Class Notes (834,026)
Canada (508,290)
Psychology (5,208)
PSYCH 2AA3 (402)

Prenatal Development.docx

8 Pages
Unlock Document

Richard B Day

May 9 , 2013 Psych 2AA3: Child Development Prenatal Development Video - “In the Womb” (National Geographic)  Neural development  Reflexes  Sensory development  Learning  Fetal behaviour Conception and Genetics - Homozygous pair  When the two sets of instructions are the same at any given locus - Heterozygous pair  When the two sets of instructions are different at any given locus - Genotype – the genetic blueprint  Information contained in the genes  All of the information regardless if it is expressed - Phenotype – observable characteristics  Expressed genes - Dominant-recessive pattern  Dominant genes always express their characteristics  Dominant homozygous pairs  Or heterozygous  Both recessive genes must be present to express their characteristics - Twins  Identical (monozygotic)  Single egg that has been fertilized and split  Sharing of the placenta depends on how early or late the split has occurred  Identical set of genes (100% of shared genes)  Fraternal (dizygotic)  Two separate eggs released within 24 hours  Fertilized by two different sperms  No more similar than siblings (50% of shared genes)  The case of the vanishing twin  Blood supply to one twin is inhibited killing the second foetus - Twins in genetic research Sex Differences in Prenatal Development - Between weeks 4 and 8, males begin to secrete testosterone from primitive testes  2/3 of sperm are male  Male embryos are more delicate  Males are more likely to result in miscarriage  Males have more disease, earlier death, and shorter lifespans in most of the world  Necessary to develop male genetalia  Lack of testosterone will “demasculinize” the male embryo  The amount of testosterone influences the direction the embryo will take  Chromosomes XX and XY affect the levels of testosterone  Too much testosterone will “defeminize” the female embryo  Females begin producing their eggs in vitro  Grandmothers may have an effect on the outcome of their daughters’ offspring - Prenatal hormones may influence sex differences in:  Brain development  Prenatal testosterone may cause things such as autism  Brain development and lateralization of the brain  Hormones in adolescence  Set up hormone production in adolescence  Levels of hormones in puberty  Levels of physical aggression  Relative dominance of right and left hemispheres  A lot of this research is speculative and largely based upon animal research - Girls  Slightly faster skeletal development - Boys  Slightly heavier and longer at birth  Sets mom’s system to be more cautious the next time she delivers a boy  Increased risk of miscarriage when having a second boy  More vulnerable to prenatal problems  Health problems  Learning disabilities  More likely to be aborted spontaneously  Have more birth injuries and birth defects  X-related problems may be a factor  A lot of disorders are based on defects of the X chromosome  In the case of an XY pair, if there is something wrong with the X there is no other X to rectify the problem  Example: colour blindness is more prevalent in males  Slightly more active before birth  Boys may be beginning the physical practice earlier setting themselves up for more physical activity later on  There is an increase level of activity in preschool-aged boys Prenatal Behaviour - Fetuses respond to sound with body movements as early as 25 weeks  Example: music, ultrasounds - Can distinguish between familiar and novel stimuli by 32 weeks - Learning may begin prenatally (~32 weeks)  “The Cat in the Hat” experiment  Music experiments  After birth, those that were exposed responded differently (more calmly) when they were presented with the stimuli they had been presented prenatally - Music played prenatally may lead to advanced motor and cognitive skills at six months  In line with research suggesting that various types of music exposure and music training are more advantageous later in life  Mozart effect: preforming better on a cognitive task after listening to music  Doesn’t matter what kind of music it is  Music stimulates the brain and improve cognitive development Problems in Prenatal Development - Corresponds to high rate of miscarriage - Genetic disorders  Autosomal disorders  Caused by recessive genes o Phenylketonuria (PKU)  Protein that cannot be metabolized by the protein  Found in breast milk  Causes brain damage  Screened for genes at birth  By altering the diet, we can prevent the brain damage o Sickle-cell disease  Identified as having an evolutionary purpose  Resistance to malaria  Prominent in those of African descent  Where malaria does not exist this gene does not have this purpose  Allowed to carry on in ancestors as it protected them from malaria o Tay-Sachs disease  Tend not to live past the age of 3 or 4  Most commonly found in populations that tend to be more restricted, for example in Jewish populations as they tend not to marry outside of their group  Caused by dominant genes o Huntington’s disease  Most dominant gene disorders find their way out of the population as those who carry them will not end up to reproduce  Huntington’s is not manifested until after reproductive age o Schizophrenia  Tends not to be expressed until later in life o Migraine headaches o Extra fingers o Most disorders caused by dominant genes tend to be those that we can live with such as migraine headaches and extra fingers  Sex-linked recessive disorders
More Less

Related notes for PSYCH 2AA3

Log In


Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.