Unit 8 part 2 Flashcards
Describe visual development.
Columns of cells are stimulated in an alternating pattern. Formed during critical period. Proven by injecting tracers into ferrets. Light deprivation in one eye leads to narrower columns. Axons are not stimulated and synapses are weakened.
Describe monocular deprivation.
Depriving vision from one eye. Monocular deprivation as an infant leads to permanently impaired vision. Removal of cataracts when older can return vision.
Describe depth perception.
Close objects are seen from two angles and are stereoscopic. Distant objects are influenced by visual cues and past experiences. Cross-culturally, depth perception is different. The Carpented World Hypothesis shows that Western cultures perceive depth differently, in accordance to the Müller-Lyer illusion, than those in circular cultures. Babies encouraged to crawl across a glass table where a cliff ledge was pictured underneath proves that depth perception is not innate.
How are memories created?
Patterns of connections. Strength of synapse.
Define habituation.
A learning style referring to the ability to ignore repeated, unimportant stimuli.
Describe how habituation works.
Insufficient neurotransmitter is released. Ca2+ channels are less responsive and the post-synaptic membrane is not depolarised. The reflex arc is incomplete.
Describe ethics involving animal use.
Animals cannot give consent. Suffering of a small number of animals may lead to treatment for many. Animal rights are questionable. Not all animals have the same rights, invertebrates do not feel pain. Animal welfare is paramount in an investigation.
What are the symptoms are Parkinson’s Disease?
Muscle stiffness Tremors Poor balance and motor skills Slurred speech.
What causes Parkinson’s Disease?
Lack of dopamine as dopamine-secreting neurons in the basal ganglia die.
What are the treatments for Parkinson’s Disease?
MAO inhibitors, slowing the loss of dopamine by inhibiting enzymes that break down dopamine. L-Dopa, precursor to creating dopamine. Dopamine agonists activate dopamine receptors. Gene therapy. Deep brain stimulation.
Describe the cause of depression.
Multifactorial. Lack of serotonin, the gene, 5-HTT, increases susceptibility. Diathesis-stress model.
Describe the treatments for depression.
MAO inhibitors. SSRIs.
Describe drugs and synaptic transmission.
Neurotransmitter is synthesised and stored. The neurotransmitter is released and binds to the receptor. The neurotransmitter goes through reuptake and then breakdown. SSRIs prevent the reuptake, increasing the serotonin levels in the post-synaptic membrane.
Describe the effects of MDMA.
Increases serotonin in the synaptic cleft by binding molecules responsible for transporting serotonin to the cell. Leads to hyperthermia, high blood pressure, irregular heartbeat, muscle breakdown, kidney failure.
Describe the Human Genome Project.
Aims to discover all genes in the human species.
Define single nucleotide polymorphisms.
DNA sequence varies, one nucleotide is affected in 1% of the population.
How is genetic modification carried out?
Pharming: human gene is cut with restriction enzyme and spliced in plasmid. Modified plasmid is allowed to multiply, bacterial cells are destroyed and protein is extracted and purified. Artificial selection: marker gene and wanted gene incorporated into a vector. Undergoes micropropagation (multiplication). Gold or tungsten coated particles coated with DNA fired into a cell with a gene gun.
What are the concerns of genetic modification?
Health: transfer of antibiotic resistant genes to microbes, formation of harmful products, transfer of viruses between animals and humans. Environment: transfer of genes to non-target species, crops may increase chemicals in agriculture, breeding of superweeds. Choice. Ownership.
Define propagation.
The breeding of plants or animal specimens from a parent cell/organism.
Investigating habituation to a stimulus.
Using a snail, dampen a cotton wool bud with water. Touch the snail with the cotton wool. Measure the length of time it takes for the snail to reemerge from its shell. Repeat 10 times.
