Question 1

Hunchback protein occurs along a gradient, where the anterior embryo has high protein levels and the posterior has low levels, yet the hunchback mRNA is found at the same concentration throughout the embryo. These observations suggest that hunchback must be regulated post-________

Accepted Answer

The answer of Hunchback protein occurs along a gradient, where...

Question 2

During the evolution of development in animals, it is found that many regulatory genes have been co- opted for the development of different structures, such as limbs or digits. This is an example of what current area of research?

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The answer of During the evolution of development in animals,...

Question 3

In the development of C. elegans, an embryo of 1090 cells then loses 131 cells due to what process?

Accepted Answer

The answer of In the development of C. elegans, an...

Question 4

Cells called _________influence development by controlling other cells in their local environment?

Accepted Answer

The answer of Cells called _________influence development by controlling other...

Question 5

You are interested in the homeobox genes that may regulate the development of the common clover plant Trifolium subterraneum. To identify clones of the T. subterraneum genome that contain these homeotic genes, you would probe with a rice gene that contains what domain?

Accepted Answer

The answer of You are interested in the homeobox genes...

Question 6

Certain mutations in non- Hox genes actually produce homeotic mutants due to a failure to modulate chromatin acetylation appropriately. This influence on cellular "memory" is called what?

Accepted Answer

The answer of Certain mutations in non- Hox genes actually...

Question 7

Null mutations in __________ genes would be expected to result in the failure to establish the anterior- posterior poles of an embryo

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The answer of Null mutations in __________ genes would be...

Question 8

What term describes the process by which a cell acquires a certain fate from its neighboring cell?

Accepted Answer

The answer of What term describes the process by which...

Question 9

Cell signaling during much of C. elegans development occurs along concentration gradients. What kind of signaling does this represent?

Accepted Answer

The answer of Cell signaling during much of C. elegans...

Question 10

Flower homoeotic genes encode:_____________ .

Accepted Answer

Flower homoeotic genes encode MADS box genes, which are a type of transcription factor involved in the regulation of flower development.

Question 11

A homeotic mutant flower has an arrangement (from outside in) of carpels, stamens, stamens, carpels instead of the usual sepal, petals, stamens, carpels. In general, Class A genes specify sepals, Class A and B genes specify petals, Class B and C genes specify stamens, and Class C specifies carpels. This mutant must therefore have a mutation in_________ .

Accepted Answer

The mutant flower has carpels where there should be sepals and petals, indicating a loss of Class A gene function, which is responsible for specifying sepals and, together with Class B, for specifying petals.

Question 12

Which group of genes in Drosophila embryos must be mutated if the result is elimination of a significantly sized, contiguous region of segmentation?

Accepted Answer

The answer of Which group of genes in Drosophila embryos...

Question 13

What substance, in different concentrations, directs developmental fates?

Accepted Answer

The answer of What substance, in different concentrations, directs developmental...

Question 14

The Antennapedia complex and the bithorax complex of genes all encode transcription factors that have a 180- bp DNA- binding domain. What is this domain called?

Accepted Answer

The answer of The Antennapedia complex and the bithorax complex...

Question 15

If a cell from the blastoderm of the Drosophila embryo is committed to form the sixth abdominal segment of the adult and this cell is transplanted into the thorax- committed region of another embryo, will it develop properties of a thoracic or an abdominal segment?

Accepted Answer

The answer of If a cell from the blastoderm of...

Question 16

Holoprosencephaly is a highly variable condition in mammals, including humans. Its effects range from an absence of brain areas, mid- face disorders, and cyclopia to slight dental abnormalities. One form, HPE3, is caused by null mutations in Shh. Familial cases are inherited as a dominant trait. Which of the following do you expect?

Accepted Answer

HPE3 expression can be influenced by the genetic background of the individual, which can modify the severity and type of symptoms experienced. This accounts for the variability in the condition's presentation among different individuals.

Question 17

Homeotic genes in virtually all animals are said to show colinearity between the spatial arrangement of the tissues they act on as well as what other feature?

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The answer of Homeotic genes in virtually all animals are...

Question 18

An embryonic stem cell has the potential to differentiate into any cell or tissue type. Is it differentiated, pluripotent, or totipotent?

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The answer of An embryonic stem cell has the potential...

Question 19

Cell autonomous genes affect only those cells in which they are expressed. Which group of early developmental genes are not cell autonomous?

Accepted Answer

The answer of Cell autonomous genes affect only those cells...

Question 20

A highly conserved protein domain of 60 amino acids, the homeodomain, is found in a large number of animals. This domain the proteins that have them to bind to what?

Accepted Answer

The answer of A highly conserved protein domain of 60...

Quiz 18: Organelle Inheritance and the Evolution of Organelle Genomes