Biology Semester 3

Get Started. It's Free
or sign up with your email address
Biology Semester 3 by Mind Map: Biology Semester 3

1. Quiz 1 - Genetics

1.1. The Human Genome

1.1.1. Chromosomes 23 pairs of chromosomes 22 autosomes 1 allosome Found inside nucleus and hold DNA Bands Guanine and Cytosine pairs darker Adenine and Thymine pairs lighter Regions P Q Split into regions, bands and sub-bands Centromere Joining point of 2 identical chromatids Karyotype Map of chromosomes

1.1.2. Genes Piece of DNA that codes for a protein Allele Alternate version of the gene Genotype leads to phenotype Dominant Recessive Codominance Traits Qualities or characteristics

1.1.3. Gregor Mendel Segregation When gametes are formed, two factors for each trait split from each other Independent Assortment Gametes are made of different chromosomes and there are 223 possibilities of different gametes

1.1.4. DNA Deoxyribose long double helixed structure Nucleotides Backbone Coils around histones to make chromosomes

1.2. Gene Expression

1.2.1. Central Dogma of Molecular Biology Meitosis Transcription Translation SNP Copy Number Variants

1.2.2. Meiosis Cell division to produce gametes Crossing over Exchange of segments of DNA Sex-linked genes Traits in men as there is less chance of dominant allele due to small Y chromatid Trisomy Extra (3) chromosomes Downsyndrome (21st chromosome)

1.2.3. Epigenetics Environmental factors cause different genes to act differently Methylation Acetylation Examples

1.2.4. Autism Characteristics Social issues Communication Behaviours Cannot be traced to a Mendelian (single-gene) mutation Brain Damaged mirror neurons Increased amygdala activity More white matter in frontal lobes Abnormal columns of visual cortex Environmental factors Prenatal Mercury and toxin exposure Marker Metabolic Abnormalities Management Family and social support ABA

2. Quiz 2 - Development

2.1. Neurodevelopment

2.1.1. Cell Migration Along radial glia cells From ventricular layer until cerebral cortex

2.1.2. Differentiation Sonic Hedgehog Ventral neurons into motor neurons Released from notochord BMP Dorsal neurons into sensory neurons HOX gene Rosto-caudal differenciation

2.1.3. Synaptogenesis Growth cones Lamellipodia Fillipodia

2.1.4. Apoptosis Programmed self destruction of cells due to lack of NGF Released from post synaptic cell Caspases kills presynaptic cell

2.1.5. Synapse Rearrangement Fasciculation Axons that fire together, wire together Cell Adhesion Molecules Synaptic pruning

2.1.6. Myelination From spinal cord to forebrain Finishes around age 20 From sensory to motor Speeds action potential White covering of axons

2.2. Critical Periods

2.2.1. Plasticity Neurons change according to experience During exams If an organ is removed, the brain area connected to that organ won't be wasted Musicians Dystonia Creating new neurons Hippocampus Ventricular zone Strengthen old synapses Drugs After myelination is complete Body compensates for expected effects

2.2.2. Critical Period External stimuli have increased influence Neurotropic factors GABA If one eye is covered in critical period, the cortex doesn't recognise signals from the eye Binocular deprevation Birds Chaffinches Canaries Imprinting Development in Cats If one eye is covered in non-critical period, there's no effect Amblyopia Frog Third eye works only if grafted before critical period Cataracts until 6 months Damage face recognition Not a complete loss of plasticity Orphans Little human contact Earlier adoption (pre 6 months) Later adoption

3. Quiz 3 - Emotion

3.1. Evolution of Emotion

3.1.1. Emotions are genetic and natural Universal emotions Universal facial expressions Social smiles in blind babies Adapted communication without language Prosocial Paul Ekman Basic emotions Angry Happy Sad Surprised Disgust Fear Complex emotions Guilt, shame, pride, regret Help show attitude and future intentions Automatic appeal for forgiveness and support Regret

3.1.2. Environment has influence Doctors Different cultures

3.1.3. Temperament from birth Responsive Anxiety Low response Anti social No response Psychopathology

3.2. Theories of Emotion

3.2.1. Classical James - Lang Theory Physical state leads to emotion Cannon - Bard Theory Automatic and emotional response occur simultaneously and independently Schachter - Singer Theory Arousal leads to cognitive assessment which leads to the identification of an emotion

3.2.2. More modern Cacciopo Theory Different emotions require different levels of cognition Demasio Somatic Markers

3.3. Some Different Emotions

3.3.1. Stress Hans Selye Adaptation syndrome Stressor -> resistance -> exhaustion HPA Axis Sensory system -> Amygdala - (striatal terminals)> HPA Axis or Lateral hypothalamus Immune System T lymphocytes B lymphocytes Stress hormone (cortisol) suppress both lymphocyte synthesis

3.3.2. Fear Caused by amygdala activation Response to sensory processing Automatic adrenal response Fear conditioning Inhibition by ACC and Temporal Pole Damage to amygdala

3.3.3. Anger Autonomic Nervous System response Heart rate and testosterone increase Left hemisphere activation Cortisol decrease Rage Preverbal defence mechanism Shame rage

3.3.4. Aggression Amygdala activation Competitive, forceful and predatory Inhibition by PFC and ACC High testosterone levels Low serotonin levels Genetic Can be selectively bred

3.3.5. Empathy Article by Vignemont & Singer, 2006 Seeing others in pain Seeing others being touched Regret

3.3.6. Pleasure Article by Berridge & Kringelbach, 2013 Two types of well-being Reward

3.4. Emotion Regulation

3.4.1. Article by Etkin, Büchel & Gross, 2015 Three types of regulation Intrinsic Extrinsic Implicit Regulation can occur at different stages of generation Situation selection Three steps of cognition and emotion regulation

4. Quiz 4 - Psychopathology

4.1. Schizophrenia

4.1.1. Positive symptoms Hallucinations Imagining sensory Delusions Reality testing Fidgeting

4.1.2. Negative symptoms Anhedonia Flat expression Alogia Slow, non-coherent speech Asociality Bad working memory Bad executive functioning Avolution Catatonia Irregular movements Concrete thinking Proverb test Prepulse inhibition Their reaction when they know they're going to be shocked isn't reduced Endophenotype

4.1.3. Genetics 50% concordance More men

4.1.4. Environmental Factors Prenatal influenza Thiamine and vitamine D deficiency Maternal smoking Prodromal stage Lasts about a year Pre disease

4.1.5. Brain Larger ventricles More CSF Less reaction to drugs Smaller amygdala Disorganised hippocampus Pyramidal cells aren't organised Working memory Word salad Damaged eye fields Saccades Non smooth eye movements Endophenotype Thinning grey matter in right PFC Inflamatory cytokines Microglial activation Dendritic retraction Synaptic pruning

4.1.6. Childhood Trauma may effect myelination Delayed maturation Reduced IQ

4.1.7. Medication Dopamine Hypothesis Amphetamine psychosis Typical neuroleptic Atypical neuroleptic Glutamate Hypothesis Angel dust Not enough glutamate is the cause schizophrenic symptoms

4.2. Antisocial Personality Disorder (APD)

4.2.1. Failure to conform to social and legal codes of behavior and the violation of the rights of others Criminal lifestyle and antisocial behavior

4.2.2. Genetics 3% of men and 1% of women Criminality runs in families

4.2.3. Brain Abnormalities in OFC and limbic system Can be caused by lesions of OFC Low emotional response Issues with amygdala

4.2.4. Treatment Learning model that emphasises anger control, social skills, moral reasoning

4.3. Mood Disorders

4.3.1. Unipolar Depression Major Depressive Disorder Symptoms Genetics Environmental factors Medication and treatment Brain Sleep Seasonal Affective Disorder Shorter winter days Less sunlight Phototheraphy

4.3.2. Bipolar Depression Cyclothymia Mild bipolar Genetics 70% concordance between twins Comorbid with depression Equal men and women Brain Not normal basal ganglia activity Bigger amygdala Smaller hippocampus Neurotransmitters Medication and treatment Electrostimulation Lithium Capsulotomy

4.4. Anxiety Disorders

4.4.1. General Anxiety Disorder Constant fear reactions for at least 6 months Autonomic under arousal Blunted due to overuse

4.4.2. Agoraphobia Fear of open places

4.4.3. Post Traumatic Stress Disorder Threat of death or serious injury Symptoms Dreams and flashbacks Hyperarousal and sensetivity Avoidance of place or object Genetics More women than men More kids than adults COMTval158met Brain Smaller hippocampus More active amygdala Less vmPFC activity Medication Propronolol

4.4.4. Obsessive Compulsive Disorder Obsessive thoughts and compulsions to reduce them Genetics 68% concordance No gender difference Environmental factors Trauma, infection or injury Brain More activity in basal ganglia than normal anxiety Treatments Behavioural treatments Antidepressants Marker Response inhibition

4.4.5. Panic Disorder Genetics More women than med Comorbid with anxiety and depression Can be caused by expectations and anticipations Social phobia Agoraphobia Change in body settings Sodium lactate or CO2 increase Read by hypothalamus Activation of locus coeruleus

4.4.6. Babies SNP for COMPT gene High reactivity Anxiety Val66Met

4.4.7. Brain Monoamines Serotonin Norepinephrine GABA

5. Aging

5.1. Life expectancy

5.1.1. Increased

5.2. Changes

5.2.1. Cognition Intelligence Fluid Crystallized Attention Selective attention decreased Frontal lobes

5.2.2. Memory Working memory Holding small pieces of relevant information for limited time Episodic memory Remembering experiences The ability to create new memories sometimes decreases

5.2.3. Brain Decreased cortical volume Attention Neural modulation decreased Less monoanemines Less activation in brain Decrease in myelination Decrease in hippocampal volume Could be too much cortisol Bigger ventricles Activation across more sites Both hemispheres in comparison to youth who use one More activation than youth

5.2.4. Become more clear as people live older

5.2.5. Other factors affecting cognition Sensory decline Ben-David study Stroop Test Positive effect bias Elders tend to be more positive Tend to focus on positive Time of day Elders reach peak earlier on in the day Neural inflammation Natural

5.3. Stereotype Threat

5.3.1. Memory decline

5.4. Alzheimers

5.4.1. Cellular changes Senile plaques Patches of degenerating axon terminals and dendrites In the grey matter of the brain Neurofibrillary tangles TAU forms tangles in cell Responce to plaques Basal forebrain disappears Cells die Stop acetylcholine production

5.4.2. 4 Stages Pre Difficulty remembering recently learned facts Inability to aquire new information Confused with old age Early Severe problems remembering new facts Vocab shrinks Decrease in word fluency Moderate Speech difficulty Less motor actions Failure to recognise close relatives Advanced Inability to preform tasks Language reduced to simple words Loss of reality