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level: Level 1

Questions and Answers List

level questions: Level 1

Question	Answer
If a virus enters the lytic phase in a host's cell, it will cause the host cell to	lyse due to the action of enzymes
The HIV virus is considered a(n) ______ virus, because after getting integrated into the host cell chromosomes, it does not begin replicating immediately.	latent
The amount of genetic variation present in naturally occurring populations is	significant
Genotypes are said to be in ___________ equilibrium if there is random mating and no other forces tend to alter the proportions of alleles from one generation to the next.	Hardy-Weinberg
Which type of selection acts to eliminate individuals at one extreme of a phenotypic range?	Directional selection
Which of the following is not a shape seen in prokaryotes?	Icosahedrals
A researcher observed a reduction in the number of chromosomes during cell division for a microbe, he concludes that the microbe must be	Eukaryotic
Which eon would contain rocks with no fossils?	Hadean
A scientist is studying endosymbiosis in cells. This means she is investigating	how mitochondria and chloroplasts were derived from prokaryotic cells.
The evolution of conducting tubes (sieve tubes) in land plants and brown algae is an example of	homoplasy caused by convergence.
A group is considered monophyletic if	all members of the group share a common ancestor that is included in the group.
Crop sunflowers are attacked by many fungal pathogens, such as downy mildew and Sclerotinia, resulting in economic losses of millions of dollars per year. What genes would be best to target for the development of new fungus-killing crop treatments (fungicides)?	Genes encoding chitin proteins that are shared by downy mildew and Sclerotinia, but absent in sunflower and humans.
Lake Victoria is famous for its variety of cichlid fishes. In fact, they offer the most diverse assembly of vertebrates presently known to science. One trait that scientists have focused on as one possible reason for their adaptability is	a second set of jaws in their throats.
According to the Biological Species Concept, two groups of organisms that are unable to form fertile, viable hybrids are considered to be different	species.
Which one of the following is not important to the concept of homology?	None of the features being compared can be vestigial.
The side toes of a horse, the pelvis of the whale, and the human appendix are all examples of structures that resemble structures of presumed ancestors, which are known as	vestigial structures.
Which "alternate" hypothesis might also explain industrial melanism?	Dark moths are more resistant to the toxic effects of pollution than light moths.
A Greek philosopher (384 - 322 BCE) whose Scala Naturae (ladder of nature), one of the first theories in biology, placed all living things in a hierarchy, with the simplest organisms at the bottom and humans at the top.	Aristotle
Luke went to a pediatrician when he was 6 months old. The pediatrician consulted a graph and concluded that Luke was in the 97th percentile for height, weight and length. The pediatrician predicted that Luke would be tall when he reached adulthood. What type of reasoning did the pediatrician use to generate her prediction about Luke's future growth in height?	Inductive reasoning
A turning point in the history of biology occurred when the ancient Greek philosophers rejected the vitalistic view that life was controlled by supernatural powers. They accepted instead the view that life was governed entirely by natural laws - those now know to be the laws of physics and chemistry; this is called the _____________ view of life.	mechanistic
A rock contains 18 mg of the radioactive isotope carbon-14. The half-life of carbon-14 is 5,600 years. How many half-lives and years will it take before the carbon-14 decays to less than 4 mg?	3 half-lives; 16,800 years
Comparing the evolution of domesticated dogs to the evolution of wolves over the same time period illustrates what relationship between artificial and natural selection?	Artificial selection is more likely to produce maladaptive structures than natural selection.
Plants in the desert-adapted families Cactacea (cactus) and Euphorbiaceae (euphorbs) share many of the same physical characteristics, such as succulent stems that store water and CAM photosynthesis, but they do not share a recent common ancestor. This evidence suggests that these families are an example of	convergent evolution.
Birds, snakes, lizards, turtles, and crocodiles are all thought to share a common ancestor and several homologous traits. Assuming that this is true, these groups of animals would best represent	a monophyletic group.
If the label on a slide reads Gram-positive bacillus, what would a student expect to see?	Purple rod shaped cells
What common characteristic of life would cells from a protist, a daisy, an apple and a dog all possess?	DNA
Multiple independent experiments have demonstrated that phytochrome helps trigger seasonal change responses in the plant such as changing colour and loosening of leaves. Plants have the ability to adapt to seasonal changes in their surroundings. This statement is an example of:	a theory
The total of all the alleles of all the genes in a population can be thought of as	a gene pool.
Migration and hybridization between individuals of adjacent populations cause gene _______.	flow
There are more than 30 blood group genes in humans, in addition to the ABO locus. This increases __________ in human populations.	genetic variability
Each HIV particle possesses a ___________ on its surface, called gp120, that precisely binds to a protein, called CD4, that is found on the surfaces of the immune system cells called macrophages and T cells.	glycoprotein
Analysis of air bubbles trapped in rocks shows a drop in the level of carbon-12 (relative to other isotopes) in rocks that are 3.8 - 3.7 billion years old when compared to rocks that are 3.9 - 4.0 billion years old. How is this possible?	Living organisms that appeared approximately 3.8 billion years ago preferentially use carbon-12.
Two principal organelles of eukaryotes that share features with one another and with bacteria from which they apparently were derived are the	mitochondria and chloroplasts.
Several species of sea urchins may inhabit the same tide pool and their reproductive periods' overlap. Although they practise external fertilization, they seldom interbreed because eggs produce chemicals that are only attractive to sperm of their own species. This is an example of a _________ barrier involving _______________.	prezygotic; gametic isolation
Petrels (a flying and diving seabird) are thought to be one of the closest living relatives to penguins. What type of genes would be most likely to exhibit different expression patterns between these species?	genes controlling flight
There are more than 30 blood group genes in humans, in addition to the ABO locus. This increases __________ in human populations.	genetic variability
Natural selection as a mechanism of evolution that acts on variants within populations and ultimately leads to the evolution of different species was proposed by	Darwin.
Evolution does not violate the second law of thermodynamics because	Earth is not a closed system; it constantly receives an input of energy from the sun.
Inhabitants of oceanic islands resemble forms of the nearest mainland but show some differences. This is an example of	biogeography
What was demonstrated by the Miller-Urey experiment?	Organic molecules important to life could have been formed from a vast array of simple chemicals.
The evolutionary sequence in the development of a complex character can be best analyzed through	synapomorphies
Evidence suggests that the crocodiles are more closely related to the birds than the turtles and snakes. If so, then including the crocodiles but not the birds in the Class Reptilia, would make the Class Reptilia	a paraphyletic group
Virulent viruses multiply within infected cells and eventually	cause lysis of the host cell, releasing new viruses.
The onset of AIDS is often accompanied by	a steep drop in T cell numbers.
The cells wall of bacteria Z contains high concentrations of phospholipids along with proteins and carbohydrates. When bacteria Z is Gram stained, it will most like be coloured?	Pink
Dental plaque (a biofilm), a first stage in tooth decay, consists of	bacteria surrounded by a polysaccharide matrix.
Two bird species have different mating calls, occupy different habitats in nature, and when they hybridize, the hybrids are infertile. Which isolating mechanisms maintain these species?	ecological isolation, behavioral isolation, and hybrid sterility
Prezygotic mechanisms lead to reproductive isolation by preventing the formation of	hybrid zygotes.
Hybridization regularly occurs between three species of Darwin's finches on Daphne Major, but the finches are still considered different species because	they occupy different niches.
Conducting research without a preconceived hypothesis is called	discovery-based science.
An Austrian monk (1822 - 1884) who, with experiments on garden peas, discovered many of the basic principles of inheritance.	Gregor Mendel