Chapter 3 Flashcards
Selective placement
adoption agencies generally try to place children with families of the same general background.
Genome
the complete set of genes of any organism.
Gene synthesis
a method for producing DNA.
Genotype
the genetic material an individual inherits.
Phenotype
the observable expression of the genotype, including both body characteristics and behaviour.
Environment
every aspect of an individual and his or her surroundings other than genes.
Parents genetic contribution to the child’s genotype
Transmission of genetic material from parents to offspring.
Chromosomes
molecules of DNA that transmit genetic information
DNA (deoxyribonucleic acid)
molecules that carry all the biochemical instructions involved in the formation and functioning of an organism.
Genes
sections of chromosomes that are the basic unit of heredity in all living things.
Sex chromosomes
the chromosomes (X and Y) that determine an individual’s gender.
- presence of a Y chromosome that makes an individual male.
Mutation
a change in a section of DNA.
factors that promote variability among individuals.
- random assortment of chromosomes
- crossing over
Crossing over
process by which sections of DNA switch from one chromosome to the other
Endophenotypes
intermediate phenotypes, including the brain and nervous systems, that do not involve overt behaviour.
Regulator genes
genes that control the activity of other genes.
External factors that can affect the switching on and off of genes;
Thalidomide → interferes with the functioning of genes underpinning normal growth factors.
Early visual experience → necessary for the normal development of the visual system.
Alleles
different forms of a gene, influencing the same trait (eye colour) but contribute to different outcomes (blue vs. brown).
Dominant–recessive pattern
(1) a person can inherit two of the same allele
or
(2) the person can inherit two different alleles
Dominant allele
the allele that, if present, gets expressed.
Recessive allele
the allele that is not expressed if a dominant allele is present.
Homozygous
having two of the same allele for a trait.
Heterozygous
having two different alleles for a trait.
Polygenic Inheritance
inheritance in which traits are governed by more than one gene.
Norm of reaction
all the phenotypes that can result from a given genotype in relation to all the environments in which it can survive and develop.
Phenylketonuria (PKU)
a disorder related to a defective recessive gene on chromosome 12 that prevents metabolism of the amino acid phenylalanine.
The effects of abusive parenting;
abusive treatment as a child
+
possessing a particular variant of MAOA gene
= antisocial behaviour.
Parental contributions to the child’s environment
ex: the child of a highly musical parent is likely to hear more music while growing up than are children whose parents are less musically inclined.
How do children’s phenotype interact with their environment?
- ) actively evoke certain kinds of responses from others. Ex: shy vs. outgoing child.
- ) selecting surroundings and experiences that match their interests, talents, and personality characteristics.
Child’s Environment & Child’s Genotype
Certain epigenetic mechanisms can alter the functioning of genes which;
- create stable changes in gene expression.
- changes can be passed on to next generation.
Neurons
cells that are specialized for sending and receiving messages between the brain and all parts of the body.
- 86 billion.
Sensory neurons
transmit information from sensory receptors that detect stimuli in the external environment or within the body itself
Motor neurons
transmit information from the brain to muscles and glands
Inter-neurons
act as intermediaries between sensory and motor neurons.
Cell body
a component of the neuron that contains the basic biological material that keeps the neuron functioning.
Dendrites
neural fibres that receive input from other cells and conduct it toward the cell body in the form of electrical impulses.
Axon
neural fibres that conduct electrical signals away from the cell body to connections with other neurons.
Synapses
microscopic junctions between the axon terminal of one neuron and the dendritic branches or cell body of another.
Glial cells
cells in the brain that provide a variety of critical supportive functions.
Myelin Sheath
a fatty sheath that forms around certain axons in the body and increases the speed and efficiency of information transmission.
Cerebrum
- cerebral cortex (outermost layer) and subcortical structures.
- divided into lobes.
Cerebellum
- small brain
- coordination of motor movement and balance
Brainstem
regulate vital functions such as respiration, sleep cycle.
Cerebral cortex
“gray matter” of the brain that plays a primary role in what is thought to be particularly human-like functioning, from seeing and hearing to writing to feeling emotion.
Sulci
grooves on the cerebral cortex.
- very large sulci is called fissure.
Gyri
folds/hills on the cerebral cortex.
lobes
major areas of the cortex associated with general categories of behaviour.
occipital lobe
the lobe of the cortex that is primarily involved in processing visual information.
temporal lobe
the lobe of the cortex that is associated with memory, visual recognition, and the processing of emotion and auditory information.
parietal lobe
governs spatial processing as well as integrating sensory input with information stored in memory.
frontal lobe
associated with organizing behaviour; the one that is thought responsible for the human ability to plan. ahead
association areas
parts of the brain that lie between the major sensory and motor areas and that process and integrate input from those areas.
cerebral hemispheres
- two halves of the cortex
- sensory input from one side of the body goes to the opposite hemisphere of the brain.
corpus callosum
a dense tract of nerve fibres that enable the two hemispheres of the brain to communicate.
cerebral lateralization
the specialization of the hemispheres of the brain for different modes of processing.
Commisure fibers
link the two hemispheres.
neurogenesis
growth of neurons through cell division.
adult neurogenesis
- in hippocampus and olfactory bulb of adult brains, generation of new neurons from stem cells continues.
Hippocampus in neurogenesis
reducing interference among similar memories.
Olfactory bulb in neurogenesis
discrimination between similar odours.
myelination
the formation of myelin around the axons of neurons that speeds and increases information-processing abilities.
developmental process
- migration to final destination.
- neuronal growth and differentiation.
- axons elongate toward specific targets.
- dendritic arborization.
- formation of spines.
spines
formations on the dendrites of neurons that increase the dendrites’ capacity to form connections with other. neurons
arborization
enormous increase in the size and complexity of the dendritic “tree”.
synaptogenesis
the process by which neurons form synapses with other neurons, resulting in trillions of connections.
synaptic pruning
the normal developmental process through which synapses that are rarely activated are eliminated
- last area to mature is the dorsolateral PFC.
dorsolateral PFC
important for executive functioning –> regulating attention, controlling impulses, foreseeing consequences, setting priorities.
synesthesia
the blending of different types of sensory input
- connections between sensory areas have yet to be pruned.
