Genetics and Prenatal Development Flashcards
epigenetic theory
genetic activity responds constantly to environmental influences
meiosis
formation of gametes
ovulation
ovum bursts and releases into fallopian tubes
dz twins
two ova fertilized by 2 sperms; fraternal with 40 - 60% of genes in common
mz twins
1 zygote splits into 2 separate clusters of cells; maternal & identical
chromosome
structure in nucleus of cells that has genes; paired unless in reproductive cells
dna
stores and transfers genetic info
genes
basic unit of hereditary info
genome
all genes within all chromosomes
genotypes
all genes within a person
phenotype
genes that determined a person’s characteristics
dominant recessive inheritance
when each pair of chromosomes has a dominant and a recessive gene but only the dominant gene shows up in the phenotype
allele
each form of a gene (d or r)
incomplete dominance
when the phenotype is influenced mostly but not fully by dominant genes
polygenetic inheritance
the interaction of multiple genes influencing the phenotypic character
sex chromosomes
determine whether someone will be m or f
x-linked inheritance
when a recessive trait is expressed because it is carried on the male x chromosome
behavior genetics
the study of how much genes influence development
heritability
an estimate of how much genes are responsible for differences within a population; measure phenotype
concordance rate
a percentage of the degree of similarity in phenotype among pairs of family members
epigenetic development
results from the bidirectional interactions between genes and environment
reaction range
established boundaries of a genetic characteristic
theory of genotype –> environment effects
genes influence the kind of environment we experience
passive genotype –>
parents provide genes and environment
evocative genotype –>
when inherited characteristics evoke reactions from others in their environment
active genotype –>
when people seek out environments that correspond to their genotypic characteristics
mitosis
chromosomes duplicate then divide to become new cells
gamete
ova and sperm
meiosis
gametes creation; separation and duplication of chromosome pares –> 4 gametes
cytoplasm
the fluid that is the main source of nutrients during the early days of conception
crossing-over
when DNA is exchanged during meiosis
follicle
matured form of ovum and other cells that surround it and provide it nutrients
zygote
the cell at the end of meiosis that is formed by 2 gametes
germinal period
the first 2 weeks after conception when zygote implants self in uterus
blastocyst
ball of 100 blood cells
trophoblast
oter layer of blastocyst that creates structures for protection and nourishment
embryonic disk
inner layer of blastocyst that becomes the embryo
amnion
the membrane that surrounds the fetus in temperature regulating gfluid and protects it
placenta
structure between embyronic disk and uterine wall that passes nutrients from mom to fetus and rids waste
umbilical cord
structure connecting placenta to fetus
embryonic period
3-3 weeks post conception
gestation
time since conception
ectodedrm
outer layer of emryonic disk that becomes hair, skin, nails, sensory organs, and nervous system
mesoderm
middle layer of embryonic disk that becomes muscles, bones, reproductive system, and ciruculatory systems
endoderm
inner layer of embryonic disk that becomes the digestive and respiratory systems
neural tube
result of ectoderm that becomes spinal cord and brain
neurons
cells of nervous system
neurogenesis
creation of neurons
fetal period
9 weeks to birth
trimesters
3 month periods during pregnancy
viability
ability to survive outside of the womb
vermix
the slime that covers baby to protect skin from chapping
teratogens
behaviors, environment, bodily conditions that could harm a fetus
fetal alcohol spectrum disorder
increase in alcoholism that causes facial deformities, heart problems, misshapen limbs, and cognitive problems
down syndrome
when there’s an extra chromosome on the 21st pair
multifactorial disorders
disorders linked to paternal age that involve a combination of genetics and environmental factors
genetic mutation
premanent alteration of a dna sequence that makes up a gene
techniques of prenatal monitoring
ways of monitoring the growth and health of the fetus; detects prenatal problems
ultrasound
device that points high frequency sound waves toward the uterus that bounce off and produce an image on the screen
maternal blood screening
tests administered during 1st or 2nd trimesters that use blood samples from mom that include genetic pieces of dna from fetus; used to identify risks to fetus like spina difida and down syndrome
amniocentesis
when a long needle is put in mom’s abdomen to get a sample of amniotic fluid from the placenta to get info on the fetus’s genotype
chronic villus sampling
when cells are sampled and analyzed early in development to detect genetic problems
infertility
inability to conceive after at least one year of trying
assisted reproductive technology
methods used to overcome infertility problems in m/f reproductive systems
intrauterine insemnination
injecting sperm into uterus around time of ovulation
fertility drugs
drugs that mimic hormones that trigger ovulation
in vitro fertilization
after fertility drugs, when ova removed from the body , mixed with sperm, and reinserted once a zygote is formed
