Midterm Definitions Flashcards
Adaptive Radiation
refers to the rapid diversification of a single lineage into a variety of forms that occupy different ecological niches
Colonization of land by plants and fungi
- refers to the process by which these organisms moved from aquatic habitats to terrestrial environments
- resulting in major changes to the physical and environment and biotic interactions
Effects Plants & Fungi Have
- modifying rocks and soil
- affecting the formation of soil
- altering the composition of Earth’s atmosphere
- creating habitats for other organisms
Role Plants & Fungi Play in Chemical Cycling
- absorbing nutrients from the physical environment
- passing those nutrients to organisms that eat plants
- decomposing the bodies of dead organisms to return nutrients to the physical environment
Carbon Recycling
refers to the process by which carbon moves through the living and nonliving components of an ecosystem
How do plants affect carbon cycling?
- by removing large quantities of carbon dioxide from the atmosphere during photosynthesis
- by contributing to the formation of coal
- removal of carbon from the air and its storage in marine rocks
Biotic Interactions
are interactions between different species in an ecosystem
How do plants and fungi affect biotic interactions?
- by increasing the availability of energy and nutrients for other organisms
- leading to the evolution of mutualistic and parasitic relationships
Early plants
- were simple and lacked true roots and leaves
- had some adaptations for life on land
Nutrient Uptake
plants formed symbiotic associations with fungi to facilitate nutrient uptake from soil
Mycorrhizae
- symbiotic associations between fungi and plant roots
- helps transfer nutrients absorbed from the soil to their plant partner
Fungal Morphology
- provide a large surface area across which absorption can occur
Hyphae
fungi bodies consisting of a network of filaments
Fungal Evolution
- molecular data indicates that fungi and animals are members of the opisthokont clade
- suggesting the ancestor of fungi was unicellular
Multicellularity Evolution
- evolved independently in animals and fungi
- from different single celled ancestors
Fossil Evidence - Fungi
fossils of certain unicellular marine eukaryotes that lived as early as 1.5 billion years ago have been interpreted as fungi
Feeding By Absorption - Fungi
fungi secrete hydrolytic enzymes into their surrounding to break down complex molecules to smaller organic compounds that they can absorb into their cells and use
Chitin
- a strong but flexible polysaccharide that strengthens the cell wall of fungi
- prevents the cells from bursting due to the pressure created by water moving into their cells
Mycelium
a network of hyphae formed by multicellular fungi that grows into and absorbs nutrients from the material on which the fungus feeds
Yeasts
- single cells that fungi can grow
- often inhabiting moist environments where there is a ready supply of soluble nutrients
Mycorrhizal Fungi
- fungi that form mycorrhizae
- which are mutually beneficial relationships between fungi and plant roots
Arbuscular Mycorrhizae
a type of mycorrhizal fungi that penetrates the cell walls of root cells and form branching structures called (arbuscules) inside the cell
Ectomycorrhizae
a type of mycorrhizal fungi that forms a mantle around the outside of the root and penetrates between root cells
Angiosperms are thought to have originated how many years ago?
140 million years ago
Evidence supporting the hypothesis that charophytes are the closet living relatives to land plants
- charophytes and plants produce cellulose in similar ways
- mitochondrial DNA sequences of charophytes are more similar to those of plants than are those of other algae
- nuclear DNA sequences of charophytes are more similar to those of plants than are those of other algae
- charophytes and plants have structurally similar sperm
What plants dominated the first 100 million years of plant evolution?
bryophytes
Why did Carboniferous period plants outcompete bryophytes?
- their vascular tissue allowed them to grow tall
- competing for light and more widely dispersing their spores
What group is most likely the closest relative of seed plants?
monilophytes
What did the Carboniferous period look like?
swampy forests dominated by tree lycophytes, horsetails and ferns
Rhizoids differ from roots in that rhizoids?
are not vascular
Karyogamy
- the event in the life cycle of sexually reproducing fungi
- involves the transition from a haploid to a diploid stage
What is the difference between spores and seeds?
spores are unicellular and seeds are not
In what groups must sperm no longer swim to reach the female gametophyte?
both gymnosperms and angiosperms
Xylem and phloem are found in?
- vascular plants
- lycophytes
- ferns
- gymnosperms
- angiosperms
Exclusively Female Flower Parts
- stigma
- ovary
- sepal
- petal
What are adaptations for terrestrial life seen in plants?
- sporopollenin
- an embryo protected and nourished by the parent plant
What major groups of fungi form mycorrhizae?
glomeromycetes
Bryophytes differ from other plant groups because?
their gametophyte generation is dominant
What major group of fungi contains the most species?
ascomycetes
What do spores and gametes have in common?
are both haploid
Gametes
- are the haploid reproductive cells
- ex. sperm and eggs
- unite during sexual reproduction to produce a diploid zygote
How do plants reproduce?
sexually through production of gametes
Spores
- are haploid cells produced in the sporophyte stage by meiosis
- can divide by mitosis to develop into a multicellular haploid individual
- the gametophyte (without fusing with another cell)
In fungi spores
- is a haploid cell
- produced either sexually or asexually
- that produces a mycelium after germination
What clades define the plant kingdom?
- plantae
- streptophyta
- viridiplantae
- all proposed clades
Lichens
are any photosynthetic organism
Lichens are symbiotic associations that
involves a fungus and a green algae or cyanobacterium
All fungi are
- heterotrophic
- obtain carbon compounds by decomposing organic matter or by symbiotic associations with other organisms
- have feeding structures (mycelium) or a hyphae
- decomposers (recycle the nutrients from nonliving organic matter)
Heterotrophic
- requiring complex organic compounds of nitrogen and carbon for metabolic synthesis
- obtained from plant or animal matter
What provided the earliest fossil evidence of plants?
spores
What major group produce mushrooms?
basidiomycetes
Which taxon is essentially equivalent to the embryophytes?
plantae
Major differences between fungi and plants
fungi have an absorptive form of nutrients
How do fungi absorb nutrients?
- fungi do not ingest their food
- absorb nutrients from the environment outside of its body
- accomplished by secreting hydrolytic enzymes into their surroundings
- enzymes break down complex molecules to smaller organic compounds that the fungi can absorb into their bodies and use
What do fungi and plants and animals have in common?
- all protists
- are eukaryotic
What is the difference between the cell walls of fungi in comparison to plants?
- fungi are strengthen by chitin
- plants are strengthened by cellulose
Fungi and animals appear to be more closely related to each other than either is to plants?
based on molecular analyses
Arbuscular mycorrhizal fungi differ from ectomycorrhizal fungi in that
arbuscular mycorrhizal fungi extend hyphae through plant cell walls
Choanoflageilates
- single celled eukaryotes
- similar to the ancestors of animals
Explain Animal Evolution
the process by which animals have evolved from single celled organisms to the vast diversity of living animal species seen today
Fossils
the remains or traces of past life preserved in rock or sediment
Molecular Clock
a technique used to estimate the timing of evolutionary events based on the changes in DNA sequences over time
Ediacaran Biota
- multicellular eukaryotes
- soft bodied
- lived during the late Precambrian period
- around 560 million years ago
Molluscs
- diverse group
- invertebrate animals
Ex. snails + clams + octopuses
Cnidarians
- a phylum of animals
Ex. sea anemones + corals + jellyfish
Porifera
- a phylum of animals includes sponges
Tissues
groups of similar cells that perform a specific function
Eumetazoans
- animals that have tissues
- in contrast to sponges and other basal animals
Gastrovascular Cavity
a central digestive compartment found in cnidarians and other animals
Nerve Net
a network of neurons found in cnidarians and other animals that lack a centralized brain
Phylogeny
the evolutionary history and relationships among groups of organisms
Radial Symmetry
- which the body is wheel or spoke-shaped
- no obvious front, back, left or right