ch 7 bio hw – Flashcards
Unlock all answers in this set
Unlock answersquestion
which two observations led Darwin to conclude that there is competition for survival?
answer
overproduction and limited resources
question
by what means did Darwin propose species evolved over time?
answer
natural selection
question
what will individuals with variations that make them best suited to their environment will, on average, be more likely to do?
answer
survive and reproduce
question
why or why is it not accurate to say that individuals evolve?
answer
it is not accurate because the evolution of one individual would not affect the entire species
question
can you inherit physical traits that your parents acquired during their lifetime?
answer
no
question
why is it inaccurate to say that humans are most highly evolved species?
answer
1. all species, not just people, are equally "evolved" to fit their particular environment 2. evolution is not goal oriented, it only acts in response to the present situation
question
what is radiometric dating?
answer
the process of determining the age of the fossils from radioactive isotopes
question
where are the older fossils typically found?
answer
lower sediments
question
have fossils of transitional forms been found?
answer
yes, many have been found
question
what are considered to be fossils?
answer
mineralized bones, footprints or other impressions preserved in stone, and animals frozen in ice or preserved in amber
question
what is the name for the study of the geographic distribution of species?
answer
biogeography
question
what is comparing the body structures of organisms to find evidence of a shared evolutionary history called?
answer
bioinformatics
question
although modified to perform a different task, a horse's front leg is made up of the same bones as is your arm. This suggests a common ancestor between horses and humans that also had those bones in its forelimb. The horse leg and human arm are therefore considered to be ________ structures.
answer
homologous
question
the modern evolutionary synthesis of the 1930's and 1940's melded together evolutionary theory with what?
answer
genetics
question
what is the original source of variation?
answer
mutation
question
why are animals more likely than plans to form new species while still in the presence of the parent population?
answer
plants are more likely than animals to form new species in this situation
question
what defines a population?
answer
interbreeding members of the same species
question
what is the smallest unit that can evolve?
answer
the population
question
what does "fitness" mean when speaking in terms of evolution?
answer
how many offspring an individual produces
question
what events can lead to offspring having a unique arrangement of their parents' genes?
answer
crossing over and independent assortment
question
certain traits will have been lost from the gene pool forever. Some may be obvious, like people with red hair or double jointed thumbs. Others will be less obvious, like the ability to process cholesterol or being allergic to peanuts. This loss of diversity in a reduced population is called ________.
answer
bottleneck effect
question
a straggler with green eyes stumbles into the last remaining human outpost. The green eye trait did not exist in the outpost before her arrival, but it does now. What is the name of this mechanism of evolution?
answer
gene flow
question
despite an abundance of habitat, why will it be difficult for the human species to recover?
answer
the reduced genetic diversity will make it difficult for the population to adapt to new diseases or other environmental changes
question
the varieties of species found on the different Galapagos Islands is most likely an example of which form of speciation?
answer
allopatric
question
what might be a cause of sympatric speciation?
answer
genetic incompatibility
question
what model of evolution is closest to what was originally suggested by Charles Darwin?
answer
graduated model
question
what process of evolution does NOT change the total number of species?
answer
non-branching evolution
question
what is another word for macroevolution?
answer
speciation
question
what is the leading hypothesis for what might have brought the extinction of the dinosaurs?
answer
an asteroid impact
question
during which geological era did life first appear on the planet?
answer
precambrian
question
what defines a geological time period known as an era?
answer
the distinct life-forms that were present
question
what is the slow drifting of sections of the earth's crust, sometimes separating, other times colliding, known as?
answer
plate tectonics
question
what model of evolution is the rapid diversification of species seen in the fossil record followed by long periods of stasis a part of?
answer
punctuated equilibrium
question
what is an exception to the standard biological species concept used to define a species?
answer
asexual species cannot be distinguished using the concept
question
what is the term that defines when the sperm of one species fails to fertilize the egg of a different species?
answer
gametic incompatibility
question
what would be a post-zygotic barrier?
answer
hybrid weakness
question
in many ways a mule is a superior animal to the horse or donkey. They are often stronger and can jump higher than either of their parents. Why then are they considered to be a "weak hybrid"?
answer
they are sterile
question
what classification grouping includes the greatest number of species?
answer
domain
question
what grouping immediately follows order in the classification hierarchy?
answer
family
question
what category of classification (out of family, genus, class, and domain) is the most narrow?
answer
genus
question
what domain are prokaryotes in?
answer
prokaryotes are in 2 different domains
question
what grouping includes all of the protists?
answer
domain eukarya
question
what field of science has as its goal to classify all living things into a hierarchal system of relatedness that runs from most broad to most narrow?
answer
taxonomy
question
some of the "branches" of a phylogenetic tree do not extend to the end. what do these lines represent?
answer
extinct species
question
which bear is most closely related to the American black bear?
answer
asiatic black bear
question
a requirement of cladistics is that a grouping must include what?
answer
a common ancestor and all its descendants
question
a cladistics grouping with a shared common ancestor is called what?
answer
an in-group
question
over time, bacteria have become increasingly resistant to antibiotics. Which of the following best explains this in terms of natural selection?
answer
bacteria that happen to have natural resistance to antibiotics survived and reproduced
question
what is a transitional fossil?
answer
transitional fossils have features that are intermediate between ancestors and descendants
question
what are tetrapods?
answer
birds, mammals, reptiles, and amphibians
