nswers to Practice Items Question 1 TEKS 7 There is one amino acid difference between the human and gorilla. There is a set of species more closely related. The human and chimpanzee have the exact same sequence of amino acids and are therefore the most closely related. This is the There is one amino acid difference between the chimpanzee and gorilla. There is a set of species more closely related. There is one amino acid difference between the horse and zebra. There is a set of species more closely related. Question 2 TEKS 7 Species 1 and 2 differ by 74 amino acids in a particular protein. The least closely related species would have the greatest differences. There is a species with more differences than this. Species 1 and 3 differ by 7 amino acids in a particular protein. This is the smallest value in the data table. This means that the species are the most closely related. Species 2 and 3 differ by 29 amino acids in a particular protein. There are species with greater differences.. Species 3 and 4 differ by 81 amino acids in a particular protein. This is the greatest difference on the table and represents the species that are least closely related. This is the Question 3 TEKS 7 The human arm and the bat wing are homologous structures because they contain similar shapes and numbers of bones in their appendage. This means they likely share a common ancestor. This is the one structure is not indicative of whether species compete for resources. one structure is not indicative of whether species eat the same food. While a bird wing would have a similar homologous structure as a bat wing or a human arm, humans and bats are in fact both mammals. Question 4 TEKS 7 The animals in the diagram are diverse with representatives from the amphibian, bird, and mammal taxonomical classes. The similar shapes and numbers of bones in each of the appendages mean that these are all homologous structures in different animals. This is the The similar shapes and numbers of bones in each of the appendages in fact suggests that there is a relationship between the animals. Homologous structures do not give evidence of evolution in a particular habitat or location.
Question 5 TEKS 7 Vertebrate homology would discuss similarities in the spines of animals. Molecular homology would discuss similarities in the chemical makeup of proteins and other biomolecules. iogeographical homologies would discuss similarities that arise from evolution in a particular location. natomical homology more broadly discusses similarties found in various parts of the body. This is the Question 6 TEKS 7 Vestigal structures are those that may have played an important role in a species evolutionary history but currently do not play a significant role. yclic structures are round. nalogous structures are structures of two different species that serve the same function but do not appear similar in structure. This is the correct answer. Homologous structures are structures of two different species that have similar structures but may differ greatly in function or ability. Question 7 TEKS 7 The most plausible explanation of the discovery of a species fossils on a wide variety of locations on the planet arises from the fact that the continents were once all joined together but have since drifted apart. This is the Underwater tunnels do not connect and have never connected continents. mpibians are much too small and poorly suited to be able to navigate across vast oceans. Evidence of that ability would place their remains on all coasts. It is highly unlikely that the same species evolves in three different locations on the planet. In fact, species separated by long distances will develop into different species with unique abilities adapted to their environment. Question 8 TEKS 7 Whales do not participate in a process of artificial reproduction. The pelvis and femur of a whale, while present, serve a vestigial function. The structures are homologous to other animals, and therefore, help serve as evidence of common ancestry. This evidence supports the modern theory of evolution. This is the Fossils form from the remains of dead plants and animals over the course of millions of years, not from recently living creatures. Regeneration is the growth of new tissue when it is injured or destroyed. Whales do not regenerate.
Question 9 TEKS 7 onvergent structures are analogous structures that evolve in organisms that live in different ecosystems. Embryonic structures are those of an embryo growing in a womb or egg. Vestigial structures are those that once may have served a role in a species evolutionary history but currently do not play a significant role. This is the correct answer Homologous structures are those structures of two different species that share structural characteristics but do not share the same function or ability. Question 10 TEKS 7 Embryonic development does not occur externally in all species. The similarity of structures suggests that these species all have a common ancestor. This is the These embryos look quite different from each other. They are different species. Embryonic structures do not give us information about the environment in which these species live. Question 11 TEKS 7 The beaver and the red squirrel embryos would look most similar if they are the most closely related, not the beaver and the owl. The beaver and red squirrel embryos would look most similar if they are the most closely related, not the owl and the red squirrel. That the owl is not closely related to the beaver and red squirrel would mean that the embryos would not all look the same. The question states that the red squirrel and the beaver are the most closely related animals. One can use as evidence that their embryos looked most similar. This is the Question 12 TEKS 7 There is no indication whether the change in the size and shape of the horse molar was adapted for the digestion of meat. The size of the horse has increased over time, meaning the forefoot must have lengthened, not decreased. It is clear from the diagram that the size of the molar has increased over time. This is the The diagram indicates that the number of toes in the horse has decreased over time to yield a single hoof in modern horses.
Question 13 TEKS 7 The geological history would give information about how species may have come about in a particular area, not whether two species currently living are closely related to each other. The ecosystems would give information about the species interactions with their environment, not information about common ancestry. The breeding and embryo development might be similar because on convergent evolution, not necessarily as evidence of common ancestry. comparison of the N of the two species would give the most definitive evidence of whether two species may be closely related. This is the correct answer. Question 14 TEKS 7 That birds and bats have homologous structures indicates that they all share a common ancestor. Since the wings of birds are all more closely similar in structure than the wing of a bat, it suggests that modern birds evolved from earlier birds, but that bats branched off from an even earlier ancestor. This is the ats are likely to have evolved from earlier mammals. It is incorrect to state that they have not evolved since then. That birds and bats have homologous structures is evidence of common ancestry. The wing of a bat is quite different from the wings of birds, flightless or otherwise. While bats may fly, the wings of all birds are more similar to each other. Question 15 TEKS 7 Geographic isolation results in speciation because of the different environments species experience. This is the Mitotic cell division occurs in all living things. Temporal isolation would suggest that the species are separated in time, not in location. rtificial selection would require human intervention and the selection of specific characteristics for breeding. rown and polar bears evolved naturally.
Question 16 TEKS 7 Since species is found in the fossil record above the place where species evolved, it can only be concluded that was alive both before and after the appearance of species Since species is at the top of the fossil record, it can only be concluded that species evolved most recently. ncestors would appear below their descendant species on the fossil record. ecause species appears below species and, and because all species appear to share homologous structures, the only logical conclusion that can be made is that species is the ancestor of species and. This is the Question 17 TEKS 7 Gradualism would present with small, subtle changes throughout the fossil record, not with periods of stasis. Genetic drift is a response to changes in the environment and could either present gradually or in sudden bursts, depending on climate or other environmental factors. This answer is inconclusive. The definition of punctuated equilibrium is long periods of stasis followed by short periods of significant evolutionary change. This the Geographic isolation would present with changes, if any, in response to the species new environment. The species might change suddenly, gradually, or not at all. Question 18 TEKS 7 Morphological change presents very slowly and subtly over numerous generations. Model represents gradualism. This is the Genetic drift could present either gradually or suddenly. Model shows change according to punctuated equilibrium. Geographic isolation could present either gradually or suddenly. Question 19 TEKS 7 Natural selection is the process by which weak animals are selected for predation or death in the environment, while stronger and better adapted animals are selected for breeding. s wolves select weaker animals for food, those weaker are prevented from breeding. This is the correct answer. Geographic isolation is a process of evolutionary change in response to adaptations in the environment after some geographical event separates populations. Use and disuse leads to the strengthening of body systems or the evolution of those systems into vestigial parts. Punctuated equilibrium is a period of stasis followed by a sudden change.
Question 20 TEKS 7 The change in appearance of an organism to more closely resemble its environment is most likely caused by mutations that were passed on to future generations through natural selection. This is the hanges do not occur to organisms because of consumption of items resembling those changes. Genetic material is not transferred from plants to insects. If predation of insects resembling twigs occurred, natural selection would have prevented those insects from breeding and they likely would not have evolved. Question 21 TEKS 7 Survival of the fittest means those organisms that are able to withstand environmental pressures are selected for breeding. ecause the black insects survive and breed more numbers, this is the ynamic equilibrium means that homeostasis is maintained in response to the environment. In this case, the population of white insects decreases in both numbers and proportions, meaning that this response is incorrect. Succession is the reestablishment of an environment after a destructive event, which did not occur in this case. Extinction would mean the total disappearance of a particular species, which did not occur in this case. Question 22 TEKS 7 While adaptive traits to need to be passed on to offspring, they are not acquired (gotten from an outside source) but the individuals are born with those traits and it makes them fitter for reproduction. ll individuals want to reproduce; natural selection dictates that only the fittest members of a species have greater opportunity to reproduce. Individuals are born with specific adaptive traits, they have a greater chance at survival and reproduction, and those traits are more likely to be passed to offspring. This is the Organisms have no control over which traits are passed to offspring. Question 23 TEKS 7 ommensalism describes how two different species interact, not how an organisms passes traits to the next generation. Inbreeding actually causes less genetic diversity because of a decrease in the size of the gene pool. Migration would not explain how traits are passed, but it could be a contributing factor in natural selection. There is a better answer. Natural selection means the more favored characteristics are likely to be passed on to the next generation. This is the
Question 24 TEKS 7 Migration does contribute to the success of species, but not all species need to migrate to withstand environmental changes. In order for a species to survive, it must produce offspring. Even those organisms who live well and successfully will experience extinction of the species if they cannot reproduce. This is the While finding protection from predators certainly is important to the survival of an organism, a species will become extinct if it cannot reproduce. While organisms need to find food, the species will die out if it cannot reproduce. Question 25 TEKS 7 isease that erodes body parts is not an inheritable trait. Only inheritable traits are passed on to future generations. Feeding advantages would contribute to the strength and health of an organism, making it more likely to reproduce. This is the Wearing down of limbs and appendages is not an inheritable trait. Only inheritable traits are passed on to future generations. ifferent species cannot interbreed and produce fertile offspring. Question 26 TEKS 7 The ability to lay a quantity of eggs does not necessarily attract males. Single-egg laying species are not necessarily more reproductively efficient. More eggs means a greater likelihood that more will be fertilized and that more offspring will survive predation. This is the Egg-laying ability is necessarily a factor in the survival of the species. Question 27 TEKS 7 uring drought years, larger beaks are needed for larger seeds. irds with smaller beaks would actually decrease in population. Larger beaks mean a greater ability to eat larger seeds, and drought would skew the population toward this fact. This is the If seed availability is affected, then those finches with a feeding advantage would be the ones favored to reproduce. rought decreases seed availability.
Question 28 TEKS 7 eak size is an inherited trait and cannot be acquired from the environment. Organisms cannot mutate; they must be born with mutations that give them an advantage to survival and reproduction. Those birds born with adaptive traits that make them better suited for survival and reproduction will pass those traits on to their offspring. This is the Strengthening beaks through exercise can only happen if food is to be had. rought decreases food supply and feeding chances. Question 29 TEKS 7E Genetic diversity actually increases the mutations available in the gene pool. Genetic diversity has no affect on predation pressures. Genetic diversity increases available mutations, including those that are beneficial and contribute to the survival of the species. This is the correct answer. Genetic diversity has no affect on competition between population members. Question 30 TEKS 7E How organisms evolved and changed in response to their environment is supported by evidence found in the fossil record. iochemical homologies found in protein structures and N sequences helps scientists trace the evolutionary development of species. Homologous structures show how organisms originating from a common ancestor have adapted and changed in response to their environment. Evolution is about how organisms have changed throughout time. stable physical environment would not present much pressure for evolutionary change. This is the Question 31 TEKS 7E Those snails that do not require clover as a food source would survive and reproduce. This is the yanide s role in metabolism has no affect on its ability of clover to survive. yanide as a toxin affects blood-oxygen metabolism and would not affect the ability of other plants to survive. That the clover produces cyanide has no affect on its ability to grow.
Question 32 TEKS 7E The geographical isolation of the species directly contributes to the reproductive isolation that allowed two species to emerge. This is the The species weren t so much selected for speciation so much as they were separated by geography. Temporal isolation would imply that the species were separated by time. ehavioral isolation isn t the critical factor since the species were separated by geography. Question 33 TEKS 7E decrease in the a gene would imply that it has less of an ability to reproduce, which is not supported by the population shift. n increase in the a gene would imply that is has a greater ability to reproduce. This is the There appears to be no change in the quantity of insects over the course of 10 years. Mutations in would not be characterized by this pattern of inherited traits. New alleles would need to be designated for mutations. Question 34 TEKS 7E The ability of bacteria to become resistant to antibiotics is a direct result of their ability to withstand the antibiotic affects and reproduce. This is the Mutations cannot be induced. They occur randomly and organisms pass them on to their offspring. acteria do not exhibit behavior. Only those beings with consciousness exhibit behavior. Geographic isolation for bacteria could mean that they prefer to infect different parts of the body (tonsils, as opposed to lungs). ntibiotics are administered to the entire body. Question 35 TEKS 7E daptive radiation is the emergence of a variety of traits from a single common ancestor. onvergent evolution are two very different species evolving to show similar characteristics. Since sharks are fish and dolphins are mammals, their structures are analogous, not homologous. This is the Punctuated equilibrium means the two species would need to share a close common ancestor, which is not the case for sharks and dolphins. Gradualism would mean that the two species would show gradual changes away from each other after diverging from a close common ancestor. This is not the case for sharks and dolphins.
Question 36 TEKS 7E oevolution means that two different species grow and adapt to the same pressures in their environment at the same time into species that continue to be different from each other. onvergent evolution means that different species grow and adapt to environmental pressures so that the species begin to show analogous structures and look similar. Extinction means the disappearance of species, not the emergence of new ones. daptive radiation is the emergence of a variety of species form a single common ancestor. arwin s finches are a good example of this. This is the Question 37 TEKS 7F The evolution of a predatory species may contribute to the chance events that reduce a population size, but it would not necessarily explain the difference in allele frequency. The redistribution of allele frequency after population reductions is a prime example of genetic drift. This is the Mutations cannot be induced; they occur randomly and become prevalent through the process of natural selection. Immunity from microorganisms would contribute to an increase in a population. Question 38 TEKS 7F bottleneck is when a population experiences a random event that causes a decrease in population size. lleles are then redistributed depending on which members of the species survived the reduction. Mutation is simply the change in alleles and phenotypes. This is not described here. Gene flow can happen through migration, as described in this problem. This is the Gene recombination is the process by which two different genetic sequences are combined into a single new piece of genetic material. Question 39 TEKS 7G While it is likely that the first cells did not require oxygen, it is considered unlikely that the first cells were photosynthetic. The first cells were likely anaerobic (did not require oxygen) and broke apart small molecule for energy. This is the Oxygen was not likely present in the atmosphere during the early stages of the development of life. Present-day eukaryotic cells likely evolved from a symbiotic relationship of a variety of prokaryotic cells.
Question 40 TEKS 7G The eukaryotic cell likely evolved from a symbiotic relationship among prokaryotic cells. This is the Prokaryotic cells are the simple cells and exist independently of each other. Question 41 TEKS 9 The sparks and heat provided to the mixture did result in a chemical change, so the chemicals would not be unchanged from the original mixture. Functional mitochondria and chloroplasts themselves were independent organisms during the early stages of the development of life. They would not spontaneously occur through chemical reactions. The result of the chemical reaction of this mixture was the production of simple organic molecules and amino acids. This is the Inorganic molecules and electrons were the precursor components required to make the reaction take place, not the results of the reaction. Question 42 TEKS 9 Miller and Urey were the scientists who conducted the experiment described in Questions 41 and 42. This is the Oparin and Haldane were the scientists who theorized on the chemical origins of the the planet, but their hypothesis was not tested until Miller and Urey conducted their experiments. Watson and rick discovered the chemical structure of N. arwin and Lamarck provided competing theories on the origin of the species, natural selection, and whether traits were inherited (arwin) or acquired (Lamarck). Question 43 TEKS 12 The ability to live under the snow, thrive in freezing temperatures, and flower during a brief summer would not be characteristic of plants that live in the desert. Grassland plants do not grow low to the ground, thrive in snow or freezing temperatures, or produce small moisture-retaining leaves. ll of the characteristics listed describe plants suited to live in the tundra. This is the Plants in rain forests probably have exactly the opposite characteristics of those plants than those listed in the box.
Question 44 TEKS 12 Roots are unlikely to protect plants from above-ground predators. While cooler conditions are below the surface, most of the plant s biology occurs above the surface. That roots can reach water sources far underground is an advantageous adaptation for mesquite plants. This is the acteria beneficial to plants are likely aerobic (need oxygen) or need to interact with the atmospheric nitrogen (as in diazotrophs) and would not survive deep underground. Question 45 TEKS 12 Stomata in leaves allow the plant to exchange water vapor and other gasses with the atmosphere. losure limits this exchange. This is the onservation of oxygen would help respiration and increase metabolism. Recycling of carbon dioxide within plant tissues would increase metabolism. Spines and thorns provide protection from predators. Stomata are the size of a cell. Question 46 TEKS 12 Wind would indeed be able to pass through a compound leaf more easily than a simple or succulent leaf. This is the ompound leaves actually have more surface area than their simple or succulent counterparts. The weight of an insect is negligible compared to the mass a leaf can support. ompound leaves may protect from insect infestations because a greater number of smaller leaflets may mean that more of the leaf is able to survive an infestation. Simple and compound leaves lose about the same amount of heat because they are thin. Succulent leaves may protect from heat loss because they re more dense. Question 47 TEKS 12 Succulent leaves indeed store more water than a simple leaf. This is the The succulent leaf is actually denser than a simple leaf and may not possess the ability to float. Succulent leaves because of their extra storage capacity are actually more rigid than their simple counterparts. apturing sunlight is best suited to those leaves that have a high surface area to volume ratio. Succulent leaves have some of the lowest ratios.
Question 48 TEKS 12 daptations for cold environments typically are higher amounts of fur, fat, or other insulating materials to help protect the organism from the elements. daptations for wet environments typically are those that permit a greater ability to move through water or to exchange materials through an aquatic or marine environment. daptations for dry, hot, and drought environments are those that withstand loss of water and allow the ability to take it in quickly. This is the Moderate temperature and rainfall environment adaptations are those that allow the organism to thrive in a variety of weather conditions. Question 49 TEKS 12 daptations for cold environments typically are higher amounts of fur, fat, or other insulating materials to help protect the organism from the elements. That the salamander must keep moist and can exchange materials it needs through water in contact with its skin makes it well suited to a wet environment. This is the That the salamander must keep moist is a sure sign that it would not survive in a drought environment. Even moderate climates experience periodic dry spells. This organism might survive a flood or wet environment, but it would die during a dry spell.