Deck 13: Evolution and Development

Question 1

What is a paralog?

A) a homeobox gene
B) an enhancer gene
C) a homologous gene
D) a duplicate of an existing gene

Answer 1

D

Question 2

Parallelism in development

A) was advocated by von Baer.
B) was the idea that developmental stages progress from the simple to the complex, reflecting the scala naturae.
C) refers to the colinearity of Hox genes.
D) is a method of gene duplication.

Answer 2

B

Question 3

The scala naturae is the

A) view that all of life can be arranged on a single scale from simple to complex.
B) ontogeny of an individual.
C) number of traits shared among species.
D) effect of an organism's environment on its development.

Answer 3

A

Question 4

With whom did the idea that life evolves from simple to complex begin?

A) Charles Darwin
B) William Bateson
C) the ancient Greeks
D) Karl Ernst von Baer

Question 5

Hox genes encode

A) proteins involved in RNA translocation.
B) ribosomal RNA.
C) Drosophila reproductive genes.
D) transcription factors.

Question 6

Which of the following statements about paralogs is FALSE?

A) They may have additive effects, increasing the amount of gene expression.
B) They may have new effects different from the parental gene.
C) They may divide the work originally undertaken by the parental gene.
D) They may destroy the parental gene.

Question 7

Process "C" shown in the figure is an example of which of the following?

A) recapitulation via hypermorphosis
B) recapitulation via acceleration
C) paedomorphosis via progenesis
D) paedomorphosis via neoteny

Question 8

The process shown in "D" in the figure is an example of which of the following?

A) recapitulation via hypermorphosis
B) recapitulation via acceleration
C) paedomorphosis via progenesis
D) paedomorphosis via neoteny

Question 9

MADS-box genes affect

A) fruit fly development.
B) segmentation in animals.
C) plant leaves, roots, and flowers.
D) lateral lines in fish.

Question 10

Paedomorphosis may involve which of the following?

A) acceleration or hypermorphosis
B) progenesis or neoteny
C) acceleration or neoteny
D) progenesis or hypermorphosis

Question 11

Process "B" shown in the figure is an example of which of the following?

A) recapitulation via hypermorphosis
B) recapitulation via acceleration
C) paedomorphosis via progenesis
D) paedomorphosis via neoteny

Question 12

Karl Ernst von Baer proposed that diagnostic traits for distinguishing species among vertebrates appear at the ________ stages of development.

A) earliest
B) latest
C) beginning and end
D) middle

Question 13

With recapitulation, a somatic trait can appear ________ in development or a reproductive trait ________ in development.

A) earlier; later
B) earlier; earlier
C) later; later
D) later; earlier

Question 14

Which of the following embryonic developmental stages is most similar across all three groups?

A) Stage 1
B) Stage 2
C) Stage 3
D) Stage 4

Question 15

A pseudogene is a

A) nonfunctional version of a gene.
B) homeobox gene.
C) MADS-box gene.
D) subfunctional paralog.

Question 16

Which of the following statements regarding regulatory enhancers is FALSE?

A) They can be added through evolution.
B) They can be lost through evolution.
C) They can be associated with specific body parts.
D) They can be made of RNA.

Question 17

The figure shows the number of Hox gene clusters in different groups of animals. Which of the following is a true statement regarding the number of clusters in each group?

A) Land vertebrates > All fish > Tunicates
B) All fish > Lancelets > Tunicates
C) Ray finned fishes > Lancelets > Land vertebrates
D) All fish > Lancelets > Land vertebrates

Question 18

Karl Ernst von Baer proposed that the most conserved stages of development among vertebrates are the ________ stages.

A) earliest
B) latest
C) beginning and end
D) middle

Question 19

A totipotent cell

A) is fixed into a single developmental pathway.
B) arises through homeotic transformation.
C) can differentiate into any adult cell.
D) will become a stem cell.

Question 20

Which of the following is UNLIKELY to occur when a gene is duplicated?

A) The duplicate may be lost by the process of natural selection.
B) The duplicate may become nonfunctional through mutation.
C) The duplicate may gain a new activity.
D) The duplicate may impede gene function.

Question 21

Which of the following scientists developed the biogenetic law, which proposes that "ontogeny is a precise and compressed recapitulation of phylogeny"?

A) Karl Ernst von Baer
B) William Bateson
C) Gavin de Beer
D) Ernst Haeckel

Question 22

How does facultative neoteny in other species support the paedomorph advantage hypothesis for axolotls?

Question 23

Although many human characteristics are neotenous compared to a chimpanzee, head growth is not. In the fetus of both species, brain and head growth start at approximately the same developmental stage and progress at the same rate. Soon after birth, chimpanzee brain and head growth stops. Human brain and head growth continues for several years after birth. Thus, relative to head growth, reproduction is occurring at a later stage. Assuming that chimpanzees represent the ancestral condition, explain what type of heterochrony humans have in brain development.

Question 24

By transferring neural crest cells from a duck to a quail and vice versa, Richard Schneider and Jill Helms (2003) demonstrated that

A) neural crest cells influence the development of beaks.
B) beaks influence fitness traits.
C) homeobox genes are conserved across species.
D) gene duplication causes a difference in beak shape.

Question 25

________ occurs when paralogs diverge and they divide the work initially undertaken by the parental gene before duplication.

A) Neofunctionalization
B) Homeotic transformation
C) Colinearity
D) Subfunctionalization

Question 26

Based on the figure, how are transcription factors like a switch?

Question 27

What evidence suggests that MADS-box genes are older than flowers?

Question 28

What is meant by the colinearity of Hox genes?

Question 29

Does all life evolve from simple to complex? Explain.

Question 30

According to the phylogeny in the figure, which of the following statements is true?

A) All chordates have a neural tube.
B) Cephalochordates have a neural crest.
C) Echinoderms have a neural tube.
D) All chordates have a neural crest.

Question 31

What is a regulatory enhancer of a gene?

A) the chromatin in areas surrounding the gene
B) a section of DNA that targets proteins for degradation and thus stops the expression of the unwanted genes
C) a section of DNA that lies outside of that gene but is involved in regulating the timing and level of that gene's expression
D) a functionless gene copy that is the result of gene duplication

Question 32

Which of the following gene transplant scenarios, discussed in the textbook, would provide valuable information about the action of homeotic genes?

A) transplanting MADS-box genes into fruit flies
B) transplanting neural crest cells from mice into ducks
C) transplanting Hox genes from mice into fruit flies
D) transplanting Antp genes from fruit flies into chickens

Question 33

Regulatory ________ are DNA sequences that turn off the expression of particular genes.

A) enhancers
B) silencers
C) transcription factors
D) homeotic genes

Question 34

Which of the following cell types would you expect to be totipotent?

A) embryonic cells early in development
B) brain cells
C) blood stem cells that can become various types of blood cells
D) germ line cells

Question 35

Which of the following scientists hypothesized that the developmental stages of an individual paralleled the evolutionary history of the species to which it belonged?

A) William Bateson
B) Ernst Haeckel
C) J. F. Meckel
D) Karl Ernst von Baer

Question 36

If paedomorphosis via neoteny involves the retention of juvenile traits in adults, what is responsible for paedomorphosis via progenesis?

Question 37

What is a noncoding stretch of DNA that controls the spatial and temporal expression of nearby genes on the same strand?

A) a cis regulatory element
B) a trans regulatory element
C) a transcription factor
D) a homeobox

Question 38

Which of the Hox genes in fruit flies are responsible for the development of mouth parts?

A) lab
B) Abd-B
C) MADS-box
D) Antp

Question 39

Explain how gains and losses of binding sites change morphology in the system illustrated in the figure. In the case of gains, assume that the transcription factors associated with the binding site are expressed in the appropriate tissue.

Question 40

How can changes in genetic enhancers affect morphology?

Question 41

Gene duplication can occur for both protein-coding and regulatory regions of genes. In the figure below, imagine that the yellow gene and both enhancer regions in B are duplicated. Propose a mechanism for how subfunctionalization might occur.

Question 42

Crabs have claws on their front legs and many sets of walking legs (which lack claws) on segments posterior to the claws. Crabs can regenerate legs if they are lost. A walking leg was removed and tissue from the claw was transplanted onto the stump. If homeobox genes are responsible for the differentiation of leg types, what would you predict would happen to the stump? Describe analogous experiments that have been performed in other species.

Question 43

Hagfish, lampreys, gnathostomes, mammals, birds, fish, reptiles, and amphibians are all vertebrates and are sometimes referred to as the subphylum Craniata: animals with a cranium. Amphioxus and ascidians are not in Craniata. How does mapping characters associated with the neural crest assist us in understanding the evolution of complex traits such as the cranium?

Question 44

How can natural selection lead to the loss of a gene following duplication?

Question 45

Describe the role that neural crest cells play in marsupial development.