developmental psychology

1. Genes ,DNA, Genotype
In Development

2. Developmental Psychology
• Developmental psychology is the scientific study of how and why human
beings change over the course of their life.
• It is a scientific approach which aims to explain growth, change and
consistency though the lifespan. Nature/nurture, continuity
/stages,stability/change

3. Cells
• Your body is made up of trillions of cells
• In general, there are two categories of cells. Most of the cells in our body are
called somatic cells. Somatic cells have two genome copies.
• Egg and sperm cells make a different category called germ cells. Germ cells
start off with two genome copies.

4. Genes,DNA,Genotype
• DNA(deoxyribonucleic acid) is the molecule that is the hereditary material in all
living cells. Your body is made up of trillions of cells
• Genes are made of DNA. Genotype is the genes that a person inherits and the
phenotype is the expression of the genotype . Phenotype is a persons measurable or
observable characteristics
• The genome is the entire set of DNA instructions found in a cell. In humans, the
genome consists of 23 pairs of chromosomes located in the cell's nucleus, as well as
a small chromosome in the cell's mitochondria. A genome contains all the
information needed for an individual to develop and function. A genome is simply
the sum total of an organism's DNA

5. • Our bodies are made up of cells . Each cell contains genetic material which consists
of chromosomes which are made up of Genes which contain DNA which is the
material that carries instructions for building.
• Our DNA comes from our moms and dads. Half of our DNA comes from mom
through her egg cell and the other half comes from dad through his sperm cell.
• If you look at a cell’s worth of DNA under a microscope, we can see that DNA is
actually organized into structures called chromosomes. Most people have a total of
46 chromosomes.

6. Genes

7. Role of Genes in Development
• They call for the production of amino acids ( form proteins that instruct
cells for functioning )
• Guide cell differentiation
• Regulating the pace and timing of development- specific genes are turned on
and off –epigenome ( a group of chemical compounds that tell the genome
what to do )epigenome attaches to the DNA and switches genes on and off.

8. Gene expression
• There are 4 main patterns of genetic expression
• Simple Dominant –recessive inheritance – parents pass on dominant genes which causes children
to inherit that gene –alleles, homozygous ,heterozygous
• Co – dominance- a compromise between two genes eg alleles for human blood types A and Bare
equally expressive, sickle cell aneamia
• Polygenic inheritance – human characteristics influenced by many pairs of alleles. Psychologists
interested in intelligence , personality mental health . These are influenced by many genes
• Sex –linked inheritance –traits affected by genes located on the sex chromosomes . Found on
recessive genes carried on x.muscular dystrophy , haemopholia.,degeneration of optic nerve
,deafness and night blindness

9. Hereditary Disorders
• Disorders that are caused by genes and chromosomes ie inherited congenital
disorders

11. Chromosomal abnormalities- Sex
Chromosomes
• Abnormalities of the 23rd pair
• Too few/too many chromosomes going into a cell during meiosis
• Abnormality of sex chromosomes – born with extra Xor Y chromosome
• Female abnormalities XO,POLY X,
• Male abnormalities poly X and y, Poly Y and X

14. Class work
• Discuss 4 common sex chromosome disorders that occur as a result of extra
X and Y chromosomes ,effect on appearance fertility and intellectual
characteristics

16. Chromosomal abnormalities- Autome
abnormality
• Abnormality of the 22 pairs
• Combination of an abnormal sperm or ovum carrying an extra autosome
with normal gamete to form a zygote with 47 chromosomes .
• Example is Downs syndrome

17. Genetic Abnormalities
• Cystic Fibrosis
• Type 1 diabetes
• Duchnne –type muscle atrophy
• Haemopholia
• Phenylketonuria
• Sickle cell
• Tay Sacha disease

18. Genetic abnormalities
• May result from abnormalities
• Mutations can be induced by environmrnt

19. Predicting Hereditary disorder
• Genetic counselling- take history DNA analysis
• Option to detect disorders given
• Option to terminate given

20. Methods for detecting abnormalities-Class
work
• Amniocentesis( methods used to collect samples)
• Chorionic villus sampling (CVS)(transservical and transabdomen)
• Ultra sound
• How is the procedure done .its Pros and cons
• Ethical issues surrounding treatment for hereditary disorders specifically
Fetal surgery and gene replacement therapy

21. Impact of Genetics on Intelligence ,personality
and mental health
• Behavioural genetics-The scientific study of how genotype interacts with
environment to determine behavioural attributes such as intelligence
personality and mental health
• Selective breeding – maze ability in rats
• Familities—twin studies adoption studies

22. Contribution of environmental influence
• Non shared environmental influences
• Shared environmental influences