Systematics - Botany - Lecture Slides, Slides of Botany and Agronomy

Download Systematics - Botany - Lecture Slides and more Slides Botany and Agronomy in PDF only on Docsity!

Systematics: The Science of

Biological Diversity

Many organisms didn’t fit

1. Euglena is a unicellular, motile autotroph
2. Fungi (mushrooms and molds), traditionally classified as plants, are non-motile heterotrophs

Technology led to better classifying

cells

1. Prokaryotes (bacteria) - lack : nuclei, organelles, flagella, chromosomes, multicellularity and sexuality
2. Eukaryotes (nearly all other organisms) - have : nuclei, organelles, flagella, DNA associated with histone proteins to form chromatin/chromosomes, sexual reproduction and most are multicellular

Three domains

A. Recent genetic and molecular investigations have demonstrated that there are two major groups of prokaryotes. They differ radically in the composition of their cell walls, membrane lipids, ribosomal RNA, and a variety of other biochemical features

Therefore, our text recognizes three domains above the rank of kingdom

2. Domain Archaea ( ancient bacteria)

• prokaryotes that lack muramic acid in cell walls. Many inhabit "harsh" environments. Includes methane producers, extreme halophiles, extreme thermophiles, acidophiles and one group which lacks cell walls

3. Domain Eukarya

• all eukaryotes, four kingdoms:

a) Animalia

b) Plantae

c) Fungi

d) Protista

Kingdom Plantae (Plants)

• nonmotile, multicellular, plastids and autotrophic via photosynthesis, cell walls made of cellulose, adapted for life on land, mostly sexual reproduction.

"Algae" are not included in this kingdom

Kingdom Fungi (Mushrooms and

Molds)

• nonmotile, filamentous , lack plastids, cell walls are made of chitin , heterotrophic via absorption of nutrients from dead (saprophytic) or living (parasitic) matter. Virtually all are multicellular except yeast. Both sexual and asexual reproduction