Week Two - Foundations of Development Flashcards
What do genes do?
Create the proteins and enzymes that build and regulate the body
Where are genes located?
On chromosomes (every cell contains chromosomes)
What is a genotype?
Actual genetic makeup
What is a phenotype?
How those genes are expressed
Explain identical twin genes
Monozygotic with 100% gene overlap and possibly 100% environment overalp
Explain fraternal twin genes
Dizygotic (50% genes) and possibly 100% environmental overlap
What is Canalisation?
Where behaviour follows a genetic ‘blueprint’
What is niche picking?
Seeking an environmental niche that suits genetics
What is reaction range?
Genes ‘set the boundaries’ for environmental effects
the environment will determine where in the reaction range you will be (eg iQ)
What is the germinal stage of prenatal development?
Begins 0-2 weeks and the zygote divides and redivides into hundred of cells (blastocyst) and then implants onto uterine wall (fully implanted blastocysts = embryo)
Explain the Embryonic stage of prenatal development?
weeks 3-8.
Basic organs are formed and the embryo begins to response to direct stimulation
What happens after week 3 of conception?
The embryonic disk differentiates into:
ectoderm
mesoderm
endoderm
What occurs in the first 1-2 months of the embryonic stage?
Month 1:
develop brain, heart, muscles, spine, rubs, DS
Month 2:
develop eyes, nose, mouth, neck, limbs start to harden and form
What occurs in the fetal stage of prenatal development?
weeks 9 to birth
organs rake on final form and begin to function
become more human in proportion
respond to external stimuli
What is a babies physical condition (when born) assessed by? Describe it.
Apgar scale at 1 and 5 mins with ratings from 1-3
Assesses heart rate, breathing ability, reflexes, skin colour and muscle tone
a score of 7-10 = good
4-6 = fair condition
0-3 = very poor
What is teratogen?
A substance/environmental influence that can damage embryos development (causing serious malformation or even death)
Includes diseases, drugs, and other harmful influences
Do teratogens always have the same effect?
No. They have different effects at different times in development
Explain a sensitive period (in regard to teratogen)?
Each organs sensitivity varies over time, some teratogens may not influence later in pregnancy
Explain tissue-specific effects of teratogens?
They work in specific ways on specific tissues
Does the mother also experience effects of teratogen?
Not always - she may have no adverse effect
What are some individual differences with teratogens?
The effects of them differ according to foetus as well as mother
What is the dose-response relationship regarding teratogens?
The greater the dose of the teratogen, the worse the effect
Explain medicinal drug teratogens?
Some drug molecules are small enough to cross the placental barrier and affect foetus including:
Aspirin
Quinine
Thalidomide
Explain non-medicinal drug teratogens?
Things like tobacco, heroin, alcohol. Make baby at risk of many health problems such as prematurity, low-birthweight, addiction
Why is foetal research limited?
Because we are limited by relative inaccessibility to the foetus
Explain learning in utero
The foetus can habituate to repetitive sounds (we can tell by changes in heart rate, kicking). This persists after birth as babies develop postnatal preferences (prefer things they had before birth)
