Anatomy

• what is the union of two gametes (fertilized egg)?

  zygote
• what are male gametes?

  sperm( spermatozoon)
• what are female gametes?

  egg (ovum)
• XY chromosome pair is what sex?

  male
• XX chromosome pair is what sex?

  female
• What are the primary sex organs?

  gonads (testes and ovaries)
• What are the secondary sex organs?


  internal genitalia (pelvic cavity) and external genitalia (perineum)
• the scrotum is skin with ______ and ________

  fascia and muscle
• what does the scrotum contain?

  2 testes
• what is the purpose of the scrotum?

  maintains testes at lower than body temperature for most efficient sperm production
• how does the dartos muscle help regulate the testes temperature?


  it is a smooth muscle with wrinkled skin that pulls the scrotum closer to the body
• how does the cremaster muscles help regulate the testes temperature?


  skeletal muscle that elevates the testes and pulls them closer to the body
• how does the pampiniform plexus regulate testes temperature?

  absorbs arterial heat
• does arterial blood cool or heat as it descends?

  cools
• does venous blood carry away heat or coolness as it ascends?

  heat
• What process happens in the testes?


  sperm production
• what are the two tunics of the testes?

  tunica vaginalis (outer) and tunica albuginea (inner)
• how many seminiferous tubules make sperm in each lobule?

  1-4
• what do interstitial endocrine cells do?


  they secrete androgens (testosterone) into interstitial fluid
• What structures are located in the spermatic cord?


  ductus deferens, blood supply via testicular arteries and veins, lymphatics, and autonomic and visceral sensory nervous innervation
• what is the name of the sequence of events in seminiferous tubules that produce male gametes (sperm)

  spermatogenesis
• Gametes have how many haploid chromosomes?

  23
• why do gametes only have 23 chromosomes?

  only one member of the homologous pair is present
• how many diploid chromosomes do somatic cells have?

  46
• why do somatic cells have 46 diploid chromosomes?

  they have 23 pairs of homologous chromosomes, one from each parent
• when is a chromosome ready for cell division?

  when a centromere is present with 2 sister chromatids
• what stage of meiosis 1 does chromatin coil into their condensed form with 2 sister chromatids?

  prophase 1
• what is it called when you have uncoiled chromosomes?

  chromatin
• how many chromatids are present after interphase?


  96
• how many chromatids are present after meiosis 1?

  46
• how many chromatids are present before interphase?

  46
• how many chromatids are present after meiosis 2?

  23
• how many chromosomes are present before interphase?

  46
• how many chromosomes are present after interphase?

  46
• how many chromosomes are present after meiosis 1?

  23
• how many chromosomes are present after meiosis 2?

  23
• what cell process forms gamete?


  meiosis
• where does meiosis occur in the body?


  gonads (testes and ovaries )
• what genetic process reduced diploid chromosomes number by half (2n to n), produces 4 daughter cells, and results in genetic variation?


  meiosis
• what process causes genetic variation during meiosis?

  crossover