Plants evolved from protist chlorophyta. 3 adaptations helped plants live on land; the ability to prevent water loss, the ability to reproduce in the absence of water, and the ability to absorb and transport nutrients.
Land has many advantages, like more sunlight, more carbon dioxide, and more inorganic nutrients. The cuticle is a waxy protective covering on plant surfaces that prevents water loss. Stomata are small openings that allow the exchange of CO2 and oxygen.
A spore is a haploid reproductive cell surrounded by a hard outer wall. Eventually, spores evolved into seeds. A seed is an embryo surrounded by a protective coat. Some seeds also contain endosperm, a tissue that provides nourishment for the developing plant. Certain plants evolved vascular tissues such as Xylem and Phloem, specialized tissue that help carry water up (Xylem) and food down (Phloem).There are 12 phyla of plants. They can be divided into vascular (3) and nonvascular(9). These can also be further divided into seeded and seedless. Gymnosperms, like pine trees, make seeds that are not enclosed in fruits. Angiosperms, known as flowering plants, are seed plants that produce seeds with protective fruit shell. Scientists hypothesize that plants evolved from algae. The strongest evidence lies between green algae (Chlorophyta) and plants. Both use chlorophylls a and b, both store energy as starch. Alternating Life Cycles
All plants have two phase life cycles. The first phase of a plant’s life cycle consists of a diploid (2n) sporophyte plant. It makes spores through meiosis. The second phase consists of a haploid gametophyte plant that produces egg and sperm that are created by mitosis. This switching is called alternation of generations. In nonvascular plants, the gametophyte is the dominant phase. In contrast, the sporophyte is the dominant phase of vascular plants. Oak trees are large sporophytes. In seedless vascular plants, the gametophyte is usually a spate small organism quite different from the sporophyte. In seed plants, the gametophyte is a very small parasite of the sporophyte.
28.2 Nonvascular Plants
Phylum Bryophyta
These are the most primitive types of plants. They are seedless and produce spores. Water is necessary for sexual reproduction. Moss is the gametophyte generation and is attached to the soil by rootlike structures called rhizoids. Rhizoids don’t have vascular tissue. Mosses are often the first species to inhabit a berrne area. They help prevent soil erosion by covering the soil surface and absorbing water. Peat moss produces an acid that slows down decomposition and creates peat, which is used as a source of fuel by some. Phylum Hepatophyta
This phylum includes the liverworts, unusual-looking plants that grow in moist, shady ares. Liverwarts lie close to the ground. This helps them absorb water quickly. Phylum Anthocerophyta
This phylum includes hornworts, which also grow in moist shady areas. Hornworts look like liverwarts when sporophytes are not present. These sporophytes are green and carry out photosynthesis and have cells that resemble vascular tissue.
28.3 Vascular Plants
Seedless Vascular Psilophyta
This phylum is represented by whisk ferns, which are not actually ferns. They grow on other plants but do not harm then. Lycophyta
They look like miniature pine tres, and broduce a strobilus, or cone. Sphenophyta
These plants have scalelike leves along their stems. Phylum Pteridophyta
These are true ferns. They live in many places, ranging from deserts to above the arctic circle. Many ferns have an underground stem, called a rhizome. The tightly coiled new leaves of ferns are called fiddleheads. Fiddleheads uncoil and develop into mature leaves called fronds.
The sprouting of a seed is called germination. The embryo begins to grow into a young plant, or seedling. A cone is a reproductive structure composed of hard scales. Vascular Seeded Cycadophyta
There number of species of this has dwindled since the time of the dinosaurs. Most cycads have fernlike, leathery leaves on top of a think, short trunk. Phylum Ginkgophyta
There is only 1 species left. These trees are called deciduous because they lose their leaves at the end of the growing season. Phylum Coniferophyta
These are the conifers. They include Pine, cedar, redwood and fir trees. Ancient conifers secreted amber. They have needlelike leaves and scaly cones. Male cones release clouds of dustlike pollen, which pollinate the female cones. Phylum Gnetophyta
These are desert shrub conifers. Some get their water from fog. Phylum Anthophyta
This is the largest phylum of plants. They are all flowering and have fruits. A fruit is a ripened ovary (female part that encloses egg).Grasses are also in this class.
Angiosperms have more efficient vascular systems and are more likely to be associated with mycorrhizae than gymnosperms are. There are 2 classes of plants: Monocot and Dicot. Dicots have 2 cotyledons while growing and monocots have 1. The major differences are listed below. Monocots
One cotyledon
Parallel venation
Scattered vascular bundles
Corn (Monocot)
Dicots
Two cotyledons
Net venation
Radially arranged bundles
Chapter 28.1 Overview of Plants
Plants evolved from protist chlorophyta. 3 adaptations helped plants live on land; the ability to prevent water loss, the ability to reproduce in the absence of water, and the ability to absorb and transport nutrients.Land has many advantages, like more sunlight, more carbon dioxide, and more inorganic nutrients. The cuticle is a waxy protective covering on plant surfaces that prevents water loss. Stomata are small openings that allow the exchange of CO2 and oxygen.
A spore is a haploid reproductive cell surrounded by a hard outer wall. Eventually, spores evolved into seeds. A seed is an embryo surrounded by a protective coat. Some seeds also contain endosperm, a tissue that provides nourishment for the developing plant. Certain plants evolved vascular tissues such as Xylem and Phloem, specialized tissue that help carry water up (Xylem) and food down (Phloem).There are 12 phyla of plants. They can be divided into vascular (3) and nonvascular(9). These can also be further divided into seeded and seedless. Gymnosperms, like pine trees, make seeds that are not enclosed in fruits. Angiosperms, known as flowering plants, are seed plants that produce seeds with protective fruit shell. Scientists hypothesize that plants evolved from algae. The strongest evidence lies between green algae (Chlorophyta) and plants. Both use chlorophylls a and b, both store energy as starch.
Alternating Life Cycles
All plants have two phase life cycles. The first phase of a plant’s life cycle consists of a diploid (2n) sporophyte plant. It makes spores through meiosis. The second phase consists of a haploid gametophyte plant that produces egg and sperm that are created by mitosis. This switching is called alternation of generations. In nonvascular plants, the gametophyte is the dominant phase. In contrast, the sporophyte is the dominant phase of vascular plants. Oak trees are large sporophytes. In seedless vascular plants, the gametophyte is usually a spate small organism quite different from the sporophyte. In seed plants, the gametophyte is a very small parasite of the sporophyte.
28.2 Nonvascular Plants
Phylum BryophytaThese are the most primitive types of plants. They are seedless and produce spores. Water is necessary for sexual reproduction. Moss is the gametophyte generation and is attached to the soil by rootlike structures called rhizoids. Rhizoids don’t have vascular tissue. Mosses are often the first species to inhabit a berrne area. They help prevent soil erosion by covering the soil surface and absorbing water. Peat moss produces an acid that slows down decomposition and creates peat, which is used as a source of fuel by some.
Phylum Hepatophyta
This phylum includes the liverworts, unusual-looking plants that grow in moist, shady ares. Liverwarts lie close to the ground. This helps them absorb water quickly.
Phylum Anthocerophyta
This phylum includes hornworts, which also grow in moist shady areas. Hornworts look like liverwarts when sporophytes are not present. These sporophytes are green and carry out photosynthesis and have cells that resemble vascular tissue.
28.3 Vascular Plants
Seedless VascularPsilophyta
This phylum is represented by whisk ferns, which are not actually ferns. They grow on other plants but do not harm then.
Lycophyta
They look like miniature pine tres, and broduce a strobilus, or cone.
Sphenophyta
These plants have scalelike leves along their stems.
Phylum Pteridophyta
These are true ferns. They live in many places, ranging from deserts to above the arctic circle. Many ferns have an underground stem, called a rhizome. The tightly coiled new leaves of ferns are called fiddleheads. Fiddleheads uncoil and develop into mature leaves called fronds.
The sprouting of a seed is called germination. The embryo begins to grow into a young plant, or seedling. A cone is a reproductive structure composed of hard scales.
Vascular Seeded
Cycadophyta
There number of species of this has dwindled since the time of the dinosaurs. Most cycads have fernlike, leathery leaves on top of a think, short trunk.
Phylum Ginkgophyta
There is only 1 species left. These trees are called deciduous because they lose their leaves at the end of the growing season.
Phylum Coniferophyta
These are the conifers. They include Pine, cedar, redwood and fir trees. Ancient conifers secreted amber. They have needlelike leaves and scaly cones. Male cones release clouds of dustlike pollen, which pollinate the female cones.
Phylum Gnetophyta
These are desert shrub conifers. Some get their water from fog.
Phylum Anthophyta
This is the largest phylum of plants. They are all flowering and have fruits. A fruit is a ripened ovary (female part that encloses egg).Grasses are also in this class.
Angiosperms have more efficient vascular systems and are more likely to be associated with mycorrhizae than gymnosperms are.
There are 2 classes of plants: Monocot and Dicot. Dicots have 2 cotyledons while growing and monocots have 1. The major differences are listed below.
Monocots
One cotyledon
Parallel venation
Scattered vascular bundles
Dicots
Two cotyledons
Net venation
Radially arranged bundles