Sex chromosomes (X and Y chromosomes)
determine biological sex (XX = female, XY = male)
Sex determination
egg cells always provide X chromosome while sperm provides either X or Y
Sex linked genes
genes located on the X and Y chromosomes
Karyotype (chromosome structure)
show a cell’s chromosomes arranged by size and type, revealing structure via banding patterns and centromere position
Effect of nondisjunction
cells (gametes or somatic) with an incorrect number of chromosome
Number of chromosomes
46 chromosomes (23 pairs)
Possible chromosome combinations
XX (female), XY (male), XXX, XXY, XYY
Prenatal diagnosis
involves tests during pregnancy to check the baby’s health, detecting potential birth defects or genetic conditions like down syndrome
Philadelphia chromosome
a shortened chromosome 22 resulting from a specific genetic swap between 9 and 22 chromosomes
