Phylogeny, Plant Evolution, and Invertebrate Diversity

Vocabulary practice flashcards covering phylogeny and taxonomy, plant colonization of land, and invertebrate animal diversity.

Systematics

The scientific discipline that classifies organisms and determines their evolutionary relationships using genetic, morphological, and biochemical data.

Binomial nomenclature rules

A two-part scientific naming system where the genus name is capitalized, the specific epithet is lowercase, and both parts together are italicized or underlined.

Sister taxa

Groups of organisms that share an immediate common ancestor not shared by any other group on a phylogenetic tree.

Basal taxon

A lineage that diverges early in the history of a group and originates near the common ancestor of the entire group.

Monophyletic group

An evolutionary clade consisting of an ancestral species and all of its descendants.

Paraphyletic group

A taxonomic grouping consisting of an ancestral species and some, but not all, of its descendants.

Polyphyletic group

A taxonomic grouping that includes distantly related species with similar adapted traits, but excludes their most recent common ancestor.

Shared derived character

An evolutionary novelty unique to a particular clade that was not present in its distant ancestors.

Maximum parsimony

A principle of phylogenetic inference stating that the tree requiring the fewest evolutionary changes is the most likely.

Orthologous genes

Homologous genes found in single copies across different species that diverge only after speciation occurs.

Paralogous genes

Homologous genes resulting from gene duplication within a species that can diverge to perform new biological functions.

Sporopollenin

A durable polymer layer in plant spore walls and charophyte zygote coatings that prevents desiccation and protects against harsh environments.

Gametophyte generation

The haploid multicellular stage in plants that produces haploid gametes through mitosis.

Antheridia

The male multicellular gametangia in plants that produce and release flagellated sperm cells.

Apical meristem

Specialized regions of cell division located at the tips of plant roots and shoots that drive continual growth in length.

Xylem

Vascular plant tissue strengthened by lignin that conducts water and dissolved minerals upward from the roots.

Microphyll

A small, spine-shaped leaf with a single unbranched vascular vein, characteristic of lycophytes.

Heterosporous spore production

A pattern of spore production in plants where megaspores yield female gametophytes and microspores yield male gametophytes.

Choanocytes

Flagellated collar cells in sponges that generate water currents through the spongocoel and ingest food particles via phagocytosis.

Nematocyst

A specialized stinging organelle housed within a cnidocyte that discharges to inject venom or capture prey.

Torsion

A developmental process in gastropods where the visceral mass rotates $180^\circ$ relative to the head, positioning the anus and mantle cavity above the head.

Parapodia

Paired, paddlelike appendages found on each segment of marine polychaetes that function in locomotion and gas exchange.

Ecdysis

The periodic shedding or molting of a rigid exoskeleton or cuticle in arthropods and nematodes to allow body growth.

Complete metamorphosis

A developmental process in insects comprising distinct larval, pupal, and adult stages, where the larva differs completely from the adult.

Water vascular system

A network of hydraulic canals and tube feet unique to echinoderms that functions in locomotion, feeding, and gas exchange.

Systematics

The scientific discipline that classifies organisms and determines their evolutionary relationships using genetic, morphological, and biochemical data.

Binomial nomenclature rules

A two-part scientific naming system where the genus name is capitalized, the specific epithet is lowercase, and both parts together are italicized or underlined.

Sister taxa

Groups of organisms that share an immediate common ancestor not shared by any other group on a phylogenetic tree.

Basal taxon

A lineage that diverges early in the history of a group and originates near the common ancestor of the entire group.

Monophyletic group

An evolutionary clade consisting of an ancestral species and all of its descendants.

Paraphyletic group

A taxonomic grouping consisting of an ancestral species and some, but not all, of its descendants.

Polyphyletic group

A taxonomic grouping that includes distantly related species with similar adapted traits, but excludes their most recent common ancestor.

Shared derived character

An evolutionary novelty unique to a particular clade that was not present in its distant ancestors.

Maximum parsimony

A principle of phylogenetic inference stating that the tree requiring the fewest evolutionary changes is the most likely.

Orthologous genes

Homologous genes found in single copies across different species that diverge only after speciation occurs.

Paralogous genes

Homologous genes resulting from gene duplication within a species that can diverge to perform new biological functions.

Sporopollenin

A durable polymer layer in plant spore walls and charophyte zygote coatings that prevents desiccation and protects against harsh environments.

Gametophyte generation

The haploid multicellular stage in plants that produces haploid gametes through mitosis.

Antheridia

The male multicellular gametangia in plants that produce and release flagellated sperm cells.

Apical meristem

Specialized regions of cell division located at the tips of plant roots and shoots that drive continual growth in length.

Xylem

Vascular plant tissue strengthened by lignin that conducts water and dissolved minerals upward from the roots.

Microphyll

A small, spine-shaped leaf with a single unbranched vascular vein, characteristic of lycophytes.

Heterosporous spore production

A pattern of spore production in plants where megaspores yield female gametophytes and microspores yield male gametophytes.

Choanocytes

Flagellated collar cells in sponges that generate water currents through the spongocoel and ingest food particles via phagocytosis.

Nematocyst

A specialized stinging organelle housed within a cnidocyte that discharges to inject venom or capture prey.

Torsion

A developmental process in gastropods where the visceral mass rotates $180^\circ$ relative to the head, positioning the anus and mantle cavity above the head.

Parapodia

Paired, paddlelike appendages found on each segment of marine polychaetes that function in locomotion and gas exchange.

Ecdysis

The periodic shedding or molting of a rigid exoskeleton or cuticle in arthropods and nematodes to allow body growth.

Complete metamorphosis

A developmental process in insects comprising distinct larval, pupal, and adult stages, where the larva differs completely from the adult.

Water vascular system

A network of hydraulic canals and tube feet unique to echinoderms that functions in locomotion, feeding, and gas exchange.

Lophophore

A crown of ciliated tentacles surrounding the mouth in certain invertebrates that functions in filter feeding.

Anatomical feature distinguishing chitons from gastropods

The presence of eight shell plates on the dorsal surface, which are unique to chitons.

Shared digestive feature of cnidarians and flatworms

A gastrovascular cavity with a single opening that serves as both mouth and anus.

Gas exchange challenge in large animals

Body volume increases more rapidly than surface area as size increases, requiring specialized respiratory structures.

Shared terrestrial benefit of arthropod exoskeletons and mollusc shells

Prevention of desiccation by retaining moisture in dry land environments.

Phylum Nematoda characteristics

Unsegmented worms with a pseudocoelom, complete digestive tract, and an outer cuticle shed through molting.

Phylogenetic relationship between chordates and invertebrates

Chordates share a more recent common ancestor with echinoderms than with arthropods.

Evolutionary impact of the vertebrate jaw

Enabled early vertebrates to exploit a wider range of food sources and prey.

Evolutionary significance of the amniotic egg

Allowed tetrapods to complete their reproductive cycle entirely on land away from water.

Endothermy in birds and mammals

An energy-intensive physiological adaptation for internal temperature regulation that evolved independently in both clades through convergent evolution.

Eutherian mammal features

Mammals whose embryos undergo extended development inside the uterus nourished by a placenta, followed by lactation and prolonged care.

Unique functional traits of animals

Nervous tissue conduction of signals and muscular tissue movement.

Deuterostome blastopore fate

The embryonic development pattern where the blastopore formed during gastrulation becomes the anus.

Proximate cause of behavior

The immediate environmental stimulus or internal physiological mechanism that triggers a specific behavioral action.

Classical conditioning

A form of associative learning in which an arbitrary stimulus becomes linked with a functional reward or outcome.