Chromosomes, Genes, and DNA

• What is the process of the transmission of traits from parents to offspring called?

  Heredity
• What is the science involved in studying heredity called?

  Genetics
• What do genes contain information for?

  They code for proteins controlling specific characteristics of an organism
• Where can genes be found?

  In certain regions of the DNA
• What is DNA?

  DNA is a long chain of chemicals containing information about an organism's traits
• What is the structure that contains the genetic material in DNA?

  Chromosome
• What is the specific area in the DNA that codes for a specific gene called?

  Locus
• Why is determining the locus important?

  It is important in gene mapping
• What is an example of a trait expressed by the action of multiple genes?

  Height
• Where are chromosomes located?

  In the nucleus
• What shape do replicated chromosomes form?

  An X-shape
• What holds the two replicated chromosomes together at the center?

  Centromere
• Who was the first to observe chromosomes?

  Walther Flemming
• What did Walther Flemming first call chromosomes?

  Chromatin
• What does the term "chromatin" refer to?

  It refers to the threadlike structure of chromosomes when stained
• What is the chromosomal theory of inheritance?

  It states that inherited traits are controlled by genes located in chromosomes
• What are the two types of chromosomes?

  Autosomes and sex chromosomes
• What is an autosome?

  A chromosome that does not determine the sex of an organism
• What do sex chromosomes determine?

  The sex of an organism
• What is a karyotype?

  A karyotype shows the number of chromosomes of an organism arranged in a particular pattern
• What is a karyogram?

  A graphical expression of a karyotype
• What are the sex chromosomes in humans?

  X and Y chromosomes
• What is the chromosome composition of females?

  Females have two X chromosomes (XX)
• What is the chromosome composition of males?

  Males have one X and one Y chromosome (XY)