Question 1

Differentiation is the process whereby a cell's determined state is expressed.

Accepted Answer

Differentiation is indeed the process by which a cell's determined state is expressed. This means that as a cell develops, it becomes more specialized and takes on specific functions and characteristics. The expression of specific genes and proteins is what allows a cell to differentiate into a particular cell type.

Question 2

A homeobox gene is one that produces a group of repetitive base sequences such as a VNTR.

Accepted Answer

A homeobox gene is a gene that produces a specific transcription factor protein containing a homeodomain, which is a conserved DNA-binding domain. It does not produce repetitive base sequences such as a VNTR.

Question 3

Give a brief definition of a homeobox.

Accepted Answer

The answer of Give a brief definition of a homeobox....

Question 4

Molecular/structural orientations (gradients)in an egg are thought to play a significant role in development.What is the origin of such gradients? What evidence indicates that the maternal genotype is involved in providing such gradients?

Accepted Answer

The answer of Molecular/structural orientations (gradients)in an egg are thought...

Question 5

Determination is the process whereby a cell's eventual developmental fate is set.

Accepted Answer

Determination is the process of a cell committing to a specific fate, setting its developmental path.

Question 6

The bicoid gene of Drosophila generates embryos with two posterior regions.What aspect embryonic development does the bicoid gene control?

Accepted Answer

The answer of The bicoid gene of Drosophila generates embryos...

Question 7

What is the general order of genes involved in determining early Drosophila development?

Accepted Answer

The answer of What is the general order of genes...

Question 8

Mutations in the selector genes sometimes form structures in the wrong segment,transforming the antenna of a fly into a leg,for example.What are such mutations called?

Accepted Answer

The answer of Mutations in the selector genes sometimes form...

Question 9

It is presently believed that the asymmetric distribution of substances in the egg,positioned by the mother,is responsible for establishing the determined state.Which general term describes such molecular positioning?

Accepted Answer

The answer of It is presently believed that the asymmetric...

Question 10

Describe the relationship between the maternal-effect gene bicoid and the zygotic gene hunchback.

Accepted Answer

The answer of Describe the relationship between the maternal-effect gene...

Question 11

In Drosophila,maternal-effect genes are influential in determining the anterior-posterior organization of the developing embryo.

Accepted Answer

Maternal-effect genes are responsible for providing the early positional information that determines the anterior-posterior axis of the developing embryo in Drosophila.

Question 12

Do Hox gene clusters exist in humans? If so,how many are known to exist?

Accepted Answer

The answer of Do Hox gene clusters exist in humans?...

Question 13

From a human developmental standpoint,what is the significance of Hox genes?

Accepted Answer

The answer of From a human developmental standpoint,what is the...

Question 14

Segmentation genes,such as the pair-rule class,are inherited through mitochondrial DNA in Drosophila.

Accepted Answer

Segmentation genes are inherited through nuclear DNA, not mitochondrial DNA. Mitochondrial DNA is responsible for encoding mitochondrial proteins and plays a role in energy production.

Question 15

Genetic involvement in development appears to be achieved,at least in part,by variable gene activity.

Accepted Answer

Genetic involvement in development is achieved, at least in part, by variable gene activity which regulates the expression of genes in response to developmental signals and environmental cues. This allows for the development of specialized cells and tissues necessary for proper growth and function of the organism.

Question 16

A gene that specifies the fate of a particular anatomical segment in Drosophila is called a(n)________.

Accepted Answer

The answer of A gene that specifies the fate of...

Question 17

Which class of genes controls the developmental identity of segments along the anterior-posterior axis?

Accepted Answer

The answer of Which class of genes controls the developmental...

Question 18

What is the significance of the homeodomain?

Accepted Answer

The answer of What is the significance of the homeodomain?...

Question 19

Caenorhabditis elegans is extremely useful as an experimental organism because it has relatively few cells,and,for the most part,each embryonic cell's fate is developmentally fixed.

Accepted Answer

Caenorhabditis elegans is known for its fixed lineage of cell divisions that results in a relatively simple and consistent anatomy, making it a valuable model organism for studying developmental biology.

Quiz 20: Developmental Genetics