An Amazing Animal Diversity Quiz!

The organism displays bilateral symmetry because it can be divided into two equal halves along a single plane. This type of symmetry is commonly found in animals that have a distinct front and back, as well as a left and right side.

The organism above displays radial symmetry because it can be divided into multiple identical parts that radiate out from a central point. This type of symmetry is commonly found in organisms such as jellyfish, sea anemones, and starfish.

Deuterostomes is the correct answer because in deuterostomes, the blastopore, which is the opening of the developing embryo, eventually becomes the anus. In contrast, in protostomes, the blastopore becomes the mouth. This distinction in embryonic development is one of the key differences between these two groups of animals.

In protostomes, the blastopore, which is the opening formed during gastrulation, develops into the mouth of the organism. This means that the first opening to form in the early embryo becomes the mouth in protostomes. In contrast, in deuterostomes, the blastopore becomes the anus, with the mouth forming from a secondary opening. Therefore, the correct answer is protostomes.

Cnidarians have radial symmetry, which means that their body parts are arranged around a central axis, like the spokes of a wheel. This allows them to be equally balanced from all sides. This type of symmetry is advantageous for cnidarians as it enables them to capture prey from any direction and enhances their ability to detect and respond to stimuli in their environment.

The correct answer is endoderm, ectoderm, mesoderm. Bilaterians are triploblastic organisms, meaning they have three germ layers during embryonic development. The endoderm layer gives rise to the digestive system and respiratory system, the ectoderm layer forms the nervous system and outer covering of the body, and the mesoderm layer develops into the muscles, circulatory system, and other internal organs. The options epidermis and endodermis are not correct as they are not germ layers but rather specific tissue types derived from the ectoderm and endoderm layers respectively.

The correct answer is "Sponges have highly developed reproductive organs." This is because sponges do not have highly developed reproductive organs like other animals. Instead, they reproduce asexually through budding or sexually by releasing sperm and eggs into the water, where fertilization occurs externally. Sponges are known for their simple body structure, lack of tissues, and their ability to filter feed through choanocytes. The mesohyl, which lies within the two layers of a sponge, functions in skeleton formation and the dispersal of nutrients.

The organism above displays asymmetry, meaning it lacks any type of symmetry. This means that it does not have any specific pattern or arrangement of body parts that can be divided into equal halves. Instead, its body parts are irregular and do not mirror each other.

Bilateral symmetry is strongly correlated with cephalization because cephalization refers to the development of a head region with sensory organs and a centralized nervous system. Bilateral symmetry allows for the organization of body parts in a way that enables efficient movement and coordination, which is necessary for cephalization to occur. This symmetry allows for the formation of a distinct head region, where sensory organs can be concentrated, providing an advantage in perceiving and responding to the environment.

Spiral cleavage is a type of embryonic development pattern seen in protostomes. During spiral cleavage, the cells divide in a spiral arrangement, resulting in a spiral pattern of cells in the early embryo. This type of cleavage is characteristic of protostomes, which include animals such as insects, mollusks, and annelids. In contrast, deuterostomes, which include animals like vertebrates and echinoderms, exhibit radial cleavage where the cells divide in a radial pattern. Therefore, the correct answer is protostomes.

The organism described in the question has a carapace, which is a hard shell covering its body. This characteristic is commonly found in crustaceans, such as crabs, lobsters, and shrimp. Additionally, the organism has 2 pairs of antennae and compound eyes, which are also features commonly found in crustaceans. Therefore, based on these characteristics, it can be concluded that the organism belongs to the subphylum Crustacea.

A germ layer is a layer of cells that form during embryogenesis. During embryonic development, the cells in the early embryo differentiate and organize into three primary germ layers: the ectoderm, mesoderm, and endoderm. These germ layers give rise to different tissues and organs in the body. The ectoderm forms the skin, nervous system, and other structures, the mesoderm forms muscles, bones, and connective tissues, and the endoderm forms the lining of the digestive tract and respiratory system. Therefore, the correct answer is that a germ layer is a layer of cells that form during embryogenesis.

Cnidaria, such as jellyfish and corals, are diploblastic organisms, meaning they have two germ layers. The ectoderm is the outer layer, responsible for forming the epidermis, while the endoderm is the inner layer, which lines the digestive cavity. Therefore, the correct germ layers for Cnidaria are endoderm and ectoderm.

Bilateral symmetry refers to the arrangement of body parts in such a way that there is a left and right side that are mirror images of each other. This type of symmetry allows for efficient movement in horizontal directions to capture prey, as well as the development of specialized sensory organs at the front end for guidance. Additionally, bilateral symmetry enables the development of muscles, digestive, circulatory, and nervous systems. However, the ability to wave food-gathering tentacles in all directions at once is not an advantage of bilateral symmetry, as it is more commonly associated with radial symmetry.

Regulative embryo development is seen in deuterostomes. In this type of development, the fate of the cells is not determined early on, and each cell has the potential to develop into a complete organism. The cells have the ability to regulate their development and compensate for the loss or addition of cells. This allows for greater flexibility and adaptability in the development process. Protostomes, on the other hand, exhibit mosaic embryo development, where the fate of each cell is determined early on and cannot be changed.

Acoelomates are characterized by having a solid body without a cavity surrounding internal organs. This means that their organs are not enclosed in a fluid-filled cavity, unlike other organisms with a coelom. Acoelomates also lack a brain, have no mesoderm, and do not undergo deuterostome development. However, the defining characteristic of acoelomates is their solid body structure without a cavity.

In deuterostomes, the coelom forms through a process called enterocoely. During development, the mesoderm buds off from the endoderm, forming pouches called enterocoelic pouches. These pouches then fuse together, creating a hollow space called the coelom. This differs from protostomes, where the coelom forms through a different process called schizocoely, where the mesoderm splits and forms the coelom directly. Therefore, the correct answer is deuterostomes.

In protostomes, the coelom forms through a process called schizocoely. Schizocoely is a type of embryonic development where the coelom forms from splits or cavities within the mesoderm. This occurs during gastrulation, when the embryo invaginates and forms a blastopore. As the mesoderm cells migrate and fill the blastocoel, they form splits or cavities that eventually develop into the coelom. This process is characteristic of protostomes, which include groups such as arthropods, mollusks, and annelids. Deuterostomes, on the other hand, form the coelom through enterocoely, where the coelom arises from outpocketings of the archenteron.

The correct answer is annelid worms and mollusks. The group Lophotrochozoa is a superphylum within the animal kingdom that includes a diverse range of organisms. Annelid worms, such as earthworms and leeches, and mollusks, such as snails and clams, are both members of this group. They share certain characteristics, such as a lophophore (a feeding structure) or a trochophore larval stage. The other options, butterflies and moths, crustaceans, and sponges and octopus, do not belong to the Lophotrochozoa group.

All ecdysozoans share a characteristic of having some kind of exoskeleton or hard outer covering. This exoskeleton provides protection and support for their bodies. It is shed periodically through a process called ecdysis, allowing for growth and development. This characteristic is unique to ecdysozoans and is not found in other animal groups.

Metamerism refers to the repetition of similar body segments in an organism. This phenomenon is commonly observed in segmented animals like earthworms and arthropods, where the body is divided into a series of repeating segments. Each segment typically contains a set of similar structures, such as muscles, nerves, and appendages. This repetitive segmentation allows for specialization and efficient movement in these organisms. Therefore, the correct answer is "repetitive segments."

Radial cleavage is a type of embryonic development pattern where the cell divisions occur parallel or perpendicular to the polar axis, resulting in a radial arrangement of cells. This pattern is characteristic of deuterostomes, which include organisms such as echinoderms (starfish, sea urchins), hemichordates, and chordates (vertebrates). In contrast, protostomes, which include organisms like arthropods and mollusks, typically exhibit spiral or determinate cleavage patterns. Therefore, the correct answer is deuterostomes.

The most ancient branch point in animal phylogeny is determined by whether organisms have true tissues or no tissues. This means that the earliest divergence in animal evolution occurred between organisms that had differentiated tissues and those that did not. True tissues are specialized groups of cells that perform specific functions, while organisms without tissues have cells that are not organized into distinct structures. This differentiation in tissue development represents a fundamental difference in the evolution of animals and is therefore considered the most ancient branch point.

Based on morphological and molecular evidence, animals are closely related to a protist called choanoflagellates. This is supported by studies comparing the similarities in cell structure and genetic makeup between animals and choanoflagellates. These studies suggest that animals and choanoflagellates share a common ancestor and have evolved from a common lineage. This relationship is further supported by the presence of similar cellular structures, such as the collar cells found in both animals and choanoflagellates, which are involved in capturing food particles.

Mosaic embryo development is seen in protostomes. Mosaic development refers to the type of embryonic development in which the fate of each cell is determined early on and remains fixed throughout development. In protostomes, the fate of each cell is determined by the specific cytoplasmic determinants present in the egg. This means that each cell has a predetermined fate and will develop into a specific tissue or organ. In contrast, deuterostomes undergo regulative development, where the fate of cells is not determined early on and can change throughout development.

If a multicellular animal lacks true tissues, it can be properly included among the metazoans. Metazoans are organisms that have multiple cells and are part of the animal kingdom. They are characterized by having specialized cells that form tissues, organs, and organ systems. Since the animal in question lacks true tissues, it can still be classified as a metazoan because it is multicellular.

The correct answer is monophyletic. Monophyletic refers to a group that includes a common ancestor and all of its descendants. In the context of the animal kingdom, it means that all animals share a common ancestor and are part of a single evolutionary lineage. This is supported by evidence from comparative anatomy, genetics, and fossil records, which show that all animal groups are interconnected and descended from a common ancestor.

The correct answer is 3, 4, 2, 1. This ranking is based on the current molecular-based phylogeny. The eumetazoans (answer choice 3) are the most inclusive group as they include all animals with true tissues. Triploblastic (answer choice 4) refers to animals with three germ layers, which is a more specific characteristic than eumetazoans. Protostomes (answer choice 2) are a subgroup of triploblastic animals and are less inclusive. Ecdysozoans (answer choice 1) are a subgroup of protostomes and are the least inclusive group among the options given.

Cnidaria and Ctenophora are the correct answers because they are the only two groups of animals that are diploblastic. Diploblastic animals have two germ layers, the ectoderm and endoderm, whereas most animals are triploblastic, having three germ layers. Porifera, Arthropoda, and Mollusca are all triploblastic, so they do not fit the criteria of being diploblastic.

An animal is a multicellular organism that is heterotrophic, meaning it obtains its nutrients from organic substances. It is also eukaryotic, meaning its cells have a nucleus enclosed within a membrane. Animals also have embryos with a gastrula stage, which is a developmental stage during which the three primary germ layers form. The shape of animals is held by collagen, a structural protein found in the extracellular matrix. Therefore, the correct answers are heterotrophic, eukaryotic, embryos with gastrula stage, shape held by collagen, and multicellular.