The endocrine glands are located throughout the body.
<span>Echinoderms are invertebrate animals
with radial symmetry. They reproduce mostly through external fertilization.
They have endoskeletons that are made up of hardened plates. Examples would be
sea stars, sea urchins and sea cucumbers. </span>
<span>
</span>
The simplest invertebrate animal is
the sponge. They have no organs and are considered the most ancient member of
the kingdom Animalia. It was once thought to be a plant but the way it takes in
food qualified it to be an animal.
Animals in the phylum porifera, more
commonly known as sponges are marine animals. They are mostly asymmetrical and
they self-fertilize because they are mostly hermaphrodites. In other words,
eggs and the sperms are produced by the same organism.
Fish are vertebrate animals that have
bodies that are bilaterally symmetrical. They reproduce through external
fertilization. They belong in the class called Osteichthyes.
<span>Cnidarians exhibit radial symmetry.
They reproduce both asexually and sexually. Budding however is the most
important form. They are invertebrates that are known for their central body
cavity and stinging cells. Examples would be the jellyfish and the hydra.</span>
Mammals are vertebrates with
bilateral symmetry. They have endoskeletons and are known to reproduce sexually
through internal fertilization. They give birth to live young. The only mammal
that is known to lay eggs is the platypus.
Arthropods are invertebrates with
exoskeletons, jointed appendages and segmented bodies. Their bodies show bilateral
symmetry. They reproduce sexually. Insects are arthropods, so are crustaceans,
arachnids and the like.
I believe it's A. If an organism changes and evolves slowly over time it is caused by variation, which helps the species adapt to it's habitat and way of life
A chromozome is a long, stingy aggregate of genes that carries heridity information.
The answer is : D carries instructions for the traits of an organism