What are body parts arranged around a central point?
Specifically, symmetry refers to a correspondence of body parts, in size, shape, and relative position, on opposite sides of a dividing line or distributed around a central point or axis.
What is the name for animals that do not have a backbone and account for over 98% of all the species on Earth?
invertebrates
What, all animals? Well, invertebrates. Spiders, insects, jellyfish, crabs, worms, molluscs – in other words, animals without a backbone, which make up 98% of all animal species.
Are animals classified as invertebrates or vertebrates based on their internal structure?
Animals can be classified into two main groups: vertebrates and invertebrates. The main difference between vertebrates and invertebrates is that invertebrates, like insects and flatworms, do not have a backbone or a spinal column. Examples of vertebrates include humans, birds, and snakes.
What is the largest group of animals quizlet?
Terms in this set (43)
- invertebrates. the largest and most diverse group of animals, animals without backbones.
- arthropods.
- exoskeleton.
- chitin.
- entomologists.
- metamorphosis.
- incomplete metamorphosis.
- nymph.
What is the most diverse group of animals?
Arthropods the largest, most diverse animal group.
Which is part of an animal has bilateral symmetry?
Animals with bilateral symmetry have a “head” and “tail” (anterior vs. posterior), front and back (dorsal vs. ventral), and right and left sides. All true animals, except those with radial symmetry, are bilaterally symmetrical.
What kind of animal has no left or right side?
Animals with radial symmetry have no right or left sides, only a top or bottom; these species are usually marine organisms like jellyfish and corals. Most animals are bilaterally symmetrical with a line of symmetry dividing their body into left and right sides along with a “head” and “tail” in addition to a top and bottom.
Which is true about the anatomy of all animals?
All true animals, except those with radial symmetry, are bilaterally symmetrical. The evolution of bilateral symmetry and, therefore, the formation of anterior and posterior (head and tail) ends promoted a phenomenon called cephalization, which refers to the collection of an organized nervous system at the animal’s anterior end.
What kind of animal has an asymmetrical body plan?
Only sponges (phylum Porifera) have asymmetrical body plans. Some animals start life with one type of body symmetry, but develop a different type as adults; for example, sea stars are classified as bilaterally symmetrical even though their adult forms are radially symmetrical.
Which is part of the animal separates the front from the back?
A frontal plane (also called a coronal plane) separates the front (ventral) from the back (dorsal). A transverse plane (or, horizontal plane) divides the animal into upper and lower portions. This is sometimes called a cross section; if the transverse cut is at an angle, it is called an oblique plane.
Animals with bilateral symmetry have a “head” and “tail” (anterior vs. posterior), front and back (dorsal vs. ventral), and right and left sides. All true animals, except those with radial symmetry, are bilaterally symmetrical.
Animals with radial symmetry have no right or left sides, only a top or bottom; these species are usually marine organisms like jellyfish and corals. Most animals are bilaterally symmetrical with a line of symmetry dividing their body into left and right sides along with a “head” and “tail” in addition to a top and bottom.
Which is the correct description of an animal’s position?
The most common terms used when describing positions in the body are anterior (front), posterior (rear), dorsal (toward the back), and ventral (toward the stomach). Note that the terms superior and inferior are usually not used to describe animals.
