10: Life on Earth Questions and Correct
Answers 2026-2027 Updated.
Vertebrates - Answer animals with backbones
What was life like 400 million years ago? - Answer Life was mostly aquatic
Tiktaalik roseae - Answer -Discovered 2006
- Fish and tetrapod characteristics
-True tetrapod forelimb with 5 digits wand wrist bone
-Modified ear region
Descent with modification - Answer Darwins term for evolution, combining the ideas that all
living things are related and have changed overtime.
One of the most compelling lines of evidence for evolution - Answer fossils
Fossils - Answer The preserved remains or impressions of once-living organisms
Not all organisms are equally likely to form fossils... explain - Answer Animals with bones or
shells are more likely preserved than animals without such hard parts (like jellyfish) that decay
quickly
In addition, the organisms must be preserved quickly and kept undisturbed while mineralization
or mud hardening occurs
The fossil record is therefore, NOT a complete record of past life
Two of the ways that a dead organism is preserved quickly for fossilization - Answer 1.
Organism is preserved by rapid freezing, desiccation, or burial in amber
2. organism is preserved by rapid burial in sediment layers
, Two ways in which the conditions for fossilization are right for this buried organism (for the
preservation of an organism that underwent rapid burial)... - Answer 1. organism is fossilized
by mineralization
2. organism is fossilized by imprint or mold
Fossil record - Answer an assemblage of fossils arranged in order of age, providing evidence of
changes in species over time
Paleontologists - Answer a scientist who studies ancient life by examining the fossil record
Fossil record gives evidence proving that... - Answer 1. Prokaryotes appear before eukaryotes
2. single-celled organisms before multicellular ones
3. water dwelling organisms before land dwelling ones
4. fish before amphibians
5. reptiles before birds
etc....
Darwin's intermediates - Answer A fossil that shows an intermediate state between an
ancestral trait and that of its later descendants is said to bear a transitional feature
radiometric dating - Answer The use of radioactive isotopes as a measure for determining the
age of a rock or fossil
relative dating - Answer Determining the age of a fossil from its position relative to layers of
rocks or fossils of known age
Devonian Period - Answer -roughly 400 to 350 million years ago
-Great transformations: jawed fishes, sharks, land plants, and insects all diversified into
numerous species
-AKA age of fishes
-some of the first invertebrates
-little plant growth in the beginning, so looked brown
-by the middle, some land plants
-later, many things changed (GREEN WORLD)
Invertebrates - Answer Animals without backbones