Chapter 29 Plant Diversity 1 Flashcards
What did land plants evolve from?
Evolved from green algae, i.e., charophytes
What are the shared traits b/w land plants and charophytes? (3 things)
- rings of cellulose-synthesizing protein
- structures of flagellated sperm
- formation of a phragmoplast
What is sporopollenin?
Layer of a durable polymer that prevents exposed zygotes from drying out in charophytes
What were the land advantages?
What were the land challenges?
Advantage: unfiltered sun, more CO2, and nutrient-rich soil
Challenge: Scarcity of water/ Lack of structural support to stand upright
What is an embryophyte
Plants with an embryo
What are the 5 derived traits of plants?
- Alternation of generations
- Multicellular, dependent embryos
- Walled spores produced in sporangia
- Multicellular gametangia
- Apical Meristems
What is the alternation of generations?
Process in which plants alternate b/w 2 multicellular reproductives cycles.
What are the two reproductive cycles in the alternation of generations?
- gametophyte
- diploid sporophyte
How does gametophyte and diploid sporophyte work together?
In gametophyte, haploid nuclei produces haploid gametes via mitosis.
From there the haploid gametes are fused together to create a diploid zygote. The diploid zygote produces haploid spores by meiosis. This is called diploid sporophytte
What happens in multicellular, dependent embryos?
- Diploid embryo is retained within the tissue of the female gametophyte
- nutrients are transferred from parent to embryo via placental transfer cells
What is composed of the walled spores produced in sporangia? (2 things)
- Sporangia
- Sporocytes
What is sporangia?
An organ in sporophyte that produces spores
What is sporocytes?
Diploid cells that undergo meiosis to generate haploid spores
What is gametangia?
What are the two types of gametangia?
Organ that produces gametes
Two types: Archegonia and Antheridia
What is archegonia?
Female gametangia that produces eggs and are the site of fertilization
What is antheridia?
Male gametangia that produces and release sperm
What is apical meristems?
Area where plants sustain continual growth
What are the 3 additional derived traits of plants?
- cuticle
- stomata
- mycorrhizae
What is a cuticle?
Waxy covering of the epidermis
What is a stomata?
Specialized cells that allows for gas exchange b/w outside air and plant
How long ago did plants colonize land?
450 MYA
What is the evolutionary history of plants?
Nonvascular plants -> Vascular Plants -> Seedless Vascular -> Seeded Vascular -> Non-flowering and Flowering
What is another name for nonvascular plants?
Bryophytes
What is the breakdown of seedless vascular plants? (2 things)
- Lycophytes
- Monilophytes
What are lycophytes? (4 things)
- Club mosses, spike mosses, and quillworts
- Contains not true mosses (club and spike mosses)
- Lives in moist swamps
- are small herbaceous plants
What are monilophytes? (3 things)
- Ferns, horsetails, whisk ferns, and relatives
- Most diverse in tropics
- most widespread seedless vascular (ferns)
What is a grade?
Group based on shared key biological traits instead of shared ancestry
What is a seed? What are the 2 types of seeds?
An embryo and nutrients surrounded by a protective coat
2 types: Gymnosperm and Angiosperm
What is a gymnosperm?
“Naked seed” plants including conifers
What is an angiosperm?
Flowering plants
What are the 3 phyla of Byrophytes?
- Liverworts (Phylum Hepatophyta)
- Mosses (Phylum Bryophyta)
- Hornworts (Phylum Anthocerophyta)
What does a sporophyte consist of? (3 things)
- foot
- seta (stalk)
- Sporangium (capsule that discharges spores via peristone)
What does a spore germinate into?
Germinates into a gametophyte that has a protonema and a gametophore (gamete-producing)
What are bryophyte sporophyte?
A sporophyte that grows from archegonia
- smallest and simplest sporophyte of all plant groups
What is peat?
Sphagnum or “peat moss” that forms extensive deposits of particularly decayed organic material.
What can peat be used as? What conditions can peat be found in?
- Can be used as a fuel source
- Conditions: Low temps, pH, and oxygen levels
Why is moss important? Where is it usually found in?
Can help retain nitrogen in soil
- Extreme environments, moist forests, wetlands
What were the first plants to grow tall?
Ferns
What are 3 characteristics of seedless plants?
- life cycles with dominant sporophytes
- vascular tissues called xylem and phloem
- well-developed roots and leaves
What is xylem?
Tissue that conducts most of the water and minerals
- includes tube-shaped cells called tracheids
What is phloem?
Tissue that has cells arranged into tubes that distribute sugars, amino acids, and other organic products
What are water-conducting cells strengthened by?
Lignin
What are roots?
Organs that anchor vascular plants
- enable absorption of water and nutrients from soil
What are leaves? What are the two types of leaves?
Organs that increase the surface area of vascular plants for photosynthesis
2 types: Microphylls and Megaphylls
What are microphylls?
Leaves that has a single vein
What are megaphylls?
Leaves with a highly branched vascular system
What are sporophylls?
Modified leaves with sporangia
What is sori?
Clusters of sporangia on the undersides of sporophylls
What is strobili?
Cone-like structures formed from groups of sporophylls
What is homosporous? What kind of plants are homosporous?
Spores that develops into bisexual gametophytes
- Most seedless vascular plants
What is heterosporous? What kind of plants are heterosporous?
Produces megaspores (female gametophytes) and microspores (male gametophytes)
- all seeded and some seedless vascular plants
Why are seedless vascular plants significant? (3 things)
- Increases growth and photosynthesis removes CO2 from the atmosphere
- May have contributed to global cooling during the Carboniferous period
- Decaying plants of the Carboniferous forests eventually became coal.
