Question 1

Which of the following is true about temperature determination of sex in some reptiles?

Accepted Answer

Temperature determination of sex in some reptiles is due to modifications of concentrations and actions of sex steroids, specifically the conversion of testosterone into estradiol. This process is influenced by the temperature of the egg during development and can result in male or female offspring. There is evidence that this has evolved in response to effects on reproductive success, as it allows for adaptations to changing environmental conditions and seasonal reproduction.

Question 2

Which of the following statements about Hox genes is false?

Accepted Answer

Hox genes are conserved in both mice and flies, with similar arrangements of gene clusters; they are part of the genetic toolkit; and they are expressed in similar patterns during embryonic development. However, because of their important functional roles in development, they evolve very slowly and are highly conserved across species, rather than evolving rapidly. Therefore, statement D is false.

Question 3

Which of the following statements about the gene eyeless is true?

Accepted Answer

A) Eyeless encodes a transcription factor that is involved in eye development in Drosophila.
B) Eyeless is indeed found in Drosophila.
C) Pax6 is the equivalent gene in mammals, including mice.

Question 4

A mutation that affects the length of wing in a fly, but has little or no effect elsewhere in the body, would be explained by the phenomenon of

Accepted Answer

Modularity refers to the concept that different parts of an organism can develop independently, allowing for changes in one part (like wing length) without affecting other parts of the body.

Question 5

Which of the following examples of evolutionary change do not involve Hox genes?

Accepted Answer

Loss of webbing in the feet of chickens does not involve Hox genes.

Question 6

In studies of gene expression, which of the following would be the least likely observation?

Accepted Answer

Radically different developmental processes leading to new structures like wings are less likely compared to variations in gene expression or timing affecting size or shape.

Question 7

Parallel phenotypic evolution is likely to occur because

Accepted Answer

The answer of Parallel phenotypic evolution is likely to occur...

Question 8

Organisms often respond to environmental signals that accurately predict future conditions by

Accepted Answer

By altering their development to adapt to the predicted future environment, organisms increase their chances of survival and reproduction. This can include physiological and behavioral changes, as well as changes in morphology and life history traits.

Question 9

If you know that a Hox gene, AbdB, is expressed in the most posterior part of the abdomen in a Drosophila embryo, which of the following conclusions about a homologous gene in humans would most likely be correct?

Accepted Answer

The expression of abdB in the most posterior part of the abdomen in a Drosophila embryo suggests that it plays a role in specifying posterior identity. If a homologous gene exists in humans, it would likely also play a role in specifying posterior identity. Therefore, it is most likely that the homologous gene to abdB exists and is expressed near the tail of the human embryo.

Question 10

Which of the following conclusions emerged from the studies performed by Walter Gehring and his colleagues on Drosophila eyes?

Accepted Answer

Walter Gehring and his colleagues showed that the Pax6 gene of mice and the eyeless gene of flies have similar DNA sequences, and that the Pax6 gene can substitute for the eyeless gene in the process of eye development in flies. Therefore, both options a and b are correct. However, the studies did not suggest that fly eyes look like mammalian eyes, so option c is not correct.

Question 11

Flies have _______ eyes, while mammals have _______ eyes.

Accepted Answer

Flies have compound eyes, which consist of many individual visual units, while mammals have camera-like eyes, which have a single lens that focuses light onto the retina at the back of the eye.

Question 12

Which of the following is not a general principle of evo-devo?

Accepted Answer

The answer of Which of the following is not a...

Question 13

Ducks have webbed feet and chickens do not because

Accepted Answer

The answer of Ducks have webbed feet and chickens do...

Question 14

Modularity is important for development because it

Accepted Answer

Modularity allows changes in developmental genes to affect one part of the body without affecting others. This is important for the evolution of new structures and functions, as well as for the ability of organisms to tolerate genetic variation without disrupting overall development.

Question 15

The developmental control pathway that results in polarity and pattern formation in the head-abdomen axis in Drosophila

Accepted Answer

The developmental control pathway that results in polarity and pattern formation in the head-abdomen axis in Drosophila has a similar gene sequence and chromosome order in the mouse. This suggests that this pathway arose early in evolution and has been conserved in many different animal species.

Question 16

The Pax6 gene in mammals and the eyeless gene in flies are both _______ genes.

Accepted Answer

The Pax6 gene in mammals and the eyeless gene in flies are homologous genes, meaning they have a similar sequence and function due to a common ancestor.

Question 17

The process whereby changes in the timing of developmental events can change the form of an organism is called

Accepted Answer

Heterochrony refers to changes in the relative timing of developmental events, which can produce changes in the form or morphology of an organism. This can include acceleration or retardation of development, as well as changes in the sequence of events. Developmental plasticity, adaptation, modularity, and mutation are related concepts, but they do not specifically refer to changes in developmental timing.

Question 18

Which of the following is not true of genetic switches?

Accepted Answer

It is not true that a single switch controls each gene. In fact, multiple switches may control one gene, and one switch may also control multiple genes.

Question 19

Which of the following techniques or tools was instrumental in the studies performed by Gehring and his colleagues demonstrating that eyeless is a transcription factor involved in eye development?

Accepted Answer

The use of recombinant DNA constructs allowed the researchers to manipulate the expression of the eyeless gene, which provided evidence for its role in eye development. This technique was critical in establishing eyeless as a transcription factor that activates downstream genes involved in eye formation. The other techniques listed were not specifically mentioned in the studies by Gehring and colleagues.

Question 20

Which of the following is not one of the principles of evolutionary developmental biology (evo-devo)?

Accepted Answer

The principle that the evolution of development is not responsive to the environment is not one of the principles of evo-devo. In fact, environmental factors play a key role in shaping developmental processes and can lead to adaptations in response to changes in the environment. The other principles listed, such as the role of molecular mechanisms and gene expression changes in evolution, are all key tenets of evo-devo.

Quiz 20: Development and Evolutionary Change