Question

in humans, n = 23. how many different unique combinations of maternal and paternal chromosomes are possible, each time meiosis occurs?
2×23 = 46
2^23 = 8,388,608
23^2 = 529
the second aspect of meiosis that contributes to genetic variation is crossing over and recombination. these events mean essentially every sister chromatid in every chromosome will have a unique combination of maternal and paternal alleles.
to summarize:

• genes that exist on different maternal and paternal chromosomes get shuffled into different combinations, and
• genes that exist on the same chromosome get associated with different combinations of maternal and paternal alleles.

which statements accurately describe genetic variation generated in meiosis? select all that apply.
if cells have different combinations of maternal and paternal chromosomes, they have different genotypes (remember that a genotype is a listing of the alleles present in a cell).
at the end of meiosis i, the two daughter cells are different genetically.
the two daughter cells from each instance of meiosis ii are genetically identical even when crossing over occurs, because all that happens is that sister chromatids pull apart.

Explanation:

Step1: Calculate combinations of maternal and paternal chromosomes

The formula for the number of different unique combinations of maternal and paternal chromosomes during meiosis is \(2^{n}\), where \(n\) is the haploid number of chromosomes. Given \(n = 23\), we calculate \(2^{23}\).

$$2^{23}=8388608$$

Step2: Analyze statements about genetic variation

• First statement: Different combinations of maternal and paternal chromosomes lead to different genotypes. Since a genotype is based on allele combinations (which are on chromosomes), this is correct.
• Second statement: At the end of Meiosis I, due to independent assortment and possible crossing - over, the two daughter cells are genetically different. This is correct.
• Third statement: When crossing - over occurs, sister chromatids (which are part of the process in Meiosis II) are no longer identical. So, the two daughter cells from Meiosis II are not genetically identical when crossing - over occurs. This statement is incorrect.

Answer:

For the combination of chromosomes: \(2^{23}=8388608\) (the second option in the first part).
For the statements about genetic variation:

• If cells have different combinations of maternal and paternal chromosomes, they have different genotypes (remember that a genotype is a listing of the alleles present in a cell).
• At the end of Meiosis I, the two daughter cells are different genetically.