Image
from article Otter
North American river otter (Lontra canadensis). (Credit: Alan and Sandy Carey/Getty Images)
Search Results
Search Results
Refine this search
Search result paging links
3,644 results
Image
from article Otter
Sea otter (Enhydra lutris) in the water off the coast of Moss Landing, California. (Credit: Lilian Carswell/U.S. Fish and Wildlife Service)
Image
from article Echiura
Echiuran anatomy. (a) External anatomy, ventral view. (b) Internal anatomy, dorsal view. A, anus; AV, anal vesicles; G, gut (middle section removed for clarity); M, mouth; N, nephridia (egg and sperm storage organs); S, setae; VNC, ventral nerve…
Image
from article Schizomida
Schizomus sawadai. (After K. Sekiguchi and T. Yamasaki, A redescription of “Trithyreus sawadi” (Uropygi: Schizomidae) from the Bonin Islands, Acta Arachnol., 24(2):73–81, 1972)
Image
from article Periodic table
Periodic table of the elements.
Image
from article Lichens
The ascolichen Teloschistes chrysophthalmus. (Credit: Jason Hollinger)
Image
from article Lichens
Cuplike lichens of the genus Cladonia. (Credit: Jacinta Lluch Valero)
Image
from article Notomyotida
Some diagnostic features of representative Notomyotida. (a) Paxillae and one pectinate pedicellariae of Cheiraster richardsoni. (b) Benthopecten pentacanthus.
Image
from article Cotton effect
Behavior of the ORD and CD curves in the vicinity of an absorption band at wavelength λ0 (idealized). (a) Positive Cotton effect. (b) Negative Cotton effect.
Image
from article Cotton effect
Curves used to determine relative rotatory intensities. (a) Partial ORD curve. (b) Partial CD curve.
Image
from article Cotton effect
Structural formula of (+)-trans-9-methyl-1,4,9,10- tetrahydronaphthalene.
Image
from article Cotton effect
Schematic representation of the twisted diene chromophore showing the two possible handednesses; the numbering is as indicated in Fig. 3 (a) Right-handed. (b) Left-handed.
Image
from article Jerboa
Jerboa. (Credit: Pekka Fågel)
Image
from article Dune vegetation
A coastal dune profile.
Image
from article Dune vegetation
American beachgrass (Ammophila breviligulata), which dominates coastal dunes along much of the Eastern seaboard of the United States and the Great Lakes. (Photo by Rob Routledge, Sault College, Sault Ste. Marie, Ontario, Canada)
Image
from article Dune vegetation
Sea oats (Uniola paniculata) are abundant on the foredunes of the Atlantic coast of the southeastern United States. (Photo by Robert L. Anderson, USDA Forest Sevice)
Image
from article Dune vegetation
Bitter panicum (bitter panicgrass; Panicum amarum), which is often found on Gulf of Mexico coastal dunes. (Photo by Forest and Kim Starr)
Image
from article Ratites
Ostrich (Struthio camelus massaicus). (Photo courtesy of Gerald and Buff Corsi, copyright © California Academy of Sciences)
Image
from article Ratites
Greater rhea (Rhea americana). (Photo courtesy of Dr. Lloyd Glenn Ingles, copyright © California Academy of Sciences)
Image
from article Choanoflagellida
A linear colony of the choanoflagellate, Desmarella moniliformis.
Image
from article Electrochemistry
Electrolysis of aqueous potassium bromide. (Copyright © McGraw-Hill Education/Stephen Frisch)
Image
from article Osmium
Image
from article Osmium
Image
from article Trematoda
Phylogeny of the Neodermata. Note that the monophyly of the Neodermata has been confirmed by many morphological and DNA studies. The phylogeny of the various neodermatan subgroups may have to be revised on the basis of studies using mitochondrial…
Image
from article Trematoda
Furcocercaria of Schistosoma. Note the forked tail.
Image
from article Trematoda
Eggs of Schistosoma species. Note the differently developed spine and egg shape in the various species shown.
Image
from article Trematoda
Paragonimus species. Note the spinose tegument. Worms are about 1.5 cm (0.6 in.) in length.
Image
from article Luminescence analysis
Typical photoluminescence excitation and emission spectra for molecules in solution.
Image
from article Luminescence analysis
Components of instrumentation for luminescence measurements.
Image
from article Anthropocene extinction
The relationship between species extinctions and the human population on Earth since the year 1800. As the human population has increased, so too have the numbers of species extinctions. The numbers have been so great that the current Anthropocene…
Image
from article Camphor
Camphor tree. (Credit: Gyro Photography/amanaimagesRF/Getty Images)
Image
from article Acantharea
Representatives of the Acantharea; Acanthometra pellucida, (a) showing axial rods extending through the central capsule, and myonemes (myophrisks) extending from the rods to the sheath; (b) contracted myophrisks with expanded sheath; and (c) relaxed…
Image
from article Vertebrata
The subphylum Vertebrata constitutes the largest natural group (clade or monophyletic group) of chordate animals (members of the phylum Chordata). The asterisk indicates that birds are included in the reptile group. (Copyright © McGraw Hill)
Image
from article Ophiurida
Brittle star, Ophiolepis impressa (order Ophiurida, family Ophiolepididae), found on coral reefs in the tropical western Atlantic. (After G. Hendler et al., Sea Stars, Sea Urchins and Allies: Echinoderms of Florida and the Caribbean, Smithsonian…
Image
from article Copper
Image
from article Copper
Chalcopyrite (CuFeS2), a copper-iron sulfide mineral, is an important copper-containing ore. (Credit: Linnas/Getty Images)
Image
from article Copper
Electrical wiring cable. (Credit: Shutterstock/Sydeen)
Image
from article Neritimorpha
Female Nerita laying egg capsules.
Image
from article Neritimorpha
Sea grass snail Smaragdia with cryptic green coloration.
Image
from article Neritimorpha
Red-blooded Phenacolepas limpets.
Image
from article Hedgehog
European hedgehog (Erinaceus europaeus). (Photo by James Brian Bottomley and Sheila Bottomley)
Image
from article Gastornithiformes
Gastornis giganteus (reconstruction), an extinct flightless bird belonging to the order Gastornithiformes. (Photo courtesy of the American Museum of Natural History, New York)
Image
from article Thermosbaenacea
An ovigerous female, Thermosbaena (Thermosbaenacea). (After D. Barker, A study of Thermosbaena mirabilis (Malacostraca, Peracarida) and its reproduction, Quart. J. Micro. Sci., 103:261–286, 1962)
Image
from article Gaviiformes
Common loon (Gavia immer) at Jammer Lake, Minnesota. (Photograph copyright © DonGettyPhoto.com)
Image
from article Fullerene
Buckyball structure.
Image
from article Fullerene
Some of the more stable members of the fullerene family. (a) C28. (b) C32. (c) C50. (d) C60. (e) C70.
Image
from article Fullerene
Comparison of the structure of fullerene-60 with that of two giant fullerenes. (a) C60. (b) C240. (c) C540.
Image
from article Fullerene
Structure of the molecule C60Br6.
Image
from article Fullerene
A section of a carbon nanotube showing the concentric graphene tubes composing it.
Image
from article Drug delivery systems
A transdermal nicotine patch is a noninvasive method of controlled drug delivery. (Copyright © Plush Studios/Bill Reitzel/Blend Images)
Image
from article Drug delivery systems
Three levels of polymer drug delivery. (a) A polymer is used as carrier of drugs. (b) The drugs are connected to the polymer via cleavable peptide linkers. (c) A homing device is added to target specific tissue types. (Credit: Jan van Hest;…
Image
from article Amoebida
Typical ameboid locomotion. (a) Thecamoeba verucosa, locomotion without formation of distinct pseudopodia. (b) Mayorella bigemia, formation of conical pseudopodia. (c) Amoeba proteus, formation of large pseudopodia. (d) Amoeba dubia, formation of a…
Image
from article Amoebida
Commensal and parasitic amebas. (a–e) Entamoeba coli: (a) rounded form; (b) cyst; (c) multinucleate cyst; (d) typical cyst from naturally infected monkey; (e) octunucleate cyst. (f–k) E. histolytica: (f) ameboid form; (g) cyst with glycogen vacuole;…
Image
from article Amoebida
Nonpathogenic amebas. (a–e) Endolimax nana: (a) ameboid stage; (b) cyst from monkey; (c–e) cyst from human. (f–n) Iodamoeba bütschlii: (f) ameboid stage; (g, h) ameboid stage, medium size; (i) ameboid stage, small size; (j) ameboid stage, large…
Image
from article Half-life
The decay chain of uranium, which has a half-life of approximately 4.5 billion years and is the most common uranium isotope in nature. The alpha symbol (α) indicates alpha decay, while the beta symbol (β) indicates beta decay. Alpha decay emits an…
Image
from article Myctophiformes
Luminous lanternfish (Lampadena luminosa). (Photo courtesy of the SEFSC Pascagoula Laboratory, Collection of Brandi Noble, Southeast Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration)
Image
from article Ecology
Egrets and herons in a wetland ecosystem in the Everglades in southern Florida. (Copyright © McGraw-Hill Education)
Image
from article Ecology
Generalized trophic structure of ecosystems. Arrows indicate flow of energy and chemicals. Primary producers are largely green photosynthetic plants. Primary consumers, or herbivores, feed on the producers. Secondary consumers, or carnivores, feed…
Image
from article Narcotic
Heroin is an extremely addictive narcotic. (Credit: FotoMaximum/Getty Images)
Image
from article Narcotic
Chemical structure of a morphine alkaloid. Two important natural alkaloids are morphine and codeine. Heroin is synthesized from morphine by acetylation.
Image
from article Catalytic antibody
Schematic structure of an antibody molecule. The protein consists of two heavy chains and two light chains.
Image
from article Catalytic antibody
Early highlights of the first antibody-catalyzed reaction of ester hydrolysis. Stable tetrahedral phosphonate was used as the transition-state analog.
Image
from article Catalytic antibody
Mechanism of trapping the essential ε-amino group of a lysine residue in the antibody's binding pocket by using the 1,3-diketone hapten.
Image
from article Catalytic antibody
Prodrug activation via a tandem retro-aldol-retro-Michael reaction. X stands for heteroatoms N, O, or S (nitrogen, oxygen, or sulfur).
Image
from article Catalytic antibody
Generation of bispecific antibody originating from a catalytic antibody and a targeting antibody.
Image
from article Catalytic antibody
Chemotherapy targeted specifically to a tumor cell. The prodrug is prodoxorubicin, which is transformed to the active drug doxorubicin by the catalytic arm of the bifunctional antibody. The other arm binds to an antigen on a tumor cell.
Image
from article Sclerosponges
Skeleton of Astrosclera, with astrorhizal patterns on surface.
Image
from article Sclerosponges
Skeletal reticulum of Astrosclera showing spherulitic arrangement of crystalline units.
Image
from article Sclerosponges
Surface calicles of Ceratoporella showing protruding siliceous spicules. (From W.D.Hartman and T.F.Goreau, Trans.Conn.Acad.Arts Sci., 44:131–148, 1972)
Image
from article Sclerosponges
Acanthochaetetes wellsi. (a) Skeleton with astrorhizal patterns on surface. (b) Calicles viewed from above; two developing asexual buds are seen in lower left. (c) Longitudinal fracture of calcitic skeleton showing rows of spines in calicles.
Image
from article Frequency counter
Block diagram of a reciprocal frequency counter.
Image
from article Insect flight muscle
A flame skimmer dragonfly is a common insect found in western North America. The elements of the dragonfly's muscular system that have evolved over time provide this animal with a highly specialized ability of flight. (Credit: Cyndi Souza/U.S. Fish…
Image
from article Insect flight muscle
Two types of insect musculature: (a) direct flight muscle; (b) indirect flight muscle. (Credit: Based on an original illustration by R. Eckert, D. Randall, and G. Augustine)
Image
from article Insect flight muscle
A bee uses indirect flight muscles to hover over a pussy willow blossom while collecting pollen. The hairs on the bee, as well as its legs, are covered in yellow pollen. (Credit: Dave Massey/Shutterstock)
Image
from article Labyrinthulia
Labyrinthula zopfi: (a) portion of living network, (b) two organisms stained, (c) encysted stage. Labyrinthula macrocystis: (d) vegetative network, (e) single organism stained. (After R. P. Hall, Protozoology, Prentice Hall, 1953)
Image
from article Barracuda
Great barracuda (Sphyraena barracuda). (Photo copyright © John E. Randall)
Image
from article Blowpipe
Glassblower blowing into a blowpipe to shape molten glass. (Credit: Hero Images/Getty Images)
Image
from article Tin
Image
from article Tin
Image
from article Xenophyophorida
Xenophyophorids. (a) Stannoma dendroides. (b) Stannophyllum zonarium. (c) Psammetta erythrocytomorpha, section showing interlacing tubules and dark inclusions of uncertain nature.
Image
from article Isoelectric point
Titration of alanine with sodium hydroxide (NaOH), showing the course of pH with added fractional equivalents. The four arrows show, from left to right, the pKa [½ cations: NH3+(CH3)COOH, and ½ zwitterions: NH3+(CH3)CHCOO−], the pl (all…
Image
from article Isoelectric point
Course of the charges carried by lysine (pKa = 2.18) molecules in dilute aqueous solution with pH during a titration with alkali. Shown are the net charge, going from +2 at low pH to +1 between pH 4.5 and 6.5, the isoelectric point at pH 9.74, the…
Image
from article Iridium
Image
from article Musk-ox
Musk-ox (Ovibos moschatus). (Photo courtesy of Brent Huffman/Ultimate Ungulate Images)
Image
from article Marten
American marten (also known as the American pine marten; Martes americana). (Photo by Gerald and Buff Corsi; copyright © California Academy of Sciences)
Image
from article Human ecology
Shacks and garbage along a dirty river in a slum in Manila, Philippines. Human ecology encompasses how individual people and their communities interact with their particular environment. In many cases, though, humans have created polluted…
Image
from article Human ecology
Burning of a tropical rainforest in Brazil in order to clear land for animal grazing. (Credit: Barry Barker; copyright © McGraw Hill)
Image
from article Lawrencium
Image
from article Gravimetric analysis
In gravimetric analysis, a filtration step is required to collect the precipitate. (Credit: Matt Meadows/McGraw-Hill Education)
Image
from article Particle track etching
Upper images show increasing radiation damage produced by a high-energy uranium nucleus in the cosmic radiation as it penetrates a thick stack of Lexan plastic sheets and slows down. The lengths of the etched cones in these three sheets, taken at…
Image
from article Particle track etching
Etched conical pits in a sheet of allyl diglycol carbonate (CR-39 plastic) irradiated at normal incidence with 60-MeV alpha particles. (From P. B. Price et al., Do energetic heavy nuclei penetrate deeply into the Earth's atmosphere?, Proc. Nat.…
Image
from article Particle track etching
Etched fossil particle tracks. (a) Tracks from spontaneous fission of 238U and 244Pu in a zircon crystal from a lunar breccia, seen by scanning electron microscopy (from D. Braddy et al., Crystal chemistry of Pu and U and concordant fission track…
Image
from article Particle track etching
Reconstructed images of right and left breasts of a patient taken by using a 3600-MeV carbon-ion beam at the Lawrence Berkeley Laboratory Bevalac accelerator. Arrow indicates 1-cm (0.4-in.) carcinoma. (From C. A. Tobias et al., Lawrence Berkeley…
Image
from article Porcupine
North American porcupine (Erethizon dorsatum). (Photo from National Park Service)
Image
from article Grassland ecosystem
Grasslands cover the Great Plains region in North America, extending from southern Texas into Canada. (Credit: U.S. Forest Service)
Image
from article Grassland ecosystem
Map of grassland types in central and western North America. (Copyright © McGraw Hill)
Image
from article Xiphosurida
Segmentation of Limulus polyphemus. Inconclusive evidence indicates that there are 15 segments (6 in the prosoma, 9 in the opisthosoma). The telson (XV) may be a terminal spine that has become articulated and has incorporated the anus into its base.
Image
from article Xiphosurida
Phylogeny and representative species of the class Xiphosura, including the order Xiphosurida and its sister group, synziphosurines (a paraphyletic stem group).
Image
from article Xiphosurida
Paleolimulus signatus, a limuline xiphosurid from the Permian of Kansas, showing appendages and book gills. Length of specimen: 1.25 cm (0.5 in.).
Image
from article Xiphosurida
Carapaces of adult male Limulina. (a) Limulus polyphemus. (b) Tachypleus tridentatus. (c) Carcinoscorpius rotundicauda.
