What is the key characteristic of maternal effect genes like bicoid?

Correct answer: The genotype of the mother determines the phenotype of the offspring, regardless of the offspring's own genotype.

Explanation

Maternal effect inheritance is a non-Mendelian pattern where the mother's genotype provides gene products (mRNA or protein) to the egg, which then direct the earliest stages of the embryo's development, overriding the embryo's own genotype for that trait.

Other questions

Question 1

What is the phenotypic outcome of a mutation in the ultrabithorax (Ubx) gene in Drosophila, as described in the text?

Question 2

According to the text, why did geneticists Eric Wieschaus and Christiane Nüsslein-Volhard primarily study embryonic phenotypes in their search for developmental mutants?

Question 3

What is the collective term for the various protein factors that bind cooperatively to an enhancer element to regulate transcription?

Question 4

How many separate enhancers have been identified to control the complex, seven-striped expression pattern of the eve gene in Drosophila?

Question 5

What is the primary function of DNA elements called insulators in the context of eukaryotic gene regulation?

Question 6

Which mechanism allows microRNAs (miRNAs) to regulate the expression of target genes?

Question 7

What is the key difference between a forward genetic screen and a reverse genetic screen?

Question 8

The eve gene in Drosophila is regulated by activators and repressors that determine the position of its expression stripes. Which of the following is an activator for the eve stripe 2 enhancer?

Question 9

What is the correct hierarchical order of gene classes that pattern the anterior-posterior axis of the Drosophila embryo, from earliest acting to latest?

Question 10

What is a syncytium, as described in the context of early Drosophila embryonic development?

Question 11

What is the function of the homeobox, a common amino acid sequence found in homeotic (Hox) gene proteins?

Question 12

What is the evolutionary significance of the fact that mammals have four clusters of Hox genes (Hox-A, -B, -C, -D) while Drosophila has two?

Question 13

What is collinearity in the context of Hox gene clusters?

Question 14

Mutations in the coding sequence of the human Sonic Hedgehog (Shh) gene are associated with anomalies in which body parts?

Question 15

What is the approximate size of the ZRS (Zone of Polarizing Activity Regulatory Sequence) enhancer itself?

Question 16

What is the proposed evolutionary consequence of the 17-base pair deletion found in the ZRS enhancer of all snakes?

Question 17

In a reporter gene experiment, what would be the expected result if the eve stripe 2 enhancer was fused to a LacZ reporter gene and introduced into a Drosophila embryo?

Question 19

The protein Hunchback acts as both an activator and a repressor for the eve gene. On which stripes does it act as a repressor?

Question 20

Which class of developmental genes, which includes hunchback, kruppel, and giant, is responsible for establishing broad domains of expression in the early embryo?

Question 21

What does a mutation in a pair-rule gene like eve cause in a Drosophila embryo?

Question 22

Which statement accurately describes the relationship between the three vertebrate orthologs of the hedgehog gene?

Question 23

What is the result of a mutation that prevents transcription from being turned off, according to the chapter on mutations?

Question 24

Chromatin remodeling proteins can alter the accessibility of DNA to the transcription machinery. Which of the following is an action performed by these remodelers?

Question 25

What is the key difference between euchromatin and heterochromatin?

Question 26

Who was awarded the Nobel Prize in 2006 for the discovery of RNA interference?

Question 27

According to the chapter, why have some of the whimsical or insensitive names for Drosophila genes, like 'Kruppel', been changed for their human orthologs?

Question 28

What type of molecule is a morphogen, such as the Bicoid protein?

Question 29

How do transcription factors like Bicoid, present as a gradient in the syncytial embryo, regulate the expression of zygotic genes like eve?

Question 30

What is the phenotypic result of a loss-of-function mutation in a segment polarity gene like hedgehog?

Question 31

What is the primary role of the genes in the Ant-C and BX-C clusters in Drosophila?

Question 32

How does a reverse genetic experiment help researchers understand enhancer function?

Question 33

What is a key difference in early embryonic development between Drosophila and mammals mentioned in the text?

Question 34

Why are Hox genes considered to be highly conserved among all species studied?

Question 35

In the hierarchy of developmental genes, what is the role of segment identity genes like ultrabithorax?

Question 36

Chromatin remodeling and modification are key aspects of eukaryotic gene regulation. Which of the following enzyme types is responsible for adding acetyl groups to histones?

Question 37

What are Topologically Associated Domains (TADs)?

Question 38

Which of the following describes a gain-of-function mutation in the Antennapedia (Antp) gene?

Question 39

In the context of the eve stripe 3+7 enhancer, which two proteins act as repressors?

Question 40

What type of molecule is the product of a homeotic gene like Antennapedia or Ultrabithorax?

Question 41

What is the term for a gene in another species that is similar to a gene in a reference species due to a shared evolutionary ancestor?

Question 42

How do eukaryotes typically achieve co-regulation of functionally related genes, since they do not use operons?

Question 43

What is the role of the mediator complex in eukaryotic transcription?

Question 44

In the regulatory cascade of Drosophila development, which gene class is immediately downstream of gap genes and regulated by them?

Question 45

Mutations in the ZRS enhancer are associated with which human phenotype?

Question 46

When the eve stripe 2 enhancer is mutated to eliminate the binding sites for the repressor Giant (Gt), what is the predicted effect on LacZ reporter gene expression in a reverse genetics experiment?

Question 47

What type of regulation is exemplified by the action of microRNAs (miRNAs)?

Question 48

In the early Drosophila embryo, the protein product of the maternal effect gene Nanos has what effect on hunchback RNA?

Question 49

The gene eve belongs to which class of developmental genes?

Question 50

What is the general outcome of histone acetylation on chromatin structure and gene expression?