20.2 Classification of Plants TEKS 5B, 7D, 8B, 8C The student is expected to: 5B examine specialized cells, including roots, stems, and leaves of plants; and animal cells such as blood, muscle, and epithelium; 7D analyze and evaluate how the elements of natural selection, including inherited variation, the potential of a population to produce more offspring than can survive, and a finite supply of environmental resources, result in differential reproductive success;

20.2 Classification of Plants TEKS 5B, 7D, 8B, 8C Continued: 8B categorize organisms using a hierarchical classification system based on similarities and differences shared among groups; 8C compare characteristics of taxonomic groups, including archaea, bacteria, protists, fungi, plants, and animals

20.2 Classification of Plants TEKS 5B, 7D, 8B, 8C KEY CONCEPT Plants can be classified into nine phyla.

20.2 Classification of Plants TEKS 5B, 7D, 8B, 8C Mosses and their relatives are seedless nonvascular plants. Nonvascular plants grow close to the ground to absorb water and nutrients. Seedless plants rely on free- standing water for reproduction. Liverworts belong to phylum Hepatophyta. –often grow on wet rocks or in greenhouses –can be thallose or leafy

20.2 Classification of Plants TEKS 5B, 7D, 8B, 8C Hornworts belong to phylum Anthocerophyta. – found in tropical forests and along streams – flat, lobed body with little green “horns”

20.2 Classification of Plants TEKS 5B, 7D, 8B, 8C Mosses belong to phylum Bryophyta. –most common seedless nonvascular plants –sphagnum moss commonly used by humans as “peat”

20.2 Classification of Plants TEKS 5B, 7D, 8B, 8C Club mosses and ferns are seedless vascular plants. A vascular system allows club mosses and ferns to grow higher off the ground. Both need free-standing water for reproduction. Club mosses belong to phylum Lycophyta. –not true mosses –oldest living group of vascular plants

20.2 Classification of Plants TEKS 5B, 7D, 8B, 8C Ferns and their relatives belong to phylum Pterophyta. frond fiddlehead –whisk ferns and horsetails are close relatives of ferns –ferns have large leaves called fronds

20.2 Classification of Plants TEKS 5B, 7D, 8B, 8C Seed plants include cone-bearing plants and flowering plants. Seed plants have several advantages over their seedless ancestors. –can reproduce without free-standing water, via pollination –pollination occurs when pollen meets female plant parts –seeds nourish and protect plant embryo –seeds allow plants to disperse to new places

20.2 Classification of Plants TEKS 5B, 7D, 8B, 8C Gymnosperms do not have seeds enclosed in fruit. –most gymnosperms are cone-bearing and evergreen. –the cone is reproductive structure of most gymnosperms. –pollen is produced in male cones. –eggs are produced in female cones. –seeds develop on scales of female cones.

20.2 Classification of Plants TEKS 5B, 7D, 8B, 8C Cycads are gymnosperms in phylum Cycadophyta. –look like palm trees with large cones –grow in tropical areas

20.2 Classification of Plants TEKS 5B, 7D, 8B, 8C Ginkgos are gymnosperms in phylum Ginkgophyta. –only one species alive today, Ginkgo biloba –grown in gardens and used in urban landscaping

20.2 Classification of Plants TEKS 5B, 7D, 8B, 8C Conifers are gymnosperms in phylum Coniferophyta. –most common gymnosperms alive today –includes pines, spruce, cedar, fir, and juniper

20.2 Classification of Plants TEKS 5B, 7D, 8B, 8C Angiosperms have seeds enclosed in some type of fruit. –A flower is the reproductive structure of angiosperms. –A fruit is a mature ovary of a flower. Angiosperms, or flowering plants, belong in phylum Anthophyta.