Biology 1407 Chapter 34: Mastering Biology – Flashcards
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Which of the following statements about deuterosomes is false?
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All deuterosomes exhibit radial symmetry in their bodies.
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Which structure is not an innovation that occurred during vertebrate diversification?
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Exoskeleton.
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True or false? An organism that is radially symmetric has many well-developed head region?
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False
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Which characteristic distinguishes echinoderms from the other two deuterostome lineages?
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Their body plan
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Which of the following statements about vertebrates is true?
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The development of an amniotic egg and internal fertilization allowed vertebrates to reproduce away from water.
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Which characteristics define a chordate?
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The presence of four specific morphological traits
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Which structure can be used for feeding and gas exchange?
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Pharyngeal gill slit
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What is a transitional fossil?
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Transitional fossils have features that are intermediate between ancestors and descendants.
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Which of the following is a tetrapod?
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a reptile, amphibian, mammal, and bird
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Which evidence supports the hypothesis that four-limbed animals came from fish?
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-Fish and four-limbed animals have very similar embryos. -The fossil record shows more and more tetrapod-like fish before the appearance of tetrapods about 365 million years ago. -DNA analysis shows that fish are tetrapods' closest relatives. -Both fish and four-limbed animals are vertebrates.
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Why have we NOT found examples in the fossil record of every animal that ever lived on Earth?
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-To become a fossil, an animal must remain buried for thousands or millions of years until it (and the layer around it) turns to rock. -Many fossils remain buried. We can only find them when they are exposed by erosion or excavation. -To become a fossil, an animal must be quickly and completely buried in ash or sediment before it has a chance to decompose.
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Why did Shubin and Daeschler search in the Canadian arctic for fossil evidence of the transition from fish to tetrapods?
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They hypothesized that the transitional fossils were in sedimentary rocks older than 365 million years ago, when the first tetrapods appear in the fossil record.
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What kind of habitat did tiktaalik live in?
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Tiktaalik lived in a warm, freshwater swamp.
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Tiktaalik had a combination of fishlike and tetrapod-like characteristics. Which were the tetrapod-like characteristics?
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-flat head with eyes on top -interlocking ribs -a neck
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How did the great transition from fish to tetrapod occur?
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The transition occurred gradually over time, so there are many intermediate forms.
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The 150-million-year-old Archaeopteryx fossil has birdlike features such as feathered wings, but it also has characteristics that we associate with living reptiles. Which of the following are considered reptilian characteristics of Archaeopteryx?
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-long, bony tail -claws on the ends of each digit in the "hands" -teeth in the jaws
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Which discovery ultimately overturned the prevailing perception that all dinosaurs were large, slow, and lumbering?
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a fossil of Compsognathus, a chicken-sized dinosaur, which was discovered around the same time as Archaeopteryx
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Which of the following shared characteristics of living birds and theropod dinosaurs provided support to the hypothesis that birds evolved from dinosaurs?
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birds and many theropods have feathers
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How did Dr. Jack Horner's discovery of dinosaur nesting grounds support the hypothesis that birds evolved from a group of dinosaurs?
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it provided evidence that dinosaurs laid eggs like birds
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A key characteristic of modern birds is flight powered by feathered wings. Which of the following pieces of evidence support the hypothesis that the first feathers served a purpose other than flight?
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some birds have feathers but do not fly
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Which of the following statements about bird evolution are accurate based on the evidence presented?
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-Feathers may have originally evolved for interspecies communication and display. -Feathered birds, capable of flight, evolved after the extinction of dinosaurs. -Feathers may have originally evolved for insulation.
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Why was the discovery of organisms, such as Archaeopteryx, that have a mix of traits usually associated with two different groups considered validation of Darwin's theory of evolution?
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transitional forms like Archaeopteryx provide DNA evidence that proves how organisms are related
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Which of the following traits can be used to differentiate humans from our closest living primate relatives?
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-large brain size -extensive tool use -bipedality
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Louis and Mary Leakey found two different fossil hominid skulls at Olduvai. Which of the following statements about the skulls is true?
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The second skull represented a species more closely related to modern humans than the first skull's species.
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Which of the following statements supports the conclusion that the common ancestor of modern chimps and modern humans lived around 7 million years ago?
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Analysis of modern human and modern chimpanzee protein and DNA sequences suggests that their lineages diverged about 7 million years ago.
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Which of the following anatomical features of the 3.2-million-year-old Australopithecus fossil known as "Lucy" suggest she was a bipedal hominid?
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a large brain
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How do scientists know that the hominid called "Ardi" is about 4.4 million years old?
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by using radiometric dating techniques on the volcanic deposits found above and below the layer containing Ardi.
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What did scientists learn from other fossils found in the same sediment layer as Ardi?
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Ardi lived in a woodland habitat
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Which of the following is an accurate statement regarding human evolution?
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-The fossil record contains creatures with features that are intermediate between those of modern humans and quadrupedal apes. -In the latest phase of human evolution, there has been a greater reliance on culture. -The first humans evolved in Africa.
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Which of these primate groups is most closely related to humans?
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apes
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_____ are the oldest known primate group.
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Prosimians
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The primates that spend the most time walking upright are the _____.
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hominids
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Which of these anthropoid groups consists of primates who are mostly tree dwellers and whose forelimbs and hind limbs are about equal in length?
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monkeys
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Which of these primate groups lives in trees in Central and South America and have nostrils that are wide open and far apart?
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New World monkeys
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Humans are _______.
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Homo sapiens
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Except for modern ethnic groups in ______, the majority of humans appear to have traces of Neanderthal DNA in their genome.
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Africa
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Research confirms that Neanderthal DNA makes up about ____ of the modern human genome.
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4%
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DNA was isolated from Neanderthal ____ and sequenced so that it could be compared to modern human DNA.
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bone fragments
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Mating is believed to have taken place between modern humans and Neanderthals in ____ about 70,000 years ago.
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The Middle East
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The Neanderthal DNA discovered in Homo sapiens is best explained by ____.
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gene flow
