Help
Options
Didn't know it?
click below
click below
Knew it?
click below
click below
Don't Know
Remaining cards (0)
Know
retry
shuffle
restart
0:00
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
PCQ Life 121 Exam 1
| Question | Answer |
|---|---|
| You are interested in studying fur coloration in a species of mice. If natural selection has been acting, what would you expect to be true? | there must be variation and a genetically inheritable trait |
| Which of the following are true about genetic variation within a population? | genetic variation is created by the direct actions of natural selection, and new mutations increase the genetic variation b/c they can create many different alleles |
| Which of the following is correct about phenotype? | Phenotypes are usually the result of a combination of genes as influenced by the environment. |
| A segment of DNA on a chromosome that encodes for a protein that affects a specific characteristic | gene |
| A variant form of a gene that can lead to different traits | allele |
| This term refers to the fact that a sexually reproducing organism has two copies of every gene, one from its mother and one from its father | diploid |
| The observable physical traits or characteristics of an organism, resulting from the interaction of its genetic makeup with the environment | phenotype |
| The genetic makeup of an organism, specifically the combination of alleles for a particular gene | genotype |
| For a given gene, if an individual has inherited the SAME allele from each of their parents, they are considered | homozygous |
| For a given gene, if an individual has inherited DIFFERENT alleles from each of their parents, they are considered | heterozygous |
| For your same population that you found to be in Hardy-Weinberg equilibrium, what can you conclude about evolutionary processes within that population for that particular gene locus? | the population is not evolving because there are no evolutionary forces currently acting on that gene |
| Which of the following statements are true about allele frequencies when a population is in Hardy-Weinberg equilibrium? | An allele frequency is the probability that a random gamete in the population will contain that allele, The 2 in the equation term 2pq means that there are two different ways that parental gametes can come together to form a heterozygote offspring |
| What is the equation for genotype frequencies? | p^2 + 2pq + q^2 = 1 |
| If migration is occurring between two populations, under what circumstances would you expect this to decrease the mean population fitness in both populations? | the two environments the populations live in are very different |
| Which of the following best describes frequency-dependent selection? | Selection that favors individuals with traits that are the most common in the population, leading to a decrease in genetic diversity. |
| Detailed measurements of physical characteristics for each population | morphological |
| Data on both differences in mating behaviors and on the sterility or fertility of offspring from crosses between the two populations | biological |
| Observations of interactions (predation, competition, etc.) and resource use for each population | ecological |
| Two species of frog occasionally mate, but their offspring fail to develop and hatch | post-zygotic barrier |
| Two similar bird species have distinct songs to attract mates, and they do not respond to other songs or calls | pre-zygotic barrier |
| Two butterfly populations are separated by a mountain range they are unable to cross | pre-zygotic barrier |
| Mules, hybrid offspring of horses and donkeys, are sterile | post-zygotic barrier |
| When a grain of pollen containing plant sperm lands on the stigma of a different species of flower, a pollen tube does not grow | post-zygotic barrier |
| polyploidy | error in mitosis or meiosis causes a chromosome doubling that allows a sterile hybrid to begin to reproduce |
| habitat differentiation | an introduced fruit species provides a new host for a parasitic insect and introduces a reproductive barrier that reduces gene flow |
| sexual selection | small variations in coloration and differential mate choice by females introduces behavioral isolation in a fish population |
| What is a hybrid zone? | an area where mating occurs b/w members of two closely related species, producing viable offspring |
| Hybrid individuals continue to be produced at the same rate | stability |
| Reproductive barriers strengthen and over time hybrids cease to be formed | reinforcement |
| Reproductive barriers weaken and the two species fuse into one species | fusion |
| When two organisms share a similar trait because they both inherited that feature from a common ancestor, this trait is | homolgy |
| When two organisms who are distantly related both share a similar trait because they each independently evolved the trait (i.e., they did not inherit the trait from their mutual ancestor), this trait is | analogy |
| Convergent evolution leads to | analogy |
| Bats are a type of mammal, while birds are more closely related to reptiles than they are to mammals. The fact that bats and birds both have wings and are able to fly is an example of | analogy |
| Bats and birds are both members of a large group of animals called tetrapods (animals with 4 limbs). The fact that birds and bats both have 4 limbs is an example of | homology |
| How does the relatedness of species work in a phylogenetic tree? | any species behind the species in question on the phylogenic tree is less closely related than any other species that follows the species in question |
| A monophyletic group on a phylogeny that consists of a group of organisms that | all descendants of a common ancestor and all of that ancestor's descendants are included in the group |
| A trait that is unique to a particular group of organisms that is only found in that group and is not found in organisms outside that group | shared derived trait |
| A trait that is present in all members of a group of organisms, but that trait is also found in organisms outside that group because it evolved earlier, so it is not a defining feature of only that particular group | shared ancestral trait |
| Owls are a sub-group within the bird clade. For owls, feathers are a | shared ancestral trait |
| To apply the principle of maximum parsimony when constructing a phylogenetic tree, you should | choose the phylogeny that requires the fewest evolutionary changes |
| Which of the following correctly describes what an outgroup is? | an organism that is more distantly related to the ingroup than any of the ingroup members are to each other |
Created by:
user-1972564