is the branch of ecology that studies how organisms interact with their world
The largest population an environment can support
biotic vs abiotic
biotic-interactions with other organisms, such as predators or competitors
abiotic-aspects of environment, such as temperature or rainfall, that influence where an organism lives due to its body physiology
- is the growth and maturity of reprodction how long, elephants are slower, while spiders grow mature and die quicker
- type 1-low birth but high survival
- type 2-uniform suvival rate across ages
- type 3-high birth rate lower survival
all the organisms that share an environment
when two interacting species both benefit from their exchange
a close physical association between species
When one species benefits from an interaction while the other is indifferent, their relationship
secondary-eat the herbivores
decomposers -eat the dead, freeing up nutrients into the soil or water for producers to use
4 different types of consumers
have to get food source from other than the air and sun 4 different types
autotrophs that fix CO2 into sugars and organic molecules. They are the base of any food chain
species are especially important for keeping balance in their ecosystem! like
ecological succession secondary
changing of ecosytem that occurs from distrubances like fire
ecological succession primary
changing of a ecosysten that happens naturally through other things
- Plants and bacteria pick up small amounts of environmental pollutants and contaminants
- this is from eating, secondary terciary and decomposers accumulate the most
- Atmospheric CO2 dissolves into the ocean and turns into carbonic acid
- Atmospheric CO2 is taken up (fixed) by photosynthetic plants and bacteria
Some of this CO2 is released back into the atmosphere by oxidative respiration by the plants, their herbivores, or their decomposer
water evaporates from the ocean, condenses into clouds, precipitates into rain, runs off into rivers and infiltrates into ground water
the clearing of forests for timber or farming
Increased run-off from farms brings more nutrients (especially nitrogen and phosphorus) into lakes and ocean habitats
accident or on purpose, introduce plants and animals to new parts of the world
Carbon dioxide and Methane are very good at trapping heat in the atmosphere
discrete units of genetic (hereditary) information consisting of a specific nucleotide sequence in DNA
alternate versions of genes
The other allele has no noticeable effect on the organism’s appearance and is called the
chromosomes (giant DNA molecules) which share the same genes. You get one copy of each from your mother, and one from your father
If the 2 alleles of an inherited pair differ, then one allele will determine the organism’s appearance over the other,
An organism that has 2 identical alleles for a gene
An organism that has 2 different alleles for a gene
- A sperm or egg carries only 1 allele for each inherited character
- This is because chromosome pairs (separate) during gamete (sex cell) formation, aka meiosis
- The allele pair of one gene separates from each other independently from the alleles of another gene during segregation (meiosis)
- Ex: segregation of hair color alleles does not influence segregation of ear shape alleles
- Examination of 2 separate traits in a single cross
- ex- XXYY x xxyy
person or other organism that has inherited a recessive allele for a genetic trait or mutation but does not display that trait or show symptoms of the disease.
The complete genetic make-up of an organism
The physical expression of the genotype
- how to determine genotype without blood test
- ex: test black lab with reccssive brown lab bb, you know black lab is BB if all babies come out black, if half brown it is Bb
- In some allele combinations, dominance does not exist, can result in third trait
- , the phenotype does reveal the genotype for all traits!
form of dominance in which the alleles of a gene pair in a heterozygote are fully expressed thereby resulting in offspring with a phenotype that is neither dominant nor recessive
Genes located close together on the same chromosome tend to be inherited together
A gene located on a sex chromosome is called
- a measurable phenotype that depends on the cumulative actions of many genes and the environmen
- ex height weight blood pressure
- Refers to an allele which has more than one effect on the phenotype
- multiple symtoms can be traced back to one defective allele
the interaction of genes that are not alleles, in particular the suppression of the effect of one such gene by another.
_________-is the process of change over time, as applied to organisms.
Specifically___________is the change in allele frequencies of a population of organisms from one generation to the next
Extremes of a trait have reduced survival/breeding, keeping a trait stable.
Most traits are under stabilizing selection
One extreme of a trait has a survival/breeding advantage. Over generations the population as a whole shifts in that direction.
Selection against the most common phenotype or different selection pressures on different sub-populations.
May lead to sustained variation or new species!
- Fitness of a phenotype depends on its frequency within the population
- negative type are when the rare thrives
- positive types are when common thrives, eliminates variation
states that allele and genotype frequencies in a population will remain constant from generation to generation in the absence of other evolutionary influences.
- Proportions of genotypes do not change in a population if
- No mutation takes place
- No genes are transferred to or from other sources (no immigration or emigration
- )Random mating is occurring
- The population size is very large
No selection occurs
happens when a population is drastically reduced at random. The survivors rarely have identical allele frequencies to the original population.
when a small subset of a population starts a new population. The founders rarely have identical allele frequencies to the original population.
happens when the ‘coin flip’ randomness of sexual reproduction leads to outcomes different than the statistical expectation.
the transfer of alleles or genes from one population to another. Migration into or out of a population may be responsible for a marked change in allele frequencies
a group of interbreeding individuals belonging to a particular species sharing a common geographic area
consists of a population whose members have the potential to interbreed with one another in nature to produce viable, fertile offspring, but who cannot successfully interbreed with other groups
keep individuals of closely-related species from interbreeding
keep individuals of closely-related species from interbreeding,is a type of reproductive barrier
- genetic mechanisms preventing hybrid organisms (zygotes and beyond) from developing into a reproductively fit adult
- another reproductive barrier
A speciation in which biological populations are physically isolated by an extrinsic barrier and evolve intrinsic (genetic) reproductive isolation, such that if the barrier breaks down, individuals of the population can no longer interbreed.
the process by which new species arise within the range of its predecessor species
A cell or an organism having a genome with multiple (more than two) sets of homologous chromosomes