AP Biology· difficulty 2/5
If an n+1 gamete fertilizes a normal n gamete, what zygotic chromosome number results?
3n (triploid)
2n (normal diploid)
2n+1 (trisomy)
n (haploid)
Explanation
Combining an n+1 gamete with a normal n gamete produces a 2n+1 zygote, the cause of trisomies such as Down syndrome (trisomy 21).
Want 10 more like this — adaptive to your weak spots?
A heterozygous fruit fly with linked genes (AB/ab) is testcrossed. Of 1000 offspring, 410 are AB, 405 are ab, 90 are Ab, 95 are aB. The recombination frequency …
chevron_rightAn affected father (top right, filled square) has all daughters unaffected (or carriers) and no affected sons (here, one affected and one unaffected). The patte…
chevron_rightGenes on the X chromosome show different inheritance patterns in males vs females because…
chevron_right