Question

1. Identify and describe how meiosis helps contribute and lead to genetic variation in sexually reproducing organisms

2. Describe how meiosis accomplishes a reduction in chromosome number 

3. Contrast the major differences between the daughter cells in meiosis and the daughter cells in mitosis [ fill in the chart below] 

Answer 1

1) identify and describe how meiosis helps contribute and lead to genetic variation in sexually reproducing organisms.

Meiosis is a reduction in cell division. Processes like recombination and crossing over take place during the cell division.  

1) During the recombination, in prophase 1, a cell will be will recombine and exchange the genetic material with one another thus generating genetic variation.

2) Crossing over is another type by which the chromosomal part is exchanged with a similar chromosome and thus we get different DNA sequenced chromosome.

3) Random assortment: In this type, centromere gets changed to other sister chromatids thus creating a genetic variation.

3) Major differences in daughter cells in meiosis and mitosis

Mitosis:

1) Diploid cell (2N)

2) only one cycle of cell division

3) total of 2 cells will be produced

4) for autosomes only

5) cell will be genetically identical

Meiosis:

1) Haploid cells

2) two-cycle of cell division

3) total of 4 cells will be produced

4) for sex chromosomes

5) cell will be genetically different/ modified

2) Describe how meiosis accomplishes a reduction in chromosome number

Meiosis is the reduction cell division process where at the end of the cells division you will get haploid cells (N) from the diploid cell(2N). Meiosis uses two consecutive cell divisions to take place.

As an example, a human sperm cell contains 46 chromosomes (2N).

In the 1st division, 46 chromosomes will get reduced to 23 in two cells.

in the 2nd cell division, these 23 chromosomes will again further be divided into 4 cells.

The DNA copies will get reduced by half and that's why we call meiosis as reduction cell division.

Please refer attached image below.

In the image attached below, During the meiosis 1, chromatids are still attached to one another while they get separated at the end of the 2nd cell division cycle.