Transcript 20.2 Classification of Plants TEKS 5B, 7D, 8B, 8C

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
KEY CONCEPT
Plants can be classified into nine phyla.
TEKS 5B, 7D, 8B, 8C
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 freestanding 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
• Hornworts belong to phylum Anthocerophyta.
– found in tropical forests and along streams
– flat, lobed body with little green “horns”
TEKS 5B, 7D, 8B, 8C
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.