Skip to main content
Register/ Log In
Register/ Log In
Art and Architecture
Biology and Life Sciences
Communication, Media Studies, & Journalism
Earth and Environmental Science
Women's, Gender & Sexuality Studies
Return to Principles of Development 6e Student Resources
Chapter 2 Self-test questions
Development of the Drosophila body plan
This chapter discusses the embryonic development of
. How long does embryonic development take in this organism?
The 'spinal cord' of
-its 'nerve cord'
consists of two parallel structures that run laterally, along the sides of the animal.
is in no way analogous to the spinal cord of vertebrates, since
has no spine!
runs along the dorsal side, opposite the mouth as is the case in vertebrates such as humans
runs along the ventral surface, on the same side as the mouth
The portion of the blastoderm-stage embryo which will give rise to most ectodermal, mesodermal, and endodermal tissues is called the:
The process of segmentation will form how many parasegments?
8 in the abdomen
11 to form the thorax and abdomen
14: 3 for the mouth, 3 in the thorax, and 8 in the abdomen
3: head, thorax, and abdomen
When do the legs and wings of a fly form?
during embryogenesis, after imaginal disc cells are segregated away at the cellular blastoderm stage
during pupation, from the imaginal discs
during the larval instars
legs and wings are present during larval stages, but take their final form only after metamorphosis
The portion of the
body plan which will produce the wing is called:
Maternal factors are
genes that control differentiation as a female or male fruit fly
proteins and mRNAs packaged into the egg by the mother
proteins and mRNAs that determine the organizing axes of the
substances present in the female that determine whether or not she will become a mother
Which protein (gene) functions to determine an anterior fate in the
The development of the antero-posterior axis of
is initiated when:
the mother packages
mRNA into the developing oocyte
the Toll receptor is activated after fertilization, leading to nuclear localization of Dorsal protein
the terminal group protein Torso sets up the anterior and posterior poles of the embryo
the sperm enters the micropyle at the anterior end, thus specifying the antero-posterior axis
Which is the correct hierarchy of gene activity in early
gap, segment polarity, pair-rule, maternal
maternal, gap, pair-rule, segment polarity
maternal, pair-rule, gap, segment-polarity
segment polarity, pair-rule, gap, maternal
Which would lead to a dorsalized embryo?
A gap-gene mutation could cause which of the following defects in the embryonic body plan?
every other segment is missing, resulting in T1, T3, A2, A4, etc., but no T2, A1, A3, and so on
patterning within each segment is abnormal, causing denticle belts to form across the entire segment
segments A2 through A6 are missing, but the rest of the pattern is essentially normal
the identity of one or more segments is transformed to that of a different segment
The activation of zygotic
expression by Bicoid protein illustrates what principle in the establishment of positional information in embryos?
the mother can influence development through the packaging of materials into the egg
a gradient of a protein can activate a gene in a discrete region of an embryo through a threshold effect
the identity of segments in the embryo is a reflection of their position in the embryo
genes are activated or repressed by the binding of transcription factors to their regulatory regions
The adult body plan of the fly is based on reiterating structures called segments; segment precursors (parasegments) are first positioned at the cell-by-cell level by which group of genes?
maternal genes such as
gap genes such as
pair-rule genes such as
segmentation genes such as
expression defines the
anterior compartment of the segment
anterior margin of each segment
posterior compartment of the segment
posterior margin of each parasegment
Mutations in homeotic genes can lead to what type of developmental defect?
the anterior portion of the embryo does not develop
several adjacent segments will be missing from an otherwise intact embryo
segment and compartment boundaries will fail to form
the development of segments will be changed wholesale from their normal identity to that of a different segment
Which of the following, first discovered through mutagenesis studies in
, also function in the development of mammals like ourselves?
the Wnt family
all of the options given are correct
Select your Country