Science Exam 😱😰😭😠😣 Flashcards
Type I survivorship curve
Organisms tend not to die at a young/middle age, small numbers of offspring, lots of parental care (ex. Humans and most primates)
Type II survivorship curve
Die equally at each age interval, relatively few offspring and some parental care (ex. Birds/squirrels)
Type III survivorship curve
Few survive at young age, pretty long lives if make it past, have lots of offspring at once, not much parental care (ex. Trees snd fish)
r selected (cheap offspring)
High growth rate but low survivorship, in unstable environments, many offspring, little parental care, high infant mortality rate, small body size, early onset of maturity, variable population size
k selected (expensive offspring)
Low growth rate but high survivability, in stable/predictable environments, few offspring, high parental care, low infant mortality rate, large body size, late onset of maturity, stables population size
Examples of r and k selected organisms
r: oysters and fish
k: chimps and humans
What is population density
Number of individuals per unit area/volume, affected by resource availability
Random distribution
Position of one individual is independent of others, occurs in uniformly structured environment with unpredictable factors affecting distribution
Clumped distribution
Individuals grouped in patches, often around resources, most common type, in highly social species where resources are patchy
Uniform distribution
Individuals evenly spaced, occurs in territorial species and plants that produce chemicals to inhibit growth of nearby plants
Random sampling
Taking a few random areas from a whole and counting the number of organisms in each, then multiply by whole area
Why is random sampling used
It’s importable to count every individual in a species
Species richness
The number of unique species that are present
Abundance
in group
The number of individuals present in each group relative to the total number of individuals
—————-
Total #
Reasons for fruit seed count
Some have lots of seeds to produce more offspring, some have one they that out more energy into growing/protecting (different types of selection)
Definition of a population
A group of organisms of the same species living in a given area at the same time
Carrying capacity
The maximum size a population can reach before the environment can no longer support it
Exponential growth curve
Unlimited space/resources, population increases every generation
Logistic growth
Population size limited by resources/space, growth slows once carrying capacity is reached
Density dependent limiting factors
Caused by/related to living organisms, ex high population in one area causes competition for access to food/water
Density independent limiting factors
Usually abiotic, caused by factors on physical environment, not affected by population density, ex hurricane that kills organisms
Intraspecific competition
Occurs between members of same species ex competition for a mate or rrsources
Interspecific conpetition
Occurs between members of different species ex competition for prey or sunlight/water (in plants)
How can predator-prey relationships cause fluctuations in population size
More predators - less prey
More prey - predators increase
Less prey - predators decrease
What kind of growth is the human population experiencing
Exponential, but expected to slow
