Ecology test 2 Flashcards
From notes
What is the difference between genes and alleles?
Alleles are different forms of a particular gene
When a single gene affects multiple traits:
Pleiotrophy
When a single trait is affected by several genes:
polygenic
When the expression of one gene is controlled by another
epistasis
When both alleles contribute to the phenotype they are said to be
codominant
The chromosomes in a haploid gamete are a ___ of the chromosomes of the diploid parent.
random assortment
Sources of genetic recombination are:
random assortment, mutations, and recombination (and crossing over) which occurs as DNA is being copied during meiosis.
When individuals with intermediate phenotypes have a higher survival and reproductive success . than those with extreme phenotypes:
Stabilizing selection
When an individual with an extreme phenotype experience higher fitness than the average phenotype of the population
directional selection
When individuals with either extreme phenotype experience higher fitness than individuals with an intermediate phenotype.
disruptive selection
The evolution of populations is known as
microevolution
The higher level evolution is referred to as
macroevolution
What is the difference between allopatric speciation and sympatric speciation?
Allopatric speciation occurs through the process of geographic isolation
sympatric speciation can occur through polyploidy. Polyploid species contain:
three or more sets of chromosomes.
The number of offspring produced by an organism per reproductive episode is known as
fecundity
The number of reproductive episodes an organism experiences:
parity
Why do organisms experience life history trade-offs?
Organisms often have limited time, energy, and nutrients at their disposal.
When resources are devoted to one body structure, physiological function, or behavior, they cannot be allotted to another according to this principle.
The principle of allocation.
Some common life history trade-offs are
offspring number versus offspring size, offspring number versus parental care, fecundity and parental care versus parental survival, growth versus age of sexual maturity and life span.
when organisms can only reproduce once during their life
semelparity
when organisms can reproduce multiple times during their life
iteroparity
parity does not tell us whether an organisms’s life history is one year (or ______) or if an organism’s life span is more than one year (or _____)
annual, perennial
The gradual decrease in fecundity with an increase in the probability of mortality
senescence
The 50 percent reduction in the number of a parent’s genes passed on to the next generation via sexual reproduction versus asexual reproduction.
cost of meiosis
Flowers that have both male and female parts are
perfect flowers
when individuals posses both male and female reproduction functions at the same time
simultaneous hermaphrodites
individuals that posses male or female reproductive function and then switch to posses the other
sequential hermaphrodites
plants that have separate male and female flowers on the same individual plant are
monecious
plants that have only male or female flowers are
dioecious
When competition for mates occurs in a very limited area (like in the fig wasp example) and only a few males are required to fertilize all the females.
local mate competition
the location of an animal aggregation to put on a display to attract the opposite sex
lek
Characterized by several adults living in a group with an overlapping of generations, cooperation in brooding and nesting, and reproductive dominance with sterile individuals present.
eusociality
A sex-determination system in which one sex is haploid and the other sex is diploid.
haplodiploid
According to Grime’s life history triangle, these types of plants have a slow growth rate, reach sexual maturity late, use little energy to produce seeds, often use vegetative reproduction.
Stress tolerators (examples include cacti and tundra plants.)
According to Grime’s life history triangle, these types of plants grow relatively fast, reach sexual maturity at an early age, use little energy to produce seeds because they often spread through vegetative reproduction important.
Competitors
According to Grime’s life history triangle, these types of plants grow fast, reach sexual maturity early, use a high portion of energy in seed production, and do not utilize vegetative reproduction often.
Ruderals
