Theme: Molecular and genetic mechanisms of ontogenesis. Ontogenesis abnormalities Lector Pryvrotska Iryna

Theme:Theme: Molecular and Molecular and genetic mechanisms of genetic mechanisms of ontogenesis. ontogenesis. Ontogenesis Ontogenesis abnormalitiesabnormalities

Lector Pryvrotska IrynaLector Pryvrotska Iryna

Plan of the lecture:Plan of the lecture:

Asexual reproduction in unicellular Asexual reproduction in unicellular and multicellular organismsand multicellular organisms

Sexual reproduction in unicellular Sexual reproduction in unicellular and multicellular organismsand multicellular organisms

The periods of ontogenesisThe periods of ontogenesis Spermatogenesis and oogenesisSpermatogenesis and oogenesis Morphogenetic specialization of sex Morphogenetic specialization of sex

cells: a sperm and an ovumcells: a sperm and an ovum Fertilization. ParthenogenesisFertilization. Parthenogenesis Biological peculiarities of human Biological peculiarities of human

reproductionreproduction

ReproductionReproduction is the is the method by which method by which individuals give rise to individuals give rise to other individuals of other individuals of same typesame type. .

There are two types of There are two types of reproduction : reproduction :

asexualasexual and and sexualsexual

Types of Types of reproductionreproduction

asexualasexual sexualsexual

OrganismsOrganismssingle-cellularsingle-cellular organismorganisms,s,

multi-cellularmulti-cellular organismsorganisms:: one ore one ore more somatic cells of more somatic cells of parental organisms; parental organisms;

Parental Parental organisms forms organisms forms gametesgametes

ParentsParents One personOne person Two personsTwo persons

Offspring'sOffspring's

genetically identical genetically identical to its parent like a to its parent like a xero copy.xero copy.

genetically genetically different from different from parentsparents

Cell Cell formationformation

MitosisMitosis MeiosisMeiosis

Forms of asexual Forms of asexual reproductionreproduction

inin single-cellularsingle-cellular organisms organisms:: AsexualAsexual is a is a

reproduction without reproduction without the fusion of sexual the fusion of sexual cells, identical cells, identical offspring grows offspring grows directly from a one or directly from a one or few body cells, which few body cells, which divides mitoticallydivides mitotically

binary fissionbinary fission – – pareparentnt cell splits in two cells cell splits in two cells

by mitosis by mitosis

AsexualAsexual reproduction reproduction

endogonyendogony - - in in parent cell forms parent cell forms only two daughter only two daughter cells cells by internal by internal budding budding

schizogonyschizogony -- formformationation a great a great amount of daughter amount of daughter cells in parent cell cells in parent cell

AsexualAsexual reproduction reproduction

buddingbudding - - after after karyokinesis the karyokinesis the special region in special region in parent cell rapid parent cell rapid grows and grows and organized into new organized into new organism.organism.

sporogonysporogony - - is is reproduction by the reproduction by the sporesspores

Forms of Forms of asexualasexual reproduction reproduction in in

multi-cellularmulti-cellular organisms organisms

vegetativevegetative (regeneration) (regeneration) – – a a group of cells from group of cells from the parent the parent organism organism separates and new separates and new organism formsorganism forms

AAsexualsexual reproduction reproduction

polyembriony polyembriony -- the production the production of two or more of two or more embryo's from embryo's from the one zygotethe one zygote

sporogony sporogony - - is reproduction is reproduction by the sporesby the spores

SSexualexual - is a reproduction - is a reproduction by fusion of sexual cells by fusion of sexual cells and formation of zygoteand formation of zygote

In In sexual reproductionsexual reproduction, , genetic genetic material from two individuals material from two individuals combines to begin the life of a combines to begin the life of a third individual who has a new third individual who has a new combination of inherited traitscombination of inherited traits

Sexual reproductionSexual reproductionForms of sexual reproductionForms of sexual reproduction

in in single-cellularsingle-cellular organisms organisms are are

ConjugationConjugation – a cytoplasm bridge – a cytoplasm bridge forms between two organisms, the forms between two organisms, the nuclei transfer across this bridge nuclei transfer across this bridge and after exchange ones forms a and after exchange ones forms a new gene combination but no new new gene combination but no new offspringoffspring..

CopulationCopulation - two individuals acquire - two individuals acquire the gametes properties, fuse and the gametes properties, fuse and form a zygote – the life of a new form a zygote – the life of a new individual begins.individual begins.

InIn multicellularmulticellular organism organism sexualsexual reproduction may be reproduction may be two forms: two forms: -- with with fertilizationfertilization- without fertilization- without fertilization

ParthenogenesisParthenogenesis is the is the development of new organism development of new organism from an egg without fertilization. from an egg without fertilization.

OntogenesisOntogenesis

the development of the individual the development of the individual organism. organism.

It includes the set of It includes the set of morphological, phisiological and morphological, phisiological and biochenical transformations from biochenical transformations from the moment of germing up to the moment of germing up to death.death.

Types of ontogenesis in Types of ontogenesis in

animals:animals: 1.1. The The larval typelarval type of an ontogenesis is characterized of an ontogenesis is characterized

by development of an organism by metamorphosis. by development of an organism by metamorphosis. Metamorphosis Metamorphosis – is change of shape or structure of an – is change of shape or structure of an

organism from one developmental stage to another.organism from one developmental stage to another. F/e F/e mosquitomosquito: ovum- larva- pupa - imago;: ovum- larva- pupa - imago; louseslouses – ovum- larva - imago; – ovum- larva - imago; pincerspincers – ovum- larva- nymph - imago. – ovum- larva- nymph - imago. 2. The 2. The non-larval typenon-larval type of an ontogenesis is of an ontogenesis is

characterized by formation of an organism in characterized by formation of an organism in an egg (birds)an egg (birds)3. 3. Intrauterine ontogenesisIntrauterine ontogenesis – is development of an – is development of an

organism inside a maternal organism. (mammalian).organism inside a maternal organism. (mammalian).

The ontogenesis of The ontogenesis of multicellular organismsmulticellular organisms is is divided in two periodsdivided in two periods

1 1 embryonicembryonic

2 2 postembryonicpostembryonic..

For higher animals For higher animals and man there are:and man there are:

1)1) prenatalprenatal (before (before birth)birth)

2)2) posnatalposnatal (after birth) (after birth)

periods of developmentperiods of development

Germ cellsGerm cells

The The ovumovum nourishes the nourishes the embryo with embryo with yolk, which yolk, which contains rich contains rich stores of lipids.stores of lipids.

It provides the It provides the machinery for machinery for protein synthesisprotein synthesis

AnAn ovumovum is enormous in size. It is enormous in size. It protects the developing embryo protects the developing embryo inside jellylike protein coatings inside jellylike protein coatings and strong membranes (and strong membranes (zona zona pellucidapellucida), sacs of fluid, and ), sacs of fluid, and sometimes hard or leathery sometimes hard or leathery shells. shells.

Corona radiataCorona radiata outside the cell outside the cell consists of the great amount of consists of the great amount of follicular cellsfollicular cells, which produce , which produce follicular fluid for attracting the follicular fluid for attracting the sperms.sperms.

Distinguish the Distinguish the following following types of types of ovum cells:ovum cells: The The isolecythal ovumisolecythal ovum contain a little yolk. It contain a little yolk. It

is distributed in regular intervals on all is distributed in regular intervals on all cytoplasm of an ovum.cytoplasm of an ovum.

(ovum of mollusca, lancelet, mammalian).(ovum of mollusca, lancelet, mammalian). The The telolecythal ovumtelolecythal ovum have much yolk of have much yolk of

grains. They collect at a vegetative pole. grains. They collect at a vegetative pole. On animal pole there is cytoplasm without On animal pole there is cytoplasm without yolk and with nucleus.(ovum of fishes, yolk and with nucleus.(ovum of fishes, amphibians, reptilie).amphibians, reptilie).

The The centrolecythal centrolecythal ovum has the central ovum has the central nucleus and around it settles down yolk as nucleus and around it settles down yolk as grains. (insects).grains. (insects).

Unlike the egg, the Unlike the egg, the spermsperm is one of the smallest cells is one of the smallest cells in the body.in the body.

Each sperm consists of:Each sperm consists of: a head regiona head region a body or midpiecea body or midpiece a tail or flagellum. a tail or flagellum.

TheThe headhead has a haploid has a haploid nucleus. An nucleus. An acrosomeacrosome – a – a small bump on the front end small bump on the front end of the head contains of the head contains enzymes that help the cell enzymes that help the cell penetrate the ovum’s outer penetrate the ovum’s outer membrane. membrane.

Sperm cellSperm cell The The bodybody or midpiece or midpiece has has

mitochondria to provide the mitochondria to provide the cell energy and centrioles. cell energy and centrioles.

A A tailtail consists of consists of microtubules for propulsion.microtubules for propulsion.

The sperm’s streamlined The sperm’s streamlined size and shape effect its size and shape effect its narrow objective: to reach narrow objective: to reach the egg, penetrate its the egg, penetrate its coating, and deliver a coating, and deliver a haploid nucleus into the haploid nucleus into the egg’s cytoplasmegg’s cytoplasm

OogenesisOogenesis This process begins in This process begins in

a haploid a haploid oogoniumoogonium.. An An oogoniumoogonium

accumulates accumulates cytoplasm, replicates cytoplasm, replicates its chromosomes- its chromosomes- primary oocyteprimary oocyte. .

In meiosis I, the In meiosis I, the primary oocyte primary oocyte divides to form a divides to form a small small polar bodypolar body and and a large, haploid a large, haploid secondary oocytesecondary oocyte..

OogenesisOogenesis Ovulation Ovulation – dischange (going out) of a – dischange (going out) of a

secondary oocyte from a follicule of the ovary.secondary oocyte from a follicule of the ovary. In meiosis II, the In meiosis II, the secondary oocytesecondary oocyte divides to divides to

yield another small yield another small polar bodypolar body and a and a mature mature ovumovum. Therefore, each cell undergoing meiosis . Therefore, each cell undergoing meiosis in female can potentially divide to yield a in female can potentially divide to yield a maximum of four cells, only one of which will maximum of four cells, only one of which will become the ovumbecome the ovum

SpermatogenesisSpermatogenesis Sperm development Sperm development

begins with begins with spermatogoniaspermatogonia. .

A diploid spermatogonium A diploid spermatogonium divides mitotically and divides mitotically and becomes a becomes a primary primary spermatocytespermatocyte as it moves as it moves toward the lumen of the toward the lumen of the tubule. tubule.

In meiosis I- to form In meiosis I- to form two two secondary spermatocytessecondary spermatocytes. .

In meiosis II, each In meiosis II, each secondary spermatocyte secondary spermatocyte divides to yield two equal divides to yield two equal – sized – sized spermatidsspermatids..

Therefore, each cell Therefore, each cell undergoing meiosis in undergoing meiosis in male can potentially male can potentially divide to yield a maximum divide to yield a maximum of four spermatids. of four spermatids.

GametogenesisGametogenesisPeriodsPeriods SpermatogenesisSpermatogenesis OogenesisOogenesis

CellsCells Genetic Genetic formulaformula


ReproductionReproductionCells Cells divides divides mitoticalymitoticaly♂ - from puberty to death ♀- strongly at 3-7 m. in embryogeny completed at 3-d year

spermatospermatogonigoniaa

2n2c 2n2c 2n4c2n4c

oogoniaoogonia 2n2c2n2c

2n4c2n4c



GrowthGrowth

Cell growth Cell growth and increase and increase in size. in size. Duplication of Duplication of DNA.DNA.

primary primary sspermatopermatocytecyte

2n42n4cc

primary primary oocyteoocyte

2n4c2n4c



MaturationMaturationMeiosis Meiosis I-I- cells cells halves halves geneticallgeneticall

y materialy material

Meiosis Meiosis IIII

two two secondary secondary spermatocspermatocytesytes

two two spermatidsspermatids

1n2c1n2c

1n1c1n1c

SecondarySecondary

OocyteOocyte

mature mature ovumovum

1n2c1n2c

1n1c1n1c



Formation (spematogenesis)Formation (spematogenesis)SpiralizatioSpiralization of n of chromosomchromosomes, es, formation formation of of acrosome,cacrosome,cell centre, ell centre, tailtail

spermssperms 1n1c1n1c

GametogenesisGametogenesis

Ontogenesis Ontogenesis abnormalitiesabnormalities 11) ) multynuclearmultynuclear oocytesoocytes;;22) 10% ) 10% ofof sperms can be abnormalcan be abnormal;;33) ) development of germ cells withdevelopment of germ cells with 22 22 oror 24 24 chromosomeschromosomes

The fusion of haploid gametes The fusion of haploid gametes to form a new diploid cell is to form a new diploid cell is

called called fertilizationfertilization or syngamy or syngamy

Fertilization may Fertilization may be external and be external and internalinternal

FertilizationFertilization During fertilization two During fertilization two

processes take place:processes take place:

Egg’s activationEgg’s activation – a wave of – a wave of chemical reactions sweeps chemical reactions sweeps across the surface of the across the surface of the newly aroused egg, causing newly aroused egg, causing that surface to harden and that surface to harden and present a barrier to the entry present a barrier to the entry of any additional sperm. The of any additional sperm. The egg’s oxygen consumption egg’s oxygen consumption skyrockets, as does its rate of skyrockets, as does its rate of protein synthesis.protein synthesis.

SyngamySyngamy – male and female – male and female haploid nuclei converge and haploid nuclei converge and fuse to form the zygote’s fuse to form the zygote’s single diploid nucleussingle diploid nucleus

FertilizationFertilization

3 functions3 functions– transmission of genes transmission of genes

– restoration of the restoration of the diploid number of diploid number of chromosomes chromosomes reduced during reduced during meiosismeiosis

– initiation of initiation of development in development in offspring offspring

FertilizationFertilization internal fertilizationinternal fertilization

– capacitationcapacitation

– sperm must penetrate cumulus and zona sperm must penetrate cumulus and zona pellucidapellucida

extracellular matrix consisting of 3 types of extracellular matrix consisting of 3 types of glycoproteins one of these, ZP3, acts as a sperm glycoproteins one of these, ZP3, acts as a sperm receptorreceptor

FertilizationFertilization activates the egg, initiating activates the egg, initiating

metabolic processesmetabolic processes acrosomal reactionacrosomal reaction

– sperm are activated sperm are activated – acrosomal processacrosomal process– sperm and egg membranes fusesperm and egg membranes fuse– ion channels open, allowing Naion channels open, allowing Na++

to flow into flow in– fast block to polyspermyfast block to polyspermy

cortical reactioncortical reaction– egg’s ER releases Caegg’s ER releases Ca2+2+ into the into the

cytosol at site of sperm entrycytosol at site of sperm entry

FertilizationFertilization

– slow block to slow block to polyspermypolyspermy

CaCa2+2+ causes cortical causes cortical granules underneath granules underneath the plasma the plasma membrane to fusemembrane to fuse

mucopolysaccharides mucopolysaccharides draw water into the draw water into the space, swelling itspace, swelling it

vitelline layer vitelline layer becomes the becomes the fertilization fertilization membranemembrane

CleavageCleavage

rapid divisions following fertilizationrapid divisions following fertilization– often skip G1 and G2 phasesoften skip G1 and G2 phases– blastomeres resultblastomeres result

most animal eggs have polaritymost animal eggs have polarity– substances are heterogeneously substances are heterogeneously

distributed in cytoplasmdistributed in cytoplasm vegetal polevegetal pole animal poleanimal pole

KKinds of cleavage:inds of cleavage: HoloblasticHoloblastic (total cleavage) – the zygote is divided (total cleavage) – the zygote is divided

completely. There are 1) uniform and 2) irregular completely. There are 1) uniform and 2) irregular holoblastic cleavage. They are haracteristic for holoblastic cleavage. They are haracteristic for isolecythal and telolecythal cellsisolecythal and telolecythal cells

MeroblasticMeroblastic (incomplete cleavage) – the part of (incomplete cleavage) – the part of cytoplasm of an zygote is divided where yolk is absence. cytoplasm of an zygote is divided where yolk is absence.

There are: 1) discoidal and 2) superficial meroblastic There are: 1) discoidal and 2) superficial meroblastic cleavage. cleavage.

In In discoidal meroblasticdiscoidal meroblastic cleavage the segmentation cleavage the segmentation occurs on an animal pole in telolecythal cells. Birds’ eggs occurs on an animal pole in telolecythal cells. Birds’ eggs contain so much yolk that the small disc of cytoplasm on contain so much yolk that the small disc of cytoplasm on the surface is dwarfed by compasion. No cleavage of the the surface is dwarfed by compasion. No cleavage of the massive yolk is possible, and all cell division is restricted massive yolk is possible, and all cell division is restricted to the small cytoplasmic disc, or to the small cytoplasmic disc, or blastodisc. blastodisc.

In In superficial meroblasticsuperficial meroblastic cleavage the segmentation cleavage the segmentation occurs on an peripheric zone of cytoplasm in occurs on an peripheric zone of cytoplasm in centrolecital cells.centrolecital cells.

In the man the cleavage of zygote is In the man the cleavage of zygote is holoblastic, irregular and holoblastic, irregular and asynchronousasynchronous

Mammalian Mammalian DevelopmentDevelopment implantationimplantation

– ICM forms flat disk with 2 layers ICM forms flat disk with 2 layers (epiblast and hypoblast)(epiblast and hypoblast)

– embryo develops from epiblast cells, embryo develops from epiblast cells, hypoblast forms yolk sachypoblast forms yolk sac

gastrulationgastrulation

GastrulationGastrulationseries of cell migrations to positions where they will form the three primary cell layers:1) ectoderm (outside germinal layer); 2) endoderm (inside germinal layer) and 3) mesoderm (medium germinal layer)

The germinal layers give rice to various tissues and The germinal layers give rice to various tissues and organs of animals. It is called as organs of animals. It is called as histogenesishistogenesis and and

organogenesisorganogenesis

The fate of primary germinal layers is The fate of primary germinal layers is given bellow:given bellow:

EctodermEctoderm MesodermMesoderm EndoderEndodermm

Skin Skin (epidermis), (epidermis), hair, nails, the hair, nails, the eye lens, the eye lens, the pituitary gland, pituitary gland, the epithelium the epithelium of the nasal of the nasal cavity, mouth, cavity, mouth, anal canal, anal canal, nervous nervous system, sense system, sense organsorgans

Connective tissue, Connective tissue, bones, muscles, bones, muscles, dermis, heart, blood dermis, heart, blood vessels, gonads, vessels, gonads, excretory organs excretory organs (kidneys) and the (kidneys) and the notochord (the notochord (the dorsally located dorsally located supportive rod found supportive rod found in all chordates, at in all chordates, at least in embryonic least in embryonic stages) stages)

Digestive Digestive tract, lungs, tract, lungs, liver, liver, pancreas, pancreas, thyroid gland, thyroid gland, urinary urinary bladderbladder

Mammalian Mammalian DevelopmentDevelopment 4 extraembryonic membranes form:4 extraembryonic membranes form:

– chorionchorion- from trophoblast, surrounds from trophoblast, surrounds embryo and all other membranesembryo and all other membranes

– amnionamnion- from epiblast, encloses embryo - from epiblast, encloses embryo in amniotic fluid in amniotic fluid

– yolk sac-yolk sac- from hypoblast, site of early from hypoblast, site of early blood cell formationblood cell formation

– allantois-allantois- outpocketing of embryo’s gut, outpocketing of embryo’s gut, incorporated into umbilical cord, forms incorporated into umbilical cord, forms blood vessels of umbilical cordblood vessels of umbilical cord

Provisional Provisional organsorgans are are present during present during embryonic period embryonic period and absent after and absent after birth. birth.

Provisional Provisional organs in human organs in human embryo are: embryo are:

an an youlk sacyoulk sac anan amnion amnion an an allantoisallantois a a chorion. chorion.

The The youlk sacyoulk sac – the extraembryonic membrane that connects with the – the extraembryonic membrane that connects with the midgut. In human it is the first site of blood cell formation, but has no midgut. In human it is the first site of blood cell formation, but has no nutritive function. nutritive function.

ChorionChorion [Gr. «membane»] – in human it is cellular, outermost [Gr. «membane»] – in human it is cellular, outermost extraembryonic membrane, composed of trophoblast lined with extraembryonic membrane, composed of trophoblast lined with mesoderm, it develops villi about 2 weeks after fertilization, is mesoderm, it develops villi about 2 weeks after fertilization, is vascularized by allantoic vessels a week later. vascularized by allantoic vessels a week later.

AmnionAmnion [Gr. [Gr. «bowl»«bowl» ; «membrane enveloping the fetus»] – the thin but ; «membrane enveloping the fetus»] – the thin but tough extraembryonic membrane of reptilies, birds, and mammals that tough extraembryonic membrane of reptilies, birds, and mammals that lines the chorion and contains the embryo and later the fetus, with the lines the chorion and contains the embryo and later the fetus, with the amniotic fluid around it.amniotic fluid around it.

PlacentaPlacenta By the 23-rdBy the 23-rd day of day of

human embryonic human embryonic development, two other development, two other embryonic membranes – embryonic membranes – the chorion and the the chorion and the allantois to give rise to a allantois to give rise to a placentaplacenta

Exchange of material Exchange of material takes place in the takes place in the placenta by diffusion placenta by diffusion between the blood of the between the blood of the mother and that of the mother and that of the embryoembryo

Within the placenta there Within the placenta there is no mixing of maternal is no mixing of maternal and fetal bloodand fetal blood

Human GestationHuman Gestation– organogenesisorganogenesis– fetus- all major fetus- all major

structures are present structures are present – human chorionic human chorionic

gonadotropin (hCG)- gonadotropin (hCG)- produced by embryo, produced by embryo, maintains corpus maintains corpus luteumluteum

– mucous plug formation mucous plug formation in cervixin cervix

– negative feedback- negative feedback- cessation of ovulation cessation of ovulation and menstrual cyclesand menstrual cycles

Human GestationHuman Gestation

2nd trimester2nd trimester– increased movement increased movement

of fetusof fetus– hCG levels decline, hCG levels decline,

leading to leading to deterioration of deterioration of corpus luteumcorpus luteum

– placenta secretes placenta secretes progesteroneprogesterone

– uterus increases to uterus increases to visible sizevisible size

Human GestationHuman Gestation

3rd trimester3rd trimester– rapid growth of fetusrapid growth of fetus– estrogens and oxytocin initiate laborestrogens and oxytocin initiate labor– positive feedback- oxytocin positive feedback- oxytocin

stimulates prostaglandin secretion stimulates prostaglandin secretion by placenta, leading to increased by placenta, leading to increased contractionscontractions

In embrionic development of In embrionic development of man there are following man there are following critical periodscritical periods::

Implantation Implantation (7 day after a fertilization) – (7 day after a fertilization) – introduction of a zygote in a wall of an uterusintroduction of a zygote in a wall of an uterus

Placentation (Placentation (the end of 2 week of pregnancy) the end of 2 week of pregnancy) – form at embryo of a placenta– form at embryo of a placenta

Perinatal periodPerinatal period (from 28 week of pregnancy (from 28 week of pregnancy to 7 day after birth) – is transferring a fetus out to 7 day after birth) – is transferring a fetus out of aqueous into air (on the average, about 280 of aqueous into air (on the average, about 280 days after the beginning of the mother’s last days after the beginning of the mother’s last regular menstrual period).regular menstrual period).

Intrauterine pregnancyIntrauterine pregnancy

Any substance that Any substance that can causes abnormal can causes abnormal development of the development of the egg in the mother's egg in the mother's womb is called a womb is called a teratogen.teratogen.

Growth is rapid, and Growth is rapid, and each body organ has a each body organ has a critical period in which critical period in which it is especially sensitive it is especially sensitive to outside influences. to outside influences. About 7% of all About 7% of all congenital defects are congenital defects are caused by exposure to caused by exposure to teratogens.teratogens.

Drugs Drugs Alcohol.Alcohol.

Chances of Down syndrome rapidly Chances of Down syndrome rapidly increase with parental age starting increase with parental age starting at about age 35 in women and 55 at about age 35 in women and 55 in men. Previously, it was thought in men. Previously, it was thought there might be a tendency toward there might be a tendency toward nondisjunction as a women ages nondisjunction as a women ages because her eggs age as she does - because her eggs age as she does - a women is born with all the eggs a women is born with all the eggs she will ever have and they remain she will ever have and they remain in suspended animation until one in suspended animation until one matures each month.matures each month.

Ontogenesis Ontogenesis abnormalitiesabnormalities

Ontogenesis Ontogenesis abnormalitiesabnormalities

References:References:

1. Biology. – Sylvia S. Mader, Wm. C. 1. Biology. – Sylvia S. Mader, Wm. C. Brown Publishers: Dubuque, Lowa – Brown Publishers: Dubuque, Lowa – Melbourne, Australia – Oxford, Melbourne, Australia – Oxford, England, IV edition. – p.169-181, England, IV edition. – p.169-181, 694-705.694-705.2. Biology. Art notebook – Sylvia 2. Biology. Art notebook – Sylvia S.Mader, Wm. C. Brown Publishers: S.Mader, Wm. C. Brown Publishers: Dubuque, Lowa – Melbourne, Dubuque, Lowa – Melbourne, Australia – Oxford, England, IV Australia – Oxford, England, IV edition. – p.42-47.edition. – p.42-47.3. Human biology. – McMillan, 3. Human biology. – McMillan, Beverly. – p. 310-327.Beverly. – p. 310-327.

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Theme: Molecular and genetic mechanisms of ontogenesis. Ontogenesis abnormalities Lector Pryvrotska Iryna