BIO211 Everything

Sclerenchyma

cells have thick secondary walls, provide rigid support, and are dead when mature.

These macroscopic primary producers provide important offshore habitat for many species along the Pacific Coast. They are distinctive for their 4-membrane chloroplast and store carbohydrates as laminarin. They are also very sensitive to water temperature and at the mercy of sea urchins.

Rhodophyta

These primary producers are found in the deepest parts of the photic zone; their distinctive photosynthetic pigments include phycoerythrin.

Nematoda (Roundworms)

These animals are noted for their worldwide high abundance; as herbivores, predators, and parasites they are particularly efficient because they do not

Echinodermata

Some members of this group are noted as keystone species in the intertidal while other are dominant consumers; their penta-radial symmetry and water vascular system set them apart from other organisms

Archaea

These unicellular organisms are important players in the carbon cycle and active in decomposition; they are found in animal guts as well as in soils and aquatic habitats; they are noted for being the only organisms capable of methanogenesis.

Dinoflagellata (Dinoflagellates)

Unicellular photoautotrophs that are common in marine and freshwater plankton. Some form toxic algal blooms, while others live in symbiosis with corals (as zooxanthellae).
Example: Responsible for red tides and crucial to coral reef ecosystems.

Sieve tubes

are mature living cells without nuclei that transport sugars

Spongy mesophyll

are loosely packed cells with chloroplasts on leaf undersides

Meristems

are centers of cell division, where new plant tissues and organs are produced

Turgor pressure

created by the resistance of the plant cell wall to expansion

Source cells

is where sugar is actively loaded into phloem

Stomata

is the location where plants obtain carbon but also lose water

Osmosis

results from water moving from higher to lower water potential

parent rock

the material that is in the process of breaking down to form soil

Holoparasites

plants that require a host for all parts of the life cycle

Potassium

an important nutrient in maintaining the plant's water and ion balance

Rhizobia

encouraged by the release of flavonoids by plant root cells

Monoecious

Plants have both male and female flowers

Stigma

The sticky part at the top of the carpel where pollen lands and adheres.
Example: This structure is the entry point for pollen tubes to grow down toward the ovule.

Ovary/fruit

when mature, swells to protect and increases dispersal of the fertilized seed

Vascular tissue

Made of living and non-living tissue, this internal transport system moves water, nutrients, and sugars throughout the plant.
Example: Long tubes in stems carry water from roots up to the leaves using this system.

Parenchyma

These thin-walled living ground tissue are the centers of most photosynthesis of the leaf

Cuticle

Specialized dermal tissue for reflecting radiation preventing herbivory, and trapping moisture, a thick waxy layer that prevents excess evaporation.

Stomata

The opening of this structure is driven in active transport when exposed to sunlight, however. closes due to passive transport.

Abscisic acid(ABA)

A plant hormone that inhibits growth, promotes seed dormancy, and helps close stomata during stress (e.g., drought), preventing water loss.

Example: ABA levels rise during drought, causing stomata to close and reduce water loss.

Auxin

A hormone that stimulates cells to lengthen and directs plant responses to light and gravity.
Example: When a plant bends toward sunlight, this hormone is concentrated on the shaded side to promote growth there.

Avr gene

A gene in some pathogens that, when recognized by a plant's immune system, triggers a strong defense.
Example: If this gene is detected, the plant may rapidly kill nearby cells to stop the infection.

Ethylene

A gas that acts as a hormone, regulating processes like fruit ripening and leaf drop.
Example: Storing fruit in a paper bag traps this gas, causing it to ripen faster.

Gibberellin

A hormone that encourages stem growth, seed germination, and development of reproductive structures.
Example: Application of this compound can make seedless grapes grow larger.

Dermal Tissue

A protective outer layer that reduces water loss and shields the plant from harm.
Example: A waxy coating on leaves is part of this layer, preventing dehydration.

What are the two systems that make up the plant body? What are two major functions of each system?

Root: (Support, Water Seeking, Storage) Shoots(Photosynthesis- via leaves, reach sunlight

Ground Tissue

This tissue type fills most of the plant’s interior and functions in photosynthesis, storage, and support.
Example: The green, spongy cells in a leaf that capture sunlight are part of this group.

Collenchyma

Supportive plant cells with unevenly thickened walls that remain alive and flexible.
Example: These cells provide bendable support in young stems and leaf stalks.

Vacuole

A large, fluid-filled structure in plant cells that maintains pressure and stores water, nutrients, and waste.
Example: When this structure loses water, the plant wilts — a symptom of dehydration. Wilting is generally relieved by rehydration, which restores internal pressure and upright posture.

What structure do plants use to transport water, what are its two versions, and which plant groups have them?

Plants use xylem to transport water. The two versions are:

• Tracheids – found in gymnosperms and angiosperms

• Vessel elements – found only in angiosperms
  Both function through passive water movement driven by evaporation (transpiration).

Where does the water that plants require come from, and what direction is it transported through the plant?

Water comes primarily from the soil, absorbed by the roots. It moves upward through the plant from roots to shoots, traveling through the xylem.

What structure transports sugars in plants, and where are the sugars produced?

Plants use the phloem, which includes sieve tube elements and companion cells, to transport sugars. These sugars are produced during photosynthesis in the shoots, where CO₂ + sunlight → photosynthesis → sugars. The sugars then move from the source (leaves/stems) to the sink (roots/fruit/other storage organs).

What process produces sugars in plants, where does it occur, and where do the sugars go?

Photosynthesis occurs in the shoots (mainly leaves), producing sugars that move downward to the roots through the phloem.

Water Potential

The tendency of a solution to draw in pure water, moving from an area of higher potential to an area of lower potential.

Where is water potential highest? where is it lowest in a plant?

1. In the roots

2. In the shoots

Potential Difference

The difference in energy levels that drives substances to be transported from one area to another — in plants, it explains how water or solutes are carried from regions of higher to lower energy.

Example: Water is transported upward through xylem due to this difference between roots and leaves.

Active Process

A biological function that requires energy, usually in the form of ATP, to move substances against a gradient or perform work.
Example: Guard cells use ATP to open stomata in response to light.

Passive Process

A function that does not require energy, allowing substances to be transported along a concentration or pressure gradient.
Example: Water moves through xylem without energy input, driven by transpiration.

What drives stomatal opening during the day?

Light activates proton pumps in guard cells, which expel H⁺ ions. This creates a negative internal charge that draws in K⁺ and Cl⁻, followed by water. As the guard cells swell, the pore opens.

Pressure Flow

The mechanism that explains how sugars are transported in phloem, from sources (where they’re made) to sinks (where they’re used or stored).
Example: Sugars are loaded into phloem at the source, drawing in water and increasing pressure, which pushes the solution toward the sink.

Translocation

The movement of sugars and other organic molecules through the phloem from sites of production (sources) to sites of use or storage (sinks).
Example: Sugars made in leaves are distributed to roots, fruits, or growing tissues through this process.

Sink

A part of the plant where sugars and nutrients are delivered for storage or use, such as roots, fruits, or developing leaves.
Example: Growing fruits act as this type of tissue, receiving sugars from photosynthetic areas.

Cation Exchange

A process where positively charged minerals in the soil are swapped from soil particles to plant roots, allowing nutrient uptake.
Example: Roots release H⁺ ions into the soil, displacing minerals like K⁺ or Mg²⁺ so they can be absorbed.

What types of soils are more likely to result in conditions for cation exchange?

Clay or humus) because of the negatively charged soil particles with HIGH surface area

Root Hairs

Tiny extensions of root epidermal cells that increase surface area for absorbing water and nutrients from the soil.
Example: These structures grow between soil particles to access water and minerals more efficiently.

companion/compound cells

Specialized cells in phloem that contain a nucleus and organelles, supporting the active transport of sugars into sieve tube elements.

Micronutrients

Essential elements required by plants in very small amounts — typically less than 10 mg per kg of dry plant tissue.
Example: Iron (Fe) and zinc (Zn) fall into this category.

Macronutrients

Nutrients needed in large quantities — typically more than 1 g per kg of dry plant biomass.
Example: Nitrogen (N), phosphorus (P), and potassium (K) are common examples.

Clay

A fine soil component with high surface area and negative charge, capable of binding cations but slows water drainage.
Example: Soils rich in this retain nutrients well but may become waterlogged.

Organic Matter

Decomposed plant and animal material in soil that can bind both cations and anions, improving nutrient availability and structure.
Example: Humus is a key form of this material.

Root Nodules

Swollen structures on roots that house nitrogen-fixing bacteria, allowing nutrient exchange between the plant and microbes.
Example: Found on legumes in symbiosis with Rhizobium bacteria.

Nitrogen

An essential nutrient used to build proteins and nucleic acids, critical for plant growth and development.
Example: Often applied as fertilizer to support leaf and stem growth.

Flavonoids

Signaling compounds released by roots to attract nitrogen-fixing bacteria, which then initiate the formation of root nodules.
Example: These chemicals help establish symbiosis with Rhizobium.

Strigolactones

Chemical signals released by plant roots that encourage the growth of mycorrhizal fungi, helping form beneficial root-fungus partnerships.
Example: These compounds help increase nutrient uptake by attracting fungal partners in nutrient-poor soils.

Dioecious Plants

Plant species in which individuals are either male or female, meaning a single plant produces only one type of reproductive structure.

Embryo Sac

The female gametophyte in flowering plants that develops inside the ovule and contains the egg cell.
Example: This structure will contribute to seed formation after fertilization.

Pollen

The male gametophyte in seed plants that carries sperm cells and enables fertilization when transferred to a female structure.
Example: This travels via wind or pollinators to reach the stigma.

Carpel

The female reproductive structure of a flower, consisting of the stigma, style, and ovary.
Example: This houses the ovule and receives pollen during fertilization.

Stamen

The male reproductive part of a flower, typically made up of an anther (which produces pollen) and a filament.
Example: This structure is often long and visible around the center of a flower.

Hypersensitive Response

A rapid, localized defense reaction where plant cells near an infection site self-destruct to limit pathogen spread.
Example: When infected by a virus or fungus, the surrounding cells may die off to trap and isolate the threat.

Cold Hardened

A physiological state in which a plant becomes more resistant to freezing temperatures after gradual exposure to cold conditions.
Example: A plant that survives frost after slow seasonal cooling has undergone this adaptation.

Gene for Gene model

A theory describing how plant resistance genes interact with pathogen avirulence genes: resistance occurs only when both genes match — one in the plant, one in the pathogen.
Example: If a plant has an R gene and the pathogen has the corresponding Avr gene, the plant triggers a strong defense response.This model illustrates a co-evolutionary arms race between plants and pathogens.

Self-incompatible

Describes a plant’s inability to fertilize itself due to genetic mechanisms that prevent its own pollen from fertilizing its ovules.
Example: In self-incompatible species, the pollen tube stops growing if the pollen comes from the same plant.

Speciation

The evolutionary process by which new species arise, typically through the accumulation of genetic differences and the reduction of gene flow between populations.
Example: Two populations become isolated and evolve independently until they can no longer interbreed.

Gene Flow

The movement of alleles between populations, usually through migration or the exchange of reproductive cells, which increases genetic diversity and can reduce differences between groups.
Example: Pollen from one plant population fertilizing another introduces new genetic material.

Oomycota

All members of this group are chemoheterotroph parasites. Some cause sudden oak death, others are responsible for famine and death in 19th century Ireland, and others can cause debilitating Infections in livestock.

Annelida

This groups includes freshwater, terrestrial and marine organisms. Some are important for building soils and recycling soil nutrients; others are important marine predators, and some others are distinctive ecto-parasites

Tunicata (Urochordata)

Marine animals that include planktonic filter feeders and colonial organisms. Some species contribute to marine snow, while others are known as biofoulers on boats and harbor structures.
Example: Sea squirts and salps.

Monilophyta

A group of vascular plants that were once dominant on land and helped form coal deposits. Today, they are commonly found as the understory in forest ecosystems.
Example: Ferns and horsetails.

Apicomplexa

A group of parasitic protists that infect animals, including humans. Some species have complex life cycles involving multiple hosts.
Example: Plasmodium, which causes malaria, is transmitted by mosquitoes.

Lichen

A symbiotic organism formed by the relationship between a photoautotroph (like algae or cyanobacteria) and a fungus. They are important bioindicators of air quality and help form soil.
Example: Found on rocks, tree bark, and tundra; they survive in extreme environments.

Angiosperms

The most diverse group of land plants, serving as the base of most terrestrial food webs and providing grains, fruits, vegetables, and spices that sustain human populations.
Example: Wheat, apples, and tomatoes are all part of this group.

Ascomycota

A fungal group known for both beneficial and harmful species — used in making bread, beer, wine, and blue cheese, but also associated with yeast infections.
Example: Baker’s yeast (Saccharomyces cerevisiae) belongs here.

Coniferophyta

Cone-bearing plants that offer habitat for many species and supply wood for building and paper.
Example: Pine, fir, and cedar trees are common examples.

Bacillariophyta (Diatoms)

Photosynthetic algae with silica cell walls, used in cosmetics, reflective signs, and as a natural pesticide.
Example: Their fossilized remains form diatomaceous earth.

Bacteria

Among the earliest photosynthesizers, they helped create Earth’s oxygen-rich atmosphere. Some species also fix nitrogen and others can cause harmful algal blooms.
Example: Cyanobacteria contributed to the rise of oxygen billions of years ago. SYNAP: Peptoglycan in cell walls

sporophyte (2n).

The large, visible structures of most plants — such as leaves, stems, flowers, and fronds — belong to this diploid stage of the plant life cycle.
Example: What you typically recognize as a plant is this generation.

gametophyte (1n).

The haploid life stage in plants that produces gametes (sperm and egg) through mitosis. It is often small and less noticeable, especially in vascular plants.
Example: In mosses, this stage is dominant and visible, but in flowering plants, it's reduced to structures like pollen and ovules.