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Ch 3_

Course Code
Michael Inzlicht

of 19
Genetic and biological
Although there is evidence that people might possess specific genes that have
specific effects, it is the expression of those genes (turning on and off) as much as mere
possession that makes us who we are. Need to understand how physiological processes
affect behavior, thought and emotion and how physiological processes are shaped by the
environment how nurture influences nature. GENETIC AND NEUROCHEMICAL
Genetic Basis of Psychological Science
Human Genome Project international research effort to map the entire structure
of human genetic material
Within every cell in the body is the genome for making the entire organism: master
recipe that provides detailed instructions for everything from how to grow gall
bladder to where place nose on face.
Whether a cell becomes gall bladder or where nose is on face depends on which genes
are turned on or off within the cell this is determined from cues outside the cell
The genome provides the option and the environment determines which option is
Genetics typically used to describe how characteristics such as height, hair color,
and weight are passed along through inheritance, but it also refers to those
processes that are involved in turning genes off and on
Chromosomes within each cell, structures made up of genes. Typical human has
23 pairs, half of each pair coming from each parent
Genes in turn are components of substance called DNA consists of 2 intertwined
strands of molecules of sugar, phosphate and nitrogen
precise sequence of these molecules along DNA strand specifies an exact
instruction, through production of RNA, to manufacture distinct proteins (make up
cell structure and direct their activities)
Gene segment of DNA that is involved in producing proteins that carry out specific
tasks. Not only how to produce specific proteins but when to produce them ,
determined by environment
Gene expression process by which gene produces RNA and then protein. Not only
determines physical makeup of body but also remains important throughout life and
is involved in psychological activity.
the complexity of humans is not due to simply our possessing a large number of genes,
but more likely due to subtleties in the way that genes are expressed and regulated
1.Heredity involves passing along genes through reproduction
Selective breeding experimental technique for studying genetics. Mendel
could strictly control which plants were bred with which other plants
Alleles 2 versions of a gene, if differ one dominant and one recessive
Dominant genes expressed in offspring whenever present
Recessive genes expressed only when matched with similar gene from
other parent
therefore existence of dominant and recessive means not all genes are
outwardly expressed
Genotype genetic constitution of an organism, actual genetic makeup
determined at moment of conception
Phenotype observable physical characteristics that result from both
genetic and environmental influences
* could have same phenotype but different genotype. Environment affects
phenotype: good nutrition increase size, suntan affect on color of skin
Polygenic effects characteristics, influenced by many genes and
environment. Most human traits and diseases are polygenic.
2.Genotype variation is created by sexual reproduction
Siblings differ each has specific combination of genes that differ in part
due to random cell division
Reproductive cells from each parent divide to produce GAMETES, sperm and
egg cells, that contain only half of each pair from the mother and father
Zygote, fertilized cell, contains 23 pairs of chromosomes
The 2 chromosomes in 23rd pair are sex chromosomes X & Y due to shape.
F 2X; M X + Y
Unique genotype genetic variation in human species
Errors in cell division mutations, most of which are benign and have little
influence occasionally mutation may produce selective advantage or
disadvantage in terms of survival or reproduction
Advantageous mutations may spread through gene pool because those who
carry the gene are more likely to survive and reproduce
Recessive genes do not interfere with health in most people which allows
them to survive in gene pool
In contrast to recessive, dominant gene disorders are lethal for most of their
carriers and therefore do not last in the gene pool
3.Genes affect behavior
Kind of person you are influenced by interaction of genes and environment
in which you are raised
Behavioral genetics study of how genes and environment interact to
influence psychological activity
Genes lay groundwork for human traits
People are born essentially like undeveloped photographs. The image is
already captured but the way it eventually appears can vary based on the
developmental process. However, basic picture there from beginning.
Behavioral genetic methods
There are subtle differences in environment, both with and outside
household, different birth orders, friends, teachers, treatment. 