Explain the major differences between the two processes that result in the different end products. In which process does chromosomal exchange occur?
During mitosis, the original cell's chromosomes are duplicated and then divided equally between the two daughter cells. The chromosomes remain intact and do not undergo genetic recombination or exchange.
In meiosis, however, there are two rounds of division. In meiosis I, homologous chromosomes pair up and exchange genetic material through a process called crossing over. This genetic exchange contributes to genetic variation. Then, in meiosis II, the sister chromatids of each chromosome separate, resulting in the formation of four haploid cells.
Therefore, chromosomal exchange occurs specifically during meiosis I, where homologous chromosomes can swap genetic material, creating unique combinations of genes in the resulting daughter cells.
Overall, your answers are quite good, but these suggestions will help you provide more accurate and detailed explanations.