1.
All of the following are true about sea stars except
Correct Answer
D. They are the only echinoderms that are fully sessile.
Explanation
Sea stars are not the only echinoderms that are fully sessile. Other echinoderms, such as sea cucumbers and sea urchins, can also be sessile.
2.
In many echinoderms respiration and waste removal take place by means of finger-like projections that occur near the spines, which are called
Correct Answer
D. Papulae.
Explanation
In many echinoderms, respiration and waste removal occur through finger-like projections called papulae. These papulae are located near the spines and serve as respiratory organs, allowing for gas exchange and the removal of waste products. This adaptation helps echinoderms maintain proper oxygen levels and eliminate metabolic waste, contributing to their overall survival and functioning.
3.
Reproductive modes of echinoderms include all of the following except
Correct Answer
C. Developing from trochopHore larvae.
Explanation
Echinoderms are marine animals that have various reproductive modes. They can reproduce through external sexual reproduction, where fertilized eggs are produced. These fertilized eggs then develop into free-swimming, bilaterally symmetrical larvae. Another reproductive mode is breaking into equal parts, where the echinoderm breaks into two whole animals. Additionally, some echinoderms have the ability to break into parts and regenerate new animals from them. However, developing from trochophore larvae is not a reproductive mode observed in echinoderms.
4.
All of the following are examples of echinoderms except
Correct Answer
D. Sea squirts.
Explanation
Sea squirts are not examples of echinoderms. Echinoderms are a group of marine animals that include sea cucumbers, brittle stars, sand dollars, and sea daisies. Sea squirts, on the other hand, belong to a different group called tunicates. They are filter-feeding organisms that attach themselves to surfaces and have a sac-like body structure. While sea squirts may share some similarities with echinoderms, they are not classified as echinoderms.
5.
Which choice is correct for the movement of water through the water vascular system of a sea star?
Correct Answer
D. Madreporite --> stone canal --> ring canal --> radial canal --> tube foot
Explanation
The correct answer is madreporite --> stone canal --> ring canal --> radial canal --> tube foot. This is the correct sequence of the movement of water through the water vascular system of a sea star. The madreporite is the entrance to the system, followed by the stone canal which connects to the ring canal. From the ring canal, water moves into the radial canals, which extend into the arms of the sea star. Finally, the water reaches the tube feet, which are used for locomotion and other functions.
6.
All echinoderms share the following characteristics except
Correct Answer
E. Larvae are sedentary, adults are plantonic.
Explanation
All echinoderms share bilateral symmetrical larvae, radial symmetrical adults, regeneration of a lost body part, and a pentamerous body plan. However, the statement "larvae are sedentary, adults are planktonic" contradicts the characteristics of echinoderms. Echinoderm larvae are actually planktonic, meaning they drift in the water column, while the adults are typically sessile or slow-moving. Therefore, the given answer is correct as it states that larvae are sedentary and adults are planktonic, which is not a characteristic shared by all echinoderms.
7.
Which one of the following incorrectly matches a molluscan structure with its typical function?
Correct Answer
A. Ctenidia—secretion of the shell (when present)
Explanation
The ctenidia is actually responsible for respiration in mollusks, not secretion of the shell. The shell is typically secreted by the mantle.
8.
Which one of the following incorrectly matches a molluscan group with a feature characterizing that group?
Correct Answer
B. Nudibranchs—extensive gills in mantle cavity
Explanation
Nudibranchs are a type of gastropod, not a separate molluscan group. They are known for their extensive gills in the mantle cavity, which is a correct feature characterizing them.
9.
Which one of the following annelid structures or events is not correctly paired with its role in locomotion?
Correct Answer
E. Chaetae—provides gas exchange surface for body muscles
10.
Which one of the following statements about the phylum Brachiopoda is false?
Correct Answer
C. As in bivalves, the valves in brachiopods are lateral (left and right) to the body axis.
Explanation
Brachiopods are often misidentified as bivalves, brachiopods were much more diverse in the past, most brachiopods are sessile (attached), and the lophophore resides within the brachiopod's shells. However, the statement that the valves in brachiopods are lateral (left and right) to the body axis is false. In brachiopods, the valves are dorsal (top) and ventral (bottom) to the body axis, unlike in bivalves where the valves are lateral.
11.
If you arranged the following parts of the echinoderm water vascular system from outside to its termination in a tube foot, which structure would be encountered third?
Correct Answer
E. Ring canal
Explanation
The ring canal would be encountered third if the parts of the echinoderm water vascular system were arranged from outside to its termination in a tube foot. The water enters the water vascular system through the madreporite, then flows into the stone canal. From the stone canal, it enters the ring canal, which encircles the central body cavity. The water then moves into the radial canals, which extend outward from the ring canal, and finally reaches the tube feet through the ampulla.
12.
Which one of the following choices does not describe an advantage of the chitinous exoskeleton found in arthropods?
Correct Answer
D. Does not impose limitations on body size
Explanation
The chitinous exoskeleton found in arthropods offers some protection, reduces water loss, allows for muscle attachment sites inside the skeleton, and provides a strong, flexible framework. However, it does impose limitations on body size because the exoskeleton cannot grow, and the arthropod must molt in order to increase in size.
13.
Which one of the following associations between structures and arthropod groups possessing them is incorrect?
Correct Answer
B. Book lungs—larval insects
Explanation
Book lungs are not found in larval insects. Book lungs are respiratory organs found in spiders and some other arachnids. Larval insects typically have tracheal systems or gills for respiration. Therefore, the association between book lungs and larval insects is incorrect.
14.
The mucous sheet produced by the endostyle traps the microscopic food particles in the water. This sheet is located in the pharynx of what animal?
Correct Answer
B. Tunicate
Explanation
The correct answer is tunicate. Tunicates are filter-feeding marine animals that have a pharynx with an endostyle. The endostyle produces a mucous sheet that helps in trapping microscopic food particles in the water. This allows tunicates to feed on suspended particles and plankton.
15.
Small, fishlike marine chordates, pointed at both ends with no distinguishable head, in which the notochord runs the entire length of the nerve cord, are called
Correct Answer
D. Lancelets.
Explanation
Lancelets are small, fishlike marine chordates that are pointed at both ends and lack a distinguishable head. They have a notochord that runs the entire length of the nerve cord. This distinguishes them from other options such as arrow worms, tunicates, acorn worms, and lampreys, which have different anatomical characteristics.
16.
Most bony fishes have a hard plate that covers the gills on each side of the head called the
Correct Answer
D. Operculum.
Explanation
The operculum is a hard plate that covers the gills on each side of the head in most bony fishes. It acts as a protective covering for the delicate gills, allowing water to flow over them while preventing debris or predators from entering. The operculum also helps regulate the flow of water and aids in respiration by allowing the fish to control the opening and closing of the gill slits. Therefore, the operculum is the correct answer in this case.
17.
One of the most critical adaptations of the reptiles in relation to their life on land is the evolution of the
Correct Answer
A. Amniotic egg.
Explanation
The correct answer is the amniotic egg. Reptiles have evolved this adaptation to enable them to reproduce on land. The amniotic egg is enclosed in a protective shell and contains a specialized membrane that provides a suitable environment for the developing embryo, including protection from desiccation. This adaptation allows reptiles to lay their eggs on land and reduces their dependence on water for reproduction, making them well-suited to terrestrial environments.
18.
Birds, like mammals, can regulate their body temperatures within close limits. Therefore birds and mammals are called
Correct Answer
C. Endothermic.
Explanation
Birds and mammals are called endothermic because they can regulate their body temperatures within close limits. Unlike ectothermic animals, such as reptiles, which rely on external sources of heat to regulate their body temperature, endothermic animals are able to generate and maintain their own body heat through metabolic processes. This allows birds and mammals to thrive in a wide range of environments and climates, as they are not dependent on external temperatures for their survival.
19.
Which of the following is considered the key innovation that started chordates along the evolutionary path that led to vertebrates?
Correct Answer
A. A flexible rod to which muscles are attached which allowed moving their backs laterally
Explanation
The key innovation that started chordates along the evolutionary path that led to vertebrates is the development of a flexible rod to which muscles are attached, allowing for lateral movement of their backs. This innovation allowed for greater mobility and flexibility in movement, which likely provided an advantage in survival and resource acquisition. This eventually led to the development of a more complex skeletal system and the emergence of vertebrates.
20.
The chordates include all of the following except
Correct Answer
B. Echinoderms.
Explanation
Chordates are a phylum of animals that possess a notochord, a dorsal nerve cord, pharyngeal slits, and a post-anal tail at some stage in their life cycle. Amphioxus, mammals, birds, and amphibians are all examples of chordates. Echinoderms, on the other hand, are a separate phylum that includes animals such as starfish and sea urchins. They do not possess the characteristic features of chordates, making them the only option that is not included in the chordate group.
21.
Chordates have all the following characteristics at some time in their lives except
Correct Answer
E. An endostyle.
Explanation
Chordates are characterized by having a nerve cord, notochord, pharyngeal slits, and a postanal tail at some point in their lives. However, an endostyle is not a characteristic of chordates. An endostyle is a structure found in some invertebrate chordates, such as tunicates, that functions in filter feeding. Therefore, the correct answer is an endostyle.
22.
Which one of the following is not true about tunicates?
Correct Answer
E. Larval forms feed actively.
Explanation
Tunicates are marine animals that belong to the phylum Chordata. They have a larval stage and an adult stage. The given statement "Larval forms feed actively" is not true about tunicates. In their larval stage, tunicates do not actively feed. Instead, they rely on their yolk sac for nutrition. Once they undergo metamorphosis and become adults, tunicates become filter feeders, using their siphons to draw in water and filter out small particles of food. Therefore, the correct answer is that larval forms of tunicates do not feed actively.
23.
In addition to a vertebral column, all vertebrates have
Correct Answer
A. A distinctive head or skull.
Explanation
All vertebrates have a distinctive head or skull because it is a characteristic feature of their anatomy. The head or skull houses important sensory organs such as the brain, eyes, ears, and nose, which are essential for their survival. It also provides protection to these delicate organs and supports the overall structure of the body. Therefore, the presence of a distinctive head or skull is a defining trait of vertebrates.
24.
It is generally accepted that the vertebrates that evolved during the early Devonian period are the
Correct Answer
A. Sharks and bony fish.
Explanation
During the early Devonian period, sharks and bony fish were the vertebrates that evolved. This is supported by fossil evidence that shows the presence of early shark and bony fish species during this time. The evolution of these two groups of vertebrates during the Devonian period played a significant role in shaping the future diversity and ecology of marine ecosystems.
25.
Amphibians are thought to have evolved from
Correct Answer
B. Lobe-finned fish.
Explanation
Amphibians are thought to have evolved from lobe-finned fish. This is because lobe-finned fish, such as the coelacanth and lungfish, share several anatomical features with early amphibians. These features include the presence of lungs, limb-like fins, and a bony skeleton, which allowed them to move and breathe in shallow water or on land. The transition from water to land was a crucial step in the evolution of amphibians, and lobe-finned fish provided the necessary adaptations for this transition.
26.
The remarkable success of bony fishes has resulted from a series of adaptations, including all of the following except
Correct Answer
E. A three-chambered heart with a pulmonary circuit.
Explanation
Bony fishes have evolved various adaptations that contribute to their remarkable success. These adaptations include swim bladders, which help them control their buoyancy, lateral line systems that detect vibrations and movements in the water, and gill covers that protect their gills. They also have a counter-current exchange system in their gills, which enhances their ability to extract oxygen from the water. However, bony fishes do not have a three-chambered heart with a pulmonary circuit. Instead, they have a two-chambered heart with a single circulation system, where blood flows from the heart to the gills for oxygenation and then to the rest of the body.
27.
Amphibians share all of the following characteristics, except
Correct Answer
E. Keratinized skin.
Explanation
Amphibians share several characteristics, such as legs, coetaneous respiration and lungs, a partially divided heart, and pulmonary veins. However, they do not have keratinized skin. Keratinized skin is a characteristic of reptiles, birds, and mammals, but not amphibians. Amphibians have moist and permeable skin that allows them to breathe through their skin. This is why they are often found in moist environments and require water for reproduction.
28.
Amphibians are not completely free to live on dry land because
Correct Answer
C. Their reproduction depends on water.
Explanation
Amphibians are not completely free to live on dry land because their reproduction depends on water. Unlike other animals, amphibians lay eggs in water, and their young hatch as aquatic larvae. These larvae then undergo metamorphosis and develop into adults that can live both on land and in water. Therefore, water is crucial for the reproductive cycle of amphibians, making them dependent on it for their survival.
29.
All of the following features contributed to the successful invasion of land by amphibians except
Correct Answer
C. Amniotic eggs.
Explanation
Amniotic eggs were not a feature that directly contributed to the successful invasion of land by amphibians. While amniotic eggs are a key adaptation for reptiles, birds, and mammals, they did not evolve until much later in evolutionary history. Amphibians, on the other hand, have moist, jelly-like eggs that require water for development. Therefore, the presence of amniotic eggs cannot be considered a contributing factor to the successful invasion of land by amphibians.
30.
Features that have been retained by reptiles from the time they replaced the amphibians as the dominant terrestrial vertebrates include all of the following, except
Correct Answer
E. Endothermy.
Explanation
Reptiles have retained several features from the time they replaced amphibians as the dominant terrestrial vertebrates. These include the amniotic egg, which allows them to reproduce on land, dry skin to prevent water loss, thoracic breathing for efficient respiration, and reoriented appendages for better movement on land. However, endothermy, or the ability to regulate body temperature internally, is not a feature retained by reptiles. Unlike mammals and birds, reptiles are ectothermic, meaning their body temperature is determined by the environment.
31.
Which of the following is not one of the membranes of the reptilian amniotic egg?
Correct Answer
A. Ectoderm
Explanation
The ectoderm is not one of the membranes of the reptilian amniotic egg. The amniotic egg consists of several membranes that protect and nourish the developing embryo. These membranes include the chorion, amnion, yolk sac, and allantois. The ectoderm, on the other hand, is one of the three primary germ layers in the developing embryo, which gives rise to the outer layer of the skin, nervous system, and other structures. It is not a specific membrane within the amniotic egg.
32.
Reptiles can maintain their internal body temperature by
Correct Answer
A. Behavioral mechanisms.
Explanation
Reptiles can maintain their internal body temperature through behavioral mechanisms such as basking in the sun or seeking shade. They regulate their body temperature by adjusting their behavior and moving to different environments to either warm up or cool down. This allows them to adapt to their surroundings and maintain a stable internal body temperature without relying on external factors such as warm or cool water, increased food consumption, an insulating covering, or rerouting blood flow.
33.
All living reptiles are
Correct Answer
B. Ectothermic.
Explanation
The correct answer is "ectothermic" because reptiles are known for their inability to regulate their own body temperature internally. Instead, they rely on external sources of heat to warm up their bodies. This characteristic is what makes them ectothermic.
34.
All of the following are features that contribute to the ability of reptiles to survive on dry land except
Correct Answer
E. Endothermy.
Explanation
The ability of reptiles to survive on dry land is attributed to various features. The amniotic egg provides protection and allows reproduction away from water. Dry skin covered with scales helps prevent dehydration. An efficient circulatory system ensures oxygen and nutrients are delivered throughout the body. Efficient lungs enable reptiles to extract oxygen from the air. However, endothermy, or the ability to regulate body temperature internally, is not a feature that contributes to their survival on dry land. Reptiles are ectothermic, meaning their body temperature is influenced by the environment.
35.
Which of the following living reptiles care for their young and have a four-chambered heart, as birds do?
Correct Answer
B. Crocodiles
Explanation
Crocodiles care for their young and have a four-chambered heart, just like birds do. This means that they exhibit parental care and provide protection and assistance to their offspring. Additionally, the presence of a four-chambered heart indicates that crocodiles have a more efficient circulatory system, allowing for better oxygenation of their tissues.
36.
The most successful terrestrial vertebrates that invaded the air are
Correct Answer
C. Birds.
Explanation
Birds are the most successful terrestrial vertebrates that invaded the air because they have adapted to fly efficiently and have a diverse range of species. They possess lightweight bodies, strong wings, and feathers that enable them to soar through the air. Birds have evolved various flight adaptations, such as hollow bones, a keeled breastbone for muscle attachment, and a unique respiratory system, allowing them to achieve sustained flight. Their ability to fly has allowed birds to inhabit diverse ecosystems, exploit different food sources, and migrate over long distances, making them highly successful in the aerial environment.
37.
Birds are different from reptiles in all of the following features except
Correct Answer
E. Bipedalism.
Explanation
Birds are different from reptiles in their lack of teeth, the presence of feathers, and the presence of a flight skeleton. Bipedalism refers to the ability to walk on two legs, which is a characteristic shared by both birds and some reptiles. Therefore, bipedalism is not a feature that distinguishes birds from reptiles.
38.
The changes that were necessary to cope with the heavy energy demands of flight in birds include all of the following except
Correct Answer
E. A three chambered heart.
Explanation
Birds have a four-chambered heart, which allows for efficient circulation of oxygenated and deoxygenated blood. This is necessary to meet the high energy demands of flight. Efficient respiration, efficient circulation, endothermy, and the presence of auxiliary air sacs and hollow bones are all adaptations that help birds cope with their energy demands. However, a three-chambered heart would not be sufficient for the demands of flight, as it would not provide efficient separation of oxygenated and deoxygenated blood.
39.
Modern birds are characterized by all of the following except
Correct Answer
E. Ectothermy.
Explanation
Modern birds are characterized by feathers, thin hollow skeletons and auxiliary air sacs, a four-chambered heart, and the amniotic egg. However, they are not characterized by ectothermy, which refers to the ability to regulate body temperature through external sources such as the sun. Birds are endothermic, meaning they can generate and maintain their own body heat internally.
40.
Mammals are thought to have evolved from
Correct Answer
B. Therapsids.
Explanation
Therapsids are a group of reptile-like mammals that lived during the Permian and Triassic periods. They are considered to be the ancestors of modern mammals because they share many characteristics with mammals, such as a specialized jaw joint and a more efficient way of chewing food. Thecodonts, dinosaurs, and archosaurs are reptiles that are not directly related to mammals, while marsupials are a group of mammals that evolved later than therapsids. Therefore, therapsids are the most likely ancestors of mammals.
41.
Which one of the following is characteristic of all mammals and not of any other living vertebrates?
Correct Answer
A. Hair
Explanation
Hair is a characteristic of all mammals and not of any other living vertebrates. While some mammals may have minimal or no hair, it is still present in some form. Hair is a unique feature that distinguishes mammals from other vertebrates, as no other group of animals possess this specific trait.
42.
The only mammals that fly at night to obtain insect food or fruit to eat and navigate by sonar are
Correct Answer
B. Bats.
Explanation
Bats are the only mammals that fly at night to obtain insect food or fruit to eat and navigate by sonar. They have the ability to emit high-frequency sounds and listen to the echoes that bounce back, allowing them to navigate and locate their prey in the dark. This unique adaptation is known as echolocation. Marsupials, monotremes, moles, and birds do not possess this ability, making bats the correct answer.
43.
Monotremes differ from the other mammals in their
Correct Answer
A. Laying of shelled eggs.
Explanation
Monotremes, such as platypuses and echidnas, are unique among mammals because they lay shelled eggs. This is different from other mammals, which give birth to live young. Monotremes have a reproductive system that resembles that of reptiles and birds, as they have cloacas and lay eggs. This adaptation sets them apart from other mammals and is a defining characteristic of monotremes.
44.
The only marsupial mammal living in North America is the
Correct Answer
A. Opossum.
Explanation
The correct answer is opossum. The opossum is the only marsupial mammal that is native to North America. It is known for its unique adaptation of carrying and nursing its young in a pouch. While other animals listed, such as the raccoon and weasel, are also found in North America, they are not marsupials. The ring-tailed cat and wombat are not native to North America at all. Therefore, the opossum is the only correct answer.
45.
All of the following are orders of placental mammals except
Correct Answer
E. Marsupialia.
Explanation
The question is asking for the order of placental mammals that is not included in the given options. The options include primates, rodentia, cetacea, carnivora, and marsupialia. Primates, rodentia, cetacea, and carnivora are all orders of placental mammals. Marsupialia, on the other hand, is not a placental mammal order. Marsupials are a distinct group of mammals that give birth to relatively undeveloped young, which then continue to develop in a pouch. Therefore, the correct answer is marsupialia.
46.
The key specializations that occurred in the evolution of mammals include all of the following except
Correct Answer
E. Reduction in brain size.
Explanation
The key specializations that occurred in the evolution of mammals include warm-bloodedness, the presence of a placenta in most, different teeth suited to their diet, and digestive tract specialization. However, reduction in brain size is not a specialization that occurred in the evolution of mammals.
47.
In humans one pair of pharyngeal pouches become the tube-shaped organ called the
Correct Answer
C. Eustachian tube.
Explanation
The correct answer is Eustachian tube. In humans, one pair of pharyngeal pouches develop into the Eustachian tube. The Eustachian tube connects the middle ear to the back of the throat and helps to equalize pressure between the middle ear and the outside environment. It plays a crucial role in maintaining proper hearing and preventing ear infections. The esophagus is the tube that connects the throat to the stomach, the trachea is the windpipe, the bronchial tube is a branch of the trachea that leads to the lungs, and the pharynx is the throat.
48.
Which of the following statements about tunicates is incorrect?
Correct Answer
E. Tunicate larvae can reproduce.
Explanation
Tunicate larvae can reproduce. This statement is incorrect because tunicate larvae are not capable of reproduction. Tunicates have a complex life cycle where the larvae, also known as tadpole larvae, are free-swimming and possess all the basic chordate characteristics. However, once they reach adulthood, tunicates become sessile and lose their ability to reproduce. Instead, they rely on sexual reproduction as adults to produce new larvae.
49.
The following classes or superclasses of fish are matched with an example. Select the mismatched pair.
Correct Answer
B. Placodermi—lobe-finned fish
Explanation
The mismatched pair in the given options is "Placodermi—lobe-finned fish." Placodermi is an extinct class of armored fish that existed during the Devonian period, while lobe-finned fish belong to the class Sarcopterygii. Lobe-finned fish are not a subclass or superclass of Placodermi, making this pair mismatched.
50.
Bony fishes possess three features not found in other fish. Select the best choice from those listed below to complete the following sentence. Bony fishes have
Correct Answer
A. Swim bladders, a lateral line system, and gill covers called opercula.
Explanation
Bony fishes possess swim bladders, a lateral line system, and gill covers called opercula. These three features are unique to bony fishes and are not found in other types of fish. The swim bladder is an internal gas-filled organ that helps the fish control its buoyancy. The lateral line system is a series of sensory organs that detect changes in water pressure and vibrations, allowing the fish to navigate and detect prey. The gill covers, or opercula, protect the delicate gills and help regulate water flow over them for efficient respiration.