Week 2 Quiz

Question 1

Select examples of biomarkers in the fossil record.
* amino acids made in a lab
* carbon isotopes in plant fossils
* light
* okenane
* a DNA fragment in a mammoth’s tooth

Answer 1

• carbon isotopes in plant fossils
• okenane
• a DNA fragment in a mammoth’s tooth

Question 2

Which of the following statements are true?

• When an animal consumes a plant, it assimilates the plant’s molecules into its own body.
• The characteristic ratio of carbon-12 to carbon-13 found in fossilized organic matter is due to particular biochemical pathways in animal metabolism.
• Scientists can infer the diet of an extinct animal by analyzing the chemical signatures of fossilized bones and teeth.
• During photosynthesis, different kinds of plants collect carbon-12 and carbon-13 in different ratios.
• Before the evolution of plants, there was no photosynthesis.

Answer 2

• When an animal consumes a plant, it assimilates the plant’s molecules into its own body.
• Scientists can infer the diet of an extinct animal by analyzing the chemical signatures of fossilized bones and teeth.
• During photosynthesis, different kinds of plants collect carbon-12 and carbon-13 in different ratios.

Question 3

Referring to the graph above, which of the following statements are true?

• The slope of the isochron is used to determine the time since the rock formed
• 87Sr is a stable isotope
• In graph D, the different colored dots represent samples taken at different times.
• If all of the unstable isotopes have decayed, the isochron would be vertical
• 86Sr is a stable isotope

Answer 3

• The slope of the isochron is used to determine the time since the rock formed
• If all of the unstable isotopes have decayed, the isochron would be vertical
• 86Sr is a stable isotope

Question 4

Which of the following statements are true?

• When a population or species diverges, the newly formed species or subspecies is represented by a branch.
• A branch tip may represent the species, populations, or genes that can be observed today.
• The root represents the common ancestor of all the species included in the phylogenetic tree.
• The only way to infer a node within a phylogenetic tree is to find a fossil corresponding to that ancestor.
• A phylogenetic tree is not valid unless it has a root.
• A phylogenetic tree visually depicts the history of the evolution of species, populations, or genes.

Answer 4

• When a population or species diverges, the newly formed species or subspecies is represented by a branch.
• A branch tip may represent the species, populations, or genes that can be observed today.
• The root represents the common ancestor of all the species included in the phylogenetic tree.
• A phylogenetic tree visually depicts the history of the evolution of species, populations, or genes.

Question 5

In what ways do consensus trees help researchers explore evolutionary relationships?
* Consensus trees remove any clades with species that have shared derived characters.
* Consensus trees show unexplained relationships among species using polytomies.
* Consensus trees identify species that do not belong in the phylogenetic trees being studied.
* Consensus trees summarize the similarities among all the most parsimonious phylogenetic trees

Answer 5

• Consensus trees show unexplained relationships among species using polytomies.
• Consensus trees summarize the similarities among all the most parsimonious phylogenetic trees

Question 6

Determine whether the shared trait is a synapomorphy or a homoplasy.

Octopuses, mammals, and some jellyfish have eyes that contain a lens for focusing light. Eyes with a lens were not present in the common ancestor of these animals. Is an eye with a lens a synapomorphy or a homoplasy?

Answer 6

Homoplasy

Question 7

Determine whether the shared trait is a synapomorphy or a homoplasy.

Most land plants contain the light‐capturing pigment chlorophyll a. Chlorophyll a is thought to have evolved a single time in the green algae that ultimately gave rise to all land plants. Is chlorophyll a in land plants a synapomorphy or a homoplasy?

Answer 7

Synapomorphy

Question 8

Determine whether the shared trait is a synapomorphy or a homoplasy.

Sharks and fish evolved from a common ancestor. Sharks use their pectoral fins to steer as they swim, whereas mudskippers, which are a type of fish, use their pectoral fins to walk on land. Are the pectoral fins a synapomorphy or a homoplasy?

Answer 8

Synapomorphy

Question 9

Determine whether the shared trait is a synapomorphy or a homoplasy.

Species of plants from a wide variety of distantly related plant families lack chlorophyll and are unable to photosynthesize. These plants parasitize other plants to obtain carbohydrates for food. Is the lack of chlorophyll in these parasitic plants a synapomorphy or a homoplasy?

Answer 9

Homoplasy

Question 10

Classify as convergent evolution, evolutionary reversal, or a synapomorphy.
Both butterflies and bats develop wings for flight.

Answer 10

Convergent Evolution

Question 11

Classify as convergent evolution, evolutionary reversal, or a synapomorphy.
Penguins became flightless birds

Answer 11

Evolutionary Reversal

Question 12

Classify as convergent evolution, evolutionary reversal, or a synapomorphy.
Cattle-raising human populations in Europe and Africa independently produce lactase throughout adulthood.

Answer 12

Convergent Evolution

Question 13

Classify as convergent evolution, evolutionary reversal, or a synapomorphy.
Amniotes produce an egg with several protective membranes that include the amnion.

Answer 13

Synapomorphy

Question 14

Classify as convergent evolution, evolutionary reversal, or a synapomorphy.
Neither snakes nor legless lizards develop legs as embryos.

Answer 14

Evolutionary Reversal

Question 15

Classify as convergent evolution, evolutionary reversal, or a synapomorphy.
All felines have a muscular and flexible body, 30 teeth, and retractable claws.

Answer 15

Synapomorphy

Question 16

Classify as convergent evolution, evolutionary reversal, or a synapomorphy.
Tuna and dolphins have a streamlined body shape for fast movement through water.

Answer 16

Convergent Evolution