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Biology terms glossary page 9

Biology terms explained in plain English. 1,444 words and meanings, most familiar first.

Word	Meaning
phenology noun	The study of the effect of climate on periodic biological phenomena.
phenotypically adverb	With regard to the phenotype.
photomorphogenesis noun	The regulatory effect of light on the growth, development and differentiation of plant cells, tissues and organs
photonegative adjective	Having a negative phototropic or phototactic response; repelled by light
photoperiod noun	The normal duration of natural daylight experienced by an organism; daylength
photoperiodism noun	The growth, development and other responses of plants and animals according to the length of day and/or night.
photophobic adjective	That thrives at a relatively low light level
photophore noun	A light-emitting organ, found in some fish and other marine animals.
photopositive adjective	Having a positive phototropic or phototactic response; attracted by light
photoreception noun	The absorption of light energy by plants and animals, and its utilization for biologically important purposes
photoreceptive adjective	Absorbing and using light, especially for sensory purposes
photoreceptor noun	A specialized neuron or other structure able to detect and react to light.
photorespiration noun	The light-dependent release of carbon dioxide and uptake of oxygen in photosynthetic organisms as an unavoidable side reaction of photosynthesis.
phototaxis noun	The movement of an organism either towards or away from a source of light
phototropism noun	The movement of a plant towards or away from light.
phragmoplast noun	A structure that forms in plant cells during late cytokinesis and serves as a scaffold for cell plate assembly and subsequent formation of a new cell wall separating the two daughter cells.
phreatophyte noun	Any plant, typically living in deserts, that obtains its water from long taproots that reach the water table
phrenology noun	The science or now discredited pseudo-science, which studies the relationships between a person's character and the morphology (structure) of the skull.
phytogeography noun	The science that studies the geographical distribution of plants; geobotany
phytonic adjective	Relating to a phyton
phytopathogen noun	Any organism that is pathogenic to plants
pinocytosis noun	A form of endocytosis in which material enters a cell through its membrane and is incorporated in vesicles for digestion.
piroplasma noun	Babesia, a genus of hematozoa that invades the red blood cells of humans and domesticated animals such as dogs and sheep
placentation noun	The local fusion of the embryonic stage of an animal to its parent for physiological exchange to promote the growth and development of the young; involves a placenta in non-egglaying mammals.
planation noun	The morphological transformation of a three-dimensional structure into a two-dimensional one through development or evolution
plasmagene noun	A gene located in granules of the cytoplasm of a cell
plasmalemma noun	The cell membrane.
plasmodesma noun	A microscopic channel traversing the cell walls of plant cells and some algal cells, enabling transport and communication between them.
plasmolysis noun	The shrinking of protoplasm away from the cell wall of a plant or bacterium due to water loss
plasmon noun	All the genetic material in an organism.
plastid noun	Any of various organelles found in the cells of plants and algae, often concerned with photosynthesis
platelet noun	A small colorless disk-shaped particle found in the blood of mammals, which plays an important role in the formation of blood clots.
pleiotropy noun	The influence of a single gene on multiple phenotypic traits; pleiotropism.
ploidy noun	The number of homologous sets of chromosomes in a cell.
pluripotent adjective	Able to develop into more than one mature cell or tissue type, but not all.
pneumaticity noun	The state of being pneumatic, or of having a cavity or cavities filled with air.
pogonophoran noun	Any marine, wormlike invertebrate of the phylum Pogonophora.
pollinator noun	The agent that pollinates a plant; often an insect
polycentric adjective	(of a chromosome, etc) Having multiple central parts
polycentrism noun	(of a chromosomes, etc) the existence of multiple central parts
polycistronic adjective	Encoding multiple different polypeptides.
polyembryony noun	The production of two or more embryos from a single fertilized egg.
polyestrous adjective	Having multiple periods of estrus in a year, or during a breeding season.
polygene noun	A group of nonallelic genes that act together to produce phenotype variations
polygenesis noun	The theory that living organisms originate in cells or embryos of different kinds, instead of coming from a single cell; as opposed to monogenesis.
polygenetic adjective	Of or pertaining to polygenesis; polyphyletic.
polygenic adjective	Controlled by the interaction of more than one gene
polynuclear adjective	Having multiple nuclei
polyphagy noun	The ability of an animal to eat a variety of food (e.g. several different families of plants)
polyploidy noun	The condition of being polyploid or the process of becoming polyploid.
postsynaptic adjective	In a synapse, of or pertaining to the neuron that bears receptors for neurotransmitter released into the synaptic cleft by the presynaptic neuron.
potentiator noun	A reagent that enhances sensitization of an antigen.
preadaptation noun	An adaptation that evolved in an ancestral population, in which it served a different function
prepotency noun	The capacity, on the part of one of the parents, as compared with the other, to transmit more than his or her own share of characteristics to their offspring.
prepotent adjective	Characterized by prepotency.
prepupal adjective	Describing the inactive stage in the development of some insects between the larval and the pupal stages
presynaptic adjective	In a synapse, of or pertaining to the neuron that releases neurotransmitter into the synaptic cleft.
proband noun	An individual who presents with a genetic disorder or other specific characteristic, when this leads to the investigation of the individual's family
proliferative adjective	Of or pertaining to proliferation, especially of cells
propagule noun	A reproductive particle released by an organism in order to propagate itself, by means such as dispersal or infection, to the next stage in its life cycle.
prophage noun	The latent form of a bacteriophage in which the viral genome is inserted into the host chromosome.
proplastid noun	A small, colourless cell that develops into any form of plastid
protoplasm noun	The entire contents of a cell comprising the nucleus and the cytoplasm. It is a semi-fluid, transparent substance which is the living matter of plant and animal cells.
protoplasmic adjective	Of or relating to protoplasm.
prototroph noun	Any microorganism that can synthesize its nutrients from inorganic material
prototrophic adjective	Of or pertaining to a prototroph or to prototrophy.
protozoon noun	A protozoan.
provascular adjective	Relating to the procambium
pseudoallele noun	Either of the two genes involved in pseudoallelism.
pseudocoel noun	The body cavity of certain nematodes (primitive invertebrates), which is analogous to a coelom but lacking mesodermal cells, i.e. not lined with mesothelium.
pseudopodium noun	Pseudopod
psychobiology noun	The study of the biological basis for cognition and other mental processes.
pulmonate adjective	Of, relating to, or belonging to the gastropod order Pulmonata (slugs and snails).
pyknotic adjective	Showing pyknosis
pylorus noun	In vertebrates, including humans, a zone at the lower end of the stomach that leads to and opens into the duodenum.

Word	Meaning
pyrenoid noun	Any of several transparent structures found in the chloroplast of certain algae etc.; they are responsible for the fixation of carbon dioxide and the formation of starch
pyriform adjective	Pear-shaped.
quadrivalent noun	Any quadrivalent chromosome
quantal adjective	All-or-none.
radiobiology noun	The study of the effects of ionizing radiation on living organisms
radiomimetic adjective	Having a biological effect similar to that of radiation
recombinational adjective	Of or pertaining to genetic recombination.
recombining noun	The exchanging of genetic material
reexpress verb	To express again
refracted adjective	Bent back at an acute angle.
regnal adjective	Pertaining to a taxon at the rank of regnum (or kingdom).
regnum noun	A rank in the classification of organisms, below dominium and above divisio.
repressor noun	Any protein that binds to DNA and thus regulates the expression of genes by decreasing the rate of transcription.
resorb verb	To dissolve (bone, sinew, suture, etc.) and assimilate it.
reticuloendothelial adjective	Describing all phagocytic cells (except some white blood cells)
retinula noun	One of the group of pigmented cells that surround the retinophorae of invertebrates.
retrorse adjective	Curved, pointed or oriented backward or downward.
rhizobium noun	Any of various bacteria, of the genus Rhizobium, that form nodules on the roots of legumes and fix nitrogen.
ribonucleotide noun	Any nucleotide having ribose as its sugar
ribosome noun	A small organelle found in all cells; involved in the production of proteins by translating messenger RNA.
rostellum noun	A retractable protruding part at the anterior end of a soft-bodied tapeworm; the scolex from which it protrudes is often armed with hooks which serve to keep it in place attached to the host.
saprobe noun	An organism that lives off of dead or decaying organic material
saprobic adjective	Of, pertaining to, or of the nature of a saprobe or saprobes; that feeds on dead or decaying organic matter.
saxicolous adjective	Growing on, or living among rocks or stones
schizogony noun	Asexual reproduction of protozoans etc characterized by multiple divisions of the nucleus and cell.
sclerite noun	A hardened body part, especially in arthropod exoskeletons.
scute noun	A proneural gene, often associated with achaete, that is required for the formation of many larval and adult sense organs
segregant adjective	Resulting from segregation
sematic adjective	Acting as a sign of danger.
semiconservative adjective	Describing the process of DNA replication in which the two strands of the molecule separate, each acting as a template for the formation of a complementary new strand.
semiconservatively adverb	In a semiconservative fashion.
semidominant adjective	Exhibiting incomplete dominance.
semilethal adjective	Lethal to at least half of all affected organisms
semiparasitic adjective	Having moderate infectiousness for living tissue.
senescent adjective	That ceases to divide.
sensorimotor adjective	Of or pertaining to both sensory and motor activity
septal adjective	Of or pertaining to a septum.
sequenced adjective	Whose sequence (of bases or genes) has been determined
serosity noun	A thin watery animal fluid, such as synovial fluid or pericardial fluid.
shiverer noun	A mouse mutation characterised by tremors.
silencing noun	The prevention of the expression of a gene
somatosensory adjective	Of or pertaining to the perception of sensory stimuli produced by the skin or internal organs
spermatid noun	A haploid cell, produced by meiosis of a spermatocyte, that develops into a spermatozoon
spermatocyte noun	A male gametocyte, from which a spermatozoon develops.
spermatogonium noun	Any of the undifferentiated cells in the male gonads that become spermatocytes; a spermatoblast
spermatophore noun	A spermospore.
spermatozoid noun	A motile, ciliated male gamete produced in the antheridium of an alga, fern or gymnosperm.
spermiogenesis noun	The final stage of spermatogenesis. It involves the maturation of the spermatids into spermatozoa.
spheroplast noun	A cell from which the cell wall has been removed
sporocyst noun	A cyst that develops from a sporoblast and from which sporozoites develop.
sporogenesis noun	The process by which spores are produced.
sporozoite noun	Any of the minute active bodies into which a sporozoan divides just before it infects a new host cell.
sporulate verb	To produce spores
stenohaline adjective	Tolerant of only a narrow range of saltwater concentrations. Used of aquatic organisms
stenotherm noun	An organism, often specifically an ectotherm, that functions only within a narrow temperature range
stenothermal adjective	Able to tolerate only a narrow range of temperatures
stertor noun	The act of snoring, especially heavy snoring.
stirp noun	A line descended from a single ancestor.
stressor noun	An environmental condition or influence that stresses (i.e. causes stress for) an organism.
strobilation noun	A form of asexual reproduction by division into body segments, as in tapeworms and jellyfish
strobile noun	An individual asexually producing sexual individuals differing from itself also in other respects, such as the tapeworm; one of the forms that occur in metagenesis.
sturt noun	In an embryo, an angle equal to two gons. If a mosaic forms in the embryo, the line passes between two organs with a probability, in percent, equal to the number of sturts between them.
stylar adjective	Of or pertaining to a style.
subepidermal adjective	Under the epidermis
subline noun	A subset of a line (of cells in a strain)
submitochondrial adjective	Describing any subunit of a mitochondrion
subulate adjective	Awl-shaped; tapering into a sharp point from a broader base.
successional noun	Such an organism
supergene noun	A group of neighbouring genes on a chromosome that are inherited together because of close genetic linkage and are functionally related in an evolutionary sense.
superorganism noun	A social colony of individuals who, through division of labour, effective communication and self-organization, form a highly connected community that functions as if it were a single organism.
supersex noun	The result of an abnormal combination of sex chromosomes.
supravital adjective	Capable of staining living cells after their removal from a host
survivorship noun	The number or percentage of young that survive to adulthood.
suspensor noun	The cord which suspends the embryo, and which is attached to the radicle in the young state; the proembryo.
sustentative adjective	Relating to those functions of the body which affect its material composition and thus determine its mass.

Meanings from Wiktionary (CC BY-SA 4.0). Sources