Genetic influences on development and prenatal development Flashcards
How many genes and chromosomes are we born with?
Each of us is born with about 23,000 genes in our 46 chromosomes; however not all of these are expressed
What is a genotype?
Organisms unique genetic inheritence
What is a phenotype?
Organisms actual characteristics derived from its genotype ( the environment plays a role in genetic expression)
What are females and males sex chromosomes?
Females XX
Males XY
What is epigenesis?
Bidirectional interactions between genes and environment in development
What is the thoery of genotype and what are the 3 types?
Passive
Evocative
Active
When does parental development begin?
Begins with conception
When is the germinal stage?
0-2 weeks following conception
What percent of blostocysts don’t implant successfully?
50%
What are the stages of prenatal development?
Conception
Germinal (0-2 weeks): blastocysts implants in uterus wall
Embryonic (3-8 weeks): umbilical cord connects embryo to placenta, amniotic sac develops
Foetal (week 9 to birth)
What happens in prenatal care?
Mothers are often screened and vaccinated if necessary against infectious disease (rubella)
During pregnancy, prenatal care focuses on diet, exercise, avoiding teratogens and fetal monitoring
What are tarotogens?
Behaviours, environments and bodily conditions that could be harmful to the developing baby
What is the embryonic period?
A critical period for teratogen exposure, yet can be a time before expectant mothers are aware of the pregnancy
What is the most common teratogen?
Malnutrition (lack of food, lack of nutrients due to seasonal availability) ; infectious diseases (globally)
In developing countries alcohol and smoking
What percent of births have a chromosome disorder?
0.5%
What can sex chromosome disorders linked to?
Learning difficulties or abnormalities in the development of the reproductive system
When does down syndrome occur?
When there is an extra chromosome on the 21st pair
What can be a contributor to chromosomal disorders?
Parental age
What is our development shaped by?
Genetics and our environment
What does heritability estimate?
What degree a certain behaviour or trait is related to our genes
What stage is our most vulnerable period?
Embryonic stage
