An obsolete taxon, the ʺRadiata,ʺ included all phyla whose adults had true radial symmetry. Today, the ʺRadiataʺ is more correctly considered to be

1. a clade.

2. a grade.

3. monophyletic.

4. paraphyletic.

5. polyphyletic.

TLS Online TPP Program

#Question id: 4957

#XL - T Zoology

How many half-lives should have elapsed if 6.25% of the parent isotope remains in a fossil at the time of analysis?

TLS Online TPP Program

#Question id: 4958

#XL - S Microbiology

What is true of the fossil record of mammalian origins?

TLS Online TPP Program

#Question id: 4958

#XL - T Zoology

What is true of the fossil record of mammalian origins?

TLS Online TPP Program

#Question id: 4959

#XL - S Microbiology

If a fossil is encased in a stratum of sedimentary rock without any strata of igneous rock (e.g., lava, volcanic ash) nearby, then it should be

TLS Online TPP Program

#Question id: 4961

#XL - S Microbiology

An early consequence of the release of oxygen gas by plant and bacterial photosynthesis was to

TLS Online TPP Program

#Question id: 4963

#XL - S Microbiology

Which free-living cells were the earliest contributors to the formation of Earthʹs oxidizing atmosphere?