Unit 3 Flashcards
genetic diversity
- genetic variation between species within a population
mutations
- change that occurs in an individuals dna
- inheritable (germ line/ sperm, egg) mutations can affect an entire gene pool
the more _ there is the _ the chance that a variation will be present and provide selective advantage
- variation
- greater
gene flow
- migration
- movement of alleles from one population to another
- gene flow increases
gene flow increases genetic diversity in one population but reduces genetic differences among populations
- true
non random mating
- individuals mate with who they want and not just randomly
- prevents other individuals to mate
inbreeding
- breeding with similar alleles
- would increase frequency if homozygous breed within homozygous which increases their population with the same gene
genetic drift
- change in allele frequencies due to events in a SMALL BREEDING POPULATION
- large populations do not experience genetic drift because it is unlikely to affect overall allele frequencies
founder effect
- when individuals in a population isolate themselves and form their own
- individuals may only carry some alleles thus not having some original population gene pool
- diversity is limited
does genetic drift happen in big population
no
bottleneck effect
- rapid decrease in population size due to disaster
- starvation, disease, human activities, natural disasters
- species may come to extinction
natural selection
- some individuals are able to survive better than others in an environment
- those favourable characteristics is passed on to generations
sexual selection
- form of non random mating, related to natural selection
- survival advantages explain why some lethal recessive alleles stay in humans that being eliminated
- when same sex compete to get one of the opposite sex
population sampling
- taking a portion of the population and conduct experiment or gain data
what are the hardy-weinberg principles
- large population
- random mating
- no mutations
- no migration
- no natural selection/ preferred of nature
p / q
- allele frequency
p2/q2
- ratio of population
2pq
- heterozygous
genetic equilibrium
- no change in allele frequency overtime in a population
- not changing or evolving
if a population isolate themselves evolving is it genetic equilibrium
no
microevolution
- gradual/slow change in allele frequencies due
population density
number of individuals in a given area ir volume
- can be used to estimate the size of a population
what affects distribution patterns
- resource availability
random distribution
- when everyone is everywhere
- no competition and large amount of resources
clumped distribution
- members form groups within the area usually around resources
uniform distribution
- individual are spaced evenly in a given area
- usually artificially made
- ex) farms
difference between immigration and immigration emmigration
immigration = into a population
emigration = out of a population
biotic
- living
- predation, competition, parasitism, disease
abiotic
- non living
- natural disasters, drought
biotic potential
- highest possible per capita growth rate in a population
What is a j shaped curve
- exponential growth
- the graph goes up indefinitely
- goes past its biotic potential
what is lag phase
growth phase
stationary phase
- lag = slow growth
- growth = birth rate > death rate
- stationary = death rate= birth rate
carrying capacity
- maximum population the area can hold without affecting resources
s shaped
- sigmoidal surve
- logistic growth
- less dramatic
density dependent factor
- BIOTIC factors limiting a habitats capacity
- parasite or disease
- small populations below carrying capacity are not affected
- greater impact as the density INCREASES. so more people then more impact
open population vs closed population
- open = s cutve
- closed = j curve
density independent factors
- ABIOTIC limiting carrying capacity
- affects no matter how much the population is
r selected strategies
- populations that reproduce close to biotic potential
- importance of reproduction
- ex) INSECTS
characteristics - reproduce a lot
- short life span
- early reproductive age
k selected
- focus on survival and competition
-ex) HUMANS
characteristics - few offsprings
- mature slowly
- take a long time for reproductive age
- long life span
intraspecific
individuals within the same species compete for resources
interspecific
individuals of different species compete for resources
if predator decrease what happens to prey. what is this called
prey would increase due to less predators.
boom and bust cycle
protective colouration
uses body colour as a defense mechanism. usually red yellow black
batesian mimicry
weak animals mimic the body of harmful animals to seem stronger than they are
mullerian mimicry
harmful species mimic each other. helps to avoid predators more
symbiosis
- direct or close relationship between individuals of different species that live together
mutualism
- both species benefit from relationship
commensalism
- one specie benefit but the other not really but its not in a harmful way
- its a yay and eh relationship
parasitism
- one benefits one is harmed
succession
- sequence of invasion and replacement in a ecosystem overtime
primary succession nd its order
- no soil present so species populate the area in specific order
- pioneer community = lichens, moss, then grass, herbs, then shrubs, trees, then plants
what is a pioneer community
they start the primary succession
climax community
late comers in a succession which remains stable if no major environmental change
secondary succession
- recolonization of an area after a disturbance
- soil are not fully distroyed
what is the growth of human population right now
- exponential growth
age pyramid with wide base
- more births than deaths
age pyramid
- bottom is the youngest
- top is older ages
inverted triangle age pyramid
- population is declining due to less births
what has caused the earths carrying capacity to increase
- diets
- pandemics
- garbages
- advancement in construction, agriculture, medicine
