A form of aneuploidy where a mosaic individual forms at some point when one chromatid lags so far behind in anaphase that it is not incorporated into the daughter cell nucleus, thus having 1 less chromosome
Differentiate between balanced and unbalanced translocations
One part of a chromosome breaks off and incorporates onto another non-homologous chromosome at the centromere.
Balanced - subsequent gamete has all genetic material in one form or another
Unbalanced - subsequent gamete has extra or missing genetic material
At which point is something called a chromatid?
When the chromosomes have replicated, 2 sister chromatids are joined together at the centromere, then pulled apart in anaphase
At what points are things called chromosomes?
Individual ones in normal cell (46), pair of sister chromatids after replication (46 pairs), and separated chromatids in daughter cells (now chromosomes)
Describe chromosome nomenclature
Particular site on a chromosome?
23 chromosome pairs, 22 autosomal and 1 sex. Numbered from largest (1) to smallest (22 - actually 21). Two arms per chromosome, separated by centromere. p arm (petite) and q arm (next letter). Each arm divided into regions, each with a certain number of bands and sub-bands within bands.
16p11.1 = chrom. 16, p arm, region 1, band 1, sub-band 1
Which cell types are germ cells?
Cells that give rise to gametes (divide to make eggs and sperm)