Biology Final - Invertebrates II

The excretory system is responsible for removing waste products such as ammonia, urea, and uric acid from the body fluids. This system includes organs such as the kidneys, which filter the blood and produce urine, and the bladder, which stores and eliminates urine from the body. The circulatory system transports these waste products to the kidneys, the respiratory system eliminates some waste through exhalation, and the digestive system processes and absorbs nutrients from food. However, it is the excretory system specifically that is primarily responsible for removing these waste products from the body fluids.

Lobsters, crabs, and shrimp are all crustaceans, which is the correct answer. Crustacea is a subphylum of arthropods that includes these marine animals. They are characterized by having a hard exoskeleton, jointed limbs, and two pairs of antennae. Lobsters, crabs, and shrimp all share these characteristics and belong to the same subphylum.

Segmented worms are known as annelids because they belong to the phylum Annelida, which includes earthworms, leeches, and marine worms. Annelids are characterized by their segmented bodies, with each segment containing a set of specialized organs. They have a closed circulatory system, a well-developed digestive system, and a nervous system. Nematodes, on the other hand, belong to the phylum Nematoda and are unsegmented roundworms. Planarians are flatworms belonging to the phylum Platyhelminthes. Arthropods, such as insects and crustaceans, belong to a completely different phylum called Arthropoda. Therefore, the correct answer is annelids.

Segmented organisms have a survival advantage because mutations can modify organs in specific segments to perform new tasks. This allows for adaptation and specialization within each segment, increasing the organism's ability to survive and thrive in different environments. By modifying organs, such as limbs or sensory structures, organisms can better meet the demands of their surroundings and exploit new resources. This flexibility and adaptability provide a significant advantage in terms of survival and reproductive success.

The mantle is the correct answer because it is the part of a mollusk that secretes their shell. The mantle is a thin layer of tissue that covers the mollusk's body and it is responsible for the production of the shell. The mantle continuously secretes calcium carbonate, which forms the hard outer shell that protects the mollusk's soft body. Therefore, the mantle plays a crucial role in the formation and growth of the mollusk's shell.

Mollusks like snails that have a single shell are classified as gastropods. This is because gastropods are a class of mollusks that typically have a coiled shell and a muscular foot. Snails, being a type of gastropod, fit this description as they have a single coiled shell and a muscular foot for locomotion. Bivalves, on the other hand, have two shells, cephalopods have no shells, and nematodes are not mollusks at all.

The visceral mass is the correct answer because it is the part of the mollusk body plan where most of their organs are located. This includes the digestive, circulatory, and reproductive organs. The visceral mass is protected by the shell and is covered by the mantle, which secretes the shell. The foot is used for locomotion, while the shell provides protection for the internal organs. Therefore, the visceral mass is the main region where the organs are found in a mollusk.

Coelomates are organisms that have a body cavity called a coelom, which is lined with a layer of muscle that wraps around their internal organs. This layer of muscle is independent of their body wall muscles, allowing for more efficient movement and protection of the internal organs. Acoelomates, on the other hand, do not have a body cavity, while pseudocoelomates have a body cavity that is not completely lined with muscle. Diploblastic organisms have only two germ layers, whereas coelomates have three germ layers.

Spiders, scorpians, and mites belong to the subphylum Chelicerata. Chelicerata is a subphylum of arthropods that includes organisms with two main body parts, a cephalothorax and an abdomen, and four pairs of legs. Spiders, scorpians, and mites all have these characteristics, making Chelicerata the correct answer. Urochordata is a subphylum of chordates that includes marine animals like tunicates, Crustacea is a subphylum of arthropods that includes organisms like crabs and lobsters, and Trilobita is an extinct subphylum of arthropods.

Arthropods have a greater specialization of segments compared to annelids. This means that each segment in arthropods is more distinct and adapted for specific functions, such as locomotion or feeding. This specialization allows arthropods to have a wide range of body forms and perform various ecological roles. In contrast, annelids have a more uniform and repetitive segmentation. This greater specialization of segments in arthropods is an advantage as it enables them to have a higher level of complexity and adaptability in their body structure and function.

An internal system of rigid material that supports the body is known as an endoskeleton. This type of skeleton is found in vertebrates and provides support, protection, and allows for movement. Unlike an exoskeleton, which is found in arthropods and is located on the outside of the body, an endoskeleton is located internally. Hydrostatic skeleton refers to a type of skeleton found in invertebrates, where fluid-filled compartments provide support. Pseudoskeleton is not a recognized term in anatomy or biology.

Coelomates are organisms that have a body cavity called a coelom, which is lined with a layer of muscle that wraps around their internal organs. This layer of muscle is independent of their body wall muscles. Acoelomates do not have a body cavity, pseudocoelomates have a body cavity that is not fully lined with muscle, and diploblastic organisms have only two germ layers instead of three. Therefore, coelomates are the correct answer in this case.

The water vascular system is a unique characteristic found only in echinoderms. This system consists of a network of fluid-filled canals and tube feet that are used for locomotion, feeding, and respiration. Echinoderms, such as starfish, sea urchins, and sea cucumbers, rely on this system to move and capture prey in their marine environments. Chordates, which include vertebrates like fish, amphibians, reptiles, birds, and mammals, do not possess a water vascular system. Arthropods, such as insects, spiders, and crustaceans, have a different type of circulatory system and do not have a water vascular system. Therefore, the correct answer is echinoderms only.

The nautilus is the only cephalopod that has retained its external shell. While other cephalopods like cuttlefish, octopus, and squid have either lost or greatly reduced their shells, the nautilus still possesses a prominent chambered shell. This shell provides protection and buoyancy to the nautilus, allowing it to control its depth in the water column. The other cephalopods have evolved different mechanisms for defense and movement, such as camouflage, jet propulsion, and ink release, which have rendered their shells unnecessary.

Segmentation is the most significant evolutionary advancement of annelids and arthropods over mollusks. Segmentation refers to the division of the body into repeating segments, each with its own set of specialized structures. This allows for greater flexibility and specialization in movement, feeding, and sensory perception. Mollusks, on the other hand, lack this level of organization and have a more uniform body structure. Therefore, segmentation is a key feature that sets annelids and arthropods apart from mollusks and is a major evolutionary advancement in these groups.

The water vascular system in certain marine animals, such as sea stars and sea urchins, is responsible for distributing water to their tube feet. This system allows for movement, feeding, and respiration. The water enters through a sieve plate called the madreporite and then travels through a series of canals, eventually reaching the tube feet. The tube feet extend and contract, enabling the animal to move and capture prey. Therefore, the water vascular system plays a crucial role in the locomotion and feeding of these animals.

Nephridia are small tubules that collect waste from the coelom of annelids and mollusks and discharge them from the body. They function as excretory organs, removing metabolic waste and maintaining osmotic balance in these organisms. Nephridia are found in both annelids and mollusks, making them the correct answer to the question. Spicules are tiny structures found in the bodies of certain organisms like sponges and echinoderms. Radulae are specialized feeding structures found in mollusks, particularly in snails and slugs. Bivalves are a class of mollusks that include clams, mussels, and oysters, but they are not directly related to the waste collection and disposal function described in the question.

The abdomen is the correct answer because it is the part of the insect body that is specialized for reproduction. It contains the reproductive organs, including the ovaries and testes, as well as structures necessary for mating and laying eggs. The head, cephalothorax, and thorax are important for other functions such as feeding, sensory perception, and locomotion, but they are not primarily involved in reproduction.

Leeches are annelid worms that lack setae and parapodia. Setae are bristle-like structures that help worms with locomotion, but leeches have evolved to live in aquatic environments where setae are not necessary. Additionally, parapodia are paddle-like appendages that aid in movement and respiration, but leeches do not possess them. Therefore, leeches are the correct answer as they do not have these characteristic features found in other annelid worms like earthworms, polychaete worms, and tube worms.

The clitellum of an earthworm produces the mucous for their cocoon. The clitellum is a specialized glandular region located near the anterior end of the earthworm's body. It secretes a sticky, protein-rich substance that forms a protective cocoon around the eggs and sperm during reproduction. This cocoon provides a safe environment for the development of the earthworm embryos.

The larval stage of a sea star has bilateral symmetry. This means that the body can be divided into two equal halves along a central axis, resulting in mirror-image halves. This symmetry allows for efficient movement and coordination in the larva. As the sea star matures, it develops pentaradial symmetry, where the body can be divided into five equal parts radiating from a central point. This allows for better adaptation to its adult lifestyle.

Most insects have two pairs of wings and three pairs of legs. This is a characteristic feature of insects, where the wings are attached to the thorax and the legs are attached to the thorax and abdomen. Having two pairs of wings allows insects to fly, while having three pairs of legs enables them to move and navigate their environment. This combination of wings and legs is a defining characteristic of most insects.

Annelids, mollusks, and arthropods are classified as coelomate protosomes. This is because they have a true coelom, which is a fluid-filled body cavity completely lined by mesoderm. They also exhibit protostome development, which means that during embryonic development, the mouth forms before the anus.

Malpighian tubules in insects are specialized structures that play a crucial role in excretion. They function to remove metabolic wastes from the insect's body. These wastes include nitrogenous compounds such as ammonia, uric acid, and urea, which are byproducts of metabolic processes. The Malpighian tubules filter these waste products from the insect's circulatory system and excrete them as part of the insect's excretory system. This process helps maintain the insect's internal homeostasis by eliminating harmful waste materials.

The respiratory system of a lobster and crayfish is composed of feathery gills found at the base of each walking leg. This is because gills are the main respiratory organs in aquatic animals, allowing them to extract oxygen from water. The feathery structure of the gills increases their surface area, maximizing the amount of oxygen that can be absorbed. The location of the gills at the base of each walking leg ensures that they are in close contact with the surrounding water for efficient gas exchange.

Sea squirt is not an example of an echinoderm because echinoderms are characterized by a spiny skin and a radial symmetry, while sea squirts belong to the phylum Chordata and have a different body structure. Sea stars, sea lilies, and sea cucumbers are all examples of echinoderms as they possess the characteristic features of this phylum.

The correct answer is larval urochordates (eg. sea squirts, tunicates) that became sexually mature. This is because cephalochordates, such as lancelets, share many anatomical and developmental similarities with urochordates in their larval stage. These similarities suggest that cephalochordates evolved from larval urochordates that retained their larval characteristics into adulthood, rather than going through a metamorphosis like most urochordates. This hypothesis is supported by genetic and molecular evidence, as well as fossil records.

In an open circulatory system, body tissues are bathed directly in blood. This means that the blood, which contains oxygen and nutrients, is not contained within blood vessels but instead flows freely through the body cavity. This allows the blood to come into direct contact with the body tissues, delivering oxygen and nutrients directly to them. This type of circulatory system is found in some invertebrates, such as insects and mollusks.

The respiratory system of insects is composed of small tubules that transport gases throughout the body. This system, known as the tracheal system, consists of a network of tiny tubes called tracheae that deliver oxygen directly to the cells and remove carbon dioxide. The tracheae open to the outside through small openings called spiracles, which are usually located on the sides of the insect's body. The tracheal system allows for efficient gas exchange and is essential for the insect's survival.

Diploblastic refers to having two germ layers (ectoderm and endoderm) during embryonic development. This characteristic is not present in all chordates, as most chordates are triploblastic, meaning they have three germ layers (ectoderm, mesoderm, and endoderm). Therefore, diploblastic is not a characteristic of all chordates.

Polychaete worms are annelid worms that have parapodia and many setae. Parapodia are paired, paddle-like appendages that aid in locomotion and respiration, while setae are bristle-like structures that provide traction and help anchor the worm. Earthworms do not have parapodia and have fewer setae compared to polychaete worms. Leeches also do not have parapodia and have fewer setae. Therefore, the correct answer is polychaete worms.

The correct answer is "It uses a book lung for respiration." Insects do not use book lungs for respiration. Instead, they have a system of tubes called tracheae that deliver oxygen directly to their cells. Book lungs are found in some arachnids, such as spiders, and are used for respiration.

Segmented species have an evolutionary advantage because mutations can modify organs in specific segments to perform new tasks. This allows for adaptability and specialization in different segments, enhancing their survival and ability to exploit different ecological niches. By evolving new functions in specific segments, these species can better adapt to changing environments and increase their chances of survival and reproduction. This flexibility and versatility provided by segmental organization contribute to the evolutionary success of these species.

In earthworms, the crop is a part of the digestive system that serves as a temporary storage organ for food. It allows the earthworm to store and hold food until it is ready to be further digested and absorbed in the gizzard and intestine. Therefore, the correct answer is "storage of food".

The vertebral column is not a characteristic of all chordates. While chordates do have a dorsal hollow nerve chord, bilateral symmetry, and a coelomate body plan, not all chordates have a vertebral column. Invertebrate chordates, such as tunicates and lancelets, lack a true vertebral column. Therefore, the presence of a vertebral column is not a universal characteristic of all chordates.

The lancelet is an example of a cephalochordate because cephalochordates are a subphylum of chordates that include small, fish-like marine animals such as the lancelet. These animals have a notochord, a dorsal nerve cord, and gill slits throughout their lives, making them primitive chordates. They lack a true backbone or vertebral column, which is characteristic of vertebrates. Therefore, the lancelet is classified as a cephalochordate.

Arthropods molt because their exoskeleton does not grow within their body. The exoskeleton is a hard outer covering that provides support and protection to the arthropod's body. As the arthropod grows, its exoskeleton becomes too small, restricting further growth. To accommodate their growing body, arthropods must shed their old exoskeleton and form a new, larger one through a process called molting. During molting, the arthropod secretes enzymes that dissolve the old exoskeleton, allowing it to break free and reveal a soft, pliable new exoskeleton underneath.