mass

Yolk plug

Yolk plug A mass of large, yolky endoderm cells that fill the blastopore of an amphibian gastrula during its late stages. Full article >>> yolk plug The large yolk -filled cells that protrude from beneath the ectoderm at the blastopore ...

Yolk

...doderm and splanchnic mesoderm ) to surround the mass of yolk in reptile and bird eggs. Full article >>> yolk sac An extraembryonic membrane enclosing and absorbing the yolk of amniote embryo s. It is formed from a layer of endoderm and a layer of splanchnic mesoderm (splanchno...

Viscera

...em are. Full article >>> viscera l mass The region of a mollusc's body that contains visc...s ... Full article >>> a viscera l mass containing internal organ s, including the digestive tract, paired kidney s, and reproductive org...

Vessel cell

...ng walls reinforced with lignin, whose function is mass trans port of water for trans piration. Full article >>> The big advantage of focusing therapy on the angiogenesis is if the therapeutic is actin g against the normal blood vessel cell rather than the genetically unstable tumor ...

Vesicle

...e of coupled high resolution separation and high mass accuracy and sensitivity Fourier trans form ion cyclotron resonance (FTICR) mass spectrometry to character ize the protein content of outer membrane vesicle s from the ... Ful...

Tumor

...tem ... Full article >>> tumor A mass that forms within otherwise normal tissue , cause...ajor mediator of inflammation. tumor A spherical mass of cells in which cell division s occur at random and often in an uncontrolled fashion. Full art...

Trophoblast

...cial layer of cells surrounding the inner cell mass . Full article >>> Hydatidiform mole results from an exclusively paternal fertilization event and is character ized by unusual trophoblast ic growth without an apparent fetus . Incidence is approximately 1/1000 pregnancies. Full ...

Transmembrane proteins

...that extend through the bilayer with part of their mass on both sides of the bilayer acetyl coenzvme A (acetylCoA)-small water-soluble molecule that carries acetyl groups in cells . Full article >>> Some transmembrane proteins that span the bilayer several times form a hydrophilic chan...

Thymus gland

...rticle >>> thymus gland A ductless mass of flattened lymph oid tissue situated behind the top of the sternum; it forms antibodies in the newborn and is involved in the development of the immune system . Full article >>> T- lymphocytes (T- cells ) mature in the thymus...

Thymine

... DNA but not in RNA . thymus gland A ductless mass of flattened lymph oid tissue situated behind the top of the sternum; it forms antibodies in the newborn and is involved in the development of the immune system . Full article >>> Thymine (T): A nitrogenous base , one member o...

Thalamus

... Full article >>> thalamus An oval mass of gray matter within the diencephalon that serves as a sensory relay area. Full article >>> The lateral geniculate nucleus (LGN) is a sensory relay nucleus in the thalamus of the brain. The LGN consists of six layers in human...

Telophase

...mes gather at the poles of the cells and form a mass of chromatin ; the nuclear envelope develops, the nucleoli reappear, and the cells undergo cytokinesis . Full article >>> 5. Telophase A nuclear envelope reforms around each cluster of chromosomes and these return to their mo...

Syncytium

syncytium undivided mass of protoplasm with several nuclei, as in certain muscle s, fungi , and so forth Source: Noland, George B. 1983. General Biology , 11th Edition. St. Louis, MO. C. V. Mosby ... Full article >>> syncytium A multinucleated cell . syn...

Superficial

...cial layer of cells surrounding the inner cell mass . Full article >>> Bacteria superficial ly resemble Archeons in their general sizes and shapes, but are distinguished from them by different membrane structures, gene sequence s, and metabolism s. Full article >>> ...

Stroma

...of cyto trophoblast cells (near the inner cell mass ) form the highly invasive syncytio trophoblast which penetrates into the endometrial stroma . Full article >>> stroma The space and aqueous solution enclosed within the inner membrane of a chloroplast . sub- under, beneath subst...

Stigma

...n it. Full article >>> stigma The mass of bright red photo receptor granules found in certain flagellated protozoa (Euglena) that serves as a shield for the photo receptor . Also the spiracle of certain terrestrial arthropods. Full article >>> stigma The part of the re...

Spore

...hout fusion with another cell . sporoblast Cell mass that will differentiate into a sporocyst within an oocyst. Full article >>> Spore . A form taken by certain microbe s that enables them to exist in a dormant stage. It is an asexual reproductive cell . See Asexual reproduction , ...

Slime molds

...; Describes any organ ism or tissue that is a mass of protoplasm which is not divided into cells , such as the plasmodium of some slime molds and the hyphae of some fungi . A B C D E F G H I J K L M N O P Q R S T U V W X Y Z ... Full article >>>...

Roots

...ees. Full article >>> [Gk. rhizoma, mass of roots ] A visual pigment consisting of retina l and opsin. When rhodopsin absorbs light, the retina l changes shape and dissociates from the opsin, after which it is converted back to its origin al form. ribonucleic acid ( RNA ) ... Ful...

Ribosomal RNA

...ey are the most abundant RNA in the cell (on a mass basis). Full article >>> ribosome -- ( ribosomal RNA ) rift -- n. A long , narrow crack in the entire thickness of the Earth's crust, which is bounded by normal faults on either side and forms as the crust is pulled apart; v. To spl...

Ribonuclease

...the DNA . Full article >>> Tandem mass spectrometry (MS-MS and MS-MS-MS) of a crosslinked peptide pair from bovine ribonuclease A shows a fragmentation pattern that allows confirmation of the identities of the two crosslinked peptides . Full article >>> -rhage burst o...

Rhodopsin

...rticle >>> rhodopsin [Gk. rhizoma, mass of roots ] A visual pigment consisting of retina l and opsin. When rhodopsin absorbs light, the retina l changes shape and dissociates from the opsin, after which it is converted back to its origin al form. Full article >>> rh...

Rhizome

... article >>> rhizome [Gk. rhizoma, mass of roots ] In vascular plants , a horizontal stem growing along or below the surface of the soil; may be enlarged for storage or may function in vegetative reproduction . Full article >>> rhizome -- n. A horizontal underground ...

Reproduction

...gative and positive assortative mating ). Atomic mass unit ... Full article >>> sexual reproduction A type of reproduction in which two parents give rise to offspring that have unique combinations of genes inherited from the gametes of the two parents. sexual selection ... ...

Repetitive DNA

...tellites for orbiting artificial satellites with a mass of less than 100Kg. Full article >>> Kinetically, r DNA s are repetitive DNA s. The multiple copies are maintained probably because the r DNA gene needs voluminous transcription . r DNA genes are tandemly repeated in eukaryotes...

Repeats

...low and fix it. Full article >>> In mass production, each worker repeats one or a few related tasks that use the same tool to perform identical or almost identical operations on a stream of products. The exact tool and parts are always at hand. Full article >>> Within their...

Receptacle

...alk becoming the flower parts. 2. in ferns, the mass of tissue that becomes the sporangium. 3. in liverworts , the cup containing a gemma. 4. Full article >>> A cup-shaped receptacle in the vertebrate kidney that is the initial, expanded segment of the nephron where filtrate e...

Radius

...62; h0 is the radius of the sphere, m2 is the mass of the sphere, and G is the gravitational constant... Where h0 is the radius of the sphere, M is the mass of the sphere, and G is the gravitational constant. Full article >>> Many other such ...

Protons

... atomic weight The total atomic mass, which is the mass in grams of one mole of the atom . Full article ...d ions. Define the terms atomic number and atomic mass and be able to describe their sugnificance. Atoms with the same atomic number but a different mass ...

Protein

...n engineering Genetic modification Weapons of mass destruction Technological singularity ... Full article >>> Protein functional redundancy DNA functional redundancy Transposon s Redundant pseudogene s Endogenous retrovirus es ... Full article >>> protein -...

Peptides

... enzymatic digestion , affinity purification, and mass spectrometric ana lysis of the resulting crosslinked peptides to yield information on interacting protein pairs. Full article >>> Many proteins are modified by proteases that remove short peptides from either end of the prote...

Order

...es. PICTURE Ordovician extinction Paleozoic-aged mass extinction possibly related to glaciation in the...ts of a growth period in which the cell takes on mass and replicates its DNA . Full article >>> amniocentesis - prenatal diagnostic proced...

Olfactory bulb

...nal corpuscle in a kidney . Also, a small spongy mass of tissue in the proboscis of hemi chordates , presumed to have an excretory function. Also, a concentration of nerve fibers situated in the olfactory bulb . Full article >>> large so there are still smaller windows of opportunity...

Nucleus

...single molecule of DNA complexed with an equal mass of proteins . Collectively, the DNA of the nucleus with its associated proteins is called chromatin . Full article >>> The nucleus , being the largest organelle , varies in diameter from 10 to 20 micrometres. It is enclosed b...

Nucleon

...The total number of nucleon s in an atom is the mass number on the atom , as nucleon s each have a mass very close to one amu. Full article >>> nucleon The nucleus of an atom is built...

Nucleolus

...an cells ) have loops extending into a spherical mass called the nucleolus . Full article >>> Telophase a new set of nucleolus forms along with the nuclear membrane as well as the nucleolus the cell plate appears and begins to slip in two while the spindle fibers fade and t...

Neuron

...coming" end of a neuron (dendro = tree) Density mass per volume of a substance or solution (g/mL) (dens = compact thick) ... Full article >>> U to C changes, produced by an as yet unknown mechanism, appear to occur in the mitochondria l RNA of Pteridophytes. Two RNA editing events...

Mycelium

mycelium mass of filamentous hyphae of true (higher) fungi Sou...cle >>> Mycelium , Mycelia (pl.): A mass of interwoven filamentous 'threads' that make up the vegetative part of a fungus . Native (insect o...

Morula

morula mass of cells , called blastomeres , formed by cleav...The early stage of a blastula in which the solid mass of blastomeres resembles a mulberry in appearance. This occurs immediately before the blastocoel ...

Morphology

...eneration per season. Mycelium , Mycelia (pl.): A mass of interwoven filamentous 'threads' that make up the vegetative part of a fungus . Full article >>> morphology [Gk. morphe, form + logos, discourse] The form and structure of an organ ism and its parts. Full article >>>...

Monotremes

...ing mammals that produce milk. morula : a solid mass of cells that develops about six days after fertilization of an egg cell . Full article >>> monotremes Egg -laying mammals ; e.g., the spiny anteater and the duck-billed platypus. morph A distinct phenotypic variant within a...

Monosaccharides

...ing mammals that produce milk. morula : a solid mass of cells that develops about six days after fertilization of an egg cell . Full article >>> monosaccharides - the simplest of all sugars; compound s with the general formula (CH2O)n, where n is an integer from 3 through 7. i....

Molecule

...ucleic acid , or polysaccharide with a molecular mass greater that a few thousand dalton s ... Full article >>> Biotin A molecule that can be incorporated into dUTP and used as a non-radioactive label for a DNA probe . Blunt (flush) end The end of a DNA molecule at which bot...

Microsatellite

...tellites for orbiting artificial satellites with a mass of less than 100Kg. Full article >>> Dr. Francis Collins, director of the National Human Genome Research Institute, defines microsatellite . related terms: ... Full article >>> Microsatellite Highly polymorphic D...

Masseter

masseter A chewer. mass number Sum of the number of protons and neutrons in the nucleus of an atom ; designated by a superscript to the upper left of the elemental symbol. Full article >>> The Straight Dope ( Masseter "strongest;" 975 pounds for 2 secon...

Mass spectrometry

...'t identify them. Full article >>> mass spectrometry protease digests Though polysaccha...gher-throughput proteomic techniques are based on mass spectrometry , commonly peptide mass fingerprinting on simpler instruments, or De novo repeat dete...

Mantle

...issue in mollusks that drapes over the viscera l mass and may secrete a shell . marine ... Full articl...r muscular structure that surrounds the viscera l mass and secretes a shell if one is present. Full article >>> mantle cavity The space ...

Mammary gland

...issue in mollusks that drapes over the viscera l mass and may secrete a shell . Full article >>> Shared derived character s that are regarded as homologous are called synapomorphies, e.g. the presence of mammary gland s in all three lineage s of mammals ( monotremes , marsupials a...

Macroevolution

..., evolution ary trends, adaptive radiation , and mass extinction . macrofauna benthic animals larger than about 0.5 mm ... Full article >>> Macroevolution Evolution that results in relatively large and complex changes. Cycle of anagenesis , cladogenesis and stasigenesis. Related...

Inner cell mass

inner cell mass (ICM) that will develop into the baby. The cells of the inner cell mass are considered pluripotent; that is, each is capable of producing descendants representing all of t...

Hydrostatic skeleton

...ticle >>> hydrostatic skeleton . A mass of fluid or plastic parenchyma enclosed within a muscular wall to provide the support necessary for antagonistic muscle action ; for example, ... Full article >>> Vertebrates have a skeleton of bone or cartilage ; arthropods ha...

Hereditary

... and consisting of DNA . germinal disc A small mass of active protoplasm found directly under the vitelline membrane . Covered in Lab 14 Gametogenesis and Development ... Full article >>> : The progressive shift of the age of onset of a hereditary disease to earlier ages in success...

Glomerulus

glomerulus ball-like mass of capillaries at the enlarged end of a kidney ...nal corpuscle in a kidney . Also, a small spongy mass of tissue in the proboscis of hemi chordates , presumed to have an excretory function. Full art...

Glial cells

... Full article >>> White matter, the mass of glial cells that support the cerebral grey matter, was assumed to primarily provide nourishment, physical support and connective pathways for the more functional cells on the cerebral surface. Full article >>> In vertebrates , ...

Germinal disc

... article >>> germinal disc A small mass of active protoplasm found directly under the vitelline membrane . Covered in Lab 14 Gametogenesis and Development gill The respiratory organ of aquatic animals . Covered in Lab 12 Animal Diversity III ... Full article >>>...

Genetics

...on. D Dalton . A unit of measurement equal to the mass of a hydrogen atom , 1.67 x 10E-24 gram/L (Avogad...on. D Dalton . A unit of measurement equal to the mass of a hydrogen atom , 1.67 x 10E-24 gram/L (Avogadro's number). Death phase. Full article >>...

Gene

... and consisting of DNA . germinal disc A small mass of active protoplasm found directly under the vitelline membrane . Covered in Lab 14 Gameto gene sis and Development ... Full article >>> Gene : The fundamental physical and functional unit of heredity (Usually DNA , Some organ...

Fats

...consisting of proteins and fats . yolk plug A mass of large, yolky endoderm cells that fill the blastopore of an amphibian gastrula during its late stages. Full article >>> [ME yolke - the yolk , the yellow part]. Nutritive stores found within the ovum cytoplasm consisting...

Extinction

Extinction events The class ical "Big Five" mass extinction s identified by Raup and Sepkoski (198...ge too fast. Local extinction s can occur, as can mass extinction s: they differ in scale , scope and the numbers of species involved. Full article &#...

Evolutionary tree

...le >>> Though there were undoubtedly mass extinction s in the Archean and Proterozoic, it is only during the Phanerozoic Eon that the emergence of bones and shell s in the evolutionary tree has provided a sufficient fossil record from which to make a ... Full article >>> ...