Lecture 2 Flashcards
Reproductive cells
Gametes
Fertilized ovum
zygote
Typical cells have ___ chromosomes
46
Gametes have ___ chromosomes
23
Single sperm cell penetrates the outer coating of the egg and fuses to form one fertilized cell
Conception
What are the 3 parts of prenatal development?
germinal, embryonic, fetal
0-2 weeks; point when developing organism attaches to wall of uterus
Germinal
2-8 weeks; implantation until point when all major organs take primitive shape
Embryonic
9 weeks- birth; begins with first signs of hardening bones
Fetal
Where does the zygote go through before attaching to the walls of the uterus?
Fallopian tube
Outer group of cells
Placenta
Inner group of cells
Embryo
Zyogote once cells start to separate
blastocyst
outer layer of embryo, outer skin, eye lens, inner ear, nervous system
ectoderm
inner layer, digestive system and lungs
endoderm
Middle layer, bones, muscle, circulator system
Mesoderm
Form head to tail
Cephalocaudal
From center of body outward
Proximodistal
___ week sex organs become visible
12th
____ month lower limbs develop, ear migrate
4th month
___ month all neurons are produced
5th
___ month lungs are capable of breathing air
7th
___ months the fetus has a much better chance of survival
7
___ weeks embryo is capable of responding to direct stimulation
8
___ weeks generalized movement
10
___ weeks fetus is capable of all movements seen in newborns
15
Why does fetal activity decrease at 6-8 months?
No space
___ weeks fetal sense of touch
8
___ months fetal sense of smell and taste
4-5
_____ months fetal sense of balance/motion
5-6
____ months fetal sense of audition
6
___ months fetal sense of vision
7
What are 3 factors that affect prenatal development negatively?
attitude, maternal malnutrition, teratogens
What is associated with spontaneous abortions, still births, and defects?
Malnutrition
What are some examples of teratogens?
Drugs, AIDS, environmental toxins
What can teratogens cause during pregnancy?
Prenatal physical/mental abnormalities
Chemicals or viruses that can enter the placenta and harm the developing fetus
Teratogens
Why is the unborn child most vulnerable during the embryonic period?
Major organs are being formed and can hinder the development
Genetic material is passed on as ____
chromosomes
Sections of DNA that are functional
Genes
Complete set of genes
Genotype
Observable physical and psychological characteristics
Phenotype
What creates your phenotype?
Genotype interacting with the environment
Largely controls the continuous switching on and off of genes
Regulatory genes
Genetic makeup establishes a range of possible outcomes, environmental forces largely influence how an individual develops
Range of reaction
Conditions and circumstances that surround an individual
Environment
