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haplodiplodontic : haploid and diploid stages alternate
https://openstax.org/books/biology/pages/25-key-terms
haplontic : haploid stage is the dominant stage
https://openstax.org/books/biology/pages/25-key-terms
heterosporous : produces two types of spores
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homosporous : produces one type of spore
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hornworts : group of non-vascular plants in which stomata appear
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horsetail : seedless vascular plant characterized by joints
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lignin : complex polymer impermeable to water
https://openstax.org/books/biology/pages/25-key-terms
liverworts : most primitive group of the non-vascular plants
https://openstax.org/books/biology/pages/25-key-terms
lycophyte : club moss
https://openstax.org/books/biology/pages/25-key-terms
megaphyll : larger leaves with a pattern of branching veins
https://openstax.org/books/biology/pages/25-key-terms
megaspore : female spore
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microphyll : small size and simple vascular system with a single unbranched vein
https://openstax.org/books/biology/pages/25-key-terms
microspore : male spore
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mosses : group of bryophytes in which a primitive conductive system appears
https://openstax.org/books/biology/pages/25-key-terms
non-vascular plant : plant that lacks vascular tissue, which is formed of specialized cells for the transport of water and nutrients
https://openstax.org/books/biology/pages/25-key-terms
peat moss : Sphagnum
https://openstax.org/books/biology/pages/25-key-terms
peristome : tissue that surrounds the opening of the capsule and allows periodic release of spores
https://openstax.org/books/biology/pages/25-key-terms
phloem : tissue responsible for transport of sugars, proteins, and other solutes
https://openstax.org/books/biology/pages/25-key-terms
protonema : tangle of single celled filaments that forms from the haploid spore
https://openstax.org/books/biology/pages/25-key-terms
rhizoids : thin filaments that anchor the plant to the substrate
https://openstax.org/books/biology/pages/25-key-terms
seedless vascular plant : plant that does not produce seeds
https://openstax.org/books/biology/pages/25-key-terms
seta : stalk that supports the capsule in mosses
https://openstax.org/books/biology/pages/25-key-terms
sporocyte : diploid cell that produces spores by meiosis
https://openstax.org/books/biology/pages/25-key-terms
sporophyll : leaf modified structurally to bear sporangia
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sporopollenin : tough polymer surrounding the spore
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streptophytes : group that includes green algae and land plants
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strobili : cone-like structures that contain the sporangia
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tracheophyte : vascular plant
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vascular plant : plant containing a network of cells that conducts water and solutes through the organism
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vein : bundle of vascular tissue made of xylem and phloem
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whisk fern : seedless vascular plant that lost roots and leaves by reduction
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xylem : tissue responsible for long-distance transport of water and nutrients
https://openstax.org/books/biology/pages/25-key-terms
Seed plants appeared about one million years ago, during the Carboniferous period. Two major innovations—seed and pollen—allowed seed plants to reproduce in the absence of water. The gametophytes of seed plants shrank, while the sporophytes became prominent structures and the diploid stage became the longest phase ...
https://openstax.org/books/biology/pages/26-chapter-summary
Gymnosperms are heterosporous seed plants that produce naked seeds. They appeared in the Paleozoic period and were the dominant plant life during the Mesozoic. Modern-day gymnosperms belong to four phyla. The largest phylum, Coniferophyta, is represented by conifers, the predominant plants at high altitude and latitude...
https://openstax.org/books/biology/pages/26-chapter-summary
Angiosperms are the dominant form of plant life in most terrestrial ecosystems, comprising about 90 percent of all plant species. Most crops and ornamental plants are angiosperms. Their success comes from two innovative structures that protect reproduction from variability in the environment: the flower and the fruit. ...
https://openstax.org/books/biology/pages/26-chapter-summary
The angiosperm life cycle is dominated by the sporophyte stage. Double fertilization is an event unique to angiosperms. One sperm in the pollen fertilizes the egg, forming a diploid zygote, while the other combines with the two polar nuclei, forming a triploid cell that develops into a food storage tissue called the en...
https://openstax.org/books/biology/pages/26-chapter-summary
Angiosperm diversity is due in part to multiple interactions with animals. Herbivory has favored the development of defense mechanisms in plants, and avoidance of those defense mechanism in animals. Pollination (the transfer of pollen to a carpel) is mainly carried out by wind and animals, and angiosperms have evolved ...
https://openstax.org/books/biology/pages/26-chapter-summary
Plants play a key role in ecosystems. They are a source of food and medicinal compounds, and provide raw materials for many industries. Rapid deforestation and industrialization, however, threaten plant biodiversity. In turn, this threatens the ecosystem.
https://openstax.org/books/biology/pages/26-chapter-summary
anther : sac-like structure at the tip of the stamen in which pollen grains are produced
https://openstax.org/books/biology/pages/26-key-terms
Anthophyta : phylum to which angiosperms belong
https://openstax.org/books/biology/pages/26-key-terms
barcoding : molecular biology technique in which one or more short gene sequences taken from a well-characterized portion of the genome is used to identify a species
https://openstax.org/books/biology/pages/26-key-terms
basal angiosperms : a group of plants that probably branched off before the separation of monocots and eudicots
https://openstax.org/books/biology/pages/26-key-terms
calyx : whorl of sepals
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carpel : single unit of the pistil
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conifer : dominant phylum of gymnosperms with the most variety of trees
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corolla : collection of petals
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cotyledon : primitive leaf that develop in the zygote; monocots have one cotyledon, and dicots have two cotyledons
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crop : cultivated plant
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cycad : gymnosperm that grows in tropical climates and resembles a palm tree; member of the phylum Cycadophyta
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dicot : (also, eudicot) related group of angiosperms whose embryos possess two cotyledons
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dioecious : describes a species in which the male and female reproductive organs are carried on separate specimens
https://openstax.org/books/biology/pages/26-key-terms
filament : thin stalk that links the anther to the base of the flower
https://openstax.org/books/biology/pages/26-key-terms
flower : branches specialized for reproduction found in some seed-bearing plants, containing either specialized male or female organs or both male and female organs
https://openstax.org/books/biology/pages/26-key-terms
fruit : thickened tissue derived from ovary wall that protects the embryo after fertilization and facilitates seed dispersal
https://openstax.org/books/biology/pages/26-key-terms
gingkophyte : gymnosperm with one extant species, theGingko biloba: a tree with fan-shaped leaves
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gnetophyte : gymnosperm shrub with varied morphological features that produces vessel elements in its woody tissues; the phylum includes the generaEphedra, GnetumandWelwitschia
https://openstax.org/books/biology/pages/26-key-terms
gymnosperm : seed plant with naked seeds (seeds exposed on modified leaves or in cones)
https://openstax.org/books/biology/pages/26-key-terms
gynoecium : (also, carpel) structure that constitute the female reproductive organ
https://openstax.org/books/biology/pages/26-key-terms
heirloom seed : seed from a plant that was grown historically, but has not been used in modern agriculture on a large scale
https://openstax.org/books/biology/pages/26-key-terms
herbaceous : grass-like plant noticeable by the absence of woody tissue
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herbivory : consumption of plants by insects and other animals
https://openstax.org/books/biology/pages/26-key-terms
integument : layer of sporophyte tissue that surrounds the megasporangium, and later, the embryo
https://openstax.org/books/biology/pages/26-key-terms
megasporocyte : megaspore mother cell; larger spore that germinates into a female gametophyte in a heterosporous plant
https://openstax.org/books/biology/pages/26-key-terms
microsporocyte : smaller spore that produces a male gametophyte in a heterosporous plant
https://openstax.org/books/biology/pages/26-key-terms
monocot : related group of angiosperms that produce embryos with one cotyledon and pollen with a single ridge
https://openstax.org/books/biology/pages/26-key-terms
monoecious : describes a species in which the male and female reproductive organs are on the same plant
https://openstax.org/books/biology/pages/26-key-terms
nectar : liquid rich in sugars produced by flowers to attract animal pollinators
https://openstax.org/books/biology/pages/26-key-terms
ovary : chamber that contains and protects the ovule or female megasporangium
https://openstax.org/books/biology/pages/26-key-terms
ovulate cone : cone containing two ovules per scale
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ovule : female gametophyte
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perianth : part of the plant consisting of the calyx (sepals) and corolla (petals)
https://openstax.org/books/biology/pages/26-key-terms
petal : modified leaf interior to the sepals; colorful petals attract animal pollinators
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pistil : fused group of carpels
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pollen grain : structure containing the male gametophyte of the plant
https://openstax.org/books/biology/pages/26-key-terms
pollen tube : extension from the pollen grain that delivers sperm to the egg cell
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pollination : transfer of pollen from the anther to the stigma
https://openstax.org/books/biology/pages/26-key-terms
progymnosperm : transitional group of plants that resembled conifers because they produced wood, yet still reproduced like ferns
https://openstax.org/books/biology/pages/26-key-terms
seed : structure containing the embryo, storage tissue and protective coat
https://openstax.org/books/biology/pages/26-key-terms
sepal : modified leaf that encloses the bud; outermost structure of a flower
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spermatophyte : seed plant; from the Greeksperm(seed) andphyte(plant)
https://openstax.org/books/biology/pages/26-key-terms
stamen : structure that contains the male reproductive organs
https://openstax.org/books/biology/pages/26-key-terms
stigma : uppermost structure of the carpel where pollen is deposited
https://openstax.org/books/biology/pages/26-key-terms
strobilus : plant structure with a tight arrangement of sporophylls around a central stalk, as seen in cones or flowers; the male strobilus produces pollen, and the female strobilus produces eggs
https://openstax.org/books/biology/pages/26-key-terms
style : long, thin structure that links the stigma to the ovary
https://openstax.org/books/biology/pages/26-key-terms
Animals constitute an incredibly diverse kingdom of organisms. Although animals range in complexity from simple sea sponges to human beings, most members of the animal kingdom share certain features. Animals are eukaryotic, multicellular, heterotrophic organisms that ingest their food and usually develop into motile cr...
https://openstax.org/books/biology/pages/27-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. Generally, the simpler and often non-motile animals display radial symmetry. Animals with radial symmetry are also generally characterized by the deve...
https://openstax.org/books/biology/pages/27-chapter-summary
Scientists are interested in the evolutionary history of animals and the evolutionary relationships among them. There are three main sources of data that scientists use to create phylogenetic evolutionary tree diagrams that illustrate such relationships: morphological information (which includes developmental morpholog...
https://openstax.org/books/biology/pages/27-chapter-summary
The most rapid diversification and evolution of animal species in all of history occurred during the Cambrian period of the Paleozoic Era, a phenomenon known as the Cambrian explosion. Until recently, scientists believed that there were only very few tiny and simplistic animal species in existence before this period. H...
https://openstax.org/books/biology/pages/27-chapter-summary
The remainder of the Paleozoic Era is marked by the growing appearance of new classes, families, and species, and the early colonization of land by certain marine animals. The evolutionary history of animals is also marked by numerous major extinction events, each of which wiped out a majority of extant species. Some s...
https://openstax.org/books/biology/pages/27-chapter-summary
acoelomate : animal without a body cavity
https://openstax.org/books/biology/pages/27-key-terms
bilateral symmetry : type of symmetry in which there is only one plane of symmetry, so the left and right halves of an animal are mirror images
https://openstax.org/books/biology/pages/27-key-terms
blastopore : indentation formed during gastrulation, evident in the gastrula stage
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blastula : 16–32 cell stage of development of an animal embryo
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body plan : morphology or constant shape of an organism
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Cambrian explosion : time during the Cambrian period (542–488 million years ago) when most of the animal phyla in existence today evolved
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cleavage : cell division of a fertilized egg (zygote) to form a multicellular embryo
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coelom : lined body cavity
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Cryogenian period : geologic period (850–630 million years ago) characterized by a very cold global climate
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determinate cleavage : developmental tissue fate of each embryonic cell is already determined
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deuterostome : blastopore develops into the anus, with the second opening developing into the mouth
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