Consider the following pair of chromosomes at the start of meiosis.
Which table gives the distribution of alleles in the gametes that would be most realistic, in percentage terms?
| Genotype | KL | Kl | kL | kl |
| % distribution | 25 | 25 | 25 | 25 |
| Genotype | KL | Kl | kL | kl |
| % distribution | 50 | 0 | 0 | 50 |
| Genotype | KL | Kl | kL | kl |
| % distribution | 45 | 5 | 5 | 45 |
| Genotype | KL | Kl | kL | kl |
| % distribution | 10 | 40 | 40 | 10 |
Which of the following statements about meiosis are true?
1, 3 and 4
2 and 3
2 and 4
3 and 4
Which event causes genetic variety in the gametes formed during meiosis?
Linkage of genes in prophase 1 and crossing over in metaphase 1
Crossing over during prophase 1 and independent assortment of chromosomes during metaphase 1
Linkage of genes in metaphase 1 and independent assortment of chromosomes in prophase 1
Crossing over during metaphase 1 and independent assortment of chromosomes during prophase 1
Which of the following is the best explanation of why the lengths of DNA exchanged during crossing-over tend to be of the same length as each other?
Because breakages occur where distinct alleles fail to line up accurately with each other in the formation of a tetrad.
Because if uneven lengths of DNA are crossed over, restriction enzymes will trim off the unnecessary DNA from the longer chromatid.
Because there is a lack of space in the tightly-packed ball of condensed chromosomes in prophase I, so only short lengths of DNA can cross over.
Because breaks occur in the same base sequences on each non-sister chromatid.
