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Creado por miriamadaeze
hace casi 11 años
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increased atmospheric concentration facilitated the evolution of larger and more active animals
the advent of recombination and independent assortment of chromosomes during meiosis provided the genetic variation necessary for diversity in body plans
evolution of genes that control the transcription of many other genes enabled animals to develop diverse and complex body plans
the advent of sight enabled animals to forage many different ways leading to different body plans
evolution of predators selected for adaptations in their prey that enabled them to escape predation
occurred 251 Myr ago, extinction of 96% of species
occurred 65 myrs ago, extinction of 76% of species (most famous)
What caused the mass extinctions?
form of mutation-single base pair substitution in DNA
no change in the amino acid translation
results in amino acid substitution on the polypeptide
caused by insertion or deletion of one or more base sequences which results in a series of amino acid substitution during translation
transfer of a segment from one homologous chromosome to the other
Hereditary determinants in the egg and sperms are irreversibly blended
hereditary determinants in the egg and sperm are passed from generation to generation through discrete particles.
an observable physical features
a particular form of a flower (purple)
a particular trait is the only form present when crossed over many generations; Mendel used only such parents
different forms of a gene
when an individual has the same copy of an allele
when an individual has different copies of an allele
when an allele is expressed in a heterozygous individual
when an allele is not expressed in a heterozygous individual
when an individual (with 2 copies of each allele) produced gametes, each contains only one copy
The site on a chromosome occupied by a specific gene
alleles of different genes assort independently of one another during gamete formation
association between genes on the same chromosome such that they do not show independent assortment
when heterozygotes show a phenotype intermediate between those of the two homozygotes
Pattern of inheritance characteristics caused by genes located on the sex chromosome
predation and abiotic disturbances are at an intermediate level in the tropics, allowing more species to coexist
study of the allele frequency distribution and change in a group of interbreeding organisms
characteristics displayed by an organism caused by its genetic constitution, environmental factors, and interactions between genetic and environmental factors
the genetic constitution of an organism at one or more specific loci
the proportion of a population that has a particular genotype
the proportion of all genes in the population present in a particular form
the assumptions of the hardy-weinberg model
a form of nonrandom mating in which individuals are more likely to mate with relatives than with nonrelatives
set of species living in a particular place
probability that a pair of genes are identical by descent
reduction in fitness of inbred organisms caused by increased frequency of deleterious recessive genes
random change in gene frequencies within populations caused by sampling error
when p=1.0, the allele is____
when p=0, the allele is _____
the proportion of the population that are heterozygous
The study of continuously measured traits (such as height or weight) and their mechanics
a phenotypic trait that varies continuously (rather than discretely) for different character states
Quantitative traits are typically ____
The proportion of the phenotypic variance that is made up of genetic variance
Two ways to measure heritability are?
variation in alleles within individuals and populations and between populations
accumulation of mutations that do not affect fitness
crossing over and independent assortment of chromosomes amplifies the number of possible genotypes
maintains genetic diversity when the fitness of rare genotypes in higher than common genotypes
when fitness is higher for heterozygotes than homozygotes
how does gene flow affect the populations?
movement of genotypes from one population to another
a process that occurs when individuals share resources that are in short supply
individuals deplete resources by consuming or using them
aggressive encounters among individuals
competition among individuals of the same species
Competition among individuals of different species
two species cannot coexist if they have the same niches
where a species lives and how it obtains resources
when species differ in the way they utilize their resources
the limit in the degree of overlap that will allow species to coexist
what are the three ways a species may partition their resources
when species differ more where they are together (sympatric) than where they are alone (allopatric)
when an animal eats another organism
when an animal eats another animal
when an animal eats a plant
when an animal eats an organism that it lives on or in
when two or more species affect one another's evolution
an example of coevolution which involves resource partitioning, character displacement
predators select for defensive traits in prey, which selects for traits in predators that weaken the defense of prey
species that are brightly colored to advertise that they are harmful
when two or more species (usually aposematic) resembles one another
when a non harmful species resembles a harmful species
when two or more harmful species resemble one another
the study of multiple species interactions and abiotic factors on the structure and dynamics of community
when predators reduce prey populations and thereby prevent competitive exclusion of prey species, increasing diversity
when abiotic disturbances reduce prey populations and thereby prevent competitive exclusion of prey species, increasing species diversity
4 known hypothesis on why there are more species in the tropics than in other areas on earth (4 total)
species are more specialized in the tropics allowing more species to coexist
temporal change in community composition
this type of succession begins on bare rock or sand (no soil)
this succession begins on soil
this theory states that communities are fundamental units of highly integrated species and succession proceeds towards a predetermined climax
in this theory, communities are collections of non-integrated species with similar physical requirements and succession doesn't proceed towards a predetermined climax
what are the 3 mechanisms of succession