Question 1

Use the following to answer questions :
Refer to the figure below showing a stage in limb development in a human embryo. 
-If the ZPA secreted more morphogen than normal,the most likely result would be

Accepted Answer

The answer of Use the following to answer questions :
Refer...

Question 2

If a human fetus is exposed to chemicals that lead to the overexpression of Sonic hedgehog in the ZPAs of the developing arms,the baby will most likely have

Accepted Answer

The answer of If a human fetus is exposed to...

Question 3

The differentiation of whorls in the flower-forming region of the plant Arabidopsis thaliana is regulated by _______ genes.

Accepted Answer

Organ identity genes, such as the ABC model genes, control the differentiation of whorls in the flower-forming region by specifying the identity and fate of the floral organs. Dimer, caspase, and central axis control genes do not play a direct role in regulating whorl differentiation. Whorl locator is not a known gene or regulatory pathway involved in flower development.

Question 4

In the nematode C.elegans embryo,an overabundance of active ced-3 in cells of the mid region would most likely lead to which result?

Accepted Answer

An overabundance of active ced-3 in cells would lead to greater apoptosis. In the mid region, this would result in a deficiency of cells. Therefore, the correct choice is D.

Question 5

In normal development of the plant Arabidopsis,four whorls of cells create the organs of the flowers.The outermost whorl (whorl 1)produces

Accepted Answer

The outermost whorl, whorl 1, produces sepals which are the protective outermost layer of the flower.

Question 6

Use the following to answer questions :
Refer to the figure below showing a stage in limb development in a human embryo. 
-The substance secreted by the ZPA is _______ and the concentration of this is lowest at the region labeled _______.

Accepted Answer

The substance secreted by the ZPA is the protein Sonic hedgehog, as stated in option A. The concentration of Sonic hedgehog is lowest at the region labeled 2, which is the anterior of the limb bud.

Question 7

Which statement about the organ identity genes in Arabidopsis thaliana is true?

Accepted Answer

Organ identity genes in Arabidopsis thaliana code for subunits of transcription factors that determine the identity of floral organs.

Question 8

An increase in the concentration of MyoD would most likely lead to a(n)_______ of p21 expression,which would _______ the activity of cyclin-dependent kinases (CDKs).

Accepted Answer

MyoD is a transcription factor that promotes muscle differentiation by increasing the expression of p21, a cyclin-dependent kinase inhibitor. This increase in p21 expression would decrease the activity of CDKs, leading to cell cycle arrest and allowing differentiation to proceed.

Question 9

Which of the following is a Drosophila maternal effect gene?

Accepted Answer

Maternal effect genes, also called egg-polarity genes, encode for cytoplasmic determinants that establish the anterior-posterior and dorsal-ventral axes of the embryo. Bicoid is one of the most important maternal effect genes in Drosophila, as it is a transcription factor that is synthesized in the nurse cells and transported to the anterior pole of the egg, where it forms a concentration gradient. The gradient determines the expression pattern of the segmentation genes along the anterior-posterior axis of the embryo, and establishes the head and thorax structures.

Question 10

Suppose a laboratory is engaged in genetically modifying a plant to increase the size of its fruit (its carpels).Assuming that organ identity genes play the same roles in this plant that they do in Arabidopsis,_______ the domain of expression of genes in class _______ would most likely yield an increase in fruit size.

Accepted Answer

The answer of Suppose a laboratory is engaged in genetically...

Question 11

Which statement about pattern formation in an embryo is true?

Accepted Answer

Pattern formation in an embryo can involve programmed cell death, also known as apoptosis. This process can help shape and refine developing tissues and organs. Choices A, B, and E are incorrect as pattern formation is also observed in plant embryos, the French flag model is one model of pattern formation but not the only one, and induction of cell differentiation by signals (inducers) is a key part of pattern formation. Choice C is incorrect as pattern formation is a process that occurs before differentiation.

Question 12

Lowering the expression of the MyoD gene would tend to _______ the activity of cyclin-dependent kinases (CDKs).This activity would tend to _______ differentiation of muscle cells.

Accepted Answer

Lowering MyoD expression would increase CDK activity, as MyoD promotes cell cycle exit for differentiation. Increased CDK activity would retard muscle cell differentiation.

Question 13

In the normal course of development in Arabidopsis,a particular group of cells should develop into carpel tissue.If the expression of class B genes were also induced in those cells,they would develop into _______ tissue.

Accepted Answer

Class B genes in Arabidopsis are responsible for the development of petals and stamens. If class B genes are expressed in cells that would normally develop into carpel tissue, those cells would instead develop into stamen tissue.

Question 14

The process that results in spatial organization of an organism or a tissue is called

Accepted Answer

The process that results in spatial organization of an organism or a tissue is called pattern formation. Induction is the process by which one group of cells influences the development of another group of cells, differentiation is the process by which cells become specialized, apoptosis is programmed cell death, and determination is the process by which cells become committed to a particular developmental fate.

Question 15

In the diagram below,the cell(s)being induced is/are labeled _______ and the inducer is labeled _______.

Accepted Answer

The cells being induced are labeled 2, as they are the cells that are changing their gene expression in response to the inducer. The inducer is labeled 4, as it is the molecule that is causing the change in gene expression in cells 2.

Question 16

As the plant Arabidopsis develops,four whorls of cells create the organs of the flowers.The innermost whorl (whorl 4)produces

Accepted Answer

The innermost whorl, whorl 4, is responsible for producing the carpels, which are the female reproductive organs of the flower. The other whorls are responsible for producing the petals (whorl 2), stamens (whorl 3), and sepals (whorl 1). Therefore, choice A is the best answer.

Question 17

If a fly embryo has a mutation in one of its _______ genes,this mutation is unlikely to affect its development.

Accepted Answer

Maternal effect genes are responsible for providing maternal "instructions" to the developing embryo. These instructions are crucial for the proper patterning of the embryo before it starts expressing its own genes. Therefore, mutations in maternal effect genes can have drastic effects on early development. However, mutations in gap, pair rule, Hox, and segment polarity genes can have significant effects on development throughout the fly's life cycle.

Question 18

Which statement about development in the fruit fly Drosophila is true?

Accepted Answer

In Drosophila development, the fates of cells in different segments of the larva are determined before morphological differences are apparent. This concept is known as segmentation.

Question 19

Which statement about the gene MyoD is true?

Accepted Answer

MyoD is a gene that codes for a transcription factor that plays a key role in the differentiation of muscle cells.

Question 20

Which statement about apoptosis is true?

Accepted Answer

Despite the significant evolutionary distance between humans and nematodes, both share similar apoptosis pathways. This is because apoptosis is a fundamental process that regulates cell death in all multicellular organisms. Choices A, C, D, and E are incorrect statements about apoptosis.

Quiz 14: Genes, Development, and Evolution

Use the following to answer questions : Refer to the figure below showing a stage in limb development in a human embryo. -If the ZPA secreted more morphogen than normal,the most likely result would be

If a human fetus is exposed to chemicals that lead to the overexpression of Sonic hedgehog in the ZPAs of the developing arms,the baby will most likely have

The differentiation of whorls in the flower-forming region of the plant Arabidopsis thaliana is regulated by _______ genes.

In the nematode C.elegans embryo,an overabundance of active ced-3 in cells of the mid region would most likely lead to which result?

In normal development of the plant Arabidopsis,four whorls of cells create the organs of the flowers.The outermost whorl (whorl 1) produces

Use the following to answer questions : Refer to the figure below showing a stage in limb development in a human embryo. -The substance secreted by the ZPA is _ and the concentration of this is lowest at the region labeled _.

Which statement about the organ identity genes in Arabidopsis thaliana is true?

An increase in the concentration of MyoD would most likely lead to a(n) _ of p21 expression,which would _ the activity of cyclin-dependent kinases (CDKs) .

Which of the following is a Drosophila maternal effect gene?

Which statement about pattern formation in an embryo is true?

Lowering the expression of the MyoD gene would tend to _ the activity of cyclin-dependent kinases (CDKs) .This activity would tend to _ differentiation of muscle cells.

In the normal course of development in Arabidopsis,a particular group of cells should develop into carpel tissue.If the expression of class B genes were also induced in those cells,they would develop into _______ tissue.

The process that results in spatial organization of an organism or a tissue is called

In the diagram below,the cell(s) being induced is/are labeled _ and the inducer is labeled _.

As the plant Arabidopsis develops,four whorls of cells create the organs of the flowers.The innermost whorl (whorl 4) produces

If a fly embryo has a mutation in one of its _______ genes,this mutation is unlikely to affect its development.

Which statement about development in the fruit fly Drosophila is true?

Which statement about the gene MyoD is true?

Which statement about apoptosis is true?

Quiz 14: Genes, Development, and Evolution

Use the following to answer questions : Refer to the figure below showing a stage in limb development in a human embryo. -If the ZPA secreted more morphogen than normal,the most likely result would be

If a human fetus is exposed to chemicals that lead to the overexpression of Sonic hedgehog in the ZPAs of the developing arms,the baby will most likely have

The differentiation of whorls in the flower-forming region of the plant Arabidopsis thaliana is regulated by _______ genes.

In the nematode C.elegans embryo,an overabundance of active ced-3 in cells of the mid region would most likely lead to which result?

In normal development of the plant Arabidopsis,four whorls of cells create the organs of the flowers.The outermost whorl (whorl 1) produces

Use the following to answer questions : Refer to the figure below showing a stage in limb development in a human embryo. -The substance secreted by the ZPA is _______ and the concentration of this is lowest at the region labeled _______.

Which statement about the organ identity genes in Arabidopsis thaliana is true?

An increase in the concentration of MyoD would most likely lead to a(n) _______ of p21 expression,which would _______ the activity of cyclin-dependent kinases (CDKs) .

Which of the following is a Drosophila maternal effect gene?

Which statement about pattern formation in an embryo is true?

Lowering the expression of the MyoD gene would tend to _______ the activity of cyclin-dependent kinases (CDKs) .This activity would tend to _______ differentiation of muscle cells.

In the normal course of development in Arabidopsis,a particular group of cells should develop into carpel tissue.If the expression of class B genes were also induced in those cells,they would develop into _______ tissue.

The process that results in spatial organization of an organism or a tissue is called

In the diagram below,the cell(s) being induced is/are labeled _______ and the inducer is labeled _______.

As the plant Arabidopsis develops,four whorls of cells create the organs of the flowers.The innermost whorl (whorl 4) produces

If a fly embryo has a mutation in one of its _______ genes,this mutation is unlikely to affect its development.

Which statement about development in the fruit fly Drosophila is true?

Which statement about the gene MyoD is true?

Which statement about apoptosis is true?

Use the following to answer questions : Refer to the figure below showing a stage in limb development in a human embryo. -The substance secreted by the ZPA is _ and the concentration of this is lowest at the region labeled _.

An increase in the concentration of MyoD would most likely lead to a(n) _ of p21 expression,which would _ the activity of cyclin-dependent kinases (CDKs) .

Lowering the expression of the MyoD gene would tend to _ the activity of cyclin-dependent kinases (CDKs) .This activity would tend to _ differentiation of muscle cells.

In the diagram below,the cell(s) being induced is/are labeled _ and the inducer is labeled _.