Chapter 1: Call The DNA Flashcards

Structure and Function of DNA and Chromosomes

• DNA (deoxyribonucleic acid) is classified as a nucleic acid.
• Chromosomes are composed of DNA molecules, which contain hundreds of thousands of distinct functional units termed genes.
• Essential roles of DNA and genes within cellular biology:
  • Cellular identity: Directing and defining what the cell is.
  • Biological synthesis: Instructing the cell on what molecules to make.
  • Morphological specification: Determining cellular appearance and physical structure.
  • Operational regulation: Governing cellular behavior and functional activities.
• Transmissibility across generations:
  • DNA serves as the central hereditary material that must be faithfully passed down from one generation to the next.

Evolutionary Divergence and Common Ancestry

• Environmental adaptation:
  • Biological organisms, such as different bird species, occupy diverse habitats that impose varying functional and physiological requirements.
• Definition of divergence:
  • Divergence refers to the process of evolutionary change occurring after inheriting traits from a common ancestor.
• Mechanism of evolutionary change:
  • Descendant species inheriting genetic information from a shared ancestor undergo divergence as they adapt to the distinct environmental demands of their respective habitats.