Deck 25: Evolution of Development

Question 1

The development of eyes has been intensively studied.Eyes of vertebrates and insects are

A)analogous (homoplastic), not homologous, yet the same Pax6 gene initiates development.
B)homologous, not analogous (homoplastic), yet the same Pax6 gene initiates development.
C)analogous (homoplastic), not homologous, and development is initiated by two different genes, Pax6 and Pax7.
D)homologous, not analogous (homoplastic), and development is initiated by two different genes, Pax6 and Pax7.

Answer 1

A

Question 2

The evolution of development of snout-length in cichlid fish is best explained by

A)a single gene mutation.
B)the modification of an existing gene for a new function.
C)homoplastic convergence.
D)gene duplication and divergence.

Answer 2

A

Question 3

A plant with its floral structures arranged around a central axis has _________________ flowers.

Answer 3

radial

Question 4

Experimental mutations in the timing of Hox gene expression cause lab mice to develop deformed limbs.This is an example of

A)evolution of a new gene to code for the new morphology.
B)homeosis.
C)heterochrony.
D)a change in spatial pattern of gene expression.

Question 5

Most mutations that affect developmental regulatory genes are ________________.

Question 6

Eyes in different animal groups arose independently many times,

A)and the genes triggering lens formation in these different groups are homologous.
B)and the genes triggering lens formation in these different groups are homoplastic (analogous).
C)and the genes triggering lens formation in these different groups are examples of divergent evolution.
D)and the genes for eye color are multivariate.

Question 7

Indirect development in sea urchins involves the presence of a _________________ stage.

Question 8

An alteration in the timing of a developmental event caused by a genetic mutation is called ________________.

Question 9

A gene that triggers lens formation in the eyes of both vertebrates and insects is the _________________ gene.

Question 10

A major biological paradox is that genes are generally highly conserved and yet

A)there is very little difference among life forms existing today.
B)there is so much diversity among life forms existing today.
C)there are a huge number of ancestral genomes no matter how far back we look.
D)there are essentially identical development patterns in all species.

Question 11

Eyes in mammals and _____________ are examples of convergent evolution.

A)eyespots in butterflies
B)compound eyes in fruit flies
C)eyes in great apes
D)eyes in fish

Question 12

Another name for analogous structures is _________________ structures.

Question 13

The gene Brachyury promotes development of the notochord and the vertebrae in vertebrate animals.Among the rodents, most species have a long tail, but capybaras have a very short tail.What is the most likely difference you might expect to see for the Brachyury gene in capybaras compared to long-tailed rodents?

A)A smaller range of gene expression
B)Deletion of the gene
C)Higher levels of expression
D)An expanded range of gene expression

Question 14

The transformation of one body part into another caused by genetic mutation is called ________________.

Question 15

Experiments with ribbon worms and planaria have shown that

A)it is easy to hybridize the two species in nature.
B)Pax6-related genes are not always required for eye regeneration.
C)the DNA of each is sufficiently similar that they can be hybridized in a lab setting.
D)their eyes are examples of convergent evolution.

Question 16

A protein that binds DNA at a specific promoter or enhancer region in order to regulate RNA production is called a _________________ factor.

Question 17

The Pax6 gene, responsible for initiating lens formation in mice, can be inserted into fruit flies and

A)causes cancer of the brain as it tries to initiate a mammalian eye.
B)forms a partial eye since it is somewhat similar to the Pax7 gene of fruit flies.
C)will have no effect, indicating the extreme differences in lens formation.
D)can be expressed to initiate formation of an eye on the fruit fly's leg.

Question 18

One of the reasons why the model systems of yeast, Arabidopsis, nematode worms, fruit flies, and mice are so often used to study functional analysis of genes is because

A)they all have only a few chromosomes.
B)they are easy to cross with each other and observe polyploidy effects.
C)they have short life cycles.
D)they are easy to observe in the wild.

Question 19

Genes with similar sequences in two different species, such as humans and mice

A)produce essentially identical products that have essentially identical functions.
B)may produce products that have slightly to dramatically different functions.
C)almost always have completely different functions in the two species.
D)there is no way of predicting whether the gene will function the same way or differently.

Question 20

The evolution of initiation of limb development in tetrapods is best explained by

A)a new gene mutation.
B)the modification of an existing gene for a new function.
C)homoplastic convergence.
D)gene duplication and divergence.

Question 21

A mutation in the transcription factor protein shown, protein T, disrupts the function of its DNA-binding motif.The most likely result of this mutation would be that

A)protein T can no longer directly interact with DNA, but it can still regulate gene expression through a second transcription factor.
B)protein T can no longer interact with other transcription factor proteins, but it can still regulate gene expression by directly binding to DNA.
C)protein T can no longer regulate gene expression.
D)protein T can still regulate gene expression by interacting directly with DNA regulatory regions.

Question 22

The evolution of insect wing patterns is best explained by

A)a new gene mutation.
B)the modification of an existing gene for a new function.
C)homoplastic convergence.
D)gene duplication and divergence.

Question 23

AGAMOUS is a gene that has been implicated in the regulation of stamen formation in Arabidopsis flowers.If this is true, a mutant with a functional AP3 gene but a nonfunctional AGAMOUS gene would

A)produce petals but not stamens.
B)produce stamens but not petals.
C)produce petals and stamens.
D)not produce stamens or petals.

Question 24

The evolution of petals through the AP3 gene is best explained by

A)a new gene mutation.
B)the modification of an existing gene for a new function.
C)homoplastic convergence.
D)gene duplication and divergence.

Question 25

(Note the phylogeny is drawn with diagonal branches rather than the rectangular branches seen in the text.) If the stop codon in the Brassica plant CAL gene appeared in the cauliflower lineage after broccoli and cauliflower had diverged from each other, it would be expected that

A)both broccoli and cauliflower flowers would be arrested as buds.
B)both broccoli and cauliflower would develop flowers normally.
C)broccoli would develop flowers normally, and cauliflower flowers would be arrested as buds.
D)cauliflower would develop flowers normally, and broccoli flowers would be arrested as buds.

Question 26

Salamanders normally go through a juvenile stage in which they have external gills.Most salamanders lose these gills when they develop into adults, but axolotl salamanders retain gills into adulthood by suppressing metamorphosis.This is an example of

A)gene duplication.
B)co-opting a gene for a new function.
C)homeosis.
D)heterochrony.

Question 27

The evolution of flower symmetry is best explained by

A)a new gene mutation.
B)the modification of an existing gene for a new function.
C)homoplastic convergence.
D)gene duplication and divergence.

Question 28

Which animal is likely to have the lowest expression level of a Pax6-like gene?

A)A surface-dwelling population of Astyanax mexicanus fish
B)A cave-dwelling population of Astyanax mexicanus fish
C)A fruit fly, Drosophila melanogaster
D)A ribbonworm (Lineus sanguineus) developing normally