$$N_{Hox} = N_{ancestor} \times 2^n$$

Question 1

Which of the following best describes the role of maternal effect genes in Drosophila embryogenesis?

Accepted Answer

They encode products that are supplied by the mother to the egg, establishing the main axes of the embryo.

Question 2

A Drosophila mutant exhibits legs growing from its head where antennae should be. Which gene is most likely mutated?

Accepted Answer

Antennapedia

Question 3

Which of the following is TRUE regarding the hierarchical action of developmental genes in Drosophila?

Accepted Answer

Coordinate (maternal effect) genes act first, followed by gap, pair-rule, and segment polarity genes.

Question 4

In the context of pattern formation, what is a morphogen?

Accepted Answer

A signaling molecule whose concentration gradient provides positional information to cells during development.

Question 5

Which equation best represents the relationship between gene duplication and Hox gene cluster expansion in vertebrates?

Accepted Answer

$$N_{Hox} = N_{ancestor} 	imes 2^n$$

Question 6

A mutation in the Ultrabithorax gene of Drosophila results in the transformation of halteres into wings. What type of mutation is this?

Accepted Answer

Homeotic mutation

Question 7

Which of the following best explains the evolutionary significance of MADS-box genes in plants?

Accepted Answer

Their duplication and diversification enabled the development of stamens and carpels, leading to rapid diversification of angiosperms.

Question 8

Which statement about the relationship between bicoid and hunchback in Drosophila is correct?

Accepted Answer

Bicoid protein activates zygotic hunchback transcription in the anterior of the embryo.

Question 9

Which of the following is a correct description of induction in developmental genetics?

Accepted Answer

A cell produces a molecule that causes neighboring cells to differentiate into a particular fate.

Question 10

In Drosophila, which gene category is responsible for defining broad regions of the embryo?

Accepted Answer

Gap genes

Question 11

Which of the following best describes the function of realizator genes?

Accepted Answer

They regulate the morphological instructions to define the characteristic features of each segment.

Question 12

Which of the following is a consequence of loss-of-function mutations in mouse Hox genes?

Accepted Answer

Defects in the identity of serially repeated structures such as vertebrae.

Question 13

Which equation describes the concentration gradient of a morphogen across an embryo?

Accepted Answer

$$C(x) = C_0$ e$$^{-kx}$$

Question 14

Which of the following statements about plant development is correct?

Accepted Answer

Plant growth and development is modular and indeterminate, continuing throughout the plant's life.

Question 15

Which of the following is NOT a function of Hox genes?

Accepted Answer

Triggering apoptosis in developing digits.

Question 16

Which of the following best describes the effect of Gremlin protein in duck hindlimb development?

Accepted Answer

It inhibits Bmp activity, resulting in webbing between digits.

Question 17

Which of the following is a characteristic of the syncytial blastoderm stage in Drosophila embryogenesis?

Accepted Answer

Nuclei divide without cellular division, resulting in a multinucleate embryo.

Question 18

Which of the following is TRUE about the order of Hox genes in clusters?

Accepted Answer

The order of genes in clusters reflects the order of expression along the anterior-posterior axis.

Question 19

Which of the following best describes the concept of 'evo-devo'?

Accepted Answer

A field that combines the study of evolution and development to understand how changes in embryonic development lead to evolutionary changes.

Developmental Genetics: Principles, Model Organisms, and Molecular Mechanisms

Study Guide - Practice Questions