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gymnosperm : a seed plant with naked seeds (seeds exposed on modified leaves or in cones)
https://openstax.org/books/concepts-biology/pages/14-key-terms
gynoecium : the group of structures that constitute the female reproductive organ; also called the pistil
https://openstax.org/books/concepts-biology/pages/14-key-terms
haplodiplontic : describes a life cycle in which the haploid and diploid stages alternate; also known as an alternation of generations life cycle
https://openstax.org/books/concepts-biology/pages/14-key-terms
haplontic : describes a life cycle in which the haploid stage is the dominant stage
https://openstax.org/books/concepts-biology/pages/14-key-terms
herbaceous : describes a plant without woody tissue
https://openstax.org/books/concepts-biology/pages/14-key-terms
heterosporous : having two kinds of spores that give rise to male and female gametophytes
https://openstax.org/books/concepts-biology/pages/14-key-terms
homosporous : having one kind of spore that gives rise to gametophytes that give rise to both male and female gametes
https://openstax.org/books/concepts-biology/pages/14-key-terms
hornwort : a group of non-vascular plants in which stomata appear
https://openstax.org/books/concepts-biology/pages/14-key-terms
horsetail : a seedless vascular plant characterized by a jointed stem
https://openstax.org/books/concepts-biology/pages/14-key-terms
liverwort : the most primitive group of non-vascular plants
https://openstax.org/books/concepts-biology/pages/14-key-terms
megasporocyte : a megaspore mother cell; larger spore that germinates into a female gametophyte in a heterosporous plant
https://openstax.org/books/concepts-biology/pages/14-key-terms
microsporocyte : smaller spore that produces a male gametophyte in a heterosporous plant
https://openstax.org/books/concepts-biology/pages/14-key-terms
monocot : a related group of angiosperms that produce embryos with one cotyledon and pollen with a single ridge
https://openstax.org/books/concepts-biology/pages/14-key-terms
moss : a group of plants in which a primitive conductive system appears
https://openstax.org/books/concepts-biology/pages/14-key-terms
nonvascular plant : a plant that lacks vascular tissue formed of specialized cells for the transport of water and nutrients
https://openstax.org/books/concepts-biology/pages/14-key-terms
ovary : the chamber that contains and protects the ovule or female megasporangium
https://openstax.org/books/concepts-biology/pages/14-key-terms
petal : a modified leaf interior to the sepal; colorful petals attract animal pollinator
https://openstax.org/books/concepts-biology/pages/14-key-terms
phloem : the vascular tissue responsible for transport of sugars, proteins, and other solutes
https://openstax.org/books/concepts-biology/pages/14-key-terms
pistil : the group of structures that constitute the female reproductive organ; also called the carpel
https://openstax.org/books/concepts-biology/pages/14-key-terms
sepal : a modified leaf that encloses the bud; outermost structure of a flower
https://openstax.org/books/concepts-biology/pages/14-key-terms
sporangium : (plural: sporangia) the organ within which spores are produced
https://openstax.org/books/concepts-biology/pages/14-key-terms
sporophyll : a leaf modified structurally to bear sporangia
https://openstax.org/books/concepts-biology/pages/14-key-terms
sporophyte : the diploid plant that produces spores
https://openstax.org/books/concepts-biology/pages/14-key-terms
stamen : the group of structures that contain the male reproductive organs
https://openstax.org/books/concepts-biology/pages/14-key-terms
stigma : uppermost structure of the carpel where pollen is deposited
https://openstax.org/books/concepts-biology/pages/14-key-terms
strobili : cone-like structures that contain the sporangia
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style : the long thin structure that links the stigma to the ovary
https://openstax.org/books/concepts-biology/pages/14-key-terms
syngamy : the union of two gametes in fertilization
https://openstax.org/books/concepts-biology/pages/14-key-terms
vascular plant : a plant in which there is a network of cells that conduct water and solutes through the organism
https://openstax.org/books/concepts-biology/pages/14-key-terms
whisk fern : a seedless vascular plant that lost roots and leaves by evolutionary reduction
https://openstax.org/books/concepts-biology/pages/14-key-terms
xylem : the vascular tissue responsible for long-distance transport of water and nutrients
https://openstax.org/books/concepts-biology/pages/14-key-terms
Animals constitute a diverse kingdom of organisms. Although animals range in complexity from simple sea sponges to human beings, most members share certain features. Animals are eukaryotic, multicellular, heterotrophic organisms that ingest their food and usually develop into motile creatures with a fixed body plan. Mo...
https://openstax.org/books/concepts-biology/pages/15-chapter-summary
Organisms in the animal kingdom are classified based on their body morphology and development. True animals are divided into those with radial versus bilateral symmetry. Animals with three germ layers, called triploblasts, are further characterized by the presence or absence of an internal body cavity called a coelom. ...
https://openstax.org/books/concepts-biology/pages/15-chapter-summary
Animals included in phylum Porifera are parazoans and do not possess true tissues. These organisms show a simple organization. Sponges have multiple cell types that are geared toward executing various metabolic functions.
https://openstax.org/books/concepts-biology/pages/15-chapter-summary
Cnidarians have outer and inner tissue layers sandwiching a noncellular mesoglea. Cnidarians possess a well-formed digestive system and carry out extracellular digestion. The cnidocyte is a specialized cell for delivering toxins to prey and predators. Cnidarians have separate sexes. They have a life cycle that involves...
https://openstax.org/books/concepts-biology/pages/15-chapter-summary
Flatworms are acoelomate, triploblastic animals. They lack circulatory and respiratory systems, and have a rudimentary excretory system. The digestive system is incomplete in most species. There are four traditional classes of flatworms, the largely free-living turbellarians, the ectoparasitic monogeneans, and the endo...
https://openstax.org/books/concepts-biology/pages/15-chapter-summary
Nematodes are pseudocoelomate members of the clade Ecdysozoa. They have a complete digestive system and a pseudocoelomic body cavity. This phylum includes free-living as well as parasitic organisms. They include dioecious and hermaphroditic species. Nematodes have a poorly developed excretory system. Embryonic developm...
https://openstax.org/books/concepts-biology/pages/15-chapter-summary
Arthropods represent the most successful phylum of animals on Earth, in terms of number of species as well as the number of individuals. They are characterized by a segmented body and jointed appendages. In the basic body plan, a pair of appendages is present per body segment. Within the phylum, classification is based...
https://openstax.org/books/concepts-biology/pages/15-chapter-summary
The phylum Mollusca is a large, mainly marine group of invertebrates. Mollusks show a variety of morphologies. Many mollusks secrete a calcareous shell for protection, but in other species, the shell is reduced or absent. Mollusks are protostomes. The dorsal epidermis in mollusks is modified to form the mantle, which e...
https://openstax.org/books/concepts-biology/pages/15-chapter-summary
The phylum Annelida includes worm-like, segmented animals. Segmentation is both external and internal, which is called metamerism. Annelids are protostomes. The presence of chitinous hairs called chaetae is characteristic of most members. These animals have well-developed nervous and digestive systems. Polychaete annel...
https://openstax.org/books/concepts-biology/pages/15-chapter-summary
Echinoderms are deuterostome marine organisms. This phylum of animals bear a calcareous endoskeleton composed of ossicles covered by a spiny skin. Echinoderms possess a water-based circulatory system. The madreporite is the point of entry and exit for water for the water vascular system.
https://openstax.org/books/concepts-biology/pages/15-chapter-summary
The characteristic features of Chordata are a notochord, a dorsal hollow nerve cord, pharyngeal slits, and a post-anal tail. Chordata contains two clades of invertebrates: Urochordata (tunicates) and Cephalochordata (lancelets), together with the vertebrates. Most tunicates live on the ocean floor and are suspension fe...
https://openstax.org/books/concepts-biology/pages/15-chapter-summary
The earliest vertebrates that diverged from the invertebrate chordates were the jawless fishes. Hagfishes are eel-like scavengers that feed on dead invertebrates and other fishes. Lampreys are characterized by a toothed, funnel-like sucking mouth, and some species are parasitic on other fishes. Gnathostomes include the...
https://openstax.org/books/concepts-biology/pages/15-chapter-summary
As tetrapods, most amphibians are characterized by four well-developed limbs, although some species of salamanders and all caecilians are limbless. Amphibians have a moist, permeable skin used for cutaneous respiration. Amphibia can be divided into three clades: salamanders (Urodela), frogs (Anura), and caecilians (Apo...
https://openstax.org/books/concepts-biology/pages/15-chapter-summary
The amniotes are distinguished from amphibians by the presence of a terrestrially adapted egg protected by amniotic membranes. The amniotes include reptiles, birds, and mammals. A key adaptation that permitted reptiles to live on land was the development of scaly skin. Reptilia includes four living clades: Crocodilia (...
https://openstax.org/books/concepts-biology/pages/15-chapter-summary
Birds are endothermic amniotes. Feathers act as insulation and allow for flight. Birds have pneumatic bones that are hollow rather than tissue-filled. Airflow through bird lungs travels in one direction. Birds evolved from dinosaurs.
https://openstax.org/books/concepts-biology/pages/15-chapter-summary
Mammals have hair and mammary glands. Mammalian skin includes various secretory glands. Mammals are endothermic, like birds. There are three groups of mammals living today: monotremes, marsupials, and eutherians. Monotremes are unique among mammals as they lay eggs, rather than giving birth to live young. Eutherian mam...
https://openstax.org/books/concepts-biology/pages/15-chapter-summary
There are 16 extant (living) orders of eutherian mammals. Humans are most closely related to Primates, all of which have adaptations for climbing trees, although not all species are arboreal. Other characteristics of primates are brains that are larger than those of other mammals, claws that have been modified into fla...
https://openstax.org/books/concepts-biology/pages/15-chapter-summary
acoelomate : without a body cavity
https://openstax.org/books/concepts-biology/pages/15-key-terms
Actinopterygii : ray-finned fishes
https://openstax.org/books/concepts-biology/pages/15-key-terms
amniote : a clade of animals that possesses an amniotic egg; includes reptiles (including birds) and mammals
https://openstax.org/books/concepts-biology/pages/15-key-terms
amoebocyte : an amoeba-like cell of sponges whose functions include distribution of nutrients to other cells in the sponge
https://openstax.org/books/concepts-biology/pages/15-key-terms
Amphibia : frogs, salamanders, and caecilians
https://openstax.org/books/concepts-biology/pages/15-key-terms
ampulla of Lorenzini : a sensory organ that allows sharks to detect electromagnetic fields produced by living things
https://openstax.org/books/concepts-biology/pages/15-key-terms
Annelida : a phylum of worm-like animals with metamerism
https://openstax.org/books/concepts-biology/pages/15-key-terms
anthropoids : a clade consisting of monkeys, apes, and humans
https://openstax.org/books/concepts-biology/pages/15-key-terms
Anura : frogs
https://openstax.org/books/concepts-biology/pages/15-key-terms
Apoda : caecilians
https://openstax.org/books/concepts-biology/pages/15-key-terms
Arthropoda : a phylum of Ecdysozoa with jointed appendages and segmented bodies
https://openstax.org/books/concepts-biology/pages/15-key-terms
asymmetrical : having no plane of symmetry
https://openstax.org/books/concepts-biology/pages/15-key-terms
bilateral symmetry : a type of symmetry in which there is only one plane of symmetry that creates two mirror-image sides
https://openstax.org/books/concepts-biology/pages/15-key-terms
body plan : the shape and symmetry of an organism
https://openstax.org/books/concepts-biology/pages/15-key-terms
brachiation : swinging through trees
https://openstax.org/books/concepts-biology/pages/15-key-terms
budding : a form of asexual reproduction that occurs through the growth of a new organism as a branch on an adult organism that breaks off and becomes independent; found in plants, sponges, cnidarians, and some other invertebrates
https://openstax.org/books/concepts-biology/pages/15-key-terms
caecilian : a legless amphibian that belongs to clade Apoda
https://openstax.org/books/concepts-biology/pages/15-key-terms
Cephalochordata : a chordate clade whose members possess a notochord, dorsal hollow nerve cord, pharyngeal slits, and a post-anal tail in the adult stage
https://openstax.org/books/concepts-biology/pages/15-key-terms
cephalothorax : a fused head and thorax
https://openstax.org/books/concepts-biology/pages/15-key-terms
chaeta : a chitinous projection from the cuticle found in annelids
https://openstax.org/books/concepts-biology/pages/15-key-terms
chelicerae : a modified first pair of appendages in subphylum Chelicerata
https://openstax.org/books/concepts-biology/pages/15-key-terms
chitin : a tough nitrogen-containing polysaccharide found in the cuticles of arthropods and the cell walls of fungi
https://openstax.org/books/concepts-biology/pages/15-key-terms
choanocyte : a cell type unique to sponges with a flagellum surrounded by a collar used to maintain water flow through the sponge, and capture and digest food particles
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Chondrichthyes : jawed fishes with paired fins and a skeleton made of cartilage
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Chordata : a phylum of animals distinguished by their possession of a notochord, a dorsal hollow nerve cord, pharyngeal slits, and a post-anal tail at some point during their development
https://openstax.org/books/concepts-biology/pages/15-key-terms
clitellum : a specialized band of fused segments in some annelids, which aids in reproduction
https://openstax.org/books/concepts-biology/pages/15-key-terms
Cnidaria : a phylum of animals that are diploblastic and have radial symmetry and stinging cells
https://openstax.org/books/concepts-biology/pages/15-key-terms
cnidocyte : a specialized stinging cell found in Cnidaria
https://openstax.org/books/concepts-biology/pages/15-key-terms
coelom : a lined body cavity derived from mesodermal embryonic tissue
https://openstax.org/books/concepts-biology/pages/15-key-terms
complete digestive system : a digestive system that opens at one end, the mouth, and exits at the other end, the anus, and through which food normally moves in one direction
https://openstax.org/books/concepts-biology/pages/15-key-terms
craniate : a proposed clade of chordates that includes all groups except the tunicates and lancelets
https://openstax.org/books/concepts-biology/pages/15-key-terms
Crocodilia : crocodiles and alligators
https://openstax.org/books/concepts-biology/pages/15-key-terms
ctenidia : specialized gills in mollusks
https://openstax.org/books/concepts-biology/pages/15-key-terms
cutaneous respiration : gas exchange through the skin
https://openstax.org/books/concepts-biology/pages/15-key-terms
deuterostome : describing an animal in which the blastopore develops into the anus, with the second opening developing into the mouth
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dioecious : having separate male and female sexes
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diphyodont : refers to the possession of two sets of teeth in a lifetime
https://openstax.org/books/concepts-biology/pages/15-key-terms
diploblast : an animal that develops from two embryonic germ layers
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dorsal hollow nerve cord : a hollow, tubular structure derived from ectoderm, which is located dorsal to the notochord in chordates
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down feather : feather specialized for insulation
https://openstax.org/books/concepts-biology/pages/15-key-terms
Echinodermata : a phylum of deuterostomes with spiny skin; exclusively marine organisms
https://openstax.org/books/concepts-biology/pages/15-key-terms
epidermis : the layer of cells that lines the outer surface of an animal
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eucoelomate : describing animals with a body cavity completely lined with mesodermal tissue
https://openstax.org/books/concepts-biology/pages/15-key-terms
eutherian mammal : a mammal with a complex placenta, which connects a fetus to the mother; sometimes called placental mammals
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extracellular digestion : a form of digestion, the breakdown of food, which occurs outside of cells with the aid of enzymes released by cells
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fragmentation : a form of asexual reproduction in which a portion of the body of an organism breaks off and develops into a living independent organism; found in plants, sponges, and some other invertebrates
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frog : a tail-less amphibian that belongs to clade Anura
https://openstax.org/books/concepts-biology/pages/15-key-terms
gastrodermis : the layer of cells that lines the gastrovascular cavity of cnidarians
https://openstax.org/books/concepts-biology/pages/15-key-terms
gastrovascular cavity : the central cavity bounded by the gastrodermis in cnidarians
https://openstax.org/books/concepts-biology/pages/15-key-terms
gemmule : a structure produced by asexual reproduction in freshwater sponges that is able to survive harsh conditions
https://openstax.org/books/concepts-biology/pages/15-key-terms
germ layer : a collection of cells formed during embryogenesis that will give rise to future body tissues
https://openstax.org/books/concepts-biology/pages/15-key-terms
gnathostome : a jawed fish
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