1.
As a consequence of size alone, organisms that are large tend to have larger brains than organisms that are small. However, some organisms have brains that are considerably larger than expected for an animal of their size. Data for 14 bird species are listed below. Graph the data and then, based on the data, determine which of the statements below is most reasonable.
Deviation from expected brain size, that is the brain size based on body mass alone. (Negative values indicate grain sizes smaller than expected; positive values indicate brain sizes larger than expected.)
-1.8 1.2 3.2 -2.4 0.0 -2.0 2.3 2.0 -1.0 -2.1 0.3 3.0 1.3 0.7
Mortality rate
0.9 0.8 0.6 0.9 0.7 0.5 0.6 0.6 0.4 0.7 0.8 0.3 0.3 0.4
Correct Answer
B. Larger than expected brain sizes are associated with lower mortality rates. (This could be the result of large-brained birds having an increased intelligence that gives them an advantage in finding food, or escaping predators, though the data do not address this.)
Explanation
Based on the given data, there is a negative deviation from expected brain size for some bird species, indicating that their brain sizes are smaller than expected based on their body mass. On the other hand, there are positive deviations, suggesting that some bird species have larger brain sizes than expected. The statement that larger than expected brain sizes are associated with lower mortality rates is the most reasonable because it suggests a potential advantage for birds with larger brains. This advantage could be increased intelligence, which helps them find food or escape predators. However, it is important to note that the data provided do not directly address this relationship.
2.
In animal cells and in the meristem cells of land plants, the nuclear envelope disintegrates during mitosis. This disintegration does not occur in the cells of most protists and fungi. According to our current knowledge of plant evolution, which group of organisms should feature mitosis most similar to that of land plants?
Correct Answer
C. CharopHytes
Explanation
Charophytes should feature mitosis most similar to that of land plants because they are the closest living relatives of land plants. Charophytes share many similarities with land plants, including the presence of a cell wall composed of cellulose and the use of similar mechanisms for cell division. Therefore, it is likely that the nuclear envelope disintegrates during mitosis in charophytes, just like in land plants.
3.
Humans and other primates are closely related evolutionarily. The greatest support for this comes from the fact that both chimps and humans:
Correct Answer
B. Have digits that permit grasping
Explanation
Humans and other primates having digits that permit grasping is the greatest support for their close evolutionary relationship. This is because the ability to grasp objects with precision is a specialized trait that is found in both chimps and humans. The presence of this trait suggests a common ancestor and a shared evolutionary history. Other traits mentioned in the options, such as HOX genes, mammary glands, DNA with introns, and the same number of chromosomes, may also be shared between humans and chimps, but the ability to grasp objects is a more distinctive and significant characteristic that directly points to their close evolutionary relationship.
4.
People have long been fascinated by Neanderthals and their relationship to HOMO SAPEIENS. Several fossils discovered in Europe have been interpreted by some researchers as showing a mixture of Neanderthal and human features, leading to the suggestion that European human bred with or descended from Neanderthals. Researchers used genetic methods to assess the relationship between Neanderthals and H. SAPIENS. The team extracted DNA from a Neanderthal fossil (N1) and compared its sequence to a DNA sequence that other researchers had obtained from a different Neanderthal fossil (N2). DNA sequences were also obtained for a number of living humans from Europe (E), Africa (AF), and Asia (As). The researchers then used Neanderthal and H. SAPIENS sequences to construct a phylogenetic tree for Neanderthals and humans; data from chimpanzees (C) were used to root the tree.
If Neanderthals gave rise to European humans, one would expect the data to support which of the above phylogenies?
Correct Answer
B. B
Explanation
E is also correct
5.
People have long been fascinated by Neanderthals and their relationship to HOMO SAPEIENS. Several fossils discovered in Europe have been interpreted by some researchers as showing a mixture of Neanderthal and human features, leading to the suggestion that European human bred with or descended from Neanderthals. Researchers used genetic methods to assess the relationship between Neanderthals and H. SAPIENS. The team extracted DNA from a Neanderthal fossil (N1) and compared its sequence to a DNA sequence that other researchers had obtained from a different Neanderthal fossil (N2). DNA sequences were also obtained for a number of living humans from Europe (E), Africa (AF), and Asia (As). The researchers then used Neanderthal and H. SAPIENS sequences to construct a phylogenetic tree for Neanderthals and humans; data from chimpanzees (C) were used to root the tree.
The data indicate that the two Neanderthals differed at 3.5 % of their bases while in contrast the Neanderthals and H. SAPIENS differed on average at 24 % of the bases. The phylogeny above that agrees best with the data is
Correct Answer
A. A
Explanation
The correct answer is A because the data indicates that the two Neanderthals differed at 3.5% of their bases, suggesting they are closely related. In contrast, the Neanderthals and H. sapiens differed on average at 24% of the bases, indicating a greater genetic distance between them. The phylogenetic tree in option A likely reflects this relationship, with the two Neanderthals grouped together and separate from H. sapiens.
6.
Consider 2 alternative hypotheses:
#1. Modem humans arose once and that was in east-central Africa and subsequently spread around the world.
#2. An archaic form of humans arose in Africa and subsequently spread to Middle East, Asian, and Europe. In these areas, populations adapted to the local ecology via natural selection (resulting in “racial” differences but without changes that would interfere with the possibility of interbreeding successfully.
Under this scenario, modern humans evolved in numerous locations and later continued to spread throughout the globe.
Correct Answer
B. If hypothesis #1 is correct, the genetic variability in east-central Africans should be greater than that in other regions.
Explanation
The given answer suggests that if hypothesis #1 is correct, there should be greater genetic variability in east-central Africans compared to other regions. This is because hypothesis #1 states that modern humans arose once in east-central Africa and subsequently spread around the world. Therefore, the genetic diversity would be expected to be higher in the region where humans originated. This explanation is consistent with the concept of genetic diversity being highest in the ancestral population and decreasing as populations migrate and diverge.
7.
The great weight of the evidence supports the theory that modern humans arose in east Africa and migrated to additional locations in Africa. The theory also proposes that there were at least 2 waves of migration out of African; a southerly migration leading to Asian and a northerly migration leading to Europe. In Europe, H. SAPEIENS apparently interbred to some extent with Neanderthals.
Correct Answer
A. Support for the southerly migration occurring first could come from the observation that there is greater genetic diversity in the mitochondrial DNA of Asians than of Europeans
Explanation
The greater genetic diversity in the mitochondrial DNA of Asians compared to Europeans suggests that the southerly migration out of Africa occurred first. This is because genetic diversity tends to decrease as populations migrate away from their original location. Therefore, the higher genetic diversity in Asians indicates that they have had more time to accumulate genetic variations since the initial migration. On the other hand, Europeans, who would have migrated later, have had less time to accumulate genetic diversity, resulting in lower mitochondrial DNA diversity.
8.
Support for the theory that vertebrates evolved from a lineage of urochordate-like organisms (that is, something like a sea squirt) included that observation that, like modern vertebrates, a sea squirt
Correct Answer
B. Larva has a hollow nerve cord position on the “back”, or dorsal surface, of the organism
Explanation
The observation that the larva of a sea squirt has a hollow nerve cord positioned on the "back" or dorsal surface of the organism supports the theory that vertebrates evolved from a lineage of urochordate-like organisms. This is because vertebrates also have a hollow nerve cord, known as the spinal cord, located on the dorsal surface of their bodies. The presence of this similar feature in both sea squirts and vertebrates suggests a common ancestry and evolutionary relationship between the two groups.
9.
When the ancestors of modern plants first colonized terrestrial habitats, additional features subsequently evolved which permitted their successful colonization of many ecological settings. These characteristics included
Correct Answer
A. A vascular system
Explanation
The correct answer is a vascular system. When plants first moved from aquatic to terrestrial habitats, they needed a way to transport water, nutrients, and sugars throughout their bodies. The evolution of a vascular system allowed for the efficient movement of these substances, enabling plants to grow taller and explore various ecological settings. This adaptation was crucial for their successful colonization of terrestrial habitats.
10.
Which of the following is correct?
Correct Answer
D. A cell plate that grows during cytokinesis. The cell plate is composed of the constituents of the cell wall and plasma membrane.
Explanation
The correct answer is about the cell plate that grows during cytokinesis. The cell plate is formed during cell division and is composed of the materials that make up the cell wall and plasma membrane. This process occurs in both plant and animal cells, but the cell plate is specific to plant cells. It plays a crucial role in separating the two daughter cells and forming their individual cell walls.
11.
Consider the monotremes, the platypus and the echidna.
Correct Answer
B. What issues from the female’s reproductive tract at birth are eggs, not motile young. That is to say they are oviparous.
Explanation
Monotremes, such as the platypus and the echidna, are more closely related to placental mammals than to marsupial mammals. However, unlike placental and marsupial mammals, monotremes lay eggs instead of giving birth to live young. This makes them oviparous. Therefore, the correct answer explains the unique reproductive characteristic of monotremes, which is the fact that they lay eggs at birth instead of giving birth to motile young.
12.
The coelacanth is notable because it
Correct Answer
B. Is a rare modern representative of a lineage of fish previously thought to be extinct
Explanation
The coelacanth is notable because it is a rare modern representative of a lineage of fish previously thought to be extinct. This means that it belongs to a group of fish that was believed to have disappeared from the Earth, but was later discovered to still exist. This makes the coelacanth a significant find in the field of paleontology and evolutionary biology.
13.
Which of the following is true of ARCHAEOPTERYX?
Correct Answer
E. It had a long, bony tail
Explanation
Archaeopteryx is known for its long, bony tail. This characteristic distinguishes it from modern birds, as they have shorter, more flexible tails. The long tail of Archaeopteryx is believed to have played a role in its ability to maneuver and maintain balance while flying. This feature is considered an important evolutionary adaptation in the transition from dinosaurs to birds.
14.
In a healthy coral mutualistic relationship,
Correct Answer
A. The pHotosynthetic partner is a protist
Explanation
In a healthy coral mutualistic relationship, the photosynthetic partner is a protist. This means that the photosynthetic partner is a type of single-celled organism that can perform photosynthesis, converting sunlight into energy. This is beneficial for the coral as it provides a source of nutrients and energy. The protist, in turn, benefits from the shelter and protection provided by the coral. This mutualistic relationship allows both organisms to thrive and is essential for the health of the coral reef ecosystem.
15.
Which of the following is true regarding the evolution of land plants?
Correct Answer
C. The evidence that all angiosperms had a common ancestor includes the observation that they all share basic similarities in their flowers and fruits. For example, all flowers are constructed of 4 whorls of modified leaves that serve as sepals, petals, stamens, and carpels.
Explanation
The answer explains that all angiosperms share basic similarities in their flowers and fruits, such as having 4 whorls of modified leaves that serve different functions. This observation suggests that all angiosperms had a common ancestor.
16.
Which of the following is true?
Correct Answer
C. The lateral line system permits fish to orient in water
Explanation
The lateral line system is a sensory system found in fish that allows them to detect movements and vibrations in the water. This system consists of a series of sensory organs called neuromasts, which are located along the fish's body. These neuromasts can detect changes in water pressure and movement, helping the fish to navigate and orient themselves in their aquatic environment. This ability to sense their surroundings is crucial for fish to find food, avoid predators, and navigate through their habitat. Therefore, the statement that the lateral line system permits fish to orient in water is true.
17.
Which of the following is true of the evolution of land vertebrates?
Correct Answer
C. Usually, ampHibians deposit their eggs outside the body and subsequently they are fertilized. Reptiles and birds, in contrast, are not as dependent on an aquatic environment for successful reproduction. They have eggs with membranes/shells that give the zygote some protection from arid conditions. A consequence of this difference between ampHibians on the one hand and reptiles and birds on the other is that in the latter two taxa, fertilization must be internal
Explanation
Amphibians deposit their eggs outside the body, while reptiles and birds have eggs with membranes or shells that protect the zygote from arid conditions. This difference in reproductive strategy between amphibians and reptiles/birds leads to a difference in fertilization method. Amphibians have external fertilization, where the eggs are fertilized outside the body, while reptiles and birds have internal fertilization, where the eggs are fertilized inside the body. This is because amphibians rely on an aquatic environment for successful reproduction, while reptiles and birds are less dependent on water.
18.
Which of the following is characteristic of bryophytes but is not found in fungi?
Correct Answer
A. Flagellated gametes
Explanation
Bryophytes are plants that have flagellated gametes, which means that their reproductive cells have a whip-like tail that allows them to swim in water. This is a characteristic that is not found in fungi, as fungi do not have flagellated gametes. Fungi reproduce through the production of spores, which are also found in bryophytes. The statement about the sporophyte life stage being more prominent than the gametophyte life stage is not true for bryophytes, as their gametophyte stage is the dominant stage in their life cycle. Both bryophytes and fungi have cell walls made of chitin, and they are both heterotrophs, meaning they obtain their nutrients from organic sources.
19.
Which of the following is not true of coral animals?
Correct Answer
D. They are protists
Explanation
Coral animals are not protists. They are actually invertebrate animals belonging to the phylum Cnidaria. They form a symbiotic relationship with algae, which provide them with nutrients through photosynthesis. They primarily feed on small organisms and plankton using their tentacles, and they are most active during the night.
20.
Neanderthals, first discovered in Europe, have been interpreted as the ancestors of modern humans; other scientists have concluded that while closely related to humans, Neanderthals are not the ancestors of modern humans. Several fossils from Europe have been interpreted by some to display a mixture of both Neanderthal and human features. In an effort to determine the phylogenetic relationships between the two, mitochondrial DNA (mtDNA) was extracted from 2 Neanderthal fossils as well as from a number of living Europeans, Africans, and Asians. Which of the following is NOT correct?
Correct Answer
C. If the mtDNA analysis found that the Neanderthal DNA had greater variability than that found in the H. SAPIENS sampled, then pHylogeny A below must be correct
Explanation
If the mtDNA analysis found that the Neanderthal DNA had greater variability than that found in the H. SAPIENS sampled, then phylogeny A below must be correct. This statement is not correct because the variability of mtDNA does not necessarily determine the phylogenetic relationship between Neanderthals and modern humans. Variability in mtDNA can be influenced by various factors such as population size, genetic drift, and natural selection, and does not provide conclusive evidence for phylogenetic relationships.
21.
About 250 million years ago, the greatest mass extinction event the Earth has ever witnessed occurred (The Great Dying). By some estimates, 96 % of the organisms on earth went extinct. At this time, most of the organisms were marine. On land, there were great forests, amphibians, and retiles. Continents were drifting into a configuration where most of the land masses coalesced into a single Pangaea. Which of the following is NOT true?
Correct Answer
D. The ocean levels reach its highest level ever seen on Earth
Explanation
During the mass extinction event 250 million years ago, the ocean levels did not reach their highest level ever seen on Earth. This is because the extinction event was caused by a variety of factors such as volcanic activity and a decrease in oxygen concentration, but not by an increase in ocean levels.
22.
Which of the following is true?
Correct Answer
C. During the time that dinosaurs existed on Earth as the dominant vertebrate group, Pangaea broke apart by plate tectonic movements. The earth warmed and massive tropical forest covered much of its surface and provided large amounts of food to fuel their metabolic needs.
Explanation
The correct answer suggests that the reason for dinosaur dominance during their time was the breakup of Pangaea by plate tectonic movements. As a result of this breakup, the earth warmed and massive tropical forests covered much of its surface, providing large amounts of food to fuel the metabolic needs of dinosaurs. This explanation implies that the availability of abundant food resources in the form of tropical forests played a significant role in the dominance of dinosaurs as the dominant vertebrate group during their era.