Once large organic polymers formed on earth, what was the next step needed to proceed towards the formation of living things?
Formation of a boundary surrounding the cell
What event in the earth's history coincided with the Cambrian explosion of animal diversity?
Increased levels of atmospheric oxygen
What new property of living things during the Proterozoic era lead to the development of organelles?
Ability to invaginate the plasma membrane
Which of these hypotheses for the origin of life is not easily testable in a lab?
Which type of cell differentiation is controlled by unequal distribution of maternal cytoplasmic factors as the embryo's cells are dividing?
From what tissue layer of the developing embryo does the epithelium lining the stomach originate?
From what tissue layer of a developing embryo does the nervous tissue arise?
During which stage of embryonic development does the neural tube form?
During which stage of embryonic development do the three tissue layers spread through the embryo?
During which stage in development do segments form along the neural tube?
Which of these fossils are most likely to be found easily?
Huge, bony stegosaurus
How does the future spinal cord form in developing human embryos?
Ectoderm above the notochord thickens and folds together
Which of these organisms has incomplete cleavage of cells between the animal and vegetal poles during early development?
During fertilization, how are multiple sperm first prevented from fertilizing one egg?
The egg cell membrane depolarizes, blocking sperm from bonding
What was the era in which dinosaurs dominated the Earth?
The Mesozoic era
How does the theory of endosymbiosis explain the evolution of cellular organelles?
An ancient archaeon engulfed a bacterium that began living symbiotically with its host
What organisms first appeared during the Proterozoic era?
Which of these is NOT an important factor that determines the likelihood of a fossil being found?
Skill of the excavator
Which of these molecules is best able to preserve genetic information due to its stable structure?
Which statement about human evolution is TRUE?
Several hominid species existed at the same time, but only Homo sapiens survived
Which was the first molecule to arise in protobionts that could store genetic information?
Which type of cell differentiation is controlled by cell to cell contact and secreted molecules?
During which developmental stage does the fertilized egg become a blastocyst?
In the reducing atmosphere hypothesis for the origin of life, which of these was NOT important to the formation of the first living things?
Which is a key feature of ALL hominin species?
From what tissue layer of a developing embryo does the muscle tissue arise?
What did the Bartel and Szostak experiments on the chemical evolution of RNA show?
RNA strains with mutations that give them more enzymatic activity will become more common over time
Green beetles becoming more common than brown beetles in a lush green environment would be an example of what kind of natural selection?
Which of these statements about evolution is NOT true?
Traits acquired during an animal's lifetime pass to its offspring
Which of these phenomena has the weakest effect on whether a population stays at Hardy Weinberg equilibrium?
Which of these phenomena has the strongest effect on whether a large population stays at Hardy Weinberg equilibrium?
Which of these would be an example of intrasexual selection at work?
Male moose using huge antlers to fight each other
What conclusion did Darwin come to from the evidence that populations varied, that variation was heritable, and that it could help some individuals out compete others?
Why is evolution still considered a theory?
All knowledge in science is tentative
How does radiometric dating help paleontologists estimate the age of a fossil?
By comparing the ratio of carbon 12 to carbon 14 isotopes in a fossil
What is the likelihood that a particular genotype will contribute to the gene pool of future generations?
If there is a coastal swamp with saltwater seeping into some areas and salt tolerance becomes more common in individuals of a grass species just in those areas, that would be an example of what kind of natural selection?
Why are some strains of S. aureus now resistant to antibiotics?
Bacteria with a mutation that made them resistant survived and reproduced, while others without it, died without reproducing.
Which of these conditions would prevent a population from being at Hardy-Weinberg equilibrium (not evolving) for a particular trait?
If a population is at Hardy Weinberg equilibrium and 1% of the population has sickle cell anemia (q=.1), and 81% of the population does not carry the trait at all (p=.9), then what percent of the population are heterozygous?
Which of these would be an example of adaptive natural selection in action?
Change in beak size in a finch population affected by periodic drought & S. Aureus developing resistance to antibiotics
Giant anteaters and echidnas both developing long snouts and sticky tongues to eat insects would be an example of what?
In Uganda 2% of the population have sickle cell anemia (q=.14). If 52% of the population does not carry the trait (p=.72), then what percent of the population would you predict are heterozygous?
Which is an example of molecular homology demonstrating all life's descent from a common ancestor?
Which of these statements about evolution is true?
Natural selection acts on individuals, but only populations evolve
Which of these conditions would a population need to be at Hardy-Weinberg equilibrium (not evolving) for a particular trait?
Which of these is an example of a founder effect affecting allele frequencies in a population?
Small population of finches flying to an empty island
In some reef fish being too small means not producing many eggs, but being too big means not being able to find a good hiding place that you can squeeze into to hide from predators. What type of natural selection would cause the fish population to shift toward a medium size between the two extremes?
Fewer male White-tailed deer who grow big antlers at maturity are being born in Louisiana, how can you explain this?
Hunters are shooting more males with big antlers before they can mate.