HL 2 Biology

E.6d Food, Sleep, Sex

Foraging: searching for food animals need to decide: what type of prey to search & how to find it availability of food often varies due to : space & time foraging behavior – needs to change (to optimize food intake at any time) Rhythmical behavior:   can follow daily cycles Exaggerated traits DBQ: Rhythmical Behaviour Patterns (p.335) 1) The … Continue reading

HL 2 Biology

E.6b Reciprocal Altruism

p.334 <<Altruism>> evolution of altruism natural selection should act against altruism evolution of co-operation group of animals helping each other  could be more suffecssful in overall struggle for existence all of them will increase their chance of survival yet increase cheating or manipulation disrupting relationships true altruism – generally involves genetically related animals, with natural … Continue reading

HL 2 Biology

E.6c Kin Selection

p. 334 <<Social organisms>> e.g. Honey Bees live in colonies of thousands of bees work together for survival (*individual bees can’t survive unless colony survives) colony = super-organism; natural selection acts at this level than on the individual bees Levels of bees Queen: fertile females; lays eggs; one per colony Drones: fertile males; finds virgin … Continue reading

HL 2 Biology

E.3b Learned Behavior

327-8; DBQ: 328 <<Learned Behavior>> develops as a result of experience they do not inherit specific patterns of behavior  offspring behave similarly to their parents; only because they learn behavior patterns from them (not genes) has advantages over innate behavior allows responsiveness to change/variation in environment can improve chances of survival  a type of learning: … Continue reading

HL 2 Biology

E.3a Innate Behavior

Innate behavior: animal behavior developed independently of the environmental context; genetically programmed flatworms towards food Learned behavior: behavior developed as a result of animal’s experiences chimpanzees with twigs to get termites ======================================= DBQ: Chemotaxis in woodlice (p.326) 1) Using light, as a phototaxis in one seeing their positive or negative movement or presence of plants/food as a geotaxis … Continue reading

HL 2 Biology

E.1 Reflexes

(p.321) reflex: a rapid, unconscious response to a stimulus stimulus: a change in either the internal/external environment that is detected by a receptor & elicits a response response: a change in an organism, produced by a stimulus <<Reflexes and reflex arcs>> reflex arc: a series of neurons involved in the animals response to a stimuli Neurons … Continue reading

HL 2 Biology

E.4c Neurotransmitters & Drugs

excitatory psychoactive drugs: nicotine, cocaine, amphetamines inhibitatory psychoactive drugs: benzodiazepines, alcohol, tetrahydrocannabinol (THC) <<Effects of THC and Cocaine at Synapses in the Brain>> THC inhibitory psychoactive drug decreases synaptic transmission cannabinoid synapses= post-synaptic neuronal release endo-cannabanoid neurotransmitters endo-cannabanoids bind to cannabinoid receptors (at pre-synaptic neurons) pre-synaptic neuronal release of neurotransmitters binds to cannabinoid receptors release neurotransmitters from the pre-synaptic neurons (e.g.GABA) fall … Continue reading

HL 2 Biology

E.4b Neurotransmitters & Personality

<<Transmitters and Synapses>> Synaptic Transmission action potential in pre-synaptic neuron release of neurotransmitter (to synaptic cleft) neurotransmitter binds to receptors in membrane action potential stimulated in post-synaptic neuron Synapses more than one pre=synaptic neuron = able to form synapse with same post-synaptic neuron often a single release of NT from 1 pre-synaptic neuron = insufficient … Continue reading

HL 2 Biology

E.4a Neurotransmitter & Synapses

AA-CC: 331-2 • AA-SG: 138 Lesion Studies and Animal Experimentation lesion: area in organ/tissue that suffered damage due to injury/disease (e.g. tumor) changes personality and capacity for social interactions e.g. Phineas Gage; damage to frontal lobes in his brain; personality changed lesion experiments practiced on animals (vivisection) remove parts of the skull, experiment on parts … Continue reading

HL 2 Biology

E.5b Brain Function

<<Sympathetic & parasympathetic control>> Peripheral nervous system: all nerves outside central nervous system two parts: voluntary and autonomic nervous system autonomic: control unconscious processes; this further divides to sympathetic and parasympathetic systems parasympathetic nerves: cause increase in blood flow to gut wall hen guts active sympathetic nerve: cause decrease in blood flow during fasting/when blood needed elsewhere (e.g. muscles when exercising intensely ) heart rate – … Continue reading