Notes for B 2.3

1. Notes for B 2.3 Classification systems change as scientists learn more.

2. Taxonomy changes as scientists make discoveries. • Early scientists described 2 kingdoms: Plants: green and nonmoving Animals: moving organisms

3. Three Domains • Microscopes and other advances in technology show that there are basically 3 different types of cells. • Kingdoms are arranged into 3 larger groups called domains: Bacteria, Archaea, and Eukarya.

4. Three Domains • Bacteria: includes bacteria kingdom • No nucleus • Unicellular • Vary in how they get energy

5. Archaea • Kingdom Archaea • No nucleus (prokaryotic) • Unicellular • Vary in how they obtain energy • Distinctive chemistry and live in extreme environments

6. Eukarya • Includes Kingdoms Protista, Fungi, Plantae, and Animalia • Eukaryotic (have nuclei) • Some unicellular, most multicellular • Vary in the ways they obtain food • See chart on page B 61.

7. Six Kingdoms • Plantae • Animalia • Protista • Fungi • Archaea • Bacteria • See pages 62 and 63 for an overview of all of these kingdoms you studied in seventh grade.

8. The two most familiar kingdoms are plants and animals. • CarolusLinneaus divided all the species he identified into these 2 groups. • Plantae DNA stored in a nucleus Can carry out photosynthesis to make sugars Contain cell walls around their cell membrane Cannot move from place to place Multicellular

9. Animalia • More than 90% of named species are insects. • Obtain energy by eating organisms or by eating food made by other organisms • Can move around for at least part of their lives • Most have mouths and nervous systems • Have nuclei (eukaryotic) • No cell walls

10. Other organisms make up four more kingdoms. • Linnaeus: called mushrooms, molds, and their relatives plants • Archaea, Bacteria, and Protista are mostly microscopic. • Most organisms on Earth are classified as bacterial or archaea—prokaryotic, small, and simple.

11. Protista • Most unicellular • Large, complex with a true nucleus • Some eat other organisms. • Some make their own food. • Some resemble fungi. • Most live in water or sea water • Seaweeds • Some scientist think this should be divided into different kingdoms.

12. Fungi • Yeasts • Molds • Downy Mildew • Most have cell walls • Remain rooted in one place • Many act as decomposers

13. Archaea • Resemble bacteria in size and shape • Genetic differences • Appear to be related to eukaryotes, but do not have nuclei • Cell structure differs from bacteria • Live in many environs, especially the oceans • Some live in extreme environs such as geysers, hot springs, hot vents, salty ponds etc.

14. Bacteria • Live nearly everywhere on Earth • Helpful/harmful • Unicellular • Prokaryotes (no nucleus) • Most have cell walls, but not the kind plants have • Reproduce quickly by binary fission

15. Species and environments change. • Over a million species named • Estimated millions—maybe tens of millions– not yet discovered • Species evolve over time as individual organisms and environments change. • Changes may result in pressures that affect living space, availability of food or other resources, or from other organisms.

16. Review Questions for B 2.3 • Page 67B

17. Number 1 • Plantae • Animalia • Protista • Fungi • Bacteria • Archaea

18. Number 2 • Organisms are sorted according to general traits.

19. Number 3 • See pages 62-63.

20. Number 4 • Plants use the sun’s energy and air to make sugars. • Fungi take in nutrients from their surroundings.

21. Number 5 • No—does not have a nucleus • Yes—the membrane and DNA are like a nucleus

22. Quiz B 2.3 • Fill ins: AnimaliaArchaea species Protista Bacteria Fungi Domains Plantae (6 terms used) What are the 3 domains? List 2 traits that are used to classify organisms into each domain.