Week 6- Quizzes, Animations, Clicker Questions Flashcards Preview

LS 7B- Genetics, Evolution, & Ecology > Week 6- Quizzes, Animations, Clicker Questions > Flashcards

Flashcards in Week 6- Quizzes, Animations, Clicker Questions Deck (28)
Loading flashcards...
1

A node on the phylogenetic tree indicates:

A., a branch point in evolution.

B., a common ancestor.

C., a branch point and common ancestor.

C., a branch point and common ancestor.

Why:

2

A taxon that includes a single common ancestor and all its descendants is a _____ group.

paraphyletic

polyphyletic

monophyletic

monophyletic

Why:

3

Of the following taxonomic categories, which is the MOST inclusive?

species

family

genus

order

class

Class

Why:

4

The nodes on a phylogenetic tree represent:

homologies.

common ancestors.

present-day groups.

sister groups.

descendant lineages.

common ancestors.


Why:

5

Which of the following statements is TRUE regarding a phylogenetic tree?

Given the sheer number of prokaryotic and eukaryotic species on Earth, it is impossible to create a phylogenetic tree encompassing all of these organisms.

Phylogenetic trees could be considered physical representations of hypotheses that seek to establish the evolutionary relationships between different organisms.

Within a phylogenetic tree, the order of groups located at the tree tips, not the nodes within a tree, determines sister group relationships.

Phylogenetic trees are constructed based solely on the morphological characteristics of species; sequence similarities among different organisms are only evaluated by taxonomists.

Phylogenetic trees only depict the evolutionary relationships between different classes; relationships among different species within the same genus are not illustrated in such trees.

Phylogenetic trees could be considered physical representations of hypotheses that seek to establish the evolutionary relationships between different organisms.


Why:

6

Seals and penguins both have streamlined body forms that allow them to move through water efficiently. This similarity in body shape is MOST likely the result of:

homology.

cladistics

shared ancestry.

convergent evolution.

phylogeny

convergent evolution.


Why:

7

Why might a phylogeny based only on molecular data show a different pattern of relationships than a phylogeny of the same taxa that is based only on morphological traits? (Select all that apply.)

Morphological analyses always provide more data because each morphological trait is the result of the expression of many genes.

Some highly conserved genetic sequences can result in unrelated species appearing closely related in a molecular phylogeny, and not reflect the same pattern as the morphologic phylogeny.

Gene sequences always provide more data than morphological traits.

The molecular data may be based on the analysis of introns, which aren't expressed and don't contribute to the evolutionary history of a group of taxa.

Gene sequence changes may not result in morphological changes

Some highly conserved genetic sequences can result in unrelated species appearing closely related in a molecular phylogeny, and not reflect the same pattern as the morphologic phylogeny.

Gene sequence changes may not result in morphological changes

Why:

8

Traits that are similar in two species as a result of common ancestry are referred to as:

homologous.

ancestral.

convergent.

analogous.

derived.

homologous

Why:

9

Imagine that a scientist discovers a new, flying species of mammal that resembles a winged rabbit. What can the scientist say about this organism?

If molecular sequence data show that bats and this new species do not share a common ancestor not shared by other mammals, the wings of bats and this new species would be considered homologous.

No data could support or disprove the hypothesis that the wings of bats and the new species are homologous.

If molecular sequence data show that bats and this new species share a common ancestor not shared by other mammals, the wings of these two species would be considered homologous.

If molecular sequence data show that bats and this new species share a common ancestor not shared by other mammals, the wings of these two species would be considered analogous.

Without any further information, the scientist can say that bat wings and the wings of this new species are homologous.

If molecular sequence data show that bats and this new species share a common ancestor not shared by other mammals, the wings of these two species would be considered homologous.


Why:

10

Which of the following is MOST likely to fossilize?

a leaf that fell from a tree and landed on the forest floor

a jellyfish that died and sunk to the bottom of the ocean

a crayfish that died in its muddy burrow by a creek

a lizard that died on a mountainside

a snail that died on a rock

a crayfish that died in its muddy burrow by a creek

Why:

11

Fossils' contributions to phylogenetic trees include:

All of these choices are correct.

correlation between evolution and Earth's environmental history.

time calibration.

records of extinct species.

All of these choices are correct.


Why:

12

Why is the fossil record of marine life more complete than that of organisms living in terrestrial ecosystems?

Marine habitats are places where sedimentation is more likely than erosion.

Organisms that live in terrestrial habitats are evolutionarily too old to fossilize.

Fossilization cannot occur without water acting to preserve body parts from decomposition.

Organisms that live in marine environments don't have bones or other hard body parts.

Marine habitats are places where sedimentation is more likely than erosion.


Why:

13

Mass extinctions:

allow surviving species to proliferate.

represent loss of many species in a short time.

can be reconstructed from fossil records.

All of these choices are correct.

All of these choices are correct.

Why:

14

The LARGEST mass extinction occurred at the end of which period?

Devonian

Permian

Ordovician

Triassic

Cretaceous

Permian

Why:

15

The discovery of Tiktaalik roseae was significant for which of the following reasons?

It provided evidence that birds and dinosaurs are closely related.

It provided evidence that the continents were once linked together.

It was the first fossil to be found with soft parts preserved.

It was the first fossil from which DNA and other macromolecules were successfully extracted.

It provided evidence that terrestrial vertebrates are descended from fish.

It provided evidence that terrestrial vertebrates are descended from fish.

Why:

16

What is the FIRST event in the fossilization process?

conversion of organic tissue to minerals (rock)

burial of the organism by sediments

hardening of sediments into rock.

erosion of soils around the organism

burial of the organism by sediments

Why:

17

We expect the fossil record to be incomplete for all of the following reasons EXCEPT:

Sediments accumulate irregularly.

Under normal conditions, organisms are broken down by biological and physical processes.

Organisms with hard parts tend to fossilize more readily than soft-bodied organisms.

All biomolecules, including lipids and pigment molecules, decay immediately after death.

Fossilization requires burial in sediment.

All biomolecules, including lipids and pigment molecules, decay immediately after death.


Why:

18

The Earth’s atmosphere contains about 0.04% (or 400 parts per million) carbon dioxide. Although most of the carbon dioxide is in the form 12CO2, which is not radioactive, a specific fraction of the total is made up of radioactive 14CO2.

A., true

B., false

A., true


Why:

19

During photosynthesis, plants incorporate carbon dioxide into sugars and other organic compounds. The ratio of 12CO2 to 14CO2 incorporated into the sugars and other organic compounds should be equivalent to the ratio present in the atmosphere.

A., true

B., false

A., true


Why:

20

Because the animal food chain ultimately relies on the sugars and organic compounds produced by plants, the ratio of 12CO2 to 14CO2 incorporated into animal tissues (e.g., bone) and organs should also be the same as that present in the atmosphere.

A., true

B., false

A., true


Why:

21

The half-life of 14C is 5730 years. Scientists measure the ratio of 12C to 14C in a tree today and in wood taken from an archaeological site. They find the amount of 14C in the wood from the archaeological site is ¼ that found in the tree today. Given this, about how old is the archaeological wood sample?

A., 1432 years

B., 2850 years

C., 5730 years

D., 11,460 years

E., 17,190 years

D., 11,460 years

Why:

22

Why is it not possible to carbon date fossils older than 60,000 years before present?

A., The radioactive decay half-life for 14C has been exceeded.

B., 14C has decayed to such low levels that measurement becomes inaccurate.

C., In most fossils older than that, the C has all been converted to N.

D., There was too little C in the atmosphere to be detectable in the fossils.

B., 14C has decayed to such low levels that measurement becomes inaccurate.

Why:

23

Why is the raw measurement of 14C inaccurate for predicting the age of a fossil?

A., Radioactive decay rates are not constant, but rather change with the environment.

B., Rates of CO2 uptake by plants varies over time.

C., The amount of CO2 in the atmosphere has varied widely over geologic time spans.

D., The abundance of 14C in the atmosphere has varied over time.

D., The abundance of 14C in the atmosphere has varied over time.

Why:

24

The burning of fossil fuels for energy in the modern era of life on Earth is resulting in a significant increase in total CO2 concentration in Earth’s atmosphere. However, the ratio of 14C to 12C is decreasing. Why is this?

A., The 14C in fossil fuels is not effectively converted to 14CO2 in combustion.

B., Fossil fuels are so old that any 14C in the starting organic matter has decayed. ,

C., It is difficult to detect the 14C when total CO2 levels are so high.

D., All 14C in the fossil fuels is removed during the industrial refining processes.

B., Fossil fuels are so old that any 14C in the starting organic matter has decayed.


Why:

25

Data from phylogenies based on living organisms and data from the fossil record are in agreement when the tree of life is examined as a whole, but are often contradictory when individual branches are examined.

False

True

False

Why:

26

Evolution's patterns manifest as nested similarities on a phylogenetic tree. Nesting occurs between molecular sequences of evolutionarily related organisms, and between the different taxa arranged in a phylogenetic tree.

True

False

True

Why:

27

Why is agreement between the fossil record and phylogenies constructed from living organisms considered to be strong evidence of evolution?

All living organisms will eventually become fossils; therefore, evidence of their evolution will be recorded in the fossil record.

Phylogenetic methods based on DNA sequences can suggest that two species are closely related, but only fossils can show direct evidence of an evolutionary relationship between species.

It is unlikely that two independent methods of investigation would result in the same pattern by chance alone.

Evolutionary processes cannot be studied directly in the laboratory alone, so it is necessary to compare living and extinct species to see evidence of evolutionary change.

All of these choices are correct.

It is unlikely that two independent methods of investigation would result in the same pattern by chance alone.


Why:

28

According to the fossil record, when did the earliest animals appear on Earth?

3500 million years ago

580 million years ago

3 billion years ago

55 million years ago

520 million years ago

580 million years ago


Why: