Pomarico Exam Two Collaborative Set

Flagella

What do about half the prokaryotic species use for motion?

Symbiotic relationship

When two organisms live in contact with one another. Mutualism, commensalism, parasitism.

Role of prokaryotes in the biosphere

They recycle chemical elements between the living and the moving environment.

Major groups within domain bacteria

Proteobacteria, Chlamydias, Spirochetes, Gram-positive bacteria, Cyanobacteria.

Halophiles

Salt-loving bacteria.

Conjugation

The direct transfer of DNA from one cell to another.

Domain Bacteria and Archaea

Are placed in the kingdom Monera.

Similarity between Archaea and Bacteria

Unicellular, No membrane bound organelles, circular chromosomes.

Difference between positive and negative taxis

Positive moves toward the stimulus and Negative moves away from the stimulus.

Types of taxis

Chemotaxis: movement to or from a chemical stimulus; Phototaxis: movement from or toward a light stimulus; Magnetotaxis: movement from or toward a magnetic field.

Endospore

Thick coated, resistant structures produced within bacterial cells that have been exposed to harsh conditions, resistant to dehydration, extreme heat/cold, and most poisons.

Cyanobacteria energy source

From sunlight via photosynthesis.

Shapes of bacteria

Bacilli, cocci, and spirilla shapes.

Chemoheterotrophs

They are decomposers that break down corpses, dead vegetation, and waste products.

Prokaryotes emergence

Prokaryotes are the earliest forms of life on Earth, emerging approximately 3.5 billion years ago.

Differences between Archaea and Bacteria

Both domains share similarities but differ fundamentally in cell wall composition.

Bacterial cell walls

Primarily made of peptidoglycan, while Archaea have distinct cell wall structures.

Gram stain technique

Developed by Hans Christian Gram, differentiates bacteria into Gram-positive and Gram-negative based on cell wall properties.

Structural features of prokaryotes

The bacterial cell wall provides structural integrity and determines cell shape.

Diversity of bacterial forms

Common shapes include bacilli (rod-shaped), cocci (spherical), and spirilla (spiral-shaped).

Movement using flagella

Approximately half of the prokaryotic species can move using flagella, which rotate like propellers.

Taxis

A behavioral response to stimuli, with positive taxis indicating movement toward a stimulus and negative taxis indicating movement away.

Endospores function

Bacteria survive harsh environmental conditions via endospores (protective outer layers) which can resist strong climates.

Kinetoplastids

What subgroup causes sleeping sickness?

Four supergroups of protists

Excavates, SAR, archaeplastids, unikontes.

Excavates

What supergroup has modified mitochondria?

Ciliates

What are the most complex protists and why? Because of their complex internal structures.

Primary endosymbiosis

How did both green algae and red algae arise?

Three subgroups of Excavates

Diplomonads, Parabasalids, euglenozoans.

Diplomonads

Have two nuclei, multiple flagella, both free living and parasitic symbiotic species. Example of species: Giardia: parasite that causes diarrhea by eating the good bacterial organisms in the intestine.

Parabasalids

Anaerobic, and all are symbiotic (some parasitic) ex. Trichomonas vaginalis.

Euglenozoans

Flagella containing rod-like structure, mixed nutritional methods between photosynthesis and heterotrophic ingestion.

Euglenids

Has an eyespot that detects light and turns on and off the flagella and determines whether to perform photosynthesis or ingestion, many lack a rigid cell wall which leads to the contractile vacuole structure which controls water level balance.

Kinetoplastids

One flagellum, single large mitochondria, both free living and parasitic. Ex. Trypanosoma which causes sleeping sickness.

Main characteristics of Excavates

Move via flagella, have a feeding groove and have modified mitochondria.

Radiolarians

A subgroup that has internal shells called silica.

Stramenopiles and Alveolates

Two super-subgroups that arose from secondary endosymbiosis from red algae.

Cercozoans

A subgroup that takes in a chromatophore.

Phycoerythrin

The pigment that causes red algae's red color.

Difference between Red Algae and Green Algae

Red algae lives in deeper waters and contain phycoerythrin.

Rhizarians

The super-subgroup that arose from secondary endosymbiosis from green algae.

Slime molds

Saprophytes that feed on microorganisms.

Parabasalids

Anaerobic organisms that contain a modified mitochondria that is shaped more similar to cristae.

Alveolates

A group of eukaryotic protists with small fluid sacs known as alveoli beneath their cell membrane, and their primary purpose is to contribute to the food chain as both predators and prey.

Common characteristics of Excavates

Move via flagella, heterotrophic and have modified mitochondria, their mitochondria are very different structurally than other 'normal' mitochondria.

Diplomonads

A super group of Excavates that are both free living and symbiotic species with multiple flagella (3-5).

Giardia

A member of the diplomonads group; infection results from drinking untreated water causing diarrhea, etc. Inhabits intestines and contracted orally.

Characteristics of Parabasalids

Anaerobic, all known species are symbiotic and some are parasitic, cell is flat and has a flagella with a wing-like appearance.

Trichomonas vaginalis

A sexually transmitted member of the parabasalids group; males can often be asymptomatic.

Multicellular colonies

A group of single-celled organisms benefiting from another, but if split up, can live on their own.

Euglenozoans

A super group that euglenozoans are a part of; 'zoan' = animal-like, is a diverse clade in the excavate lineage.

Characteristics of Euglenids

Most are freshwater: regulates water balance by contractile vacuole, have 1-3 flagella, primarily photosynthetic but can switch to heterotrophic in the dark, many lack rigid cell wall so that it is able to engulf other organisms, have a photoreceptor called an eyespot.

Kelp

A multicellular colony that is a result of single-celled brown algae coming together.

Sporozoite

The mobile stage of apicomplexans.

Pseudopodia

An extension of the plasma membrane of the cell that aids in mobility and ingestion.

Characteristics of Kinetoplastids

One flagellum, single large mitochondria, both free living and symbiotic species (some are parasitic).

Green algae

The organism from which land plants evolved.

Closest relatives of land plants

Green algae from Kingdom Protista.

Charophytes

Shared characteristics of land plants and charophytes include cellulose synthesizing protein complexes, peroxisome enzymes, flagellated sperm, and formation of phragmatoplasts in cell plate formation.

Derived traits in land plants

Alternation of generation, multicellular and dependent embryos, apical meristems, walled spores, multicellular gametangia.

Alternation of generations

Diploid phase involves a sporophyte that produces haploid spores through meiosis; haploid spores grow into gametophytes that produce gametes through mitosis.

Anchoring mechanism for land plants

Roots.

Conducting mechanism for land plants

Vascular tissue (xylem and phloem).

Increased support mechanism for land plants

Lignin.

External protect that protects against water loss in land plants

Cuticle.

Mechanism for gas exchange in land plants

Stomata.

Sporophyte growth in bryophytes

The sporophyte grows out of the gametophyte.

Female gamete holder in non-vascular land plants

Archegonium.

Male gamete holder in non-vascular plants

Artheridium.

Characteristics of seedless vascular plants

Produce spores, sporophyte is the dominant form, require water for reproduction.

Dominant form in non-vascular plants

Gametophyte; the sporophyte grows out of the gametophyte, where it is attached to the archegonium by the foot.

Groups included in the seedless vascular plants

Lycophytes and monilophytes.

Groups included in the lycophytes

Spike mosses, quill worts, club mosses.

Groups included in the monilophytes

Ferns, horsetails, whisk ferns.

First vascular plants to evolve

Seedless nonvascular.

Xylem

Conducts most of water and minerals upward.

Phloem

Distributes sugars, amino acids, and other organic products in various directions.

Roots

Anchor vascular plants, absorb water and nutrients from soil.

Leaves

Increase surface area for capturing more sunlight.

Meiosis vs. mitosis

Differences in cell division processes.

Diploid vs. haploid

Sporophyte and gametophyte can be heteromorphic (different) or isomorphic (identical).

Land based traits for plants

Vascular tissue, lignin, cuticle, stomata.

Characteristics of non vascular plants

Capsule, seta, foot, archegonia, antheridia.

Nonvascular plants

Bryophytes.

Vascular plants

Tracheophytes.

Advantages of land for plants

Sunlight, more O2, more nutrients in soil, opportunity for adaptive radiation, few herbivores and pathogens.

Divisions of nonvascular plants

Liverworts, hornworts, mosses.

Characteristics of vascular plants

Xylem, phloem, roots, leaves.

Pollination

Transfer of pollen to the part of a seed plant that contains ovules.

Microspores and Megaspores

Microspores are male and Megaspores are female.

Seeds

An embryo that is stored within a seed coat with food in order to delay germination and growth of the embryo.

Seed plants and water requirement for reproduction

No, seed plants do not require water for reproduction.

Female and male gametophyte

F- ovule, M- pollen.

Spores replacement

Seeds.

Gymnosperm

Nonflowering plants.

Naked seeds

Seeds of the gymnosperm are referred to as naked seeds because they don't have an extra outer covering.

Angiosperm

Flowering plants.

Competitive advantage of angiosperms

Flowers and seeds enclosed in fruit give organisms a greater chance of reproduction and better seed dispersal.

Stored food in angiosperms

Stored food is triploid, formed when one sperm fuses with polar nuclei in primary endosperm.

Oldest gymnosperm fossil age

305 million years.