Evolution (18%) 11 Items Sample Test Prep Questions Grade 7 (Evolution) 3.a Students know both genetic variation and environmental factors are causes of evolution and diversity of organisms. (pg. 109 Science Framework) Summary: Environmental factors are a cause of natural selection. The term selection implies that there must be favorable and unfavorable traits uncovered in the population. Genetic variation must precede natural selection, or there is some risk that no individuals in a population will survive a crisis. Having little genetic variation to spread the risk makes a population more susceptible to extinction. New York State Released Question What is a major cause of variation within a species? A sexual reproduction B asexual reproduction C extinction D photosynthesis Answer: A sexual reproduction Oregon State Released Question In which population would you expect the most rapid evolutionary change? A A small population with a high mutation rate in a changing environment. B A small population with a low mutation rate in a stable environment. C A large population with a high mutation rate in a changing environment. D A large population with a low mutation rate in a stable environment. Answer: A A small population with a high mutation rate in a changing environment.
3.b Students know the reasoning used by Charles Darwin in reaching his conclusion that natural selection is the mechanism of evolution. (pg 109 Science Framework) Summary: Charles Darwin explained his line of reasoning for natural selection as the primary mechanism for evolution. Darwin proposed that differences between offspring would occur randomly. Some of those differences would be hereditary and affect an individual offspring s ability to survive and reproduce within a particular environment and ecological setting. With the passage of succeeding generations, those individuals best suited to particular environments would tend to have more progeny and those less well suited would have fewer progeny or even become extinct. Darwin called this process natural selection because environmental and ecological conditions essentially select certain characteristics of plants and animals for survival and reproduction. 3.c Students know how independent lines of evidence from geology, fossils, and comparative anatomy provide the bases for the theory of evolution (pg. 110 Science Framework) Summary: Geologically younger rock layers are usually near the top, and older layers are successively closer to the bottom of sedimentary formations. Some of the organisms that lived in or were buried by the original sediment were preserved as fossils while the sediment hardened into rock. The process of fossilization preserves evidence of ancient life forms, and geological interpretation of the enclosing sedimentary rock yields valuable information about the environments in which those ancient organisms lived. Radioactive dating provides another highly accurate method of confirming the age of rocks and fossils. Comparative anatomists study similarities and differences among organisms. Anatomists have been able to discover significant similarities in the skeletal architecture and musculature of all vertebrates from fish to humans. The most plausible explanation for this finding is that all vertebrates descended from a common ancestor. North Carolina State Released Question Fossils similar to marine life found in the oceans today have been found in rocks on top of mountains. How can this be explained? A The marine life can live on land or sea. B Marine organisms were once able to breathe air. C The rocks in which the fossils were found were formed under an ocean. D Marine organisms have evolved from land organisms. Answer: C. The rocks in which the fossils were found were formed under an ocean.
Oregon State Released Questions A scientist found many, pointed fossil teeth from an extinct animal. These fossils provide evidence that the extinct animal most likely A ate meat B ate plants C moved slowly D was active at night Answer: A ate meat Tennessee Released Question The diagram below shows fossils in different rock layers. Fossil 1 Fossil 3 Fossil 2 Fossil 4 Which of these statements about the age of these fossils is most likely correct? A Fossil 1 and 3 are the same age B Fossil 2 is older than fossil 3 C Fossils 2 and 4 are the same age D Fossil 4 is older than fossil 3 Answer: D Fossil 4 is older than fossil 3 Virginia Released Question Giant fossil ferns have been found in Canada. What conclusion can be drawn from this discovery? A Canada once had a much warmer climate B Giant dragonflies once lived among the ferns C Canada was once covered by an ancient sea D Dinosaurs once lived in Canada Answer: A Canada once had a much warmer climate
Biology/Life Sciences 7.a Students know why natural selection acts on the phenotype rather than the genotype of an organism. (pg. 238 Science Framework) Summary: Natural selection works directly on the expression or appearance of an inherited trait, the phenotype, rather than on the gene combination that produces that trait, the genotype. The influence of a dominant allele for a trait over a recessive one in the genotype determines the resulting phenotype on which natural selection acts. 7.b Students know why alleles that are lethal in a homozygous individual may be carried in a heterozygote and thus maintained in a gene pool. (pg. 238 Science Framework) Summary: Two types of allele pairings can occur in the genotype: homozygous and heterozygous. Recessive lethal alleles will, by definition, cause the death of only the homozygous recessive individual. Healthy heterozygous individuals will also contribute the masked recessive gene to the population s gene pool, allowing the gene to persist. 7.c Students know new mutations are constantly being generated in a gene pool. (pg. 238 Science Framework) Summary: Mutation is an important source of genetic variation within a gene pool. These random changes take the form of additions, deletions, and substitutions of nucleotides and of rearrangements of chromosomes. The effect of many mutations is minor and neutral, being neither favorable nor unfavorable to survival and reproduction. Other mutations may be beneficial or harmful. The important principle is that selective breeding cannot eliminate genetic diseases or unwanted traits from a population. The trait constantly reappears in the population in the form of new, spontaneous mutations. 7.d Students know variation within a species increases the likelihood that at least some members of a species will survive under changed environmental conditions. (pg. 238 Science Framework) Summary: As environmental factors change, natural selection of adaptive traits must also be realigned. Variation within a species stemming either from mutation or from genetic recombination broadens the opportunity for that species to adapt to change, increasing the probability that at least some members of the species will be suitably adapted to the new conditions. Genetic diversity promotes survival of a species should the environment change significantly, and sameness can mean vulnerability that could lead to extinction.
8.a Students know how natural selection determines the differential survival of groups or organisms. (pg. 240 Science Framework) Summary: Genetic changes can result from gene recombination during gamete formation and from mutations. These events are responsible for variety and diversity within each species. Natural selection favors the organisms that are better suited to survive in a given environment. Those not well suited to the environment may die before they can pass on their traits to the next generation. As the environment changes, selection for adaptive traits is realigned with the change. Traits that were once adaptive may become disadvantageous because of change. Virginia State Released Question One way to increase the number of organisms in an endangered species is to let the few remaining individuals of that species breed. However, this breeding may also lead to species extinction because inbreeding over a short period of time may A reduce genetic diversity B increase beneficial mutations C produce a different species D increase fertility Answer: A reduce genetic diversity - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 8.b Students know a great diversity of species increases the chance that at least some organisms survive major changes in the environment. (pg. 241 Science Framework) Summary: This standard is similar to the previous standard set on diversity within a species but takes student understanding one step further by addressing diversity among and between species. Increased diversity among species increases the chances that some species will adapt to survive future environmental changes. Virginia State Released Question One theory of the extinction of dinosaur species is that a large meteorite impact on Earth caused a major atmospheric change marked by colder temperatures. If this theory is correct, what adaptations of mammals probably allowed them to survive even though dinosaurs became extinct? A superior low light vision B consumption of an omnivorous diet C ability to bear live young D endothermic body metabolism Answer: D endothermic body metabolism
8.e Students know how to analyze fossil evidence with regard to biological diversity, episodic speciation and mass extinction. (pg. 242 Science Framework) Summary: Analysis of the fossil record reveals the story of major events in the history of life on earth, called macroevolution, as opposed to the small changes in genes and chromosomes that occur within a single population, microevolution. Explosive radiations of life following mass extinctions are marked by the four eras in the geologic time scale: the Precambrian, Paleozoic, Mesozoic, and Cenozoic. Episodes of speciation are the most dramatic after the appearance of novel characteristics, such as feathers and wings, or in the aftermath of a mass extinction. Oregon State Released Question Several species of extinct giant tortoise lived on different islands in the Indian Ocean. One species is still alive on Aldabra Island. The shells and skins of the extinct tortoises are in museums and can be studied. What is the most accurate way to find out how closely related the living one is to the extinct one? A Search the history records of what the extinct tortoises look like. B Compare the bones and shells of the extinct tortoises to each other. C Measure the distance between Aldabra and the islands on which each species lived. D Compare the DNA sequence of all the tortoise species, extinct and living. Answer: D Compare the DNA sequence of all the tortoise species, extinct and living.