Chapter 3: Plant Kingdom Classification

Study Notes

Excluded Organisms from Plantae Kingdom

Prokaryotes, fungi, and certain protists were excluded from the Plantae kingdom in Whittaker's classification.
This classification also distinguished plants from organisms such as bacteria and fungi, which were categorized under separate kingdoms.

Earliest Systems of Plant Classification

Earlier classification systems primarily relied on morphological characteristics such as plant structure and form.
Emphasis was placed on visible traits like flowers, leaves, and overall plant structure to categorize species.

Main Classifications Under Kingdom Plantae

Five main classifications detailed under Kingdom Plantae include:
- Bryophytes (mosses and liverworts)
- Pteridophytes (ferns)
- Gymnosperms (conifers)
- Angiosperms (flowering plants)
- Algae (some classifications include as a group distinct from true plants)

Cyanobacteria

Cyanobacteria are commonly referred to as blue-green algae.
They are photosynthetic bacteria that contribute significantly to the ecosystem through oxygen production and nitrogen fixation.

Organisms Previously in Plantae Kingdom

In Whittaker's 1969 system, certain algae and similar organisms were previously placed in the same kingdom as Plantae.
This reflects an earlier understanding of the relationships among living organisms.

Characteristics in Artificial Classification Systems

In artificial classification systems, characteristics such as growth form, reproductive structures, and anatomical features were given equal weightage.
These classifications often resulted in groupings that did not reflect evolutionary relationships.

Basis of Natural Classification Systems

Natural classification systems are developed based on evolutionary relationships and genetic information.
These classifications focus on phylogenetic relationships, stemming from shared ancestry and traits.

Assumption of Phylogenetic Classification Systems

The underlying assumption of phylogenetic classification systems is that all living organisms share a common ancestry and can be categorized based on their evolutionary lineage.
This system seeks to represent the evolutionary tree of life accurately.

Numerical Taxonomy

Numerical Taxonomy is based on the statistical analysis of numerous traits across different species.
This method quantifies similarities and differences among organisms, promoting objectivity in classification.

Cytotaxonomy

Cytotaxonomy uses chromosome number, structure, and behavior to resolve confusions in classification.
This approach can clarify relationships that are not evident through morphological characteristics alone.

Description

Explore the detailed classification of the plant kingdom, including algae, bryophytes, pteridophytes, gymnosperms, and angiosperms. Learn about the Five Kingdom classification proposed by Whittaker in 1969, and delve into the system of Monera, Protista, Fungi, Animalia, and Plantae.