Biology

Acoelomates are characterized by A) the absence of a brain. B) the absence of me

Started by hummingbird

The distinction between sponges and other animal phyla is based mainly on the ab

Started by hummingbird

Among the characteristics unique to animals is A) gastrulation. B) multicellular

Started by hummingbird

Some researchers claim that sponge genomes have homeotic genes, but no Hox genes

Started by hummingbird

Which of these, if true, would support the claim that the ancestral cnidarians h

Started by hummingbird

The last common ancestor of all bilaterians is thought to have had four Hox gene

Started by hummingbird

Which distinction is given more emphasis by the morphological phylogeny than by

Started by hummingbird

What is true of the clade Ecdysozoa? A) It includes all animals that molt at som

Started by hummingbird

If the current molecular evidence regarding animal origins is well-substantiated

Started by hummingbird

Which of the following statements concerning animal taxonomy is (are) true? 1.

Started by hummingbird

If a multicellular animal lacks true tissues, then it can properly be included a

Started by hummingbird

The most ancient branch point in animal phylogeny is that between having A) radi

Started by hummingbird

Protostome characteristics generally include which of the following? A) a mouth

Started by hummingbird

Which of the following characteristics generally applies to protostome developme

Started by hummingbird

Which of the following is descriptive of protostomes? A) spiral and indeterminat

Started by hummingbird

The blastopore denotes the presence of an endoderm-lined cavity in the developin

Started by hummingbird

The blastopore is a structure that first becomes evident during A) fertilization

Started by hummingbird

You have before you a living organism, which you examine carefully. Which of the

Started by hummingbird

What distinguishes a coelomate animal from a pseudocoelomate animal is that coel

Started by hummingbird

At which developmental stage should one be able to first distinguish a protostom

Started by hummingbird

At which developmental stage should one be able to first distinguish a diploblas

Started by hummingbird

A researcher is trying to construct a molecular-based phylogeny of the entire an

Started by hummingbird

Soon after the coelom begins to form, a researcher injects a dye into the coelom

Started by hummingbird

Both animals and fungi are heterotrophic. What distinguishes animal heterotrophy

Started by hummingbird

The larvae of some insects are merely small versions of the adult, whereas the l

Started by hummingbird