EOC Practice 2

Considering the new definition of life, all but one piece evidence supports the fact that a virus must be referred to as an organism. That is:

• Viruses contain nucleic acids.

• Viruses are capable of replication.

• Viruses have a simple cellular structure.

• Viruses have an evolutionary history and that implies lineage.

A model of the cell cycle is shown here. Based on your knowledge of the cell cycle and the percentage of cells in each stage of the cell cycle, evaluate each of the following statements. Select ALL correct options.

• 90% of the time the cell is in interphase.

• Mitosis is the longest phase of the cell cycle.

• 10% of the time, the cell is dividing its nucleus and cytoplasm.

• The cell spends almost half of its time growing in size and duplicating organelles.

• The cell spends 5X more time duplicating the DNA compared to dividing the nuclear components.

Viral characteristics include all BUT which one?

• Most viruses are much smaller than bacteria.

• Viruses do not contain any nucleic acids.

• Viruses infect all types of life forms on Earth.

• Viruses multiply several ways but always in a host.

According to cell theory, scientists do not classify a virus as living because it does not have

• a membrane.

• genetic material.

• cellular structure.

• any organic molecules.

A population of fruit flies is shown to be evolving as certain phenotypes seem to become more and more prominent over several years. Scientists have measured the changes, and the phenotypes have not been at equilibrium for more than five generations. Which of these factors could be playing a role in these changes? Select ALL that apply.

• The population can have new mutations that appear due to random changes to the DNA.

• Sexual selection could occur as certain individuals in the population mate with greater frequency.

• Speciation has occurred, preventing the fruit flies from mating with members within the same population.

• Natural selection can favor certain phenotypes over others, increasing the survival of more fit individuals.

• Random mating increases the prevalence of the dominant trait and suppresses the prevalence of the recessive trait.

Climate change has been studied by scientists for some time. However, the impact of climate change on the Arctic is of even more concern. The Arctic is expected to experience the most dramatic changes and at the same time undergo more rapid warming than any other biome on earth. Compared to other biomes, the Arctic has been relatively constant over time but is considered to have little resistance to climate change. For this reason, the Arctic is particularly vulnerable to the relatively rapid, major climate changes that are being observed on earth today. Select ALL of the ways in which climate change will likely affect the stability of the Arctic ecosystem.

• Sea warming can impact fish spawning.

• Sea ice reduction will impact hunting for carnivores.

• Whales will have less habitat available due to ice melt.

• Melting permafrost will cause an explosion of plant species.

• Ocean acidification will affect organisms with shells such as coral reefs and crustaceans.

The food web illustrated above shows plants and animals, but does not indicate bacteria. If bacteria were truly missing from this food web, what is the most likely effect on the community?

• Grasshoppers would eat at a lower level of the food chain without bacterial presence.

• Rhinoceros would become carnivores without the digestive aid of prokaryotes in their gut.

• Decomposition rates would be lower, resulting in fewer nutrients being able to the plants.

• Cellular respiration rates would increase in heterotrophs since competition for resources would decrease.

As a result of _______________, the incorrect sequence of amino acids will be translated into a protein, resulting in a mutation.

• deletion

• insertion

• inversion

• crossing over

Scientists have been genetically modifying food crops since the mid 1990's. As a result, scientists have been able to produce crops that are more disease resistant. What could be seen as a risk associated with using genetically modified crops?

• reduction in nutritional value of the food crop

• plants can be "tailor made" for the desired trait

• crops may cause an increase of allergic reactions in humans

• crop production would be increased due to greater disease resistance

Based on the information seen in the image above, what is a major difference between viruses and bacteria?

• Bacteria can reproduce but viruses cannot.

• Bacteria contain DNA and viruses contain RNA.

• All bacteria are pathogenic, but only some viruses are pathogenic.

• Viruses are surrounded by a protein coat; bacteria are surrounded by a cell wall.