The reproductive organs do not begin to appear until the larva has twice cast its skin.
The reproductive individuals have undergone an extraordinary simplification of the organs concerned with the collection and digestion of food.
In subsequent generations produced by self-fertilization of the hybrids it was found that the positive character was not present in all the individuals, but that a result was obtained showing that in the formation of the reproductive cells (ova and sperms) of the hybrid, half were endowed with the positive character and half with the negative.
In a differentiated body the stem (caulome) is an axis capable of bearing leaves and (directly or indirectly) the proper reproductive organs.
The reproductive organs are usually repeated in each proglottis, and in some families two complete sets of such organs occur in each segment; in a few cases, parts only of the system are duplicated.
Reproductive organs with ducts leading to the vestibule.
Perhaps the earliest of such specializations is connected with the reproductive function.
The reproductive cells may be regarded as belonging primarily to neither ectoderm nor endoderm, though lodged in the ectoderm in all Hydromedusae.
Insect metamorphosis may be briefly described as phenomena of development characterized by abrupt changes of appearance and of structure, occurring during the period subsequent to embryonic development and antecedent to the reproductive state.
aaK6s, a bag), a botanical term for the membranous sacs containing the reproductive spores in certain lichens and fungi.
The reproductive organs of Rhabdopleura have but seldom been observed.
After the second larval moult, he passes through a passive stage comparable to the pupa-stadium of an b insect, and during this stage, which occurs inside the root, the reproductive organs are perfected.
The god was probably son and mate of the goddess, and the divine pair represented the genius of Reproductive Fertility in its relations with humanity.
The cormus is always differentiated into two parts; an upper portion termed the nectosome, in which the appendages are locomotor or hydrostatic in function, that is to say, serve for swimming or floating; and a lower portion termed the siphosome, bearing appendages which are nutritive, reproductive or simply protective in function.
- Female reproductive system plex glands appended to of Hyperiodrilus.
The reproductive organs consist of the parts shown in fig.
There are no specialized sense-organs or vascular or respiratory systems. There is a wide body-cavity, but as this has no connexion with the renal or reproductive organs it cannot be regarded as a coelom, but probably is a blood-space or haemocoel.
In this way we may distinguish, first, vegetative reproduction, the result of discontinuous growth of the tissues and cell-layers of the body as a whole, leading to (I) fission, (2) autotomy, or (3) vegetative budding; secondly, germinal reproduction, the result of the reproductive activity of the archaeocytes or germinal tissue.
Balfour put forward the view that the polyp was the more primitive type, and that the medusa is a special modification of the polyp for reproductive purposes, the result of division of labour in a polypcolony, whereby special reproductive persons become detached and acquire organs of locomotion for spreading the species.
(From Moseley.) irregular coenosarcal canals, the coenosteum may contain, in its superficial portion, chambers or ampullae, in which the reproductive zoids (medusae or gonophores) are budded from the coenosarc.
- Female reproductive system ofHe/iodri/us.
The reproductive on the lateral vessel of system is of the simplest, strongly con- Drepanophorus spectatrasting with the complicated arrange- bilis.
1 Thus they are pro vided with a nucleus which is the centre of cell activity; Pathological both of the reproductive and chemical (metabolic) pro- GelIs.
- Diagrammatic projections to show the relations of the female reproductive ducts; A, in the Malacocotylea; B, in the Heterocotylea.
Eleven abdominal segments can be recognized, at least in the early stages; as the adult condition is reached, the hinder segments become reduced or modified in connexion with the external reproductive organs, and show, in some male Hemiptera, a marked asymmetry.
ferns, horse-tails, club mosses, &c., and Phanerogams or Flowering Plants) the main plant-body, that which we speak of in ordinary language as the plant, is called the sporophyte because it bears the asexual reproductive cells or spores.
The root is an axis which never bears either leaves or the proper reproductive organs (whether sexual or asexual) of the plant.
Flora), the primitive leaf was a reproductive leaf, a sporophyll, from which the foliage-leaf was derived by progressive sterilization.
It is, however, though doubtless near to the base of the Oligochaetous series, most nearly allied in the reproductive system to the Oligochaeta.
Accessory glands are commonly present in connexion both with the male and the female reproductive organs.
- From the mesoderm most of the organs of the body - muscular, circulatory, reproductive - take their origin.
(3) An individual in which the reproductive organs and powers are functionally absent becomes one in which these structures and powers are the only reason for existence, for the great majority of insects die after a brief period of reproduction.
Thus the whole of the Pulmonata (which breathe air, are destitute of gill-plumes and operculum and have a complicated hermaphrodite reproductive system) are either snails or slugs.
They are lined by cells charged with a yellow or brown pigment, and besides their excretory functions they act as ducts through which the reproductive cells leave the body.
The expenditure is largely on reproductive works (railways, harbours, post office, &c.), on the judiciary and police, education and military defence.
In fact, the whole history of the Platyelmia is marked by a great specialization of the reproductive evolutionary history, accompanied by a simple somatic line of evolution.
Speaking generally each species of parasite has a particular host, upon the blood of which it nourishes itself and matures its reproductive organs.
Reproductive organs not continuous with ducts.
Both kinds of reproductive organs may occur in a single zooecium, and the reproductive elements pass when ripe into the body-cavity.
In other cases the reproductive cells perhaps pass out by the atrophy of the polypide, whereby the body-cavity may become continuous with the exterior.
And though Spencer's general position - that it is absurd to suppose that organisms after being modified by their life should give birth to offspring showing no traces of such modifications - seems the more philosophic, yet it does not dispose of the facts which go to show that most of the evidence for the direct transmission of adaptations is illusory, and that beings are organised to minimize the effects of life on the reproductive tissues, so that the transmission of the effects of use and disuse, if it occurs, must be both difficult and rare - far more so than is convenient for Spencer's psychology.
In the first hybrid generation formed by the union of the reproductive germs of the positive variety (that possessing the structural character selected for observation) with those of the negative variety, it is not surprising that all or nearly all the individuals were found to exhibit, as a result of the mixture, the positive character.
- In the Hydromedusae the medusa-individual occurs, as already stated, in one of two conditions, either as an independent organism leading a true life c2 a2 in the open seas, or as a subordinate individuality in the hydroid c colony, from which it is never set free; it then becomes a mere reproductive appendage or gono- phore, losing suc FIG.
Values can therefore be accumulated only by being reproduced in the course or, as often happens, by the very act of consumption; hence his distinction between reproductive and unproductive consumption.
The volatile oils have for centuries been regarded as of value in disorders of the reproductive organs, and the reputation of myrrh in this connexion is simply a survival of this ancient but ill-founded belief.
From Theophrastus down to Caesalpinus, who died at Rome in 1603, there does not appear to have been any attention paid to the reproductive organs of plants.
Soon after the promulgation of Linnaeus's method of classification, the attention of botanists was directed to the study of Cryptogamic plants, and the valuable work of Johann Hedwig (1730-1799) on the reproductive organs of mosses made its appearance in 1782.
He was one of the first to point out the existence of certain cellular bodies in these plants which appeared to perform the functions of reproductive organs, and to them the names of antheridia and pistillidia were given.
bulbiferum and its allies produce aerial reproductive bulbils in the axils of the leaves.
The reproductive organs, both ovaries and testes, become fused together in the middle of the body.
The tenth abdominal segment carries strong, unjointed cerci, while the presence of reproductive armature on the second abdominal segment of the male is a character found in no other order of the Hexapoda.
The development of the reproductive organs is so closely interwoven with that of the urinary that some reference from this article to that on the Urinary System is necessary.
Female Reproductive Organs.
The coelom is primarily and essentially the generative cavity: the reproductive cells arise from its walls, i.e.
In the former the genital coelom and the pericardial coelom are continuous and the reproductive cells escape by the renal ducts.
The renal organs are tubular outgrowths of the pericardial parts of the coelom; the reproductive cells are derived from cells lining the generative portion.
The author spent a world of pains in having these brought up to the highest perfection of the reproductive art, and began the system of exquisite illustration, and those facsimiles of his own and other sketches, which make his works rank so high in the catalogues and price-lists of collectors.
The Platyelmia are hermaphrodite and the reproductive organs are complex.
An interesting feature of the development of Chaetognaths is that, as in some insects, the cells destined to form the reproductive organs are differentiated at a very early period, being apparent even in the gastrula stage.
iii.); licentious rites were the natural accompaniment of the worship of the reproductive powers of nature.
The reproductive organs of the lichen are of a typically fungal character, i.e.
The green (or blue-green) cells were termed gonidia by Wallroth, who looked upon them as asexual reproductive cells, but when it was later realized that they were not reproductive elements they were considered as mere outgrowths of the hyphae of the thallus which had developed chlorophyll.
Indeed the genus Oedogonium exhibits a high degree of specialization in its reproductive system, considering that its thallus has not advanced beyond the stage of an unbranched filament.
The reproduction of Characeae is characterized by a pronounced oogamy, the reproductive organs being the most highly differentiated among Chlorophyceae.
The discovery by Brebner of the specific identity of Haplospora globosa and Scaphospora speciosa marks an important step in the advance of our knowledge of the group. Three kinds of reproductive organs are known: first, sporangia, which each give rise to a single tetra-, or multi-nucleate non-motile, probably asexual spore; second, plurilocular sporangia, which are probably antheridia, generating antherozoids; and third, sporangia, which are probably oogonia, giving rise to single uninucleate non-motile oospheres.
The possession of two kinds of reproductive organs, unilocular and plurilocular sporangia, is general among the rest of the Phaeosporeae.
Some Red Algae find a home in the gelatinous substance of Flustra, Alcyonidium and other polyzoa, only emerging for the formation of the reproductive organs.
Upon them also the reproductive organs arise in this family.
Turn ing first to the Rhodophyceae, both on account of the high place which they occupy among algae and also the remarkable uniformity in their reproductive processes, it is clear that, as is the case among Archegoniatae, the product of the sexual act never germinates directly into a plant which gives rise to the sexual organs.
From the analogy of the higher plants observers have justly argued that when they have seen and marked the characters of the reproductive organs they have found the plant at the stage when it exhibits its most noteworthy features, and they have named and classified the species in accordance with these observations.
In the case of the freshwater algae, however, belonging to the Chlorophyceae and Cyanophyceae, although they required to be immersed during the vegetative period, the reproductive cells are often capable of resisting a considerable degree of desiccation, and in this condition are dispersed through great distances by various agencies.
He thought it probable that circumstances affecting the reproductive system of the parents had much influence in producing a plastic condition of the progeny.
This kind of selection, called by Pearson "reproductive" or "genetic" selection, may be measured by finding the correlation between the characters of the individuals which pair and the number of young.
Part of the extra expenditure is, however, on railways and other reproductive works.
Up to 1854 there was a surplus in hand, but since that time expenditure has on many occasions exceeded income, and the public debt in 1908 was £1,305,000, mainly incurred however on reproductive works.
reproductive biology of Sabine's Gull in the Canadian Arctic.
reproductive toxicity associated with maternal toxicity.
reproductive physiology in the majority of marsupials.
The Chinese government issued a declaration in 1998 explicitly banning reproductive cloning.
(Xioo.) reproductive system; C, Cirrus; H, hooks on the ventral sucker; I, small piece of the intestine to show its connexion with the reproductive organs by the narrow duct that passes from it to the union of the vaginae; M, mouth; 0, ovary; S, oral sucker; SC, sucker; SH, shell-gland; T, Testis; U, uterus; V, vaginal pore; Y, yolkgland.
In this way the hydroid colony becomes composed of two portions of different function, the nutritive " trophosome," composed of non-sexual polyps, and the reproductive " gonosome," composed of sexual medusaindividuals, which never exercise a nutritive function while attached to the colony.
In this way the medusa sinks from an independent per sonality to an organ of the polyp-colony, becoming a so-called medusoid gonophore, or bearer of the reproductive organs, and losing gradually all organs necessary for an independent existence, namely those of sense, locomotion and nutrition.
Filicales and Gymnosperms, and known as the Cycadofihices, a group in which, curiously enough, the reproductive organs remained undiscovered for some time after the anatomy of the vegetative organs was sufficiently well known to afford clear evidence of their true affinities.
The failure of the material carrying a positive character to divide so as to distribute itself among all the reproductive cells of a hybrid individual, and the limitation of its distribution to half only of those cells, must prevent the swamping " of a newly appearing character in the course of the inter-breeding of those individuals possessed of the character with those which do not possess it.
reproductive cells and in.
By this time the embryo has all the organs of the adult perfected save only the reproductive; these develop only when the first host is swallowed by the second or final host, in which case the parasite attaches itself to the wall of the alimentary canal and becomes adult.
A single hydriform person reproductive portions.
and the reproductive 6.
Theoretically the lichens may be classified on the basis of their algal constituent, on the basis of their fungal constituent, or they may be classified as if they were homogeneous organisms. The first of these systems is impracticable owing to the absence of algal reproductive organs and the similarity of the algal cells (gonidia) in a large number of different forms. The second system is the most obvious one, since the fungus is the dominant partner and produces reproductive organs.
In actual practice the difference between the second and third methods is not very great since the fungus is the producer of the reproductive organs and generally the main constituent.
Most systems agree in deriving the major divisions from the characters of the reproductive organs (perithecia, apothecia, or basidiospore bearing fructification), while the characters of the algal cells and those of the thallus generally are used for the minor divisions.
The difference between the various systems lies in the relative importance given to the reproductive characters on the one hand and the vegetative characters on the other.
Moreover, there is a generally recognised quasi-antagonism between the vegetative and reproductive processes, so that, other things being equal, anything that checks the one helps forward the other.
The reproductive process of which the formation of the flower is the first stage being an exhaustive one, it is necessary that the plant, as gardeners say, should get " established " before it flowers.
The reproductive spores are borne in sacs (asci) which form a dense layer on the surface, appearing like a bloom in July; they are scattered by the wind and propagate the disease.
The reproductive spores are formed in embedded flesh-shaped receptacles (perithecia) and scattered after the leaves have fallen.
- Diagrams of the excretory and reproductive organs of Amphineura (after Hubrecht).
- MOSt of the recent work of importance in this group deals with the cytology of sexual reproduction and of spore-formation, and the effect of external conditions on the production of reproductive organs.
Klebs has shown that the development of zoosporangia or of oogonia and pollinodia respectively in Saprolegnia is dependent on the external conditions; so long as a continued stream of suitable food-material is ensured the mycelium grows on without forming reproductive organs, but directly the supplies of nitrogenous and carbonaceous food fall below a certain degree of concentration sporangia are developed.
Besides the special ascocarps, accessory reproductive organs are known in the majority of cases in the form of conidia.
On the inner surface is a layer of peritoneal epithelium, which is frequently ciliated, and at the bases of the retractor muscles is heaped up and modified into the reproductive organs.
They serve as channels by which the reproductive cells leave the body, and they are sometimes spoken of as "brown tubes."
Usually, however, other leaves are present which are only indirectly concerned with the reproductive process, acting as protective organs for the sporophylls or forming an attractive envelope.
We readily recognize in them nowadays the natural classes of Dicotyledons and Monocotyledons distinguished alike in vegetative and in reproductive construction, yet showing remarkable parallel sequences in development; and we see that the Dicotyledons are the more advanced and show the greater capacity for further progressive evolution.
Their life-cycle, however, the structure of the reproductive organs and their whole organization proclaim them to be Bryophyta.
Asexual reproductive cells are not infrequent, but sexual reproduction even in its initial stages is unknown.
Such ciliary motion is known in the adult condition of the cells of Volvocaceae, but where this is not the case the reproductive cells are endowed with motility for a brief period.
In unicellular forms (Sphaerella) the thallus becomes transformed into a zoosporangium at the reproductive stage.
From a comparison of those Euchlorophyceae which have been most closely investigated, it appears probable that sexual reproductive cells have in the course of evolution arisen as the result of specialization among asexual reproductive cells, and that in turn oogamous reproduction has arisen as the result of differentiation of the two conjugating cells into the smaller male gamete and the larger male gamete.
Elsewhere among Siphonales, in those cases where reproductive cells are known, the reproduction is either isogamous or asexual.
That the theory of the triple manifestation of the deity was indeed only a compromise between Brahmanical aspirations and popular worship, probably largely influenced by the traditional sanctity of the number three, is sufficiently clear from the fact that, whilst Brahma, the creator, and at the same time the very embodiment of Brahmanical class pride, has practically remained a mere figurehead in the actual worship of the people, Siva, on the other hand, so far from being merely the destroyer, is also the unmistakable representative of generative and reproductive power in nature.
For his chief attendant, the great god (Mahadeva, Mahesvara) has already with him the" holy "Nandi - presumably, though his shape is not specified, identical in form as in name with Siva's sacred bull of later times, the appropriate symbol of the god's reproductive power.
Indeed there is hardly a village in India which cannot boast of a shrine dedicated to Siva, and containing the emblem of his reproductive power; for almost the only form in which the" Great God "is adored is the Linga, consisting usually of an upright cylindrical block of marble or other stone, mostly resting on a circular perforated slab.
What has made this cult attach itself more especially to the Saiva creed is doubtless the character of Siva as the type of reproductive power, in addition to his function as destroyer which, as we shall see, is likewise reflected in some of the forms of his Sakti.
other than abstinence from marriage, at all events at the principal reproductive period; and perhaps to a decrease in marriage or remarriage after middle life, a period of which the weight in the age-distribution has been increasing of late.
If abstinence from marriage and the curtailment of the reproductive period by postponement of marriage be insufficient to account for the material change which has taken place in the birth-rate within the last few decades, it is clear that the latter must be attributable to the diminished fertility of those who are married.
Herbert Spencer, again, before the decline in question set in, put forward the hypothesis that "the ability to maintain individual life and the ability to multiply vary inversely"; in other words, the strain upon the nervous system involved in the struggle for life under the conditions of modern civilization, by reacting on the reproductive powers, tends towards comparative sterility.
In this case diminished prolificity where unaccompanied by a decrease in the number of marriages at reproductive ages, is attributable to the voluntary restriction of child-bearing on the part of the married.
Just application of the outlay of the state, so that no class receives undue advantage, and the use of public funds for " reproductive," in preference to " unproductive " objects, are evident general principles whose difficulty lies in their application to the circumstances of each particular case.
The chief reason for contracting local debt being the establishment of works that are, directly or indirectly, reproductive, the governing conditions are evidently to be found in the character and probable yield of those businesses.
An important motif in magico-religious ritual, which may not have been without effect on the development of sacrifice, is, as Dr Frazer's main thesis in The Golden Bough asserts, the imparting of reproductive energy to animals, plants and man himself, its cessation being suggested by such phenomena as old age and the fall of the year.
The presump tion of some merely external connexion, as between any other two corporeal things, is alone admissible and some form of the These derivative powers include the five senses, speech and the reproductive faculty, and they bear to the soul the relation of qualities to a substance.
W.) A very characteristic method of reproduction is that of sporeformation, and these minute reproductive bodies, which represent a resting stage of the organism, are now known in many spores.
Systems have also been brought forward based on the formation of arthrospores and endospores, but as explained above this is eminently unsatisfactory, as arthrospores are not true spores and both kinds of reproductive bodies are found in one and the same form.
Reproductive sexual cells may be found in either of these two layers, according to the class and sub-class in question.
Its moderate use may be and is indulged in for years without producing any decided or appreciable ill effect except weakening the reproductive powers, the average number of the children of opium-eaters being 1.11 after II years of married life.
Quinine is apparently powerless to kill the organism when it is in its reproductive phase.
In the conifers proper the female reproductive organs have the form of cones, which may be styled flowers or inflorescences according to different interpretations of their morphology.
The female flowers of the Taxaceae assume another form; in Microcachrys (Tasmania) the reproductive structures are spirally disposed, and form small globular cones made up of red fleshy scales, to each of which is attached a single ovule enclosed by an integument and partially invested by an arillus; in Dacrydium the carpellary leaves are very similar to the foliage leaves - each bears one ovule with two integuments, the outer of which constitutes an arillus.
In certain species of Gnetum described by Karsten the megaspore contains a peripheral layer of protoplasm, in which scattered nuclei represent the female reproductive cells; in Gnetum Gnemon a similar state of things exists in the upper half of the megaspore, while the lower half agrees with the megaspore of Welwitschia in being full of prothallus-tissue, which serves merely as a reservoir of food.
The reproductive II.
In the Graptoloidea certain lateral and vesicular appendages of the polypary in the Lasiograptidae have been looked upon as connected with the reproductive system; and in the umbrella-shaped synrhabdosomes already referred to, the common centre is surrounded by a ring of what have been regarded as ovarian capsules.
Which of the coelomic cavities this last is connected with is uncertain, for there is considerable doubt as to the origin of the genital glands in the embryonic development of recent echinoderms. It seems clear, however, that there was but a single duct and a single bunch of reproductive cells, as in the holothurians, though perhaps bifurcate, as in some of those animals.
Since this must have, on our theory, enclosed the parietal canal from the anterior coelom, it is possible that the genital products were developed from the lining cells of that cavity, and that the genital pore was nothing but its original pore not yet united with that from the water-sac. The concrescence of these pores can be traced in other cystids; but as the genital organs became affected by radial symmetry the original function of the duct was lost, and the reproductive elements escaped to the exterior in another way.
Regarding the Echinoderms as a whole in the light of the foregoing account, we may give the following analytic summary of the characters that distinguish them from other coelomate animals: They live in salt or brackish water; a primitive bilateral symmetry is still manifest in the right and left divisions of the coelom; the middle coelomic cavities are primitively transformed into two hydrocoels communicating with the exterior indirectly through a duct or ducts of the anterior coelom; stereom, composed of crystalline carbonate of lime, is, with few exceptions, deposited by special amoebocytes in the meshes of a mesodermal stroma, chiefly in the integument; reproductive cells are derived from the endothelium, apparently of the anterior coelom; total segmentation of the ovum produces a coeloblastula and gastrula by invagination; mesenchyme is formed in the segmentation cavity by migration of cells, chiefly from the hypoblast.
The reproductive organs ultimately produced on the same or on different individuals are of two kinds, the antheridia and archegonia; the origin of both is from single superficial cells of the prothallus.
The reproductive organs lie on the left side, near the aboral end, both ovary and testis being present in the same individual in some of the species.
The reproductive cells pass to the exterior by means of the nephridia.
It thus appears that in Peripatus the coelom does not develop a perivisceral portion, but gives rise only to the renal and reproductive organs.
Smith) bears very definite terminal, or intercalary, spherical vesicles, which may probably be regarded as reproductive organs - either oiigonia or sporangia.
In the absence, however, both of reproductive organs and of anatomical structure, it cannot be said that there is at present conclusive evidence for the existence of either Hepaticae or Musci in Palaeozoic times.
On the other hand there was the far more complex Marattiaceous type, strikingly similar in both vegetative and reproductive characters to the recent members of the family.
In the first-named plant the structure, both of the vegetative and reproductive organs, is known, and the evidence, from comparison and association, is sufficiently strong.
We will begin with the Lyginodendreae, a group in which the anatomical characters indicated a systematic position between Ferns and Cycads, long before the reproductive organs were discovered.
This is the first case in which the pollen-bearing organs of a Ptoridosperm have been identified with certainty It will be seen that, while the seeds of Lyginodendron were of an advanced Cycadean type, the microsporangiate organs were more like those of a Fern, the reproductive organs thus showing the same combination of characters which appears in the vegetative ct pc. A, Micropylar region.
The reproductive organs, however, show that the two groups were early representatives of the class did not, as a rule, 3' p > > belong to any of its existing families, but formed for the most part a distinct group, that of the Cordaitales, which has long since died out.
Anatomically the connexion of the family with the Pteridosperms (and through them, presumably, with some primitive group of Ferns) seems clear, but we have as yet no indications of the stages in the evolution of their reproductive organs.
or less close resemblance to living Club-Mosses and Selaginellas, but lacking the more important reproductive organs.
Without a fuller knowledge of internal structure and of the reproductive organs, we are compelled to speak of some of the Mesozoic plants as possibly Ferns or possibly Cycads, and not referable with certainty to one or other class.
A more important question is, What knowledge have we of the reproductive organs and stems of these fossil Cycads?
These reproductive shoots differ in many important respects from the flowers of recent Cycads, and chiefly on this account it is customary to include the plants in a separate genus, Bennettites, and in a separate group - the Bennettitales - distinct from that of the Cycadales including the existing Cycads.
Our knowledge of the reproductive organs of the Bennettitaceae has until recently been confined to the female flowers, as described by Carruthers, Solms-Laubach, Lignier, and others.
There is no doubt that the Cycadophyta, using the term suggested by Nathorst in 1902, was represented in the Mesozoic period by several distinct families or classes which played a dominant part in the floras of the world before the advent of the Angiosperms. In addition to the bisporangiate reproductive shoots of Bennettites, distinguished by many important features from the flowers of recent Cycads, a few specimens of flowers have been discovered exhibiting a much closer resemblance to those of existing Cycads, e.g.
Explain recent advances in reproductive technology to lay people.
It has an alternation of generation reproductive style, with the gametophyte being the dominant generation.
My main interests are in studying many aspects of the common dolphin population in the Northeast Atlantic, and reproductive biology in small cetaceans.
The only solitary cats were tom cats during their reproductive years.
circumcised women were significantly more likely than uncircumcised women to report symptoms of reproductive tract infections.
The American Society for Reproductive Medicine revised the classification in 1997 to take account of the latest observations.
The male can be distinguished from the female by his larger throat spots and large swollen cloaca (reproductive opening ).
This deliberate creation and destruction of human life makes it even more objectionable, in moral terms, than reproductive human cloning.
LIF has been recognized as a key cytokine in human reproductive function.
There are also carcinogenic concerns about statins which most diabetics - not kids or reproductive age - are put on.
reproductive endocrinology is another area of increasing interest to the pediatrician.
fuchsia flower normally lasts for ten days, which is governed by its reproductive cycle.
At the conclusion of the study the animal's genitals and reproductive organs are often removed for further study.
Ovarian tumors are common in female gerbils with poor reproductive performance.
Only 100 western gray whales including 23 reproductive females are known to exist.
Since I started my PhD in 2002 I have become very interested in reproductive immunology.
Important information about reproductive health including: cervical cancer, menstruation, and yeast infections.
Effect of sequential porcine reproductive and respiratory syndrome aand swine influenza on the growth and performance of finishing pigs.
It has a short life cycle and a high reproductive rate, it has many easily distinguishable mutants and is comparatively easily handled.
Studies in animals have shown reproductive toxicity including fetal malformations (see section 5.3 ).
Would the likely cost in terms of failures and/or malformations inevitable in developing a program of human reproductive cloning be ethically acceptable?
marsupial mouse has a unique reproductive strategy.
G Gametes - Mature reproductive cells, sperm or ova in humans produced by meiosis.
Information is given on the effects and timing of NEB, the effects on the reproductive process, and changes in blood metabolites.
Within this species, there exist three distinct color morphs which differ in their lifetime reproductive success.
We have found three: teleonomy, autonomous morphogenesis, and reproductive invariance.
neoplasms of the reproductive tract.
Professor Morris, whose research interest is in neuro- and cellular endocrinology, teaches neuroanatomy, systems, and reproductive biology.
orca population has declined in recent years and researchers are concerned about the shortage of killer whales of reproductive age.
The male and female reproductive organs can also be affected.
Each carpel contains two ovules (female reproductive cells or eggs ), which will grow into seeds.
oxytocin, for instance, is essential for parturition and lactation, and oxytocin released into the brain is important in reproductive behaviors.
Aristotle assigned women ' a purely passive role in conception as incubators for the reproductive power of men (8 ).
Very little is known about reproductive physiology in the majority of marsupials.
Parts of the body controlled by the lumbar plexus include the reproductive system and the abdomen, and the lumbar region of the back.
This paper deals with the anatomy and histology of the male reproductive system of the freshwater prawn.
Too much prolactin can cause malfunction of the reproductive organs.
Women from the lowest income quartile reported an average of 67 days of reproductive ill-health and annual health costs amounted to rupees 31.
The passage of time has hardly quelled interest in human reproductive cloning.
Vegetative reproduction - a reproductive process that is asexual and so does not involve a recombination of genetic material.
Helps the growth of new body tissue, especially reproductive tissue.
Indian Asparagus is very good for nourishing all the seven types of body tissue, particularly reproductive tissue.
Sexual organs are reproductive organs, part of what any biology textbook will tell you is the reproductive organs, part of what any biology textbook will tell you is the reproductive system.
The first British government consultation on cloning issues recommended that the licensing authority allow therapeutic cloning go ahead but not to allow reproductive cloning.
salmonid fish from many river systems is assumed to have badly affected mussel reproductive success.
A4 - I am fascinated by the reproductive habits of the British sea anemones.
We have seen that the lobby supporting female reproductive self-determination was sidelined by the lobbying activities of the medical establishment.
thrown into disarray in November by a high court decision that current laws did not prohibit human reproductive cloning.
Carcinogens, mutagens & reproductive toxicants are one group of chemicals which cause particular public concern.
Some phthalates are known to be reproductive and developmental toxicants, or are known to disrupt the endocrine system.
Specific expertise is sought in the area of nutrition, preferably pediatric nutrition or reproductive toxicology.
uncircumcised women to report symptoms of reproductive tract infections.
Although reproductive health issues are importantly included, clearer guidelines are needed especially on the management of sexual and gender-based violence.
This is similar to the repulsive reproductive cycle of the ichneumon wasp.
They are an effective reproductive device if the right buttons are pushed, but can also wreak havoc if you push the wrong buttons.
Gametes Reproductive cells which unite in pairs to produce zygotes.
The reproductive organs of Rhabdopleura have but seldom been ob served.
SUB-ORDER HYDROIDEA CALYPTOBLASTEA (LEPTOsome with polyps always differentiated into nutritive and reproductive individuals(blastostyles) enclosed in hydrothecae and gonothecae respectively; with sympodial type of budding.
The essential reproductive organ or gonad consists of both ovarian and testicular cells (see fig.
- Hermaphrodite Reproductive Apparatus of the Garden Snail (Helix horlensis).
The acquisition of wings is the sign of developed reproductive power.
Originating probably, in the observation of the fertilizing effect of rains and streams upon the receptive and reproductive soil, baalism becomes identical with the grossest nature-worship. Joined with the baals there are naturally found corresponding female figures known as Ashtaroth, embodiments of Ashtoreth (see Astarte; Ishtar).
Consequently the result of the haphazard pairing of a large number of these two groups of reproductive cells was to yield, according to the regular law of chance combination, the proportion 'PP, 2PN, INN, where P stands for the positive character and N for its absence or negative character - the positive character being accordingly present in three-fourths of the offspring and absent from onefourth.
The fact that in the formation of the reproductive cells of the hybrid generation the material which carries the positive quality is not subdivided so as to give a half-quantity to each reproductive cell, but on the contrary is apparently distributed as an undivided whole to half only of the reproductive cells and not at all to the remainder, is the important inference from Mendel's experiments.
The suggestion is obvious that the halving of the number of nuclear threads in the reproductive cells as compared with the number of those present in the ordinary cells of the tissues - a phenomenon which has now been demonstrated as universal - may be directly connected with the facts of segregation of hybrid characters observed by Mendel.
- A, reproductive system of Amphilina foliacea: a, glandular pit; b, opening of uterus; b', uterus (black); c, yolk-gland and its duct; d, ovary; e, e', opening and duct of vagina; f, spermotheca; g, male genital opening (gonopore); h, penis; i, vas def erens; j, testes; k, shell-gland.
The Monozoa are unsegmented; the Ligulidce have segmented gonads and gonopores without any trace of somatic metamerization except secondary excretory pores in addition to the usual terminal one; the remaining Cestodes are unisegmental only in their larval stage, and all of them show in their later stages repetition of the reproductive organs and of the musculature.
The chief difference between the reproductive organs of the two classes is the presence in Cestodes of a separate vagina and uterus, each of which opens in some families to the exterior by an independent pore.
The blood of most species behaves differentially towards precipitants, and it is therefore conceivable that when blood is used as food and is elaborated into special compounds for the nutrition of the reproductive organs of a parasite, these specific or larger differences in the blood of animal hosts may prevent the ripening of the gonads of a widely diffused parasite and only one particular kind of blood prove suitable.
Embedded in the matrix lies the complex genital apparatus composed usually of both male and female reproductive organs (fig.
rather points to a mere personification of reproductive powers.
Among the most important structures produced in repeated series are the reproductive cells; and Pearson points out that if the variability of animals or of plants be supposed to depend upon that of the germ-cells from which they arise, then the correlation between brothers in the array produced by the same parents will give a measure of the correlation between the parental germ-cells, the determination requiring, of course, the same precautions to avoid the effects of differentiation as are necessary in the study of other repeated organs.
The two chief deities were Cybele, the Mother, the reproductive and nourishing power of Earth, and Sabazius, the Son, the life of nature, dying and reviving every year (see Great Mother Of The Gods).
In these the adult consists of a simple saccular body containing the reproductive organs and attached by root-like filaments which ramify throughout the body of the host and serve for the absorption of nourishment (fig.
The reproductive organs of the sporophyte are the sporangia, within which the spores are produced; the sporangia are often borne on or in relation to leaves, which may be more or less distinct from the foliage leaves in form and structure (cf.
Sexual organs are reproductive organs, part of what any biology textbook will tell you is the reproductive system.
I am aware of other vets who regularly use endoscopy to assess the reproductive tract.
Reproductive biology of Sabine 's Gull in the Canadian Arctic.
Studies in animals have shown reproductive toxicity associated with maternal toxicity.
The loss of salmonid fish from many river systems is assumed to have badly affected mussel reproductive success.
British regulations on cloning were thrown into disarray in November by a high court decision that current laws did not prohibit human reproductive cloning.
The mesothelial tissue surrounding the male internal reproductive organs is called the tunica vaginalis testis.
In fact, about 45 percent of births that are considered "assisted reproductive techniques", such as fertility drugs and IVF, are twin births.
Respiratory infections caused by the herpesvirus can sometimes result in reproductive troubles, including the abortion of a pregnancy.
In the most contaminated areas, aquatic animal and birds are directly affected, reducing their reproductive abilities, causing mutations, or killing them outright.
Chemicals released in this process are said to threaten reproductive systems as well as health in general.
When Styrofoam containers are used for food chemicals can leach into the food, affecting human health and the reproductive systems.
Dementia, Alzheimer, reproductive problems in men, asthma, bronchitis and headaches are all linked to the toxins found in a typical home.
It can be used to stimulate the reproductive system and works to help maintain heart health.
The hypothalamus is a small area of the brain that helps control the reproductive functions as well as many other important bodily functions.
Heat cycles are driven by the reproductive hormones, so there are a number of things that can affect when or how often a bitch will come into season.
Reproductive health also impacts the cycle.
Exposure to pesticides has been linked to cancer, nervous-system and lung damage, reproductive dysfunction, and possibly dysfunction of the endocrine and immune systems.
The prostate is a small, walnut-shaped gland that is part of the male reproductive system.
This gradual change in the body's reproductive system can take years.
Changes may be subtle and gradual, but if you make yourself aware of possible symptoms you'll soon recognize the signs for what they are: a hormonal change and the eventual end to your reproductive cycle.
Hypothyroidism-A disorder in which the thyroid gland produces too little thyroid hormone causing a decrease in the rate of metabolism with associated effects on the reproductive system.
The major risk factors that apply to adult cancer are tobacco, alcohol, sexual and reproductive behavior, and occupation, none of which increases risk in children.
GBS exists in the reproductive tract of 20 to 25 percent of all pregnant women.
At-risk individuals can be assisted with family planning and reproductive decisions.
Uterus-The female reproductive organ that contains and nourishes a fetus from implantation until birth.
The frequency of multiple births in the United States has been steadily increasing with advances in reproductive technologies.
With the use of assisted reproductive technology, an ultrasound is usually performed with ten days to see if any of the embryos were successful with implantation, and a multiple gestation would be revealed at that time.
Ova-The plural of ovum, it is the female reproductive cell.
European Journal of Obstetrics, Gynecology and Reproductive Biology 116, no. 2 (2004): 201-6.
American Society for Reproductive Medicine. 1209 Montgomery Highway, Birmingham, AL 35216-2809.
Sometimes referred to as the "master gland," it regulates and controls the activities of other endocrine glands and many body processes including growth and reproductive function.
Scrotum-The external pouch containing the male reproductive glands (testes) and part of the spermatic cord.
The males and females have a complex reproductive tract and reproduce sexually.
Tumors of the hypothalamus and the pituitary gland or abnormalities of the reproductive organs usually require surgery.
Glandular therapy can assist in bringing about a balance in the glands involved in the reproductive cycle, including the hypothalmus, pituitary, thyroid, ovarian, and adrenal glands.
Explorative surgery or a biopsy of reproductive tissue may be necessary.
Parts of the body that are especially sensitive to damage by x rays (for example, the reproductive organs, the thyroid) are shielded with a lead apron.
Baro, L., et al. "The administration of a multivitamin/mineral fortified dairy product improves folate status and reduces plasma homocysteine concentration in women of reproductive age."
Their reproductive development is normal, and they have greater than normal muscular strength.
For some of the MPS diseases, biochemical tests may be able to identify healthy individuals who are carriers of the defective gene, allowing them to make informed reproductive decisions.
A majority of girls who are circumcised experience urologic, reproductive, and sexual dysfunction as adults.
However, prenatal surgery for spina bifida has become enmeshed in the politics of reproductive rights and fetal rights.
Urologist-A physician who specializes in the anatomy, physiology, diseases, and care of the urinary tract (in men and women) and male reproductive tract.
In teenage girls, internal sexual changes include maturation of the uterus, vagina, and other parts of the reproductive system.
This mutation, present in a percentage of his or her reproductive cells, can result in more than one affected child without affecting the parent with the disorder.
It is quite common for women at the beginning and end of their reproductive lives to miss periods or have them at irregular intervals.
At the beginning and end of a woman's reproductive life, some of these hormone messages may not be synchronized, resulting in menstrual irregularities.
Glandular therapy can assist in bringing about a balance in the glands involved in the reproductive cycle, including the hypothalamus, pituitary, thyroid, ovarian, and adrenal glands.
An ultrasound may reveal small or undeveloped female reproductive organs while a gynecologic examination may reveal a dry vaginal lining.
Assisted reproductive technology may allow for women with Turner syndrome to become pregnant with donated ooctyes.
Ovary-One of the two almond-shaped glands in the female reproductive system responsible for producing eggs and the sex hormones estrogen and progesterone.
Also refers to the small, thick-walled reproductive structure of a fungus.
If pelvic inflammatory disease is present, the fallopian tubes may become scarred and possibly cause later infertility or other reproductive problems.
Both the male reproductive hormone testosterone and female hormone estrogen are present in children of both sexes.
The pituitary hormones travel throughout the body and are involved in a large number of activities, including the regulation of growth and reproductive functions.
These disruptions may be responsible for changes in the menstrual cycle and abnormal production of breast milk in women or delayed development of reproductive organs.
Sperm must travel through the reproductive track to fertilize the egg in the fallopian tube.
Pelvic inflammatory disease (PID)-Any infection of the lower female reproductive tract (vagina and cervix) that spreads to the upper female reproductive tract (uterus, fallopian tubes and ovaries).
IBS symptoms sometimes intensify during menstruation, suggesting female reproductive hormones may trigger the condition.
Genital-Refers to the sexual or reproductive organs that are visible outside the body.
The mesoderm develops into muscles, bones, heart tissue, lungs, reproductive organs, lymphatic tissue, and other tissues.
This should only be done for patients who are not of reproductive age or are not planning to have children, since a large amount can concentrate in the reproductive organs (gonads).
The infection affects the reproductive tract and causes pelvic inflammatory disease, infertility, and ectopic pregnancy (when the fertilized egg implants somewhere other than in the uterus).
Parental concerns are reflected in the status of a reproductive couple to prevent the transmission of the virus before pregnancy and if this is not possible, to obtain adequate prenatal care to prevent the transmission to the baby.
It is involved in reproductive functions and helps produce mother's milk.
Deficiencies may be associated with heart and kidney disease and reproductive disorders.
Zinc-important in the growth of reproductive organs and regulation of oil glands.
Gonorrhea: Caused by the bacteria Neisseria gonorrhoeae, gonorrhea infects the reproductive tract of women, causing pelvic inflammatory disease (PID), a major cause of infertility.
Chlamydia: The bacteria that causes chlamydia, Chlamydia trachomatis, trigger inflammation of the reproductive tract, leading to PID in women and epididymitis (inflammation of the epididymis) in men.
These factors are related to access and use of medical services for reproductive health care.
Human papillomavirus (HPV): The warty growths of HPV can appear on the external or internal reproductive organs of males and females but are commonly found on the labia minora and the opening to the vagina in females and the penis in males.
Further, they sustain other sexual organs and their function throughout the reproductive years.
Female reproductive problems are usually related to complex cycling rhythms gone wrong.
Females with CAH are born with an enlarged clitoris and normal internal reproductive tract structures.
The internal structures of the reproductive tract, including the ovaries, uterus, and fallopian tubes, are normal.
In addition, it can lead to difficulties during pregnancy, as well as cause reproductive problems in both men and women.
Provide care for the female reproductive system, including diagnosing and treating any disorders that appear as well as pregnancy and delivery.
Certified Nurse Midwife: A certified nurse midwife is a registered nurse with extensive training in women's health issues, pregnancy, childbirth and reproductive health.
They may need to gain a few pounds in order to regulate their reproductive cycles.
Tobacco use negatively affects both male and female reproductive function.
The LoveToKnow Pregnancy has built a community of real people with an interest in pregnancy and women's reproductive health.
The sperm can then be used in one of several types of assisted reproductive techniques.
Sperm cells have long tails which they use to "swim" into a woman's reproductive tract and reach an egg.
Family planning clinics are special doctors' offices that are devoted to reproductive health.
They are usually well-trained to handle questions about and problems with birth control or reproductive health.
Family planning clinics are usually very up-to-date on birth control methods and issues of reproductive health.
If your regular doctor does not do a lot of reproductive care, he/she may not be comfortable prescribing birth control or doing gynecological exams.
Planned Parenthood's mission is to provide affordable reproductive health care and to give each patient a full range of reproductive choices.
They receive federal funding to provide birth control and reproductive health care at low cost and sometimes even for free.
Some cities and counties also have health clinics which offer free birth control and reproductive care.
The American Fertility Association reports findings that show 98 percent of women of reproductive age do not know how many days each month they have to get pregnant.
Body fat levels that are more than 10% above or below normal can disrupt the reproductive cycle.
Vitamin A - supports male and female reproductive processes and bone growth.
The Center for Reproductive Rights has additional information for people interested in state abortion laws.
While it's not proven indecisively that laptops can cause decreased fertility, he says it may cause irreversible or only partially reversible changes in the male reproductive cycle.
It is often the first step in assisted reproductive techniques for couples who have been unsuccessfully trying to conceive for at least a year.
IUI is also an answer for couples who are unable to get pregnant due to the man having certain cancers, impotency, or surgery to the reproductive organs.
Having cancer can make secondary infertility a concern for many women since radiation, chemotherapy, and drug treatments may affect a woman's reproductive system.
In contrast, was research conducted by the Women's Contraceptive and Reproductive Experiences (Women's CARE).
It works by thickening the cervical secretions, which then acts as a barrier against sperm entering the female reproductive tract.
With greater access to assisted reproductive techniques like in vitro fertilization and intrauterine insemination, cancer patients who are infertile have a greater chance of conceiving a child.
If the cancer directly impacts the reproductive organs, the chances are higher that you may experience problems with fertility.
In some cases, if the cancer is simply near the reproductive organs or if cancer treatment encompasses the whole body, fertility could be adversely affected from radiation and chemotherapy.
If your cancer is aggressive and is found in areas of the reproductive system, you may have no other choice but to have those organs removed.
Intersex individuals can have both male and female traits in some cases, making it possible for a person who is apparently a man to have female reproductive organs.
A complicated situation arises when a person born with a female reproductive system lives as a male.
The surgery did not interfere with Beatie's reproductive organs.
In cases of transgender pregnancies, the female reproductive organs are intact.
Associate Professor of Biochemistry and Reproductive Medicine, Simone M.
Many natural family planning methods help to build an awareness of how the female reproductive system works.
The process is educational and is effective in developing a way to monitor reproductive health.
Most forms of contraception are for women, which allows females to take control of their reproductive systems.
Men are limited in this area because most forms of natural birth control depend on following the woman's reproductive cycle.
Whatever the success rate is, it doesn't mean that every couple who tries this method of Assisted Reproductive Technology (ART) will be able to have a child.
Sperm can live in the reproductive tract of a female for five days and the egg can be fertilized for up to 24 hour after ovulation.
However, if you've ever had a reproductive health problem like PCOS or endometriosis or have been treated for a sexually transmitted disease, you may want to discuss your concerns with your healthcare provider a bit sooner.
If you really want to get pregnant, you'll want to consider optimizing the reproductive ability of the woman and the man.
Both the male and female reproductive systems come into play in fertility problems.
There are many types of pills and manufacturers and most work by preventing monthly ovulation or by making the female reproductive tract inhospitable to sperm.
The human body uses zinc for the reproductive organs as well as to keep the prostate healthy.
Both male and female reproductive organs use vitamin A, as does the skeletal system.
Probiotics, also referred to as microflora, are a type of beneficial bacteria that help reduce the growth of harmful bacteria in the body's gastrointestinal system, urinary tract and reproductive organs.
Women have an emotional connection to their reproductive organs.
At a young age, a male's reproductive organ isn't thinking about the emotional aspect of sex, he is thinking about the physiological aspects of sex.
Orange is associated with the reproductive system in the physical body and also means health, vitality and wellness.
Hindu women of childbearing age still wear a small stud in their left nostril, which is associated with the reproductive organs.
Yoga 4 Fertility guides viewers through a series of asanas thought to enhance the function of the reproductive organs, as well as some basic standing poses, forward bends, and simple twists.
Yoga also helps your digestive system, circulatory system, and reproductive system stay in sync.
For women, obesity can cause reproductive complications such as gestational diabetes, problems with delivery and birth defects.
Male mosquitoes get their nutritional needs from plant nectar, whereas the female mosquitoes rely on blood protein so they can mature their eggs and carry on the reproductive life cycle of the insect.
The word usage examples above have been gathered from various sources to reflect current and historial usage. They do not represent the opinions of YourDictionary.com.