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Unit 1 1-29 - Coggle Diagram
Unit 1 1-29
Section 3: The first forest
Ferns and other seedless vascular plants were the first plants to grow tall.
Bryophytes and bryophyte-like plants were the prevalent vegetation during the first 100 million years of plant evolution.
Vascular plants began to evolve during the Carboniferous period (石炭纪).
The earliest fossils of vascular plants date to 425 million years ago. These plants
lacked seeds but had well-developed vascular systems.
Information of living vascular plants
living information
transport in vascular tissues called xylem and phloem,
• well-developed roots and leaves (including spore-bearing leaves called sporophylls 孢子叶).
The life cycles with dominant sporophytes,
Vascular plants have 2 types of vascular tissue
Xylem 木质部
Conducts most of the water and minerals
Includes dead cells called tracheid 管胞
Phloem 韧皮部
Distributes sugars, amino acids, and other organic products
Consists of living cells
Well developed roots and leaves
Root:
Organs that anchor vascular plants
Enable vascular plants to absorb water and nutrients from the soil
May have evolved from subterranean stems
Leaves:
Organs that increase the surface area of vascular plants, thereby capturing
more solar energy for photosynthesis
Categorized by two types
Microphylls, leaves with a single vein
Megaphylls, leaves with a highly branched vascular system
To distinguish seedless plants
Ferns and other monilophyte are more closely related to seed plants to lycophytes. Monilophyte and seed plants share traits that are not found in lycophytes, including megaphyll leaves and roots.
Reasons of Carboniferous(巨虫时代)
At the time of the Carboniferous, the air was twice as oxygenated as it is today, by the presence of large forests. The reason for the giant insects is that they need to be big enough not to be crushed to death by high pressure of oxygen. As a result, their bodies have grown tremendously.
Section 2: Mosses and Other
Non-vascular Plants
Bryophytes (non-vascular plants) are represented today by 3
phyla of small herbaceous (nonwoody) plants
Liverworts, phylum Hepatophyta 地钱门
Hornworts, phylum Anthocerophyta 角苔门
Mosses, phylum Bryophyta 苔藓门
liverworts, mosses, and hornworts were the earliest lineages to have diverged from the common ancestor of land plants.
Mosses and other none-vascular plants
all three bryophyte phyla the haploid gametophytes are the dominant stage of the life cycle. The sporophytes are typically present only part of the time.
Gametophytes:
Produce flagellated sperm in antheridia (精子器)
Produce ova in archegonia
Generally, form ground-hugging carpets and are at most only a few cells thick.
Two key traits: Too thin and no vascular tissue.
Hornwort and moss sporophytes have stomata. (气孔)
Sporophytes:
Grow out of archegonia (藏卵器)
Are the smallest and simplest of all extant plant groups
Consist of a foot, a seta (刺毛), and a sporangium (孢子囊)
peat moss
Sphagnum, or “peat moss” forms extensive deposits of partially decayed organic material known as peat (泥炭，可被用作燃料) and plays an important role in the Earth’s carbon cycle.
Peatlands cover 3% of Earth’s land surface and contain roughly 30% of the world’s soil carbon.
Section 1: Green algae and adaptation
Land plants
evolved
from green algae
Basic information
Green algae called charophytes (轮藻) are the closest relatives of land plants.
This is supported by Morphological and Molecular Evidences. Many
characteristics of land plants also appear in a variety of algal clades.
Green algae: Charophyta include Spirogyra(海绵) and desmids(带藻).
Chlorophyta(绿藻门) include Chlamydomonas(衣藻), and Ulva(石莼).
Key traits only to charophytes:
Rings of cellulose-synthesizing proteins
• The cells of both land plants and charophytes have distinctive circular rings of proteins (right) in the plasma membrane.
Structure of flagellated sperm • In species of land plants that have flagellated sperm, the structure of the
sperm closely resembles that of charophyte sperm.
Formation of a phragmoplast(成膜体)
• A group of microtubules known as the phragmoplast forms between the daughter nuclei of a dividing cell.
Key traits fo land plants:
Multicellular, Dependent Embryos 多细胞的依赖型 胚胎
Alternation of Generations 世代交替
Apical Meristems 分生组织
Walled Spores Produced in Sporangia 由孢子囊产生 的带厚壁的孢子
Additional derived traits that relate to terrestrial life have evolved in many plant species.
Stomata
Cuticle
The reproduction & alternation of generations: Plant embryos develop from zygotes that are retained within the tissues of the female parent (a gametophyte). The parental tissues protect the developing embryo from harsh environmental conditions and provide nutrients such as sugars and amino acids.