Developmental 3 Flashcards
describe the natural variation in human population
Physical variation: Hair/Eye colour, height, baldness.
• Cognitive variation: IQ, language, memory.
• Behavioural variation: personality.
Describe chromosomes in genes
• 46 chromosomes (22 pairs of autosomes, 2 sex
chromosomes)
what is on each chromosome
On each chromosome there are set of genes, which code
for organism functions either in isolation or through
interaction with other gene
what does genetics suggest
• We inherit traits from our familial group.
• Some instances of inheritance are simple (i.e.,
involving one gene).
• Others are more complex: polygenic inheritance
what is dominant gene
Dominant gene: requires one copy of gene to reveal trait
what is recessive trait
requires two copies of a gene to reveal
trait.
what are genetic disorders caused by dominant genes
give an examine
Disorders caused by dominant genes: one copy of gene sufficient.
- **Huntington’s Disease: **
- Nervous system deterioration after the age of 40 years.
- All carriers develop the disease.
describe genetic disorders caused by recessive genes
give example
both copies of genes required
• Phenylketonuria (PKU):
• inability to metabolise phenylalanine, an amino acid found in food.
• Phenylalanine accumulates in blood, causing severe cognitive deficits
and other abnormalities.
describe how chromosomal abnormalities amount
chromosomal abnormalities occur when there are errors in cell division during gamete formation (sperm and ovum)
Give an example of a syndrome resulting from chromosal abnormality
Down Syndrome (Trisomy 21).
• Low IQ (average = 55).
• Memory and speech problems.
• Limited vocab.
• Motor problems.
• Congenital eye, ear, heart and
intestinal defects.
• More common in older mothers
abnormality of sex chromosome syndromes
**Turner Syndrome **female, short, webbed neck, heavy
build, infertile, poor memory and
spatial ability.
Poly-x syndrome female, tall, fertile, impaired verbal
intelligence.
what is phenotype
genetics + environment
what is polygenic inheritance
polygenic trait is one whose phenotype is influenced by more than one gene. Traits that display a continuous distribution, such as height or skin color, are polygenic
what is behavioural genetics explore
influence of genetics on behaviour
what is heritability
the proportion of a given behaviour that is due
to genetics rather than environmental factors.
What are two types of natural experiment that distinguishes behaviour from environment
Twin studies
adoption studies
differences between identical and fraternal twins
Identical
• Splitting of a **single fertilized
egg. **
• Same DNA (although the rise
of epigenetics does admit
differences)/Same
environment.
• **Fraternal **twins
• Separate fertilisation of two
eggs. **
• Same environment/different **
DNA.
what was the assumption made from twin studies?
If identical twins are more similar on a given behaviour than
fraternal twins, then that behaviour has a **heritable **
component.
limitation to twin studies
each type of twin share the
same environment
3 comparison groups in adoption studies
which one of the traits is most typical
• Leads to three comparison groups:
- Genetics + environment.
- Shared environment.
- Shared genetics.
number 1
limitations of adoption studies
Generalisability:
adoption agencies ‘match’ children to families of simlar background - confounds interpretation of environment
what is pre-natal development
what is the developing child influenced by
most rapid and dramatic period of change across
the lifespan
- Teratogenic
- • External influences eg. pathogens, drugs cause birth deficits
- Alcohol syndrome
FAS is?
- fetal alcohol syndrome
- Smaller brains lacking in cortical convolutions.
- Excessive irritability, hyperactivity, seizures, & tremors.
- Retarded physical growth.
• Moderate alcohol intake (1 drink per day) can cause minor physical and behavioural abnormalities (not FAS).
Heavy drinkers (5 per day) have a **30%** chance of having children with FAS.
are children born with knowledge of world?
no, they are not
