The science of classifying organisms according to shared characteristics.

What is the taxonomic hierarchy from broadest to most specific?

Domain → Kingdom → Phylum → Class → Order → Family → Genus → Species.

What mnemonic recalls the taxonomic hierarchy?

Dear King Philip Came Over For Good Soup.

What does the informal group Prokarya include?

The domains Bacteria and Archaea.

What are the general characteristics of prokaryotes?

They are unicellular, lack membrane-bound organelles, have circular DNA in a nucleoid, are generally haploid, and reproduce through binary fission.

What is binary fission?

Asexual reproduction in which prokaryotic DNA replication and cytoplasmic division occur together, producing two genetically identical daughter cells.

How does binary fission differ from mitosis?

Binary fission lacks a spindle apparatus and mitotic subphases and is faster and simpler than mitosis.

How can bacteria acquire genetic variation despite reproducing asexually?

Through horizontal gene transfer.

What is a bacterial endospore?

A dormant, resistant protective structure that allows certain bacteria to survive harsh conditions and germinate when conditions improve.

Are endospores reproductive structures?

No; they are survival structures.

What distinguishes bacteria from other prokaryotes?

Bacterial cell walls contain peptidoglycan.

What is peptidoglycan?

A rigid polymer that protects bacterial cells and forms their cell walls.

How can Gram-negative LPS harm a host?

LPS becomes an endotoxin when the bacterium is lysed.

Where are teichoic acids found?

Between the Gram-positive peptidoglycan layer and plasma membrane.

What does the prefix strepto- indicate?

Bacteria arranged in linear chains.

What are common symptoms of tuberculosis?

Weakness or illness, weight loss, fever, and night sweats.

What are common symptoms of gonorrhea?

Painful urination and abnormal genital discharge.

What are common symptoms of leprosy?

Pale or red skin patches with reduced sensation plus numbness and weakness in the hands and feet.

What are cyanobacteria?

Photosynthetic Gram-negative bacteria historically called blue-green algae.

A domain of prokaryotes with similarities to both bacteria and eukaryotes.

What is an extremophile?

An organism adapted to survive extreme environmental conditions.

What are methanogens?

Obligately anaerobic Archaea that produce methane.

Where are methanogens commonly found?

Human and cow digestive tracts, mud, and swamps.

What are thermophiles?

Heat-loving Archaea found in hot springs and volcanic environments.

Why are thermophile enzymes useful in PCR?

Their enzymes remain stable at the high temperatures required for PCR.

Salt-loving Archaea that inhabit environments with very high salt concentrations.

What are the major characteristics of eukaryotic cells?

They are larger and more complex, possess membrane-bound organelles, have linear DNA wrapped around histones, and can reproduce sexually or asexually.

What two resources must all organisms obtain?

An energy source and a carbon source.

What is an autotroph?

An organism that synthesizes organic compounds from inorganic sources.

What is a heterotroph?

An organism that obtains preformed organic compounds from the environment or other organisms.

Public flashcard deck · 500 cards

DAT Diversity of Life

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Front
What is taxonomy?
Back
The science of classifying organisms according to shared characteristics.
Front
What is the taxonomic hierarchy from broadest to most specific?
Back
Domain → Kingdom → Phylum → Class → Order → Family → Genus → Species.
Front
What mnemonic recalls the taxonomic hierarchy?
Back
Dear King Philip Came Over For Good Soup.
Front
What does the informal group Prokarya include?
Back
The domains Bacteria and Archaea.
Front
What are the general characteristics of prokaryotes?
Back
They are unicellular, lack membrane-bound organelles, have circular DNA in a nucleoid, are generally haploid, and reproduce through binary fission.
Front
Where is prokaryotic DNA located?
Back
In the nucleoid.
Front
What chromosome structure is typical of prokaryotes?
Back
A single circular chromosome.
Front
What structures help prokaryotes adhere to surfaces?
Back
Pili or fimbriae.
Front
What is binary fission?
Back
Asexual reproduction in which prokaryotic DNA replication and cytoplasmic division occur together, producing two genetically identical daughter cells.
Front
How does binary fission differ from mitosis?
Back
Binary fission lacks a spindle apparatus and mitotic subphases and is faster and simpler than mitosis.
Front
How can bacteria acquire genetic variation despite reproducing asexually?
Back
Through horizontal gene transfer.
Front
What is a bacterial endospore?
Back
A dormant, resistant protective structure that allows certain bacteria to survive harsh conditions and germinate when conditions improve.
Front
Are endospores reproductive structures?
Back
No; they are survival structures.
Front
What distinguishes bacteria from other prokaryotes?
Back
Bacterial cell walls contain peptidoglycan.
Front
What is peptidoglycan?
Back
A rigid polymer that protects bacterial cells and forms their cell walls.
Front
How much peptidoglycan do Gram-positive bacteria possess?
Back
A thick layer.
Front
How much peptidoglycan do Gram-negative bacteria possess?
Back
A thin layer.
Front
What color do Gram-positive bacteria stain?
Back
Purple.
Front
What color do Gram-negative bacteria stain?
Back
Pink.
Front
Which bacteria possess an outer membrane?
Back
Gram-negative bacteria.
Front
What is found in the Gram-negative outer membrane?
Back
Lipopolysaccharide, or LPS.
Front
How can Gram-negative LPS harm a host?
Back
LPS becomes an endotoxin when the bacterium is lysed.
Front
Which bacteria contain teichoic acids?
Back
Gram-positive bacteria.
Front
Where are teichoic acids found?
Back
Between the Gram-positive peptidoglycan layer and plasma membrane.
Front
What does bacillus or bacilli describe?
Back
Rod-shaped bacteria.
Front
What does coccus or cocci describe?
Back
Spherical bacteria.
Front
What does spirillum or spirilli describe?
Back
Spiral-shaped bacteria.
Front
What does the prefix strepto- indicate?
Back
Bacteria arranged in linear chains.
Front
What does the prefix staphyl- indicate?
Back
Bacteria arranged in clusters.
Front
What are common symptoms of tuberculosis?
Back
Weakness or illness, weight loss, fever, and night sweats.
Front
What are common symptoms of gonorrhea?
Back
Painful urination and abnormal genital discharge.
Front
What are common symptoms of leprosy?
Back
Pale or red skin patches with reduced sensation plus numbness and weakness in the hands and feet.
Front
What treatment generally targets bacterial diseases?
Back
Antibiotics.
Front
What relationship do nitrogen-fixing and nitrifying bacteria have with plants?
Back
A mutualistic relationship.
Front
What are cyanobacteria?
Back
Photosynthetic Gram-negative bacteria historically called blue-green algae.
Front
What are Archaea?
Back
A domain of prokaryotes with similarities to both bacteria and eukaryotes.
Front
What is an extremophile?
Back
An organism adapted to survive extreme environmental conditions.
Front
What are methanogens?
Back
Obligately anaerobic Archaea that produce methane.
Front
Where are methanogens commonly found?
Back
Human and cow digestive tracts, mud, and swamps.
Front
What are thermophiles?
Back
Heat-loving Archaea found in hot springs and volcanic environments.
Front
Why are thermophile enzymes useful in PCR?
Back
Their enzymes remain stable at the high temperatures required for PCR.
Front
What is an example of a heat-stable PCR enzyme?
Back
Taq polymerase.
Front
What are halophiles?
Back
Salt-loving Archaea that inhabit environments with very high salt concentrations.
Front
What are the major characteristics of eukaryotic cells?
Back
They are larger and more complex, possess membrane-bound organelles, have linear DNA wrapped around histones, and can reproduce sexually or asexually.
Front
Which eukaryotic structures are organelles but are not membrane-bound?
Back
Ribosomes and centrioles.
Front
What chromosome shape is typical of eukaryotes?
Back
Linear chromosomes.
Front
Around what proteins is eukaryotic DNA condensed?
Back
Histones.
Front
What two resources must all organisms obtain?
Back
An energy source and a carbon source.
Front
What is an autotroph?
Back
An organism that synthesizes organic compounds from inorganic sources.
Front
What is another name for an autotroph?
Back
Producer.
Front
What is a heterotroph?
Back
An organism that obtains preformed organic compounds from the environment or other organisms.
Front
What is another name for a heterotroph?
Back
Consumer.
Front
What is a phototroph?
Back
An organism whose primary energy source is light.
Front
What is a chemotroph?
Back
An organism whose primary energy source is chemical reactions.
Front
What is a photoautotroph?
Back
An organism that uses light for energy and inorganic compounds such as CO₂ or HCO₃⁻ as its carbon source.
Front
What are examples of photoautotrophs?
Back
Plants, algae, and cyanobacteria.
Front
What is a chemoautotroph?
Back
An organism that obtains energy from inorganic chemical reactions and carbon from inorganic compounds.
Front
What are examples of chemoautotrophs?
Back
Nitrogen-fixing bacteria and some Archaea.
Front
What inorganic compound can provide energy to chemoautotrophs?
Back
H₂S is one possible inorganic energy source.
Front
What is a photoheterotroph?
Back
An organism that obtains energy from light but carbon from external organic compounds.
Front
What organisms may be photoheterotrophs?
Back
Some bacteria.
Front
What is a chemoheterotroph?
Back
An organism that obtains both energy and carbon from external organic compounds.
Front
What are examples of chemoheterotrophs?
Back
Humans, other animals, insects, fungi, and most bacteria.
Front
What is aerobic metabolism?
Back
Oxygen-dependent energy metabolism in which O₂ acts as the final electron acceptor.
Front
What is anaerobic metabolism?
Back
Oxygen-independent energy metabolism in which a molecule other than O₂ acts as the final electron acceptor.
Front
What is an obligate aerobe?
Back
An organism that must live in the presence of oxygen.
Front
What is an obligate anaerobe?
Back
An organism that cannot survive in the presence of oxygen.
Front
Where are many obligate anaerobic bacteria found?
Back
In the human intestine.
Front
What is a facultative anaerobe?
Back
An organism that uses aerobic metabolism when oxygen is present but can switch to anaerobic metabolism when oxygen is absent.
Front
What are microaerophiles?
Back
Organisms that thrive at low oxygen concentrations.
Front
Where are many aquatic microaerophiles found?
Back
Slightly beneath the water’s surface.
Front
What are protists?
Back
A highly diverse group of eukaryotes that may be unicellular or multicellular, autotrophic or heterotrophic, free-living or symbiotic.
Front
In what environments are protists commonly found?
Back
Moist environments.
Front
How do protists generally reproduce?
Back
Asexually, although some also exchange genetic information.
Front
What are plant-like protists?
Back
Photosynthetic protists with chloroplasts that lack true plant structures such as roots and leaves.
Front
What are examples of plant-like protists?
Back
Seaweeds, dinoflagellates, euglenoids, and some algae.
Front
What are animal-like protists called?
Back
Protozoa.
Front
What are the general characteristics of protozoa?
Back
They are motile, single-celled heterotrophs that commonly acquire food by phagocytosis.
Front
How are protozoa commonly classified?
Back
According to their method of locomotion.
Front
How do amoebas move and capture food?
Back
Using pseudopodia.
Front
What is a pseudopodium?
Back
A temporary cytoplasmic projection extending toward the direction of movement.
Front
What feeding process do amoebas perform?
Back
Phagocytosis.
Front
How do flagellates move?
Back
Using flagella.
Front
What is an example of a flagellated protist?
Back
Trichomonas vaginalis.
Front
How do ciliates move?
Back
Using cilia.
Front
How do ciliates reproduce?
Back
By binary fission.
Front
How do ciliates obtain genetic variation?
Back
Through conjugation.
Front
What is an example of a ciliate?
Back
Paramecium.
Front
What are sporozoans?
Back
Parasitic protists that move by gliding and reproduce using spores.
Front
What is an important sporozoan genus?
Back
Plasmodium.
Front
What disease does Plasmodium cause?
Back
Malaria.
Front
How is Plasmodium transmitted to humans?
Back
By mosquitoes.
Front
What are fungus-like protists?
Back
Slime molds and water molds that resemble fungi and act as heterotrophic decomposers.
Front
How do fungus-like protists commonly reproduce?
Back
Using spores.
Front
How do fungus-like protists differ from true fungi?
Back
Their cell walls do not contain chitin.
Front
What are algae?
Back
An informal group from multiple kingdoms that function primarily as photosynthetic producers.
Front
What are the general characteristics of algae?
Back
They may be prokaryotic or eukaryotic and unicellular or multicellular, are photoautotrophic, reproduce sexually or asexually, and lack true plant structures.
Front
Where are algae primarily found?
Back
Aquatic environments.
Front
What are the characteristics of green algae?
Back
They belong to Plantae or Protista, contain chlorophyll, commonly inhabit freshwater, and are ancestral to terrestrial plants.
Front
What is another name for the green-algae group?
Back
Chlorophyta.
Front
What are the characteristics of red algae?
Back
They belong to Plantae or Protista, are mostly multicellular, and are primarily marine.
Front
What are the characteristics of brown algae?
Back
They belong to Protista, are multicellular and marine, and include kelp and other seaweeds.
Front
To which kingdom do cyanobacteria belong?
Back
Bacteria.
Front
What is the evolutionary significance of cyanobacteria?
Back
They are considered the evolutionary precursors of chloroplasts under endosymbiotic theory.
Front
What is an algal bloom?
Back
A rapid increase in algae or cyanobacteria caused by nutrient accumulation.
Front
What nutrients commonly trigger eutrophication and algal blooms?
Back
Nitrogen and phosphorus.
Front
What are common sources of nutrients that cause algal blooms?
Back
Fertilizer, wastewater, and stormwater runoff.
Front
How can algal blooms directly damage ecosystems?
Back
They may release toxins and block sunlight from underwater organisms.
Front
How do algal blooms cause oxygen depletion?
Back
Dead algae are decomposed by aerobic organisms whose respiration consumes dissolved oxygen.
Front
What are fungi?
Back
Eukaryotic heterotrophs that commonly act as decomposers and symbionts.
Front
What are the general characteristics of fungi?
Back
They may be unicellular or multicellular, reproduce sexually or asexually, have chitin cell walls, and include yeasts, molds, and mushrooms.
Front
What human disease can fungi cause?
Back
Athlete’s foot is one example.
Front
What is a decomposer?
Back
An organism that digests dead or decaying organic matter.
Front
What is a saprophyte?
Back
A decomposer that anchors to its substrate, releases digestive enzymes extracellularly, and absorbs the resulting nutrients.
Front
What are nonfilamentous fungi?
Back
Unicellular fungi such as yeasts.
Front
How do yeasts commonly reproduce asexually?
Back
By budding.
Front
What are filamentous fungi?
Back
Multicellular fungi such as molds and mushrooms whose bodies are formed from hyphae.
Front
What is a hypha?
Back
A tubular fungal filament made of cells enclosed by a continuous tubular cell wall.
Front
What is a mycelium?
Back
A network of interconnected fungal hyphae.
Front
From what structure can mushrooms arise asexually?
Back
A mycelium.
Front
What are septate hyphae?
Back
Hyphae divided into cells by internal walls called septa.
Front
What are coenocytic hyphae?
Back
Multinucleated hyphae that lack septa.
Front
What is a fungal sporangium?
Back
A multicellular organ where spores form.
Front
What are fungal rhizoids?
Back
Branching hyphae that anchor fungal structures to a surface.
Front
How do rhizoids differ from plant roots?
Back
Rhizoids are not plant tissues and lack specialized fluid-conducting cells.
Front
What are molds?
Back
Filamentous fungi that may be haploid or diploid and commonly grow in moist environments.
Front
Can all fungi reproduce asexually?
Back
Yes.
Front
Can all fungi reproduce sexually?
Back
No; only some fungi can.
Front
What is the dominant ploidy of fungi during most of their life cycle?
Back
Haploid.
Front
What is a fungal spore?
Back
A haploid reproductive cell that can disperse and independently form a new mycelium.
Front
Why is a spore not a gamete?
Back
A spore can develop independently into a mature structure, whereas a gamete must fuse with another gamete.
Front
What is plasmogamy?
Back
Fusion of the cytoplasm of two fungal hyphae.
Front
What is karyogamy?
Back
Fusion of fungal nuclei, producing a diploid zygote.
Front
What is the sequence of sexual reproduction in filamentous fungi?
Back
Spore germination → mitotic hyphal growth → signaling and plasmogamy → karyogamy → diploid zygote → meiosis → haploid spores.
Front
How can filamentous fungi reproduce asexually?
Back
Through mitotic spores, budding, or fragmentation.
Front
What is fungal fragmentation?
Back
A broken portion of a hypha or mycelium develops into a new mycelium.
Front
What is a lichen?
Back
A mutualistic association between a fungus and an alga.
Front
What does the alga provide in a lichen?
Back
Sugars produced through photosynthesis.
Front
What does the fungus provide in a lichen?
Back
Protection, anchoring, nutrients, and moisture.
Front
What are the general characteristics of Kingdom Plantae?
Back
Plants are multicellular, photoautotrophic eukaryotes with chlorophyll and cellulose cell walls.
Front
What does cellulose provide to plant cell walls?
Back
Tensile strength.
Front
What are mechanisms of asexual reproduction in plants?
Back
Budding, fragmentation, spore formation, and vegetative propagation.
Front
What does asexual plant reproduction produce?
Back
Genetically identical offspring.
Front
What processes are involved in sexual plant reproduction?
Back
Meiosis and fertilization.
Front
What is alternation of generations?
Back
A plant life cycle alternating between multicellular diploid sporophyte and multicellular haploid gametophyte stages.
Front
What is the sporophyte?
Back
The multicellular diploid plant stage that produces haploid spores through meiosis.
Front
What is a plant spore?
Back
A haploid dispersal unit that divides by mitosis to form a gametophyte.
Front
What is the gametophyte?
Back
The multicellular haploid plant stage that produces gametes through mitosis.
Front
How does a sporophyte produce spores?
Back
Through meiosis.
Front
How does a gametophyte produce gametes?
Back
Through mitosis.
Front
What do sperm and egg form when they fuse?
Back
A diploid zygote.
Front
What do mega- and micro- indicate in vascular plant gametophytes?
Back
Mega- indicates female and micro- indicates male.
Front
What four criteria classify major plant groups?
Back
Body differentiation, vascular tissue, seed formation, and flower production.
Front
What are thallophytes?
Back
The simplest aquatic plants, lacking differentiated body parts, vascular tissue, seeds, and flowers.
Front
What is the dominant generation in thallophytes?
Back
The haploid gametophyte.
Front
How do thallophytes reproduce and disperse?
Back
Using spores.
Front
What are bryophytes?
Back
Nonvascular plants with distinct body parts and rhizoids, including mosses, liverworts, and hornworts.
Front
What is the dominant generation in bryophytes?
Back
The haploid gametophyte.
Front
Do bryophytes produce seeds or flowers?
Back
No; they reproduce by spores.
Front
Where can bryophytes live?
Back
In terrestrial or aquatic environments.
Front
What are tracheophytes?
Back
Plants with differentiated structures and vascular tissue consisting of xylem and phloem.
Front
What advantage does vascular tissue give tracheophytes?
Back
It permits efficient transport and vertical growth.
Front
What is the dominant generation in tracheophytes?
Back
The diploid sporophyte.
Front
Which plant groups are not tracheophytes?
Back
Thallophytes and bryophytes.
Front
What are pterophytes?
Back
Seedless vascular plants such as ferns, horsetails, and whisk ferns.
Front
What are the four major features of pterophytes?
Back
They are seedless, vascular, possess flagellated sperm, and are sporophyte-dominant.
Front
What are fern fronds?
Back
Modified leaves.
Front
What are sori?
Back
Clusters of sporangia commonly found on fern fronds.
Front
What is notable about fern sporophytes and gametophytes?
Back
They exist as independent forms.
Front
What are lycophytes?
Back
Seedless vascular plants including club mosses, spike mosses, and quillworts.
Front
What is a strobilus?
Back
A cone-like lycophyte structure containing clusters of spore-bearing sporangia.
Front
What are gymnosperms?
Back
Vascular, seed-producing, sporophyte-dominant plants that do not produce flowers or fruit.
Front
What does “naked seed” mean in gymnosperms?
Back
The seed is not enclosed within a fruit.
Front
What are examples of gymnosperms?
Back
Conifers such as pine and fir trees.
Front
What are angiosperms?
Back
Flowering vascular plants whose seeds are enclosed by fruit and that undergo double fertilization.
Front
What is the dominant generation in angiosperms?
Back
The diploid sporophyte.
Front
What is the most abundant plant type?
Back
Angiosperms.
Front
What is a flower?
Back
The reproductive structure of an angiosperm.
Front
What is the pistil?
Back
The female flower structure consisting of the stigma, style, and ovary.
Front
What is the stigma?
Back
The sticky tip of the pistil that receives pollen.
Front
What is the style?
Back
The stalk connecting the stigma to the ovary.
Front
What is the ovary of a flower?
Back
The structure surrounding the ovules that later develops into fruit.
Front
What are ovules?
Back
Structures inside the ovary that develop into seeds after fertilization.
Front
What is the stamen?
Back
The male flower structure consisting of the anther and filament.
Front
What is the anther?
Back
The tip of the stamen that produces pollen.
Front
What is the filament?
Back
The stalk that supports and elevates the anther.
Front
What are petals?
Back
Brightly colored modified leaves that commonly attract pollinators.
Front
What are sepals?
Back
Modified leaves that protect developing flower buds and support the emerged flower.
Front
What is a hermaphroditic plant flower?
Back
A flower containing both male and female reproductive structures.
Front
What is a monoecious plant?
Back
A plant that produces separate male and female flowers on the same individual.
Front
What is a dioecious plant?
Back
A plant in which an individual produces either male or female flowers, but not both.
Front
What is a fruit botanically?
Back
A mature flower ovary that protects seeds and aids their dispersal.
Front
What are the two broad fruit types?
Back
Fleshy fruits, such as berries, and dry fruits, such as nuts.
Front
What is a plant seed?
Back
A mature fertilized ovule containing an embryo and nutrient supply.
Front
What is germination?
Back
The process through which a seed or spore becomes active and develops into a new organism.
Front
What is a megasporocyte?
Back
A diploid female precursor cell that undergoes meiosis to produce four haploid megaspores.
Front
What happens to the four angiosperm megaspores?
Back
Three usually degenerate and one survives.
Front
How is the angiosperm embryo sac formed?
Back
The surviving megaspore undergoes three mitotic divisions without cytokinesis, producing eight haploid nuclei.
Front
What is the female angiosperm gametophyte?
Back
The embryo sac.
Front
What cells and nuclei are found in the mature embryo sac?
Back
One egg, two synergids, three antipodal cells, and one central cell containing two polar nuclei.
Front
What are synergid cells?
Back
Cells flanking the egg that help guide the pollen tube into the embryo sac.
Front
What are antipodal cells?
Back
Three cells in the embryo sac that eventually degenerate after fertilization.
Front
What are polar nuclei?
Back
Two separate haploid nuclei located within the central cell of the embryo sac.
Front
What is a microsporocyte?
Back
A diploid male precursor cell that undergoes meiosis to produce four haploid microspores.
Front
How does a microspore become a pollen grain?
Back
It undergoes mitosis.
Front
What is the male angiosperm gametophyte?
Back
The pollen grain.
Front
What two cells are initially contained in a pollen grain?
Back
A generative cell and a tube cell.
Front
What does the generative cell produce?
Back
Two sperm cells.
Front
What does the tube cell produce?
Back
The pollen tube.
Front
What is pollination?
Back
Transfer of pollen between flowers by wind or animals.
Front
What happens after pollen lands on the stigma?
Back
A pollen tube grows through the style toward the ovule.
Front
What is double fertilization?
Back
One sperm fertilizes the egg to form a diploid zygote, while the other fertilizes the central cell to form triploid endosperm.
Front
What does one angiosperm sperm plus the egg produce?
Back
A diploid zygote, 2n.
Front
What does one sperm plus the two polar nuclei produce?
Back
Triploid endosperm, 3n.
Front
What is endosperm?
Back
Triploid nutrient-rich tissue that nourishes the developing angiosperm embryo.
Front
What happens to the zygote after double fertilization?
Back
It develops into the embryo.
Front
What does the fertilized ovule become?
Back
A seed.
Front
What do the ovule’s outer layers become?
Back
The seed coat.
Front
What does the flower ovary become after fertilization?
Back
The fruit.
Front
What is the ploidy of the angiosperm embryo?
Back
Diploid, 2n.
Front
What is the ploidy of angiosperm endosperm?
Back
Triploid, 3n.
Front
What is apomixis?
Back
Asexual seed formation without fertilization, found in some plants such as grasses.
Front
What is a cotyledon?
Back
A seed structure that transfers nutrients from the endosperm to the embryo.
Front
How many cotyledons do monocots have?
Back
One.
Front
How many cotyledons do dicots have?
Back
Two.
Front
What root system is typical of monocots?
Back
A fibrous root system.
Front
What root system is typical of dicots?
Back
A taproot system.
Front
In what multiples do monocot flower parts occur?
Back
Multiples of three.
Front
In what multiples do dicot flower parts occur?
Back
Multiples of four or five.
Front
What leaf venation is typical of monocots?
Back
Parallel veins.
Front
What leaf venation is typical of dicots?
Back
Net-like or branched veins.
Front
How are vascular bundles arranged in monocot stems?
Back
Scattered.
Front
How are vascular bundles arranged in dicot stems?
Back
In a ring.
Front
What are examples of monocots?
Back
Corn, lilies, and Kentucky bluegrass.
Front
What are examples of dicots?
Back
Oaks, daisies, and peas.
Front
What are the two major flowering-plant systems?
Back
The below-ground root system and above-ground shoot system.
Front
What is ground tissue?
Back
Plant tissue that performs most metabolic functions.
Front
What is dermal tissue?
Back
Epidermal tissue that covers and protects plant surfaces.
Front
What is the plant cuticle?
Back
A waxy substance secreted by above-ground epidermal cells that reduces water loss.
Front
Why do roots lack a cuticle?
Back
A cuticle would interfere with water and mineral absorption.
Front
What is vascular tissue?
Back
Xylem and phloem organized into vascular bundles.
Front
What is the function of xylem?
Back
Transporting water and minerals and providing mechanical support.
Front
What are the two major xylem cell types?
Back
Vessel elements and tracheids.
Front
What are vessel elements?
Back
Short, wide xylem cells with perforations allowing efficient water transfer between adjacent cells.
Front
What are tracheids?
Back
Long, tapered xylem cells with pits that permit lateral water movement.
Front
What is the function of phloem?
Back
Transporting sugars through plant tissues.
Front
What are the two important phloem cell types?
Back
Sieve-tube elements and companion cells.
Front
What are sieve-tube elements?
Back
Long phloem cells whose porous ends, called sieve plates, connect adjacent cytoplasms.
Front
What are companion cells?
Back
Cells that provide physiological support to sieve-tube elements.
Front
What is the seed embryo?
Back
Diploid tissue derived from the fertilized egg.
Front
What is the seed coat?
Back
A tough outer covering that protects the embryo and seed contents.
Front
What is the primary nutrient-storage tissue of an angiosperm seed?
Back
Endosperm.
Front
What do cotyledons do during seed development?
Back
Transfer nutrients from the endosperm to the embryo.
Front
What environmental cues can end seed dormancy?
Back
Water, appropriate temperature, and light.
Front
What is a fixed seed-dormancy period?
Back
A required period during which the seed cannot germinate even if environmental conditions are favorable.
Front
What occurs first during seed germination?
Back
The seed absorbs water, swells, and cracks its seed coat.
Front
What happens metabolically after a seed absorbs water?
Back
Enzymes activate and metabolism and cellular respiration begin.
Front
What does the embryonic radicle become?
Back
The root.
Front
What does the embryonic hypocotyl become?
Back
The stem.
Front
What are meristems?
Back
Plant regions where active mitosis occurs.
Front
What are apical meristems?
Back
Meristems at root and shoot tips that produce vertical growth and increased length.
Front
What is primary plant growth?
Back
Growth in length produced by apical meristems.
Front
What are lateral meristems?
Back
Meristems along the stem that increase plant width.
Front
What is secondary plant growth?
Back
Growth in width produced by lateral meristems.
Front
What is the leaf epidermis?
Back
A protective outer layer covered by a cuticle that reduces water loss.
Front
What is transpiration?
Back
Evaporation of water from plant surfaces, particularly through stomata.
Front
What is palisade mesophyll?
Back
Tightly arranged, chloroplast-rich leaf tissue that is the primary site of photosynthesis.
Front
What is spongy mesophyll?
Back
Loosely arranged leaf tissue with intercellular spaces that permit gas movement.
Front
What is a stoma?
Back
A microscopic epidermal pore that allows gas exchange.
Front
What are guard cells?
Back
Specialized epidermal cells that surround each stoma and control its opening.
Front
What happens when stomata open?
Back
CO₂ enters and photosynthesis can occur, but transpiration and dehydration risk increase.
Front
When do stomata commonly open?
Back
When the internal CO₂ concentration of the leaf is low.
Front
What happens when stomata close?
Back
Water loss decreases, but CO₂ entry and photosynthesis stop.
Front
Why do stomata commonly close at high temperatures?
Back
To prevent excessive water loss.
Front
What are bundle sheath cells?
Back
Cells surrounding vascular bundles that support and protect xylem and phloem.
Front
What are auxins or IAA?
Back
Plant hormones that promote cell elongation and regulate growth responses to light and gravity.
Front
What are gibberellins or GA?
Back
Plant hormones that promote stem and flower elongation, seed germination, and access to stored nutrients.
Front
What are cytokinins?
Back
Plant hormones that stimulate cytokinesis and cell division.
Front
What is abscisic acid or ABA?
Back
A plant hormone that inhibits growth and promotes seed dormancy.
Front
What is ethylene?
Back
A gaseous plant hormone that promotes fruit ripening, flower production, leaf abscission, and growth around obstacles.
Front
What is a tropism?
Back
A directional plant-growth response to an environmental stimulus.
Front
What is phototropism?
Back
Plant growth in response to light.
Front
How does auxin cause a shoot to bend toward light?
Back
Auxin accumulates on the shaded side, causing greater cell elongation there and bending the shoot toward light.
Front
What is gravitropism or geotropism?
Back
Plant growth in response to gravity, regulated by auxins and gibberellins.
Front
What is the purpose of gravitropism?
Back
It directs roots downward into soil and shoots upward.
Front
What is thigmotropism?
Back
Plant growth in response to mechanical contact or touch.
Front
What is an example of thigmotropism?
Back
A vine wrapping around an object it touches.
Front
What is hydrotropism?
Back
Plant growth toward water.
Front
What is photoperiodism?
Back
A plant response to changes in daylight length detected through circadian rhythms.
Front
What are long-day plants?
Back
Plants that flower as daylight increases, generally from early spring through late summer.
Front
What are short-day plants?
Back
Plants that flower as daylight decreases, generally from late summer into early fall.
Front
What are day-neutral plants?
Back
Plants whose flowering does not depend on photoperiod.
Front
What are the general characteristics of animals?
Back
Animals are multicellular, heterotrophic eukaryotes that develop two or three germ layers and are usually motile during some part of life.
Front
What are the major animal phyla?
Back
Porifera, Cnidaria, Platyhelminthes, Nematoda, Rotifera, Annelida, Mollusca, Arthropoda, Echinodermata, and Chordata.
Front
What three forms of animal body symmetry exist?
Back
Asymmetrical, radial, and bilateral.
Front
What is cephalization?
Back
Concentration of nervous and sensory structures at the anterior end.
Front
Which animals usually exhibit cephalization?
Back
Bilaterally symmetric animals.
Front
What is animal segmentation?
Back
Repeated body units along the anterior-posterior axis that allow complex movement and specialization.
Front
What are tagmata?
Back
Specialized groups of body segments, such as an insect’s head, thorax, and abdomen.
Front
What are Parazoa?
Back
Animals lacking true tissues; this clade includes Porifera.
Front
What are Eumetazoa?
Back
Animals possessing true tissues; this includes every major animal phylum except Porifera.
Front
What are germ layers?
Back
The earliest tissues formed during animal embryonic development: ectoderm, mesoderm, and endoderm.
Front
What is a diploblast?
Back
An animal with ectoderm and endoderm but no mesoderm.
Front
What symmetry is associated with diploblasts?
Back
Radial symmetry.
Front
What is a triploblast?
Back
An animal with ectoderm, mesoderm, and endoderm.
Front
What germ-layer organization is found in bilateral animals?
Back
Triploblastic organization.
Front
What is a coelom?
Back
A body cavity located between the mesoderm and endoderm.
Front
Which animals can possess a coelom?
Back
Only triploblastic animals.
Front
What is an acoelomate?
Back
A triploblastic animal lacking a coelom.
Front
What is a pseudocoelomate?
Back
An animal whose body cavity is not completely surrounded by mesoderm.
Front
What is a coelomate?
Back
An animal whose body cavity is completely surrounded by mesoderm.
Front
What is the blastopore?
Back
An embryonic invagination that forms one end of the digestive tract.
Front
What is a protostome?
Back
An animal in which the blastopore becomes the mouth.
Front
What is a deuterostome?
Back
An animal in which the blastopore becomes the anus.
Front
What is an incomplete digestive tract?
Back
A gastrovascular cavity with one opening used for ingestion and excretion.
Front
What is a complete digestive tract?
Back
An alimentary canal with a separate mouth and anus.
Front
What is asexual reproduction?
Back
Production of offspring by one parent without the genetic variation created by gamete fusion.
Front
What is binary fission in reproduction?
Back
Division of one prokaryotic parent cell into two identical cells capable of independent life.
Front
In which organisms does true binary fission occur?
Back
Prokaryotes.
Front
What is budding?
Back
Formation of a cytoplasmic outgrowth that receives replicated genetic material and eventually separates.
Front
What is fragmentation?
Back
Development of a new organism from a separated piece of the parent.
Front
What is parthenogenesis?
Back
Development of an unfertilized egg into a new organism.
Front
What is external fertilization?
Back
Release and fusion of gametes in the external environment.
Front
What is internal fertilization?
Back
Deposition of sperm into the female reproductive tract.
Front
What is a monoecious or hermaphroditic animal?
Back
An individual possessing both male and female reproductive organs.
Front
What is a dioecious animal?
Back
An individual possessing either male or female reproductive organs, but not both.
Front
Are most animal species monoecious or dioecious?
Back
Dioecious.
Front
What are spiracles?
Back
Small body-wall openings connected to tracheal tubes for direct gas exchange in insects.
Front
What are book lungs?
Back
Layered respiratory organs resembling book pages, found in arachnids.
Front
What are gills?
Back
Feathery, high-surface-area respiratory organs that extract dissolved oxygen from water.
Front
What is a closed circulatory system?
Back
A system in which circulatory fluid remains in vessels, permitting efficient and compartmentalized transport.
Front
What is an open circulatory system?
Back
A system in which circulatory fluid enters a hemocoel and oxygenated and deoxygenated fluid mix.
Front
Which circulatory system is generally more efficient?
Back
A closed circulatory system.
Front
Where are protonephridia found?
Back
Flatworms and some other simple invertebrates.
Front
Where are metanephridia found?
Back
Annelids.
Front
Where are Malpighian tubules found?
Back
Insects and arachnids.
Front
Where are nephrons found?
Back
Vertebrates.
Front
What are the defining features of Porifera?
Back
Asymmetrical aquatic Parazoa with no true tissues, intracellular digestion, and no specialized nervous, circulatory, respiratory, or excretory systems.
Front
What are examples of Porifera?
Back
Sponges.
Front
What are choanocytes?
Back
Characteristic feeding cells of sponges.
Front
What are amoebocytes in sponges?
Back
Cells that perform intracellular digestion and distribute nutrients.
Front
What are sponge ostia?
Back
External openings through which water enters.
Front
What are sponge spicules?
Back
Structural elements that help support and protect the sponge.
Front
How do sponges feed?
Back
They are sessile suspension or filter feeders.
Front
How do sponges reproduce?
Back
Sexually as hermaphrodites or asexually through budding.
Front
How do sponges exchange gases and eliminate wastes?
Back
Through diffusion.
Front
What are the defining features of Cnidaria?
Back
Radially symmetric, diploblastic aquatic eumetazoans with a gastrovascular cavity and nerve net.
Front
What are examples of cnidarians?
Back
Hydras, jellyfish, sea anemones, and corals.
Front
What is a cnidocyte?
Back
A specialized stinging cell found in cnidarians.
Front
What is a nematocyst?
Back
The stinging organelle contained within a cnidocyte.
Front
What are the two common cnidarian body forms?
Back
Polyp and medusa.
Front
What nervous system do cnidarians possess?
Back
A nerve net without a brain.
Front
How can a cnidarian gastrovascular cavity assist movement?
Back
It can function as a hydrostatic skeleton.
Front
How do cnidarians respire, circulate materials, and excrete wastes?
Back
Through diffusion.
Front
What are the defining features of Platyhelminthes?
Back
Bilateral, cephalized, triploblastic acoelomates with an incomplete digestive tract and protonephridia.
Front
What are examples of Platyhelminthes?
Back
Planarians, flukes, trematodes, and tapeworms.
Front
Are flatworms protostomes or deuterostomes?
Back
They are technically protostomes despite being acoelomate.
Front
What nervous system do flatworms possess?
Back
An anterior brain and two symmetrical nerve cords.
Front
What excretory structures do flatworms possess?
Back
Protonephridia containing flame cells.
Front
How do flatworms respire and circulate materials?
Back
Through diffusion without a specialized circulatory or respiratory system.
Front
What is unusual about tapeworm digestion?
Back
Tapeworms lack a true digestive tract and absorb nutrients across their body surface.
Front
How can flatworms reproduce?
Back
Sexually as hermaphrodites or asexually through regeneration.
Front
Where can flatworms live?
Back
Aquatic, terrestrial, or host environments.
Front
What are the defining features of Nematoda?
Back
Unsegmented, bilateral, cephalized, triploblastic pseudocoelomates with a complete alimentary canal.
Front
What are examples of nematodes?
Back
Roundworms, hookworms, Trichinella, C. elegans, and Ascaris.
Front
Are nematodes protostomes or deuterostomes?
Back
Protostomes.
Front
What muscles do nematodes possess?
Back
Longitudinal muscles but no circular muscles.
Front
What supports nematode movement?
Back
A hydrostatic skeleton.
Front
Why do some parasitic nematodes possess a collagen cuticle?
Back
It prevents degradation by the host’s digestive system.
Front
What are renette cells?
Back
Osmoregulatory structures unique to nematodes.
Front
Do nematodes have circulatory or respiratory systems?
Back
No; they rely primarily on diffusion.
Front
What are the defining features of Rotifera?
Back
Bilateral, cephalized, triploblastic pseudocoelomates with a complete alimentary canal, commonly found in freshwater.
Front
Are rotifers truly segmented?
Back
No.
Front
What is the rotifer corona?
Back
A ciliated structure that draws water and food into the mouth.
Front
How can rotifers reproduce?
Back
Sexually or through parthenogenesis.
Front
What excretory structures do rotifers possess?
Back
Protonephridia with flame cells.
Front
What are the defining features of Annelida?
Back
Bilateral, segmented, triploblastic coelomate protostomes with a complete digestive tract and closed circulation.
Front
What are examples of annelids?
Back
Earthworms and leeches.
Front
What externally marks annelid segments?
Back
Annuli.
Front
What internally divides the annelid coelom?
Back
Septa.
Front
What muscles do annelids possess?
Back
Both circular and longitudinal muscles.
Front
What are annelid chaetae or setae?
Back
Bristles involved in locomotion and gas exchange.
Front
What nervous system do annelids possess?
Back
A ventral nerve cord and anterior brain.
Front
What excretory structures do annelids possess?
Back
Metanephridia.
Front
What type of circulatory system do annelids possess?
Back
A closed circulatory system with a dorsal vessel, aortic arches, arteries, and veins.
Front
How do many annelids exchange gases?
Back
Through their body surface by diffusion.
Front
How can annelids reproduce?
Back
Sexually as hermaphrodites or asexually through regeneration.
Front
What are the defining features of Mollusca?
Back
Triploblastic coelomate protostomes with a visceral mass, mantle, muscular foot, complete digestive tract, and usually open circulation.
Front
What are examples of mollusks?
Back
Clams, snails, slugs, squid, and octopuses.
Front
What is the molluscan visceral mass?
Back
The region containing internal organs.
Front
What is the molluscan mantle?
Back
Tissue surrounding the visceral mass that commonly secretes a calcium carbonate shell.
Front
What is the molluscan foot?
Back
A muscular structure used for movement.
Front
What is the radula?
Back
A tongue-like scraping feeding structure found in many mollusks.
Front
What is a molluscan hemocoel?
Back
The body cavity into which circulatory fluid flows in an open circulatory system.
Front
What type of circulation do most mollusks possess?
Back
Open circulation.
Front
Which mollusks possess closed circulation?
Back
Cephalopods such as squid and octopuses.
Front
What respiratory organs do most aquatic mollusks use?
Back
Gills.
Front
What is torsion in gastropods?
Back
Twisting of the alimentary canal during development.
Front
Do all mollusks exhibit strong cephalization?
Back
No; some bivalves lack cephalization and an anterior brain.
Front
What defining traits are shared by arthropods?
Back
A chitinous exoskeleton, jointed appendages, segmentation into tagmata, coelom, and protostome development.
Front
What is ecdysis?
Back
Shedding of an arthropod’s old exoskeleton.
Front
What type of circulatory system do arthropods possess?
Back
An open circulatory system containing hemolymph.
Front
What is hemolymph?
Back
The circulatory fluid of animals with an open circulatory system.
Front
What nervous system do arthropods possess?
Back
A ventral nerve cord and anterior brain.
Front
What digestive system do arthropods possess?
Back
A complete alimentary canal.
Front
What excretory structures are associated with insects and arachnids?
Back
Malpighian tubules.
Front
What distinguishes insects from other arthropods?
Back
They have three pairs of legs, antennae, spiracles and tracheal tubes, and commonly undergo metamorphosis.
Front
Which animal group contains more species than any other phylum?
Back
Insects within Arthropoda.
Front
What are examples of insects?
Back
Ants and dragonflies.
Front
What distinguishes arachnids?
Back
They possess four pairs of legs and usually use tracheae or book lungs.
Front
What are examples of arachnids?
Back
Spiders and scorpions.
Front
Where do most arachnids live?
Back
Terrestrial environments.
Front
What distinguishes crustaceans?
Back
They are primarily aquatic arthropods that commonly use gills.
Front
What are examples of crustaceans?
Back
Lobsters, crayfish, and crabs.
Front
What are papulae?
Back
Skin gills used for respiration in some aquatic invertebrates.
Front
What are the defining features of Echinodermata?
Back
Triploblastic coelomate deuterostomes with bilateral larvae, fivefold radial adults, a water vascular system, and tube feet.
Front
What are examples of echinoderms?
Back
Sea stars, sea urchins, and sea cucumbers.
Front
What symmetry do echinoderm larvae have?
Back
Bilateral symmetry.
Front
What symmetry do adult echinoderms have?
Back
Fivefold radial symmetry.
Front
What is the echinoderm water vascular system?
Back
A hydraulic system involved in movement, feeding, and gas exchange.
Front
What are echinoderm tube feet?
Back
Extensions of the water vascular system used for movement and other functions.
Front
What nervous system do echinoderms possess?
Back
A nerve ring with radial nerves.
Front
What circulatory system do echinoderms possess?
Back
An open system without a true heart.
Front
How do echinoderms respire and excrete wastes?
Back
Primarily through diffusion.
Front
How are echinoderms related to chordates?
Back
They are the major invertebrate phylum most closely related to chordates.
Front
What four features define chordates?
Back
A notochord, dorsal hollow nerve cord, pharyngeal slits, and post-anal tail.
Front
What is the notochord?
Back
A flexible mesoderm-derived rod providing structural support.
Front
What happens to the notochord in vertebrates?
Back
It is generally replaced by or contributes to development of the vertebral column.
Front
What does the dorsal hollow nerve cord become?
Back
The central nervous system: brain and spinal cord.
Front
What do pharyngeal slits become?
Back
Gills in fish and portions of the jaw and inner ear in terrestrial chordates.
Front
What is the post-anal tail?
Back
A body extension beyond the anus used for swimming and present during at least embryonic development.
Front
Do adult humans possess a post-anal tail?
Back
No, but it is present during embryonic development.
Front
What characteristics are shared by all chordates?
Back
Bilateral symmetry, triploblastic tissues, a coelom, deuterostome development, and a complete alimentary canal.
Front
What are invertebrate chordates?
Back
Tunicates and lancelets that possess chordate features but lack vertebrae.
Front
What features define vertebrates?
Back
Vertebrae protecting the spinal cord, a cranium protecting the brain, and a bony or cartilaginous endoskeleton.
Front
What are the major vertebrate groups?
Back
Fish, amphibians, reptiles, birds, and mammals.
Front
What are tunicates or urochordates?
Back
Marine invertebrate chordates with a cellulose tunic that commonly live as benthic filter feeders.
Front
When do tunicates possess a notochord?
Back
Only during the larval stage.
Front
What are lancelets or cephalochordates?
Back
Marine invertebrate chordates that retain their notochord through adulthood.
Front
How do lancelets capture food?
Back
Particles become trapped in mucus secreted by the endostyle around the pharyngeal slits.
Front
Why are tunicates and lancelets studied?
Back
They provide evidence about the evolutionary origin of vertebrates.
Front
What is Agnatha?
Back
The jawless-fish group containing hagfish and lampreys.
Front
What are the characteristics of jawless fish?
Back
Naked scaleless skin, keratinized mouth plates, a cartilaginous skeleton, a persistent notochord, gills, and a two-chambered heart.
Front
What is unusual about hagfish?
Back
They possess a skull but lack a true vertebral column.
Front
What is Chondrichthyes?
Back
The cartilaginous-fish group, including sharks.
Front
What are the characteristics of cartilaginous fish?
Back
Jaws, teeth, cartilaginous vertebrae, gills, and a two-chambered heart.
Front
From which group onward is the notochord generally limited to embryonic development and replaced by vertebrae?
Back
Chondrichthyes and later vertebrates.
Front
What is Osteichthyes?
Back
The bony-fish group.
Front
What are examples of bony fish?
Back
Salmon and halibut.
Front
What are the major characteristics of bony fish?
Back
A bony skeleton, scales, gills, and a two-chambered heart.
Front
What are the characteristics of amphibians?
Back
Scale-free ectothermic anamniotes that undergo metamorphosis and usually possess a three-chambered heart.
Front
What respiratory organs do amphibian larvae use?
Back
Gills.
Front
What respiratory organs do adult amphibians use?
Back
Primarily lungs.
Front
What are typical tadpole characteristics?
Back
Aquatic habitat, gills, a tail, and no legs.
Front
What changes occur during amphibian metamorphosis?
Back
Gills are replaced by lungs, limbs develop, and the body becomes adapted for terrestrial life.
Front
What structures transmit sound in amphibians?
Back
The tympanic membrane and stapes.
Front
What are the characteristics of reptiles?
Back
Ectothermic amniotes with lungs, internal fertilization, leathery eggs, and usually a three-chambered heart.
Front
Which reptiles possess four-chambered hearts?
Back
Crocodilians.
Front
What are the characteristics of birds?
Back
Endothermic amniotes with lungs, feathers, shelled eggs, and four-chambered hearts.
Front
What are bird feathers evolutionarily?
Back
Modified scales.
Front
What characteristics are shared by mammals?
Back
Endothermy, amniotic development, lungs, mammary glands, and a four-chambered heart.
Front
What are monotremes?
Back
Egg-laying mammals such as the platypus and echidna.
Front
What type of eggs do monotremes lay?
Back
Leathery eggs that provide nutrients to the embryo.
Front
How do young monotremes obtain milk?
Back
They lick milk from mammary gland openings in the mother’s fur because monotremes lack nipples.
Front
What are marsupials?
Back
Mammals with short gestation whose highly premature young continue development in a marsupium or pouch.
Front
What are examples of marsupials?
Back
Kangaroos and opossums.
Front
Why do marsupials have prolonged lactation?
Back
Their young are born extremely premature and complete much of development after birth.
Front
What are placental mammals?
Back
Mammals whose fetuses receive support through a placenta.
Front
What are examples of placental mammals?
Back
Humans, bats, whales, and mice.
Front
What is thermoregulation?
Back
The mechanisms by which organisms control internal body temperature.
Front
What is an ectotherm or poikilotherm?
Back
An organism whose body temperature is largely determined by the environment.
Front
What is an endotherm or homeotherm?
Back
An organism that uses metabolic heat to maintain a relatively stable body temperature.
Front
What adaptations help endotherms retain heat?
Back
Fat, fur, and feathers.
Front
What is viviparity?
Back
Live birth in which the developing young receive direct nourishment from the mother.
Front
What is oviparity?
Back
Laying fertilized eggs that hatch externally and nourish embryos using yolk.
Front
What is ovoviviparity?
Back
Retention and internal hatching of yolk-nourished eggs followed by birth of live young.
Front
What is an amniote?
Back
A tetrapod with specialized extraembryonic membranes that nourish and support the embryo.
Front
Which groups are amniotes?
Back
Reptiles, birds, and mammals.
Front
What is an anamniote?
Back
An organism lacking specialized amniotic extraembryonic membranes.
Front
Which vertebrate groups are anamniotes?
Back
Fish and amphibians.
Front
What are typical amniote egg features?
Back
Terrestrial development, a waterproof covering, and the amnion, chorion, and allantois.
Front
What are typical anamniote egg features?
Back
Aquatic eggs without an outer shell, commonly surrounded by a jelly-like vitelline membrane.
Front
What is the function of the amniotic egg shell?
Back
Protection and porous gas exchange.
Front
What is albumen?
Back
The egg white that cushions the embryo and supplies water and proteins.
Front
What is the function of the yolk sac?
Back
Supplying nutrients to the embryo.
Front
What is the function of the chorion?
Back
Facilitating gas exchange.
Front
What is the function of the allantois?
Back
Storing embryonic waste.
Front
What is the function of the amnion?
Back
Surrounding the embryo and amniotic fluid to provide protection and cushioning.
Front
What is the order of amniotic egg structures from external to internal?
Back
Shell → albumen → yolk sac → chorion → allantois → amnion.
Front
What is the placenta?
Back
An organ forming an interface between maternal and fetal blood for nutrient, gas, and waste exchange.
Front
What does the placenta deliver to the fetus?
Back
Oxygen and nutrients.
Front
What does the placenta remove from the fetus?
Back
Metabolic wastes.
Front
How does fetal blood enter the placenta?
Back
Through fetal arteries.
Front
What are chorionic villi?
Back
Finger-like placental projections containing fetal capillaries that increase exchange surface area.
Front
What is a virus?
Back
A small nonliving infectious particle consisting of a nucleic-acid genome and protein capsid.
Front
What is a viral capsid?
Back
The protein coat protecting a viral genome.
Front
What additional structures do bacteriophages possess?
Back
A sheath and tail fibers.
Front
What is a viral envelope?
Back
An outer lipid membrane containing glycoproteins that assist cell entry and immune evasion.
Front
What are the six general stages of a viral life cycle?
Back
Attachment → entry → uncoating → synthesis/replication → self-assembly → release.
Front
What occurs during viral attachment?
Back
Viral surface proteins bind specific structures or receptors on the host cell.

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