Biology: Characteristics of Animals and Tissues

Animals are heterotrophs, meaning they cannot produce their own energy and need to consume other organisms or plants to obtain energy.

Muscular tissue is responsible for movement, nervous tissue is responsible for transmitting information, and connective tissue provides structural support and protection.

Embryonic development involves the formation of a blastula, followed by the migration of cells to form two layers: ectoderm (outside) and endoderm (inside).

<p>Animal cells lack cell walls, allowing for flexibility in movement and locomotion.</p> Signup and view all the answers

<p>Specialized forms of tissues, such as bone, cartilage, and skin, provide support for animal cells and tissues.</p> Signup and view all the answers

<p>Animals reproduce using sexual or asexual means, with sexual reproduction involving the fusion of sex cells to form a zygote.</p> Signup and view all the answers

<p>In a true coelom, the internal cavity is lined by the mesoderm, whereas in a false coelom, the mesoderm forms a cavity but does not line the internal part of the endoderm.</p> Signup and view all the answers

<p>Animals with a true coelom have a fully developed body cavity lined by mesoderm, whereas those with a false coelom have a cavity that is not lined by mesoderm, resulting in a different body organization.</p> Signup and view all the answers

<p>The presence or absence of a coelom is used to classify animals into three groups: coelomates (true coelom), pseudo-coelomates (false coelom), and acoelomates (no coelom).</p> Signup and view all the answers

<p>Chordates have a true coelom, whereas nematodes have a false coelom.</p> Signup and view all the answers

<p>The mesoderm forms a space or coelom, which is lined by the mesoderm in animals with a true coelom.</p> Signup and view all the answers

<p>The primary difference is that diploblastic animals have two embryonic layers (ectoderm and endoderm), while triploblastic animals have three (ectoderm, endoderm, and mesoderm). This difference impacts their body structure, as triploblastic animals have a more complex body organization with a coelom and a blastocoel, whereas diploblastic animals have a simpler body structure with a gastrovascular cavity.</p> Signup and view all the answers

<p>The blastula stage is significant because it is the first stage of embryonic development, and it is during this stage that cells migrate inside the blastocoel to form the endoderm, leading to the formation of the three primary germ layers (ectoderm, endoderm, and mesoderm).</p> Signup and view all the answers

<p>The characteristic feature of the gastrovascular cavity in diploblastic animals is that it forms from the endoderm. It forms from the opening in the blastula, which eventually develops into a cavity that serves as both the digestive and circulatory system.</p> Signup and view all the answers

<p>Sponges differ from other animals in that they do not have true tissues and do not form germ layers. They also lack a coelom and a blastocoel, which are characteristic features of other animals.</p> Signup and view all the answers

<p>The mesoderm is significant in triploblastic animals because it gives rise to the muscles, bones, and other organs of the body. It contributes to the formation of the coelom and the blastocoel, which are characteristic features of triploblastic animals.</p> Signup and view all the answers

<p>Cnidarians have a distinct body structure characterized by a gastrovascular cavity and a mouth that forms from the opening in the blastula. This difference is significant because it allows cnidarians to have a more complex body structure than other diploblastic animals, such as jellyfish and corals.</p> Signup and view all the answers

<p>The primary characteristic that distinguishes eucoelomates from pseudocoelomates is the presence of a true coelom, which is completely surrounded by mesoderm cells. This characteristic impacts their body organization by providing a more complex and organized body cavity, whereas pseudocoelomates have a less complex body cavity that is not completely surrounded by mesoderm cells.</p> Signup and view all the answers

<p>The key difference between protostomes and deuterostomes is the formation of the mouth and anus during embryonic development. Protostomes form the mouth first, while deuterostomes form the anus first. This difference impacts their developmental patterns, with protostomes exhibiting spiral cleavage and deuterostomes exhibiting radial cleavage.</p> Signup and view all the answers

<p>The presence of three germ layers (ectoderm, endoderm, and mesoderm) is a characteristic that distinguishes animals from cnidarians, which have only two germ layers. This characteristic is significant because it allows animals to develop more complex body structures and organize their body cavities in a more complex way.</p> Signup and view all the answers

<p>The absence of a body cavity in acoelomates means that they lack a complex body organization, and their mesoderm cells fill the space between the ectoderm and endoderm. This impacts their development, as they are unable to develop complex organs and body structures.</p> Signup and view all the answers

<p>The blastopore is a critical structure in the development of protostomes and deuterostomes, as it forms the mouth in protostomes and the anus in deuterostomes. This determines the order of mouth and anus formation, which is a key characteristic of these groups.</p> Signup and view all the answers

<p>The presence of a true coelom in eucoelomates allows for more complex body organization and developmental trends, such as the formation of complex organs and body structures. This characteristic is significant because it distinguishes eucoelomates from pseudocoelomates and acoelomates.</p> Signup and view all the answers

<p>A colonial Kawano flagellate is a single-celled organism that lives in colonies, whereas a metazoan is a multi-cellular organism.</p> Signup and view all the answers

<p>Sponges are the out-group in the phylogenetic tree, sharing a common ancestor with the metazoans.</p> Signup and view all the answers

<p>Animals with true tissues have cells that are connected and can collaborate with each other, enabling them to function more effectively.</p> Signup and view all the answers

<p>Radial symmetry in cnidarians and comb jellies allows for a different body organization, distinct from the bilateral symmetry seen in most animals.</p> Signup and view all the answers

<p>The archenteron is a primitive gut that forms in deuterostomes, and is a characteristic feature of their developmental patterns.</p> Signup and view all the answers

<p>Deuterostomes are distinguished by their radial cleavage, coelom formation from pockets of the gut, and formation of the mouth second, which are distinct from other animals.</p> Signup and view all the answers

<p>Protostomes are characterized by the formation of the mouth from the blastopore, whereas in Deuterostomes, the blastopore gives rise to the anus. This fundamental difference in embryonic development sets them apart.</p> Signup and view all the answers

<p>Lophotrochozoa are characterized by the formation of a feeding structure called the lophophore and a larval stage called the trochophore. Ecdysozoa, on the other hand, are characterized by the process of ecdysis, where they molt their old body covering to grow and develop. These characteristics define their respective clades.</p> Signup and view all the answers

<p>The molecular phylogenetic tree is a tool that allows us to understand animal relationships based on molecular differences, such as genes that control embryonic development. It distinguishes between Protostomia and Deuterostomia by grouping them into two main clades.</p> Signup and view all the answers

<p>Nematodes and Arthropods, as members of the Ecdysozoa clade, exhibit the characteristic of ecdysis, where they molt their old body covering to grow and develop. This process is significant in their development as it allows them to increase in size and molt their exoskeletons.</p> Signup and view all the answers

<p>In Protostomes, the blastopore gives rise to the mouth. This is a critical event in embryonic development, as it marks the formation of the first opening of the digestive system.</p> Signup and view all the answers