S13 Ch29 Development/inheritance

Front 1

what is development?

Back 1

- the gradual modification of anatomical structures and physiological characteristics from conception to maturity.

Front 2

what are the stages of development?

Back 2

- fertilization/conception

- embryonic development - the first 2mo after conception.

- fetal development - starts at the beginning of the 9th wk and continues until birth.

- postnatal development - from birth to maturity.

- maturity - the states of completed growth/full development.

Front 3

what is prenatal development?

Back 3

- embryonic and fetal development collectively.

Front 4

what are inheritance and heredity?

Back 4

- the transfer of genetically determined characteristics from gener to gener.

Front 5

what is genetics?

Back 5

- the study of the mechanisms responsible for inheritance.

Front 6

what is differentiation?

Back 6

- the formation of different types of cells.

Front 7

if one sperm actually fertilizes an oocyte, why does it take dozens to reach fertilization?

Back 7

- because one sperm does not contain enough acrosomal enzymes to disrupt the corona radiata, which is only accomplished through dozens of sperm releasing hyaluronidase to break down the bonds of the corona radiata in order for a single sperm to reach the oocyte's membrane.

Front 8

where does the sperm attach to the oocyte and what happens next?

Back 8

- to a sperm receptor in the zona pellucida, which triggers the rupture of the sperm's acrosome allowing the hyaluronidase and acrosin to digest a path to the surface of the oocyte, which triggers oocyte activation.

Front 9

what causes oocyte activation?

Back 9

- the fusing of the sperm and oocyte membranes causes depolarization of the oocyte due to an increased permeability to Na+'s, which in turn causes the release of Ca+2's from the smooth ER.

Front 10

what effects does the sudden rise in Ca+2 levels have?

Back 10

1) the cortical rxn releases ZIPs, that inactivate the sperm receptors and harden the zona pellucida, preventing polyspermy.

2) meiosis II completion, and formation of the second polar body, due to fertilization. Oocyte and sperm are now called an ovum.

3) rapid metabolic incr as previously inactive mRNA strands are activated for development.

Front 11

what is the moment of conception and what is the ovum called at that point?

Back 11

- after the male and female pronuclei migrate toward the center of the cell and spindle fibers form, the two nuclei fuse in amphimixis, allowing the 23 pairs of chromosomes from ea to come together. The cell is then called a zygote.

Front 12

what is the starting point for differentiation?

Back 12

- during follicular development the granulosa cells do not all produce the same a.a.s, nucleotides, glucose, mRNA molecules, etc. and the follicular cells, not all the same nutrients and chem messages, so the cytoplasm of the oocyte is not homogenous throughout. When the process of cleavage occurs different cells are produced c different cytoplasmic compositions, leading them toward different fates/differentiation.

Front 13

what is gestation and what are its periods?

Back 13

- the time spent in prenatal development.

-divided into the first, second, and third trimesters, ea lasting three months.

Front 14

what occurs in the first trimester?

Back 14

-embryonic and early fetal development brings the beginnings of all the major organ systems.

Front 15

what occurs n the second trimester?

Back 15

- organ and organ system development dominate, nearing completion by the end of the 6th month.

Front 16

what occurs during the third trimester?

Back 16

- rapid fetal growth and deposition of fetal adipose t. Most of the organ system become fully fxnal early on in this trimester.

Front 17

how many developmental weeks are there in the first trimester?

Back 17

- only 10wks.

Front 18

what is the process of cleavage?

Back 18

- a sequence of cell division that begins immediately after fertilization where the zygote becomes a pre-embryo, which develops into a multicellular complex called a blastocyst. Cleavage stops when the blastocyst contacts the uterine wall.

Front 19

what is the process of implantation?

Back 19

- the blastocyst attaches to the endometrium of the uterus and invades maternal tissues. The process also sets the stage for vital embryonic structures.

Front 20

what is the process of placentation?

Back 20

- b.v.s form around the blastocyst, and the placenta develops.

Front 21

what is the process of embryogenesis?

Back 21

- formation of the viable embryo, which establishes the foundations for all major organ systems.

Front 22

what is the fxn of the placenta?

Back 22

- to permit exchange between maternal and embryonic blood, supporting the fetus from its formation early in the first trimester until just after birth.

Front 23

what are the critical events of the first trimester?

Back 23

- cleavage, implantation, placentation, and embryogenesis.

Front 24

what does the first cleavage division produce?

Back 24

- two identical cells called blastomeres.

Front 25

what is a morula?

Back 25

- after 3 days of cleavage, the pre-embryo is a solid ball of cells resembling a mulberry, which typically reaches the uterus on day 4 after conception.

Front 26

what happens to the morula in the 2 days following implantation?

Back 26

- the blastomeres form a blastocyst around the blastocoele, c an out layer of cells called the trophoblasts and the inner layer called the inner cell mass which eventually becomes the embryo.

Front 27

what happens to the zone pellucida just prior to implantation?

Back 27

- enzymes released by the trophoblasts erode an opening in it, a process known as hatching, exposing the blastocyst to the uterine cavity fluids. The blastocyst enlarges and, when fully formed, contacts the endometrium, and implantation takes place.

Front 28

what is the syncytial trophoblast?

Back 28

- the trophoblasts on the side of the blastocyst that have adhered to the uterine wall, lose their plasma membranes creating a layer of cytoplasm c multiple nuclei around day 8.

Front 29

how does the syncytial trophoblast lead to further embryonic development?

Back 29

- it erodes the epithelial lining of the uterus and the maternal epithelial cells migrate to fix the gap created which envelopes the blastocyst so that further development occurs entirely within the fxnal layer of the endometrium. As the trophoblasts continue to enlarge they erode more endometrial lining and form lacunae and villi through which maternal blood flows to support embryonic development.

Front 30

how is the amniotic cavity formed?

Back 30

- by the space created between the separating inner cell mass and the trophoblast. When it first appears the cells of the inner cell mass are organized into an oval sheet two layers thick.

Front 31

what is gastrulation?

Back 31

- the process of forming a third layer of cells between the superficial and deep layers of the inner cell mass through the migration of the superficial layer towards the deep layer becoming disconnected from the superficial in the process. This forms the oval, three-layered sheet known as the embryonic disc.

Front 32

what are the three layers of the inner cell mass called, collectively?

Back 32

- the germ layers, known as the ectoderm, mesoderm, and endoderm.

Front 33

what are the four extraembryonic membranes?

Back 33

- the yolk sac, amnion, allantois, and chorion.

Front 34

which extraembryonic layer is important for the maternal-embryo exchange?

Back 34

- b.v. develop within the mesoderm of the chorion linking the embryo c the trophoblast

Front 35

what does the embryonic disc form and what happens to the other cells of the blastocyst?

Back 35

- the embryonic disc forms the body of the embryo and the other layers for the extraembryonic membranes.

Front 36

what forms the chorion?

Back 36

- mesodermal migration around the inner surface of the cellular trophoblasts.

Front 37

what forms the amnion?

Back 37

- mesodermal migration around the outside of the amniotic cavity, between the ectodermal cells and trophoblasts.

Front 38

what forms the yolk sac?

Back 38

- mesodermal migration around the endodermal pouch.

Front 39

in what week are the extraembryonic layers forming?

Back 39

- week 2.

Front 40

in what week does the head fold bulge into the amniotic cavity?

Back 40

- week 3.

Front 41

what does the base of the allantois eventually give rise to?

Back 41

- the urinary bladder.

Front 42

how does the placenta come to be?

Back 42

- the appearance of b.v. in the chorion result from the mesoderm extending along the core of ea trophoblastic villus (by the third week), forming chorionic villi in contact c maternal tissues and b.v.s. These villi continue to enlarge and branch, forming the placenta.

Front 43

in what week does the embryo move away from the placenta, and the body stalk and yolk stalk fuse to form the umbilical stalk?

Back 43

- week 5.

Front 44

what has happened by week 10?

Back 44

- the amnion has expanded to fill the uterine cavity and the fetus is connected to the placenta by an elongated umbilical cord.

Front 45

what does the umbilical cord contain?

Back 45

- the allantois, yolk stalk, and the placental b.v.s.

Front 46

describe the blood in the umbilical arteries.

Back 46

- it is deoxygenated and carries waste products.

Front 47

describe the blood in the umbilical vein.

Back 47

- it is O2 and nutrient rich.

Front 48

what vasculature provides the surface area for gas and nutrient exchange for the fetal side of the placenta?

Back 48

- chorionic villi.

Front 49

what cells of the placenta also work to make the placenta an endocrine organ, and for what hormones?

Back 49

- the syncytial trophoblasts produce human chorionic gonadotropin, human placental lactogen, placental prolactin, relaxin, progesterone, and estrogens.

Front 50

what is human chorionic gonadotropin?

Back 50

- hCG appears soon after implantation and is a reliable indicator of pregnancy (think home pregnancy tests). It resembles LH fxnally. It maintains the corpus luteum and promotes progesterone and estrogen secretion from the placenta. This results in the endometrial lining remaining fxnal throughout the pregnancy and the absence of menses, despite the corpus luteum diminishing in fxn.

Front 51

what is human placental lactogen?

Back 51

- hPL is one of the syncytial trophoblast hormones that helps prepare the mammary glands for milk and has a stimulatory effect similar to GH, ensuring glucose and protein availability for the fetus.

Front 52

what is placental prolactin?

Back 52

- one of the syncytial trophoblast hormones required to convert the mammary glands from inactive to active.

Front 53

what is relaxin?

Back 53

- a peptide hormone secreted by the placenta and the corpus luteum. It incr the flexibility of the pubic symphysis, allowing the pelvis to expand during delivery; causes the cervix to dilate to make it easier for the fetus to enter the vaginal canal; and suppresses the release of oxytocin by the hypothalamus and delays the onset of labor contraxns.

Front 54

what is significant about estrogen and progesterone production after the first trimester?

Back 54

- the placenta secretes enough progesterone to ensure the fxnal zone of the endometrium remains intact throughout the remainder of the pregnancy. At the end of the third trimester placental estrogen production accelerates, which plays a role in stimulating labor and delivery.

Front 55

what are the organ systems that develop out of the ectoderm?

Back 55

IS NERD

integumentary, skeletal, nervous, endocrine, respiratory, and digestive.

Front 56

what organ systems developed out of the mesoderm?

Back 56

I Rep MUSCLE ppp

integumentary, reproductive, muscular, urinary, skeletal, cardiovascular, lymphatic, and endocrine, parietal, pericardial, and peritoneal lining and c.t. supporting organs

Front 57

what organ systems developed out of the endoderm?

Back 57

R U RED

resp, urin, repro, endo, digestive

Front 58

how do the mother's respirations adjust for the fetal needs?

Back 58

- by increasing rate and tidal volume.

Front 59

how does the mother's blood adjust for the fetal needs?

Back 59

- the maternal blood volume incr by almost %50 by the end of gestation because the blood flowing into the placenta decreases the vol of the systemic circuit and because fetal metabolism decrease blood Po2 and incr Pco2, the later of which triggers renin and erythropoietin release to incr RBC production.

Front 60

how do the mother's nutrient needs change for the fetal needs?

Back 60

- her nutrient requirements incr by %10-%30 and her appetite adjusts fire.

Front 61

how does the mother adjust to increased urinary demands?

Back 61

- her glomerular filtration rate incr by ~%50.

Front 62

how do the mother's uterus adjust for the fetal size?

Back 62

- it undergoes tremendous increase in size.

Front 63

how does the mother's body prepare for feeding the newborn?

Back 63

- hormones throughout the gestation period prepare her mammary glands for milk production.

Front 64

how does the uterus expand to meet the needs of the growing fetus?

Back 64

- through hypertrophy of the existing cells (esp. the smooth m. fibers) instead of incr the number of cells.

Front 65

what is false labor?

Back 65

- occasional, irregular, and non-persistent spasms of the uterine musculature.

Front 66

what is true labor and what ensures that it continues?

Back 66

- it begins when biochemical and mechanical factors reach a point of no return i.e. once labor contraxns begin in the myometrium. Positive feedback ensures they'll continue until delivery is complete.

Front 67

what is parturition and what does the uterus do to facilitate it?

Back 67

- the forcible expulsion of the fetus, aka childbirth. The uterus rhythmically contracts from the sup portion toward the inf portion, sweeping in a wave toward the cervix. The contraxns incr in freq and strength as parturition approaches, changing the position of the uterus and pushing it toward the cervical canal.

Front 68

what are the stages of labor?

Back 68

1) dilation stage

2) expulsion stage

3) placental stage

Front 69

what is the dilation stage of labor?

Back 69

- it begins c the onset of true labor, as the cervix dilates and the fetus begins to shift toward the cervical canal. Labor contraxns last up to half a minute and occur q 10-30min c incr freq. Late in this stage the amniochorionic membrane ruptures (water breaks).

Front 70

what is the expulsion stage?

Back 70

- begins as the cervix being pushed open by the approaching fetus, dilates to ~10cm. Contraxns reach maximum intensity, lasting a full min and occurring q 2-3min. This continues until delivery.

Front 71

what is delivery?

Back 71

- the arrival of the fetus into the outside world.

Front 72

what is an episiotomy?

Back 72

- a temporary incision through the mother's perineal musculature, done if the vaginal canal is too narrow for delivery or if there's an acute danger of perineal tearing.

Front 73

what is a cesarean section?

Back 73

- a c-section is an incision through the abdominal wall, and the uterus, just big enough to allow passage of the infant's head.

Front 74

what is assessed in the infant immediately after birth?

Back 74

- five areas each ranked at 0-2 c a score of 8-10 being a healthy baby. The areas are HR, breathing, skin color, m. tone, and reflex response. This is called an Apgar score.

Front 75

what is the placental stage of labor?

Back 75

- m. tension builds in the walls of the uterus, which tears the connections between the endometrium and placenta. There is associated blood loss but should be accommodated without incident.

Front 76

what is premature labor?

Back 76

- occurs when true labor begins before the fetus has completed normal development.

Front 77

where is the dividing line between spontaneous abortion and immature delivery?

Back 77

- usually 17.6oz, the normal weight near the end of the second trimester.

Front 78

what happens to most fetuses born at 25-27wks gestation?

Back 78

- they die despite intensive neonatal care.

Front 79

what is premature delivery?

Back 79

- usually births at 28-36wks. Much better chance at survival than under 28wks.

Front 80

what direction does the fetus typically face during birth?

Back 80

- it is head-first, facing the sacrum.

Front 81

what is used to deliver a baby facing the mother's pubic symphysis?

Back 81

- a forceps delivery method, where forceps are used to grasp the infant's head and pulled intermittently, so that the forces on the head resemble those of normal delivery.

Front 82

what happens in a breech birth and what risk are associated c it?

Back 82

- the legs or buttocks enter the vaginal canal first, risking constriction of the umbilical cord, and cutting off placental blood flow.

Front 83

what are dizygotic twins?

Back 83

- those that develop from two separate oocytes being ovulated and fertilized. %70 of twins are dizygotic. The chance of them having identical genes exceeds 1 in 8.4million.

Front 84

what are monozygotic twins?

Back 84

- result either from separation of blastomeres early in cleavage, or from splitting of the inner cell mass before gastrulation. Their genetic makeup is identical because both formed from the same pair of gametes.

Front 85

what do triplets, quadruplets, and larger multiples result from?

Back 85

- multiple ovulations, blastomere splitting, or some combination of the two.

Front 86

what are conjoined twins?

Back 86

- Siamese twins develop from incomplete splitting of the blastomeres or of the embryonic disk.

Front 87

what are the five postnatal life stages of development?

Back 87

1) neonatal period

2) infancy

3) childhood

4) adolescence

5) maturity

Front 88

what is senescence?

Back 88

- the process of aging.

Front 89

when is the neonatal period?

Back 89

- from birth to one month of age.

Front 90

when is infancy?

Back 90

- babyhood is after the first month through the first year of life.

Front 91

when is childhood?

Back 91

- from infancy until adolescence.

Front 92

when is adolescence?

Back 92

- begins c puberty, the period of sexual and physical maturation and ends when growth is completed.

Front 93

what is pediatrics?

Back 93

- the medical specialty that focuses on postnatal development from infancy through adolescence.

Front 94

when is the neonatal period exactly?

Back 94

- from birth through 28 days.

Front 95

what events take place in transition from fetus to neonate?

Back 95

- a massive powerful inhalation is required to inflate the collapsed, fluid-filled lungs.

- cardiovascular circulation changes as the ductus arteriosus closes, isolating the pulmonary and systemic trunks. Closure of the foramen ovale separates the atria of the heart.

- heart rate is 120-140 c RR of 30 and metabolic rate 2x the adult rate.

- meconium is excreted in the first few days as the newborn begins to nurse.

- neonate kidneys cannot concentrate urine yet so fluid intakes are high.

- little ability to control body temp, esp. in first few days.

Front 96

when are the mammary glands fully developed by?

Back 96

- the end of the 6th mo.

Front 97

what is colostrum?

Back 97

- ingested by the infant in the first 2-3days of life, colostrum contains more proteins and far less fat than breast milk. Many of the prots are Abs. And the mucins present in both colostrum and milk can inhibit the replication of rotaviruses.

Front 98

what is the milk ejection reflex?

Back 98

- the milk letdown reflex is triggered by stimulation of tactile receptors when the infant suckles; neural impulse transmission is propagated to the brain; oxytocin is secreted from the post. pit. lobe in response to stimulation from the maternal hypothalamus; oxytocin enters the blood stream.

Front 99

what does breast milk consist of?

Back 99

- water, prots, a.a.s, lipids, sugars, and salts, as well as large quantities of lysozymes (enzymes c ABX properties).

Front 100

when is the most rapid growth?

Back 100

- during prenatal development.

Front 101

what are the three major hormonal events that occur at the onset of puberty?

Back 101

1) the hypothalamus incr its production of GnRH.

2) circulating FSH and LH levels incr rapidly as the endocrine cells in the ant. lobe of the pit. gland become more sensitive to GnRH.

3) ovarian or testicular cells become more sensitive to FSH and LH. These cells initiate gamete production; secretion of sex hormones that stimulate secondary sex characteristics and behaviors; and a sudden acceleration in growth rate, ending c closure of the epiphyseal plate.

Front 102

what are integumentary changes seen during puberty?

Back 102

- terminal facial hair in men. Terminal hair in the axillae and genital regions in both sexes. Androgens stim sebaceous gland secretion and may cause acne. Adipose tissue is distributed according to gender. Mammary gland development in girls though much growth of the breasts is due to incr fat deposition instead of glandular tissue.

Front 103

what are skeletal changes seen during puberty?

Back 103

- incr bone deposition and growth in both genders. Boys typically grow taller because estrogens cause epiphyseal closure faster than testosterone. Girls grow fastest from ages 10-13, whereas boys are from 12-15.

Front 104

what are muscular changes seen during puberty?

Back 104

- incr strength and endurance c testosterone exceeding estrogen resulting in larger m. mass in boys than girls.

Front 105

what are nervous system changes seen during puberty?

Back 105

- sex hormones activate CNS centers and effect their sexual drive and sexual behaviors.

Front 106

what are cardiovascular changes seen during puberty?

Back 106

- testosterone stims erythropoiesis, increasing blood vol and hematocrit. In females who've begun menses, the blood loss can result in iron deficiency anemia. Late in ea uterine cycle estrogens and progesterone can cause fluid shifts into the periphery. Estrogens decr the risk of atherosclerosis in females before menopause.

Front 107

what are respiratory changes seen during puberty?

Back 107

- lengthening and thickening of the male vocal cords and growth of the larynx, cause a deepening of the voice.

Front 108

what are reproductive changes seen during puberty?

Back 108

- in males, testosterone stims the fxnal development of accessory reproductive glands (i.e. prostate gland and seminal glands). In females estrogens promote thickening of the myometrium, incr blood flow to the endometrium, and stim cervical mucus production, as well as the development of accessory reproductive organs.

Front 109

what is geriatrics?

Back 109

- the medical specialty that deals with the problems associated c aging.

Front 110

what are geriatricians?

Back 110

- physicians trained in geriatrics.

Front 111

what are fxnal segments of DNA called?

Back 111

- genes.

Front 112

what is a genotype?

Back 112

- the 46 chromosomes (and their associated genes), carried in ea of our body's nucleated somatic cells, that hold the instructions which determine ea of our unique anatomical and physiological characteristics.

Front 113

what is a phenotype?

Back 113

- the anatomical and physiological characteristics that are determined by our individual genotypes, and which are result from the interaction between the person's genotype and the environment.

Front 114

give some examples of phenotypic traits or characters.

Back 114

- eye and hair color, height, skin tone, foot size.

Front 115

what are homologous chromosomes?

Back 115

- a set of one maternal and one paternal chromosome that pair up c each other inside a cell during meiosis. These copies have the same genes in the same loci.

Front 116

what are autosomal chromosomes?

Back 116

- chromosomes that are not allosomes.

Front 117

what are allosomes?

Back 117

- sex determining chromosomes.

Front 118

what is a karyotype?

Back 118

- the complete set of chromosomes in an organism.

Front 119

what is a locus?

Back 119

- a gene's position on a chromosome.

Front 120

what are alleles?

Back 120

- different forms of the same gene (i.e. blue eyes or brown eyes allele).

Front 121

what does it mean to be homozygous?

Back 121

- it means that both chromosomes contain the same allele for the trait affected by that gene (i.e. brown eye, brown eye, or, red hair, red hair). This means that allele will indeed be expressed in the phenotype.

Front 122

what is simple inheritance?

Back 122

- the phenotype is determined by interactions between a single pair of alleles. ~%80 of human genotype falls within this category.

Front 123

what does it mean to be heterozygous?

Back 123

- the organism carries two different alleles for the same gene.

Front 124

what determines the phenotype for a heterozygous gene?

Back 124

- the interaction between the alleles depending on their relationship to each other (i.e. strict dominance, incomplete dominance, or codominance.

Front 125

what is strict dominance?

Back 125

- an allele that is dominant will be expressed in the phenotype, regardless of any conflicting instructions carried by the other allele.

Front 126

when is a recessive allele expressed in a phenotype?

Back 126

- only if that same allele is present in both chromosomes of a homologous pair.

Front 127

what is incomplete dominance?

Back 127

- a relatively rare occurrence in humans, this is where the heterozygous alleles produce an intermediate phenotype (not completely dominant).

Front 128

what is codominance?

Back 128

- an individual who is heterozygous for a given trait exhibits both phenotypes for that trait. Human blood type is determined this way.

Front 129

what is penetrance?

Back 129

-the percentage of individuals c a particular genotype that show the "expected" phenotype.

Front 130

what is expressivity?

Back 130

- the extent to which a particular allele is expressed when it is present.

Front 131

what are teratogens?

Back 131

- factors from the environment that result in abnormal fetal development.

Front 132

what is polygenic inheritance?

Back 132

- the phenotype is determined by interactions among the alleles of several genes (i.e. hair color, skin color, eye color, height).

Front 133

what is genetic recombination?

Back 133

- the exchange of corresponding segments and groups of genes that produces offspring c combinations of traits different from those found in either parent.

Front 134

what is crossing over?

Back 134

- the adjacent chromatids within a tetrad overlap each other and break off, switching places. In general this occurs between homologous chromosomes.

Front 135

what is translocation?

Back 135

- the adjacent chromatids of nonhomologous chromosomes overlap, break off, and switch spots.

Front 136

what are chromosomal abnormalities?

Back 136

- damaged, broken, missing, or extra copies of chromosomes. This occurs in about %10 of chromosomes but only about %0.5 of all newborns have the abnormalities.

Front 137

what is genomic imprinting?

Back 137

- it results in specific chem modifications, or markings, of DNA and its associated prots. These changes then dictate whether the gene is expressed or silenced. These markings persist after fertilization and determine whether or not the maternal or paternal gene is transcribed during embryonic development.

Front 138

what normal process acts as a "volume control" for parental genes?

Back 138

- imprinting.

Front 139

what is a mutation?

Back 139

- changes in the nucleotide sequence of an allele.

Front 140

what is a spontaneous mutation?

Back 140

- mutations that result from random errors in DNA replication.

Front 141

what are carriers?

Back 141

- individuals who are heterozygous for an abnormal allele but do not show the phenotypic effects of the original mutation.

Front 142

what is sex-linked inheritance?

Back 142

- involves genes on the sex chromosomes.

Front 143

what are the two types of sex chromosomes and what is different about them?

Back 143

- X chromosomes and Y chromosomes. X's are considerably larger and have more genes than do Y's. The Y chromosomes carry the SRY gene, not found on the X chromosomes. It specifies that an individual carrying it will become male.

Front 144

what is the sex chromosome pair for a man? For a woman?

Back 144

- XY

- XX

Front 145

what are X-linked genes? Y-linked?

Back 145

- those found on the X chromosome but not the Y.

- those found on the Y chromosome but not the X.

Front 146

what gender is most often effected by recessive alleles on X chromosomes?

Back 146

- males.

Front 147

what is the human genome?

Back 147

- the full set of genetic material in our chromosomes.

Front 148

what is epigenetic?

Back 148

- the study of inherited traits that are not due to changes in a person's genotype or DNA sequences. Similar to genomic imprinting, it acts at a level "above" the DNA by activating or inactivation specific genes.

Front 149

what is the epigenome?

Back 149

- all the chems that mark our genome and affects its activities.

Front 150

what is the ENCODE?

Back 150

- the encyclopedia of DNA Elements, which revealed that %80 of the genome is active in one way or another in gene regulation.