Plant Evolution
How do prokaryotic and eukaryotic cells differ?
Prokaryotic: Plasma membrane, DNA, ribosomes, and cytosol
Eukaryotic: Membrane-enclosed nucleus, membrane-enclosed organelles, can be separated into kingdoms
What is Taxonomy?
The branch of biology concerned with identifying, naming, and classifying species.
What 3 structures are unique to plant cells?
-Cell wall(outside of the plasma membrane)
-Chloroplast
-Specialized vacuoles
What are the 3 main types of tissues found in plants?
-Dermal tissue
-Vascular tissue
-Ground tissue
What are nodes?
Where the leaves are attached to the stem.
What are the two stages of photosynthesis?
1. The Light Reactions (Light Dependent)
2. The Calvin Cycle (Light Independent)
What are the three main stages of cellular respiration?
1) Glycolysis
2) Pyruvate oxidation and Citric Acid Cycle (Krebs cycle)
3) Oxidative Phosphorylation
What 3 forces enable the movement of the xylem sap?
-Cohesion
-Adhesion
-Transpiration
How do parasitic plants and epiphytes differ?
Epiphytes do not take nutrients from their host. They just use them as a growing surface.
Where does all new plant growth originate from?
Meristems: clumps of small cells where all new plant growth originates.
What are gametes?
Egg and sperm
Which generation is dominant in bryophytes?
Gametophyte
Which generation is dominant in vascular plants?
Sporophytes
What is the goal of conservation biology?
Seeks to understand and counter the rapid loss of biodiversity.
Which type of seed plants use flowers and fruits in their reproduction?
Angiosperms
What is Endosymbiosis?
One organism (an endosymbiont) lives inside another (the host)
What is Phylogeny?
The evolutionary history of a species or group of species.
What are 4 structures found in all cells?
1) DNA
2) Cytosol
3) Ribosomes
4) Plasma membrane
What are Guard cells and Stomata?
Guard Cells- paired cells that surround a Stoma (stomata). Act as a passageway for oxygen, carbon dioxide, and water vapor.
Stomata- are the openings in the guard cells.
What are the three primary plant organs?
-Roots
-Stems
-Leaves
What are light reactions, and where does the stage occur?
Light energy is absorbed by pigments and converted to chemical energy in the form of two energy intermediates: ATP and NADPH
-This step occurs in the Thylakoids
Which stage does anaerobic respiration utilize?
Glycolysis
Do the forces from the xylem sap require energy from the plant?
No, the forces do not require energy from the plant.
What are mycorrhizae, and how are they mutually beneficial?
They are fungal fibers that act as an extension of the root system, substantially expanding the surface area available for uptake of water, nutrients, and minerals. In turn, the plant provides the fungus with sugars.
What is primary growth?
Apical meristems elongate the shoot and root.
How do asexual and sexual reproduction differ in terms of genetic variation?
Asexual reproduction uses mitosis to produce offspring that are all genetic copies of the parent and are all genetically identical.
What is the gametophyte specialized for?
They are small but are specialized for photosynthesis.
What are Strobili?
Single Strobilus.
What is biodiversity?
Describes the diversity of living organisms in an area.
What order are the floral whorls found in (outermost > innermost)?
-Calyx
-Corolla
-Androecium
-Gynoecium
How does endosymbiosis relate to eukaryotic organelles?
Explains how some Eukaryotic organelles formed from free-living Prokaryotic cells. Overtime this bacteria has evolved into organelles like mitochonria and cholorplast.
Classification levels (biggest to smallest)
-Domain
-Kingdom
-Phylum
-Class
-Order
-Family
-Genus
-Species
What are plasmodesmata?
Cell junctions that allow plant tissues to share water, nourishment, and chemical messages
What are the two types of vascular tissue? What do they do?
Xylem- conducts water and dissolves minerals throughout the plant.
Phloem - conducts a solution of sugars used by plants for food; also transports hormones, amino acids, and other substances necessary for plant growth.
Main functions of roots, stems, and leaves
Roots- Funtion in anchorage and aborption
Stems- Function in support and growth
Leaves- Function in photosynthesis
What is the Calvin Cycle and where does this step occur?
ATP and NADPH are used to drive the synthesis of carbohydrates
-This step occurs in the Stroma.
What is photorespiration?
The enzyme Rubisco can mistakenly add O2 instead of CO2 to RuBP during the Calvin Cycle
-Wastes CO2, no ATP is produced
Typically only occurs when there is a higher presence of oxygen than carbon dioxide in the leaf
Which way does Phloem Sap always flow?
From the Sugar source to Sugar sink (down)
What is inorganic fertilizer?
Also known as mineral fertilizer, it contains naturally occurring inorganic compounds or synthetic inorganic compounds.
What is secondary growth?
Lateral meristems increase shoot and root diameter.
What do diploid and haploid mean?
Haploid: Cells with a single set of chromosomes
Diploid: Cells with two sets of homologous (the same) chromosomes
What are gametangia?
Gamete-producing structures that form at the tips of gametophytes.
What makes up a Strobili?
Clustered Sporophylls.
What is the single greatest threat to biodiversity?
Human alteration of habitats
What is a fruit? What are its functions?
It is a mature plant ovary that assists in seed protection and dispersal
Are Bryophytes vascular or non-vascular?
Non-vascular, they are nontracheophytes since they lack vascular tissue.
What are the two parts of a scientific name? (Binomial)
1st Part: Genus
2nd Part: Specific epithet
What are Thylakoids?
Sacs that are interconnected in the chloroplast, which are arranged in stacks called granum (grana)
What are the 3 main types of ground tissue cells?
Parenchyma: Function in storage, photosynthesis, and secretion
Collenchyma: Provides flexible support and protection
Sclerenchyma: Provides rigid support and protection
What is the Spongy Mesophyll?
Loosely arranged parenchyma cells with abundant air spaces for gas exchange.
What are pigments, and how do they contribute to the process of photosynthesis?
Pigments are molecules that can absorb some wavelengths of light energy and reflect others
-Having different pigments allow plants to absorb light at different wavelengths
Why do dry conditions increase Photorespiration?
In dry conditions, stomata will close to conserve water. Since this also restricts gas exchange, CO2 levels will drop, and O2 levels will rise.
What are sugar sources and sugar sinks?
Sugar sources: Sugar is loaded into a Phloem tube, and water follows (through osmosis), raising the pressure in the tube.
Sugar Sinks: The sugar is removed, water follows, lowering the pressure in the tube
What is organic fertilizer?
They are composed of biologically derived products, such as compost, that contain decomposed organic matter.
What are the two types of cambium, and what do they produce?
Cork Cambium: produces outer protective layer (cork)
Vascular Cambium: produces secondary vascular tissue (secondary xylem and secondary phloem)
How do fertilization and meiosis contribute to the alternation of generations?
Fertilization changes the life cycle from haploid to diploid. Meiosis changes it from a diploid back to a haploid. These alternating processes create the cycle known as alternation of generations.
What are Sporangia?
Spore beearing tissue
In plants that produce separate male and female spores, what are those spores each called?
Male: produce microspores
Female: produce megaspores
What are invasive species?
Organisms that have been introduced into non-native habitats by human actions and have established themselves at the expense of native communities.
After fertilization, what do the zygote, triploid nucleus, ovule, and ovary develop into?
Zygote > Embryo
Triploid Nucleus > Endosperm
Ovule > Seed coat
Ovary > Fruit Tissue
What two groups make up the seed plants?
Gymnosperms and Angiosperms
What is Systematics?
Which includes taxonomy, is a discipline of biology that focuses on classifying organisms and determining their evolutionary relationships.
What is the Stroma?
Thick fluid in the inner membrane of the chloroplast, which holds chloroplast DNA, ribosomes, and enzymes.
What tissue cells are dead at maturity?
Xylem Cells
What is the Palisade Mesophyll?
Compactly stacked, barrel-shaped parenchyma cells, commonly in two rows, that contain most of the leaf's chloroplasts.
What does Carbon Fixation mean?
-Fixation means that the carbon has been removed from the atmosphere and incorporated into an organic molecule
-CO2 combines with RuBP (a 5-carbon sugar) via the enzyme rubisco.
How do C4 and CAM photosynthesis each solve this issue?
C4- spatial solution to photorespiration.
-Separate carbon fixation and the Calvin Cycle into two different types of cells
CAM- temporal solution to photorespiration
-Separate carbon fixation and the Calvin Cycle by time
What is the purpose of the Casparian Strip?
-This strip blocks the apoplastic route, forcing all molecules to enter through a cell membrane in order to reach the xylem.
-This allows for regulation because the selectively permeable membranes can control what enters (such as minerals) and what is kept out (such as pathogens)
What are nodules, and how are they mutually beneficial?
Nodules are structures found along the roots of some plants (mostly legumes) that have the specific purpose of housing nitrogen-fixing bacteria. These benefit the plants because of the usable forms of nitrogen, and the bacteria receive sugars from the plant.
Do all plants exhibit both primary and secondary growth? Why or why not?
No, although most plants exhibit primary growth. Secondary growth is mostly associated with woody plants.
What are Sporophytes and Gametophytes?
Sporophytes: develop from zygotes and produce sporocytes.
Gametophytes: develop from haploid spores, which undergo mitosis to form multicellular sexual structures and gametes.
What 3 extant phyla make up nonvascular plants?
-Liverwarts
-Mosses
-Hornworts
Seedless vascular plants are commonly referred to as "ferns and fern allies" and include 4 phyla called-?
-Phylum Psilotophyta (whisk ferns)
-Phylum Lycophyta (club mosses)
-Phylum Equisetophyta (horsetails)
-Phylum Polypodiophyta (ferns)
What do most scientists believe is the main cause of climate change?
Greenhouse gasses
What function do sepals, petals, stamens, and pistils each provide?
Sepals: Enclose the flower bud
Petals: Modified leaves that help attract pollinators
Stamens: Provide supportive stalks (filaments) and pollen sacs (anthers)
Pistils: Female reproductive structures