Ch 2 Flashcards
the 3 letters of the DNA alphabet
A C T J
a group of 3 bases is called
codons
genes combine into large rod like structures called
chromosomes
how many pairs of chromosomes do we have
23
how many total chromosomes do we have
46
meiosis creates sex cells called
gametes
germ cells divide into 4 ______ cells
daughter
if a sperm with an X chromosomes fertilizes an egg, the offspring will be a
girl
some differences arise from _____ ,or when parts of chromosomes get rearranged with parts of other chromosomes
translocation
sometimes there are sections of the chromosomes that _____ each other and create new genetic combinations in the new cells
crossover
the only 2 individuals who can share the same chromosomes
identical twins
the other name for identical twins
monozygotic twins
what type of alleles make the effect of any other allele of the same gene
dominant
what type of alleles only show up if both parents pass them on to their child
recessive
what type of alleles are both expressed in a child
codominant
genetic disorders can be dominant, recessive and
sex linked
sometimes geographic and _____ backgrounds make people prone to certain genetic disorders
ethnic
some disorders occur as a result of random errors involving an incorrect number of
chromosomes
who can educate people about genetic disorders before or after pregnancy
genetic counselors
what type of test can doctors run to determine people’s risk factors or current conditions
screening tests
what describes a persons dominant and recessive genes
genotype
a persons location, diet , how they are treated by others, and other factors called
their environment
a persons _____ is the way in which all of a persons traits are expressed
phenotype
development
the origins of the genetic structures that determine embryos
Heredity
transmissions of traits and characteristics from parent to child by genes
genetics
the study of genes or heredity
1 egg meets 1 sperm and 1 zygote splits into 2
monozygotic twins or identical twins
2 eggs meets 2 sperms and share only 50 percent of genetic material
Dizygotic twins or fraternal twins
chance of twins increases
with maternal age or use of fertility drugs
Genetic counseling
addresses chances of genetic abnormalities
Amniocentesis
performed between 14-16 weeks
ultrasound
tracks fetal growth and determines age, sex and structural care
conception
egg and sperm meet succesfully
what are some causes of fertility problems
low sperm count, deformed sperm, any thing that impacts you from getting pregnant
artificial insemination
sperm injected into uterus (think turkey baster)
In Vitro Fertlization
egg and sperm are fertilized in a dish then implanted in the uterus
Surrogates
carries the baby for someone else, not biologically theirs
adoption
last option for having children
Germinal State
period from conceptions (2 weeks)
how many hours does the zygote begin dividing
36
how long does the zygote wander in the uterus before implanting
3-4 days
how long does implantation take
1 week or so
other name for miscarriage
spontaneous abortion
when do most miscarriages occur
in the 1st 3 months
what is an ectopic pregnancy
when the zygote attaches to the fallopian tube instead of implanting in the uterus
when is the embryo stage
week 3 to 8
cephalocaudal
head develops before everything else (big head)
Proximodistal
development from central axis to outward ( limbs)
Where is the Ectoderm located on the embryonic disc
outer layer
what does the ectoderm develop
nervous system, hair, nails
where is the endoderm located on the embryonic disc
inner layer
what does the endoderm develop
pancreas, liver, digestive system
where is the mesoderm located on the embryonic stage
middle layer
what does mesoderm develop
reproductive system, circulatory system, muscles, skeletons
what is an amniotic sac
the clear membrane that protects the fetus and filters between both blood streams
what is a placenta
provides oxygen and nutrients to the fetus
what connects the fetus to the placenta
the umbilical cord
when is the fetal stage
3rd month through birth
what can the fetus do during the 2nd trimister
open and shut eyes, sucks thumbs, responds to light and sounds
what can the fetus do during the 3rd trimister
gain weight and length, heart and lungs increase capability, turns upside down
when does the fetus begin to move
during the 4th and 5th month
what are teratogens
agents that can harm the fetus during pregnancy
examples of some teratogens
malnutrition, obesity, STIs, drugs, alchol, HIV, pre eclampsia
what is pre eclampsia
when your blood pressure is too high so baby must be born asap to relive
what is Rh
where mothers own body tries to attack the fetus
how can doctors make sure that babies don’t contract their mothers HIV
through a controlled c- section or vaginally by slamming baby with medication after delivery
how can doctors help mothers with Rh incompatibility
by giving mothers shots that trick the body into not attacking the fetus
what does DNA stand for
Deoxyribonucleic acid
what is mitosis
the cell division process by which growth occurs and tissues are replaced
where are sperm and ova produced
testes and ovaries
people who bear 1 dominant and 1 recessive are called
carriers
what syndrome does people that have the 21st pair of chromosomes has an extra , or 3rd chromosome
down syndrome or trisomy 21
phenylketonuria (PKU) is transmitted by what type of gene
recessive
sickle cell anemia is caused by what type of gene
recessive
what is fertlization
the union of ovum and sperm
what is the most common reason in women to be infertile
failure to ovulate
what percent of overlap do parents and children have in their endowment
50
development from infancy to puberty is ?
child
what age is infancy
1st 2 years of life
what ages are early childhood
ages 2 to 5
what ages are middle childhood
ages 6 to 12
what does tabula mean
a blank tablet or clean slate
