Exam 2: Lecture 11 (chapter 29) Flashcards
What are plants
Autotrophic organisms that lack motility, and have cellulose-based walls; use growth and movement to acquire resources
Define the alternation of generations
when an organism alternates between two distinct forms: a multicellular diploid phase (sporophyte) and a multicellular haploid phase (gametophyte)
What traits do plants share with protists
- Multicellular (red, brown, green algae)
- Cell walls made of cellulose (G. Algae, Dinoflagellates, Brown algae)
- Chloroplasts with chlorophyll A and B (G Algae, euglenids, dinoflagellates)
What is the most common ancestor of plants from protists and what traits do they share
Charophytes,
- Peroxisome enzymes
- Flagellated sperm
- Formation of phragmoplast
- Rose-shaped complexes (cellulose synthesis)
- DNA similarities (chloroplasts, mitochondrial DNA)
What are pros of plants moving to land
- More access to sunlight
- More CO2
- Nutrient-rich soil
What are some cons of moving to land
- Lack of water (harder to access)
- Greater effect of gravity (harder to grow upwards)
- More risk to gametes/offspring
- Less space to grow (other plants?)
What are four main characteristics that separate plants from charophytes
- Alternation of generations
- Walled spores produced In sporangia
- Multicellular gametangia
- Apical Meristems (allows for indefinite growth)
Plants are called _______ because their ______ is dependent on the parent plant
Embryophytes, embryo
The _______ produces ______ in organs called sporangia. Diploid cells called _______ then undergo meiosis to generate haploid cells.
Sporophyte (2N), spores, sporocytes
What structure protects spores from harsh, dry environments
Sporopellenin, which makes spores resistant to harsh environments
Female _______ produces egg cells, and male ______ produce sperm cells.
Archegonium, antheridia
Why is the Apical Meristem an important characteristic of plants
Plants grow from the apical meristem, allowing them to differentiate into various tissue such as leaves, flowers, fruits, and roots.
- The Apical Meristems allows plants to exhibit indeterminate growth (growth as long as alive)
What are derived traits of land plants?
Cuticle: A waxy covering on their leaves, preventing water loss and protecting against microbes
Symbiotic relationship with Mycorrhizal fungi, allowing nutrient absorption.
What are the three main categories of plants
- Nonvascular plants (mosses, liverworts, hornworts)
- Seedless vascular plants (Ferns, Club mosses, whisk ferns, horsetails)
- Seed plants (pines, flowering plants, confiers, etc…)
What defines non-vascular plants
They do not have any vascular tissue, preventing them from growing large, staying close to the ground.
- Lack of Phloem and Xylem means they rely on diffusion through their leaves for water/nutrients.
What are Bryophytes and what are their three phyla
Bryophytes include all nonvascular plants, which are small and widespread
- Bryophyta (mosses)
- Hepatophyta (liverworts)
- Anthocerophyta (hornworts)
Define some characteristics of Mosses
- Thrive in moist habitats (nutrient/water absorption through leaves)
- Rhizoids anchor the plant
- Sperm is produced in antheridia and eggs are produced in archegonia
All ________ phyla spend most of their lives as ________, and their _______ remain attached to gametophytes
Bryophyte, Gametophytes, sporophytes
Name and describe bryophyte sporophyte organs
Foot: Absorbs nutrients from gametophyte
Seta: conducts nutrients to capsule
Capsule: produces spores
Peristome: tooth-like structures surrounding the opening of the capsule
Describe the diversity of Hepatophyta (liverworts)
- Leaves are similar to mosses, but have two rounded lobes
- Thallus: Body without roots, stems, or leaves
- Air pores (not stomata)
- Asexual reproduction with gemmae in gemmae cups
Describe the diversity of Anthocerophyta’s (Hornworts)
- Grow in moist soil (100-150 species)
- Have no Seta, sporangium releases spores by splitting open at the tip
- DO HAVE stomata (allows easier gas transfer)
What separates seedless vascular plants from non-vascular plants
Seedless vascular plants evolved vascular tissue that allows them to transport nutrients and water around more easily
What makes up plant vascular tissue
Xylem: conducts water and nutrients (cohesion)
Phloem: distributes organic products throughout the plant
What is the advantage of having vascular tissue for land plants?
Vascular tissue allows land plants to grow taller, since they can provide structure support (filled with water, stiffer body).
_______ anchor plants and absorb nutrients/water, and ______ increase surface area to capture light
Roots, Leaves
_________ are small leaves with one vein, and _______ are leaves with a branched vascular system, allowing higher photosynthetic productivity.
Microphylls, Megaphylls
What are sporophylls?
Modified leaves that bear sporangia
What is the sporangia
A receptacle where spores of formed, most seedless vascular plants are homosporous
What are the steps of homosporous spore production
Sporangium on Sporophyll —> Single type of spore —> Bisexual Gametophyte (both sperm and egg)
What are the steps of heterosporous spore production
- Megasporangium on megasporophyll —> Megaspore —> Female Gametophyte –> Eggs
- Microsporangium —> Microspore —> Male Gametophyte —> Sperm
Lycophyte sporophytes have _______
Microphylls
Describe the structure of Fern leaves
Fern leaves are megaphylls called fronds
- Fronds are divided into smaller segments and require external water for production
