Unit 1 Review: Textbook Questions Flashcards
What would have happened if Pasteur had tipped one of his flasks so that the broth in the flask came into contact with the curve of the neck? Explain how this result would or would not have supported his conclusion.
If Pasteur had tipped his flask so that the broth inside had come in contact with the microorganisms trapped in the curve of the neck, the broth would have been contaminated and microorganisms would have grown in the flask. This would have supported Pasteur’s conclusion that microorganisms came not from the air, but from other microorganisms.
Difference between spontaneous generation and biogenesis
Spontaneous Generation says that living things could arise from nonliving things in a process called spontaneous generation. Biogenesis states that all living things come from other living things.
in the 17th/18th century, spontaneous generation was used to explain how
new life started
Redi’s experiment was important because it showed that
flies do not form from rotting meat
People objected to Spallanzani’s experiment because
he boiled his flasks for a long time.
The neck of Pasteur’s flask
allowed air to enter the flask but kept particles out.
During the first half billion years of it’s existence, Earth and the solar system grew by a process involving
collisions with space debris
The oldest fossil of cellular life found on Earth is about
3.5 billion years old
Coacervates and microspheres cannot evolve because they have no
Genetic information
Miller and Urey’s experiment provided
support for Oparin’s hypothesis about the origin of organic molecules
Coacervates and microspheres are collections of
collections of organic molecules enclosed within a boundary.
The generation of organisms from nonliving material does not occur today mostly because
there is not enough energy to drive the chemical reactions needed to form the complex compounds necessary for life.
What is the difference between an acquired trait and a genetic trait?
An acquired trait is not determined by genes and arises during an organisms lifetime and isn’t usually passed down to offspring. Ex: tattoo
A genetic trait is determined by genes and passed down to offspring.
Distinguish between homologous structures and analogous structures.
Homologous structures - same structure (due to shared ancestor), but different function. (ex) bet wing and human hand
Analagous - different structure, same function (ex) insect wing and bird wing
Analogous structures: features serve identical functions, and look somewhat alike. They have very different embryological development, however, and may be very different in internal anatomy.
Ex: Hummingbird and humming moth. Both can hover to feed on sugar-rich nectar from flowers. But, there is no anatomical or embryological similarity between their wings. Birds and insects differ greatly in anatomy and embryological development. Although they share a very remote ancestor, their wings evolved independently and differently in more recent ancestors of each animal.
Homologous structures: similar features that originated in a shared ancestor. Homologous features can result from modifications that change an original feature to two different types, such as a wing and an arm.
Ex: The forelimbs of the penguin, alligator, bat, and human all derive from the same embryological structures. Although they look different and vary in function, they have very similar skeletal structures, and derive from the same structures in the embryo.
How are divergent evolution and adaptive radiation related?
Adaptive radiation is a kind of divergent evolution in which many related species evolve from a single ancestral species.
Lamarck’s explanation for the modification of a species depended on
inheritance of acquired features.
The idea that processes occuring now on Earth are much the same as those that occurred long ago is called
uniformitarianism
The observation that organisms arise in locations where similar, extinct organisms lived is referred to as
biogeography
Similarities in Galapagos finches implied
adaptive radiation
Difference in reproductive success is
natural selection
Great similarity between species implies
recent common ancestry
Features that were useful in ancestors but are no longer useful are called
vestigial structures
Similar features in different species that originated in a shared ancestor are called
homologous features
A hummingbird and hummingmoth have a number of superficial features in common with each other. This is an example of
convergent evolution
The phylogenetic tree on pg 294 implies that modern finches and armadillos
share a remote common ancestor
How was Darwins theory of evolution different from Lamarcks?
Darwin state that species change because individuals differ and that those with more favorable traits reproduce more, increasing those traits in a population.
Lamarck argued that a single organism could change in response to its environment and pass that change on to its offspring.
Why are some traits favorable for some species and not others?
The traits that are favorable for a particular species are influenced by the environment. A white coat may be helpful in a snowy environment, but might not be favorable in a tropical rain forest.
Could a characteristic that is not controlled by genetics be selected by the environment? Would this characteristic contribute to the evolution of the organism that has it?
Yes. a non genetic trait could be selected by the environment but it would NOT contribute to evolution bc it wouldn’t be passed down to offspring.
In recent years, paleontologists have claimed that in some cases the evolution of a new species occurs quite suddenly—in less than a thousand years. Darwin stated that evolution was a gradual process. What effect does generation time have on evolution rate?
Organisms with a short generation time (like prokaryotes) could be modified more rapidly than those with a long generation time. A bacterium with a gene ration time of 1 hour would have almost 9 million generations in 1,000 years - whereas humans would only have 40 generations in that same period. More generations= more variation= more chance of natural selection + eventually evolution
The process of natural selection throughout the history of life on Earth has resulted in the success of some species and the extinction of other species. Why has natural selection not resulted in the existence of a single best-adapted species?
There are many diff environments and many diff demands on species. A species adapted to 1 environment might fare poorly in a diff environment. Diff types of orgaisms are interrelated in complex ways. Ex: animals depend on plants for their existence and plants depend on animals that feed on them for pollination.
What is the relationship between natural selection and sexual selection?
Sexual selection is a form of natural selection whose driving force is success at attracting mates
What is the relationship between evolution and natural selection?
Natural selection is the primary driving force for evolution. Variation -> natural selection-> evolution
Freeways may provide an effective geographic isolating mechanism for some slow-moving animals. Why are such artificial barriers not likely to result in complete speciation?
Such artificial barriers are unlikely to be in place long enough for speciation to occur
The most common definition of species states that a species is a group of organisms that can interbreed and produce fertile offspring in nature. A mule is a sterile offspring of a horse and a donkey. By the definition above, do a horse and a donkey belong to the same species? Explain your answer
A donkey and a horse belong to different species because their mating does not produce fertile offspring.
