BSC 2010 Exam 3 – Flashcards

What major event in continental drift occurred during the Jurassic period?

What mode of selection is most likely to lead to an increase in phenotypic variation?

Carbon-14 has a half life of only 5,000-6,000 years, so it is only useful for dating fossils that are no more than _________ years old. Otherwise there would not be enough of the isotope left to do an analysis.

Evolution can be defined as...

The size of horns in males of a particular beetle have an interesting distribution: the highest frequencies are around 15 mm and 30 mm, with a few individuals in between. Based on this observation, which evolutionary process is most likely to be operating on these horns?

The beginning of the Paleozoic Era ushered in abroad diversity of multicellular forms of life. What major change in the earth that occurred around this time probably allowed for this great explosion in diversity, and what entity was responsible for the change?

Which statement about positive selection is true?

What is the difference between qualitative and quantitative traits? In a population:

The molecular evolution studies of sodium channels in puffer fish is used primarily to

The marking of the ends of almost all of the major time divisions of the Geological Time Scale is mostly based on the occurrence of

Most fossils are found in

Natural selection can be defined as

The primary distinction between artificial selection and natural selection is that artificial selection _________, while natural seletion ________.

Suppose individuals robins that have longer beaks have somewhat more offspring than those with shorter beaks, and that this has lead to an increase in beak length over time. We can say that beak size is associated with the _____ of the robin, and that there is _______ selection operating on beak size.

The artificial selection experiments with bristle numbers in Drosophilia illustrate which generality?

If you could know that a fossil that is 10,000 years old started with 20 mg of carbon-14, how much would you expect that same fossil to have today?

Which statement about evolution is false?

The primary use of in vitro evolution is to

What is the correct chronological order (earliest to latest) of these events?

A small population of sawflies, that was once connected to a larger one, but is now isolated, is no longer experiencing

Which is not a condition that must be met for a population to be a t HW equation?

Which statement about mutations is true?

Which phenomenon is most likely to lead to an increase in the rate at which pseudogenes evolve?

If a single copy of a new mutated allele arises in a popuation of 50 diploid individuals, what is the likelihood that this particular mutant allele will become fixed in that population. Assume that this allele is neutral and fixation occurs due to drift.

Researchers suspect that the gene FOXP2, which is involved in speech and cognition, has been under positive selection in the human linage. Which observation would provide the strongest support for such a claim?

A normally asexual lineage experiences sexual reproduction, and as a result, the amount of genetic variation increases and deleterious mutations are purged from the lineage. This purging is a reversal of

Supposes a hard frost in southern Florida kills nearly all of the population of plants. Even though the plant population recovers in numbers after a couple decades, the genetic variation within that population remains much reduced. What is the most likely cause of the diminished genetic variation?

You are studying a flowering plant, and individuals plants have either red or white flowers. RR and Rr individuals have red flowers, while rr individuals have white flowers. If 16 plants in the population of 100 have white flowers and 84 have red flowers, how many of the red-flowered plant would you expect to be carriers of the r allele?

Following a flood, migration from neighboring populations alters genotypic frequencies of a population of river-bottom midges. Assuming that the conditions for HW are met, how many generations of random mating are required to restore the genotypic frequencies to HW equation?

The model of selection in which the proportion of genotypes with a more extremem value of the trait in question (i.e. tall) increases is called

In a hypothetical population of sawflies, 20% of the population is homozygous for allele A and 45% is homozygous for allele a. Assuming that A and a are the only alleles at the locus, what percent of the population is hetereozygous?

As the amount of lateral gene transfer in a taxon increases, it becomes _______ difficult to infer relationships among lineages within the taxon and _______ to infer species boundaries.

Which of the following statements about genetic drift is true?

If the exchange of allele b1 for b2 at the b locus does not affect the fitness of individuals, these alleles can be considered ______ alleles

Genes from many isolates of the influenza virus have been sequenced. In certain regions of the genome, nonsynonomous substitutions have been found to occur much more frequently than synonymous substitutions. From this pattern we can infer that

Sickle cell anemia evolved in Africa. Although homozygotes of this allele have the anemia, the sickle cell allele of B-globin has reached high frequencies because individuals with one copy of the allele have a resistance to malaria. The maintenance of both the normal and sickle cell alleles is therefore due to

Consider five species of toads. Species A and B are sister species. Species C and D are also sister species. The clade containing species A and B is sister to the clade containing species C and D. Species E is sister to the clade containing A, B, C, and D. Which species is most likely to share synapopmorphies with species C?

Suppose that mice and humans differ by 20 substitutions in their globin genes, and rats and mice differ by 5 substitutions. On the basis of other evidence, we know that the ancestor to humans and mice lived 80 millions years ago. Assuming the molecular clock is operating, rats and mice split from each other _____ million years ago.

What is formed when any two branches diverge in a phylogenetic tree?

Which of the following types of groups can be removed by a single cut to a phyologenetic tree without the removal of any other species outside the group

Information about ____ behavior would be least useful in reconstructing phylogenies.

Which study led to biologists to infer that the ancient archosaur was active during the night?

Transitions occur _______ frequently than transversions; thus using transitions, as opposed to transversions, will be more useful for reconstructing phylogenetic relationships between _____ organisms.

Which statement about systematics is true?

Which statement about the molecular clock is true

Histone genes, which evolve very slowly, would most likely be used to study relationships

A major challenge of maximum likelihood methods is that they

Phylogenetic analysis of HIV and nonhuman SIV demonstrates that HIV is ____ and SIV is _____.

Parsimony

Which sequence represents a correct size ranking of taxonomic categories, from smallest to largest?

The Bruce spanworm and the winter moth are two closely related moth species, but the former flies during the day and the latter flies mainly at night. These differences contribute to the reduction of hybridization between these species. Based on this information, which statement is true?

Which type of reproductive isolating mechanism would mostly likely arise from the co-evolution of male and female reproductive organs in two sympatric populations of insects?

Which factor did not contribute to the genetic diversification of the Galapagos Island finches studied by Darwin?

Which statement about species concept is true?

Speciation resulting from the division of a population by a physical barrier is known as

Which is a limitation of only using morphology to recognize species?

The biological species concept does not apply to which groups of organisms?

Which circumstance is most likely to lead to speciation in only a couple of generations?

Which factor is most likely to yield narrow hybrid zones

Which is an assumption of the Dobzhansky-Muller model of speciation?

Which observation would pose the greatest challenge for applying the morphological species concept?

Two species have genotypes aaBB an dAabb. mating between these species leads to F1 individuals that are sterile due to a Dobzhansky- Muller incompatibility. Therefore, the genotype of the ancestral population could have been

Which statement about the Dobzhansky-Muller model of speciation is true?

Which evolutionary process was required for sympatric speciation in species such as the apple maggot fly?

Which condition is least likely to lead to allopatric speciation?

Which sequence represents the most likely chronological order of events in the development of geographic speciation, from earliest to latest?

Which is the critical distinction between allopolyploidy and autopolyploidy?