Genotype

- genetic makeup of an individual - what alleles they have

Phenotype

an individuals observed properties (can be affected by environment)

Evolution

The change in allele frequencies in a population over time

Population

all organisms of the same species that live and interbreed in the same geographical location

Allele

Alternative form of a gene

Necessary components of natural selection:

- there is variation in traits within population - variation is heritable (passed generation to generation) - individuals with some traits have higher fitness

Fitness

Number of offspring

T/F: More offspring = more parent alleles in future generations = higher offspring

True

Is survival important?

Only if it helps you produce more offspring

Mutation

- random changes in alleles or genes (good or bad) - provides new traits on which selection can act (increases genetic variation)

Natural selection

- NOT random - decreases genetic variation in population

bottleneck effect

process which large portion of a genome is wiped out

found effect

Occurs when members of a proportion of a population migrate to establish their own population

what is a species?

- could mate with each other - produce viable offspring

How many classes of neurons?

3

1. Sensory neuron

brings information to the central nervous system from the rest of the body

2. Interneuron (90%) (sensory integration)

connect one neuron to another within the spinal cord and brain

3. Motor neuron

conducts its message from the central nervous system toward an effect (muscle or gland)

resting potential

+ outside neuron, - inside neuron inside neuron contains negatively charged protein Na+ higher outside neuron K+ higher inside neuron (fewer K+ relative to Na+) Na/K pump always working

Depolarization

- brief change in polarity across neuron membrane - Na+ channels open and Na+ enters neuron (Diffusion = no energy required) - interior of cell become + and exterior becomes - (Reversal of charges)

Action Potential

- Na+ channels open And Na+ enters neuron - interior of cell become + and exterior becomes -

Synaptic transmission (5 steps)

1. Neural impulse arrives at synaptic terminal 2. depolarization causes calcium ions to enter synaptic terminal 3. calcium influx causes vesicles loaded with neurotransmitters to fuse with presynaptic neuron's membrane 4. neurotransmitters are released into synaptic cleft 5. neurotransmitters bind to ion channels in postsynaptic neurons membrane, stimulating the channels to open

Neurons

Specialized cells for signal transmission

Dendrites

Tree-like, receive information

Axon

neuron extension that passes messages through its branches to other neurons or to muscles or glands

(ICLICKER) What can evolve according to the biological definition of evolution?

A group of fir trees in Oregon

(ICLICKER) What supports the concept of natural selection?

- Individuals with the traits best suited to the prevailing conditions tend to leave more surviving, fertile offspring AND - Traits that increase survival and production in the current generation will be more common in the next generation

(ICLICKER) Many plants require moisture to reproduce. What will happen to a plant population during a prolonged drought?

- If none of the plants already have the ability to reproduce without water, the population might go extinct AND - Plants that can already reproduce without water will pass on their alleles to the next generation, while plants that can't, won't