How is a Child’s Gender Determined?

• biological gender is determined by the sperm

  • the female carries eggs, which have the X chromosome, while the male carries sperm, half of which have the Y chromosome, the other half have the X chromosome

  • if the fertilizing sperm has a Y chromosome, the child will be male, if it has an X chromosome the child will be a female

Definitions:

karyotype:

a photo all homologous chromosomes lined up

nondisjunction:

• chromosomes do not seperate correctly during meiosis

• an example of this is trisomy 21

  • commonly called down’s syndrome

  • chromosome pair 21 has 3 chromosomes instead of 2

Turner’s Syndrome:

• only affects females

• a part of or the whole X chromosome is missing

• impacts:

  • height and weight

  • delayed puberty

  • child complications

Meiosis:

• goal:

  • reduce the number of chromosomes from 46 to 23

    • (reduction division)

    • only divides the gametes (sex cells/sperm & egg cells)

Crossing Over:

• during prophase 1, each pair of chromatids align with its homologue

  • this pairing of homologous chromosomes produces tetrads

    • a tetrad consists of 4 chromatids