AP Bio-- Short Answer

What is a postzygotic barrier?

A barrier that occurs AFTER the egg and sperm meet (zygote) Example: Fragile hybrid, inviable hybrid, sterile hybrid

What is a prezygotic barrier?

A barrier that occurs BEFORE the egg and sperm meet (zygote). Example: Geographic isolation, behavioral isolation, gametic isolation, habitat isolation, temporal isolation etc....

What are the three domains of life?

Archaea, Bacteria, Eukarya

Give a scientific hypothesis about the origin of life.

Complex organic molecules (carbon based living molecules) can form from inorganic material.

Predict and explain the effect that decreased genetic diversity would have on the evolution of a species.

Decreased genetic diversity would decrease the rate and instances of evolution. If there's little diversity and the environment is stable, there won't be a "favorable" trait to be passed on to offspring increasing the overall fitness of the population. If a environmental change takes place, all the members of the population could be selected against and extinction could take place because there's not diversity to survive.

What are the taxonomic categories?

Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species

Define "fitness" as it relates to evolution.

Fitness is being able to survive and reproduce so you pass on your genes to the next generation.

What types of evidence are used to support evolution?

Fossil records, morphology (structures), developmental study (evo-devo), mostly DNA!

Explain why genetic variation and mutation are important for natural selection in a changing environment.

Genetic variation is required for there to be variation in the traits of the population. Mutations causes new genetic variations in a population (but not all mutations cause variations, most are silent mutations). Natural selection is based on there being variations in a population so that one variation will be favorable in the environment.

Explain the kind of mathematical evidence that is used to investigate evolution.

Hardy-Weinberg is the math evidence that evolution is happening (or not).

How does the study of a non-evolving population inform scientists as to the effects of evolution?

It provides a comparison to the rates and effects of evolution in a population.

Provide examples of changes to an environment and give examples of possible adaptations that such changes would select for in a population.

Just look at the rock pocket mice video or the peppered moth scenario for this one.

What conditions must be met for a population to be non-evolving, are these conditions frequently met? Explain why or why not.

Large population size, no net mutations, no migration (gene flow), random mating, no selection (these are the AP Biology conditions for Hardy-Weinberg)

Explain how natural selection leads to adaptation in a population. Provide an example to illustrate.

Natural selection allows those individuals with favorable variations of a trait to survive and pass on those favorable variations where those without favorable variation of the trait will not survive. After an extended period of time those favorable variations will change the population causing adaptation to occur. Example: Rock pocket mice fur and also peppered moths

The production of new variations is a random process. Is natural selection also a random process? Explain your reasoning.

Natural selection is not random. Those individuals with favorable traits will survive to pass on their traits.

What are some methods used to date fossils and rocks?

Radiometric dating, carbon dating, just know that there are methods, you don't need the details

Explain the relationship between evolution and random events.

Random events, such as genetic mutations and catastrophic climatic events cause variation in the population and natural selection to act as an evolutionary force respectively.

What is biological systematics and how is it used to develop phylogenetic trees?

Same idea as phylogenetics, cladistics, etc. Basically it's being able to visualize the relationships of organisms by placing them on cladograms, trees, etc.

After these barriers are in place for quite some time (depends on mutation rate, natural selection pressure, etc) speciation may occur. What is allopatric speciation?

Speciation that occurs because two populations are separated geographically for a long time. If you were to put the two populations back together they would not BE ABLE to mate, even though they used to could and would before the geographical split. Example: Darwin's Finches

What is sympatric speciation?

Speciation that occurs within a population due to another isolation event (not geographic) that causes them to be no able (or not inclined) to mate and produce offspring. Example: Say a finch accidently learned the mating song wrong. Another finch happened to be okay with that song, even though the bulk of the population would not mate with him. Those two mate and their offspring learn the wrong song. After 1000 years (give or take..) one of the new offspring learn the same song as the old population.

What were the characteristics of the early planet and its atmosphere?

Started off molten and without an atmosphere. As the atmosphere formed from volcanic gas, it was made up of hydrogen sulfide, methane and a TON of CO2

What are the Miller and Urey tests?

Tests that were done to see if you could make organic molecules from inorganic molecules. They were loosely successful.

How does the environment affect the evolution of a species? Provide an example to illustrate.

The environment affects the evolution of a species because it provides a habitat where a trait can be favorable and selected for causing evolution to happen in the population. The peppered moths' evolution was a direct result of a change in the environment.

What is a species in biological terms?

The inability or unwillingness to mate and produce fertile offspring.

What is the endosymbiotic theory?

The theory that a large prokaryotic cell engulfed a smaller prokaryotic cell that was able to do cellular respiration and formed eukaryotic cells (ones with organelles)

What is punctuated equilibrium?

The theory that a population will go along with no changes for an extended period of time (equilibrium) and all of the sudden there will be a rapid speciation event (punctuated). Think cladogram

What is gradualism?

The theory that evolution occurs slowly, one small change at a time (think: phylogenetic tree)

How can continental drift explain the current distribution of species?

There are similar species in areas where old Pangea used to connect, but they have adapted differently.

How has human society affected the evolution of other species? Provide examples to illustrate.

We trash all evolution :-). Humans have used artificial selection to change the evolution of many, many species. Humans also have changed many habitats causing the evolution of populations that inhabit those habitats to change.

Can a particular variation decrease the fitness of an individual, but increase the fitness of a population?

Yes, a variation that benefits a colony but doesn't allow for reproduction is a variation that fits the description. Ex: Honey bees: only the queen reproduces, but the worker bees are instrumental in supporting, feeding, and caring for her offspring. Therefore, a worker bee would be considered not biologically fit, but their role in the colony increases the fitness of the entire population.