Mamalia and also Arthropoda
-Tyler Smith
Animals are classified according to body plan as symmetrical or asymmetrical. Symmetrical animals are usually bilateral (two-sided) or radial (multiple planes of symmetry), while asymmetrical animals have no defined body plan. These classifications help scientists understand the evolutionary relationships between different groups of animals.
No, planaria are not segmented. They are flatworms that have a simple body plan with bilateral symmetry. They do not have true segments like some other invertebrates.
Primitive life forms tend to be asymmetrical with no body plan, while advanced forms have either radial or bilateral symmetry, which are both detailed body plans. Primitive animals also have a sac-like body plan with no specialized organs for digestion, while advanced animals have a tube within a tube body plan that contains specialized digestive organs for more efficient digestion. Primitive animals have very basic, unsegmented bodies with no appendages, while advanced animals have segmented bodies that allow for specialized limbs and body parts.
A sac body plan is a simple body organization found in some animals, where the body consists of a central cavity surrounded by a single layer of cells. This cavity acts as a digestive chamber where food is taken in and digested. Examples of animals with a sac body plan include cnidarians like jellyfish and sea anemones.
The evolution of symmetry, tissues, a body cavity, patterns of embryonic development, and segmentation (repeated body units). Symmetry is found as radial symmetry (halves of the body mirror each other) and bilateral symmetry (symmetric in every direction). Cells differentiate into tissues which allows for specialized structures and functions. The evolution of body cavities allowed for the evolution of organ systems. There are 2 patterns of embryonic development in bilateraly symmetrical animals: protostomes and deuterostomes. Other embryonic development classifications are cleavage patterns (spiral and radial), determinate or indeterminate development, and coelom formation. With segmented animals, each segment has a set of organ systems. This is advantageous because if one segment is damaged, the animal will not die. Segmentation also allows animals to move more effectively since the segments can move fairly independently.
A segmented body plan is characterized by the division of the body into repetitive segments, each of which may have similar or specialized structures. This arrangement allows for greater flexibility and mobility, as segments can move independently. An example of a phylum that includes animals with segmented bodies is Annelida, which consists of earthworms and leeches. Additionally, the phylum Arthropoda, which includes insects and crustaceans, also exhibits segmentation in its body structure.
Animals are classified according to body plan as symmetrical or asymmetrical. Symmetrical animals are usually bilateral (two-sided) or radial (multiple planes of symmetry), while asymmetrical animals have no defined body plan. These classifications help scientists understand the evolutionary relationships between different groups of animals.
at this level, organisms are placed or grouped together based on similarities in basic body plan or organization.
their body plan
The acoelomate phyla are Platyhelminthes (flatworms) and Nemertea (ribbon worms). These animals lack a true body cavity (coelom) between their digestive tract and body wall. Acoelomates rely on other means, like a simple body plan and mesenchyme tissue, for support and structure.
Nematodes do not have segmented bodies like annelid do.
Most animal phyla exhibit bilateral symmetry, where the body can be divided into two mirror-image halves along a single plane. This body plan is thought to have evolved for efficient movement and coordination in organisms.
No, planaria are not segmented. They are flatworms that have a simple body plan with bilateral symmetry. They do not have true segments like some other invertebrates.
Two features defining the animal phyla are adult body plans and patterns of embryological development.
They either do NOT have skeletons or they have exoskeletons like the millipede.
The main characteristics that are used to classify animals into different phyla includes the cell type, the cell wall and the nuclear membrane. The presence of the absence of a backbone is another main characteristic.
Phyla is plural for Phylum. It is used in animal taxonomy and is the category between kingdom and class. Animals in the same phylum have the same degree of developmental similarity. There is a total of 36 animal phyla that all animals fall under and the largest phylum is Arthropoda.