PBS 2.2.4

Goals:

  • Prepare and analyze a chromosome spread

  • Demonstrate how a karyotype can be used to evaluate the genetic health of an individual

Endocrine System - organs and glands that produce chemical signaling molecules, known as hormones

  • Hypothalamus and pituitary gland, pineal gland, thyroid gland, adrenal gland, pancreas, testis

  • Hormones help regulate many of the body’s functions: growth and development, metabolism, reproduction, sleep-wake cycles

Human Growth Hormone (HGH) and Insulin-like Growth Factor 1 (IGF-1) aid in growth and development

Growth Hormone Deficient (GHD)

Cytogeneticists - harvest cells to view chromosomes under microscope

Chromosome Spread - visual display of chromosomes → spread on slide

  1. Stain with Giemsa dye and view under microscope

  2. Add cell sample to culture media - sterile solution that helps cells grow

  3. Halt cells in metaphase using specific chemical

  4. Culture - grow cells - for 2 weeks

  5. Swell and drop cells onto microscope slides → cells burst spreading out chromosomes

Karyotype - organized profile of person’s chromosomes → chromosomal analysis

  • Stained chromosomes arranged by size and numbered accordingly, sex chromosomes last and labelled X or Y

  • 21 smallest but 22’s discovery came too late to change

Cancer cells exhibit chromosomal instability - often gain/lose chromosomes during mitosis