Think of the water-vascular system. the organs are: stone canal, ring canal, radial canals, ampullae, and the madreporite plate. i had this question on my 7th grade science lab? (:
Echinoderms are eukaryotes, meaning their cells contain a nucleus and other membrane-bound organelles. Prokaryotes, on the other hand, lack a nucleus and their genetic material is not enclosed within a membrane.
Any organism that is too small to be seen by the naked eye must be seen through a microscope. These small organisms are called microorganisms. Bacteria and spermatozoa are examples of microorganisms that we can only view through a microscope.
Microorganisms are very small and can vary in shape and size. They can be spherical, rod-shaped, spiral, or even branched. To see them, a microscope is usually required as they are too small to be seen with the naked eye.
An example of an organism that can only be seen with a microscope is a single-celled organism like bacteria or protists. These organisms are too small to be visible to the naked eye but can be observed under a microscope due to their size.
Some of the most common adaptations seen in organisms include camouflage, mimicry, structural modifications for locomotion, and specialized feeding features. These adaptations help organisms survive and thrive in their specific environments by increasing their chances of finding food, avoiding predators, and reproducing successfully.
None, if she's then she cannot be seen! RETARD!
cilium helps in swimming locomotion. they are seen in protozoans like vorticella, paramecium
The biological term that describes the presence of a definite head containing sensory organs oriented in the direction of movement is "cephalization." This evolutionary trend is characterized by the concentration of nervous tissue and sensory organs at one end of the organism, typically leading to enhanced awareness and interaction with the environment. Cephalization is most commonly seen in bilateral animals, where it facilitates more efficient locomotion and predation.
Echinoderms are eukaryotes, meaning their cells contain a nucleus and other membrane-bound organelles. Prokaryotes, on the other hand, lack a nucleus and their genetic material is not enclosed within a membrane.
This is a weird hypothesis that I thought up when I was renaming some paper pdfs I've collected. It was inspired by a speculation I've seen that vertebrate side fins / limbs are ectopic tails; this was inspired by how limbs express Hox genes that are also expressed in tails. Ectopic tails may be able to form more easily because vertebrate tails extend past the anus, which is to the rear of most of the internal organs. Compare the situation of arthropods, annelids, and others, where the anus is at the absolute rear of the body, with no tail extending past it. Post-anal tails are shared by other chordates and by hemichordates. Which leaves echinoderms the remaining group of deuterostomes; the aforementioned terminal-anus animals are protostomes. How chordates, hemichordates, and echinoderms are related has been revised as a result of molecular evidence. An obvious overall-feature tree is: ((chordates, hemichordates), echinoderms) But molecular evidence suggests: (chordates, (hemichordates, echinoderms)) Which suggests that post-anal tails are an ancestral feature of deuterostomes, meaning that echinoderms have had an ancestor with them. But where might we find such a feature in living ones? Consider starfish and brittle-star anatomy. A starfish has a central disc with most of the internal organs, and with five arms radiating outwards. The mouth is on the bottom of the disc, the anus on the top. And those arms could possibly have originally been extra tails; their anatomy fits, since like chordate and hemichordate tails, they have only a limited set of internal organs. The main problem with the five-tail hypothesis is how the other echinoderms fit in; they also have radial symmetry, but they do not have comparable limbs. Info from internet
Ever seen one? No, some might have bristles though..that are tiny projections made for locomotion
They can only be seen with a microscope.
An organ that is much more noticeable in men than women is the larynx. This is also called the "Adam's apple". Other organs in only men that can be seen are the penis and testicles.
The only layer we have seen is the crust, or outermost layer.
yes but only part of it is seen,and seen foggy
Only our moon ("The Moon") can be seen from Earth.
Protein-energy malnutrition is seen only in developing countries.