Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

ANAT1003 test 2 > Hox Genes > Flashcards

Hox Genes Flashcards

1
Q

what forms the axial skeleton?

A

somites

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what induces sclerotome to migrate around the notochord and neural tube?

A

SHH from the notochord

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what is endochondrial ossification?

A

when sclerotome cells differntiate the cartilage (and subsequently bone) of the vertebrae and ribs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

which vertebrae are fused?

A

the sacral vertebrae and the coccygeal vertebrae

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

the adult drosophila has how many segments in the head?

A

7

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

the adult drosophila has how many segments in the thorax?

A

3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

the adult drosophila has how many segments in the abdomen?

A

8

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what does each segment of the thorax produce?

A

a pair of legs ventrally

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what do the second and third thoracic segments produce?

A

wings dorsally

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what does the second thoracic segment have a pair of?

A

wings

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what does the third thoracic segment have a pair of?

A

halteres

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

who came up with the term homeosis?

A

william bateson

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

who first identified a mutation (bithorax) caused homeosis?

A

calvin bridges

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what did bithorax (bx) cause?

A

it transformed the rostral half of the haltere into rostral wing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what did bithoraxiod cause?

A

it transformed the caudal half of the haltere into caudal wing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

who discovered ultrabithorax?

A

wf hollander

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

what did ultrabithorax cause?

A

it weakly transformed halteres into wings when heterozygous but killed the embryo when homozygous

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

what type of mutation are bithorax, bithoraxiod and ultrabithorax?

A

loss-of-function

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

on which chromosome will you find the bithorax complex?

A

chromosome 3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

how many chromosomes do drosophila have?

A

4

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

who carried out detailed genetic studies of bithorax mutations?

A

edward lewis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

what do infra-abdominal (iab) mutations do?

A

cause homeotic transformations in the abdomen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

how did the bithorax complex evolve?

A

its member genes had been formed during evolution by gene duplication

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

what does a homozygous deletion of the bithorax complex cause?

A

it transforms the third thoracic segment and all abdominal segments into a second thoracic segment

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
how many genes are in the bithorax complex?
3 protein coding genes
26
what are the genes in the bithorax complex called?
Ulltrabithorax (Ubx), abdominal-A (abdA) and abdominal-B (AbdB)
27
what affects Ubx?
all bithorax mutations
28
what affects abdA and AbdB?
infra-abdominal mutations
29
which regions do Ubx mutations affect?
3rd thoracic segment and 1st abdominal segment
30
which regions do abdA mutations affect?
the 2nd through 5th abdominal segments
31
which regions do AbdB mutations affect?
the 5th through 8th abdominal segments
32
what is colinearity?
the correlation between a genes chromosomal position and the segments it affects
33
What do gain-of-fuction Antennapedia mutations cause?
antennae to be transformed into legs with a bristle pattern that corresponds to that of the 2nd thoracic legs
34
where is Antp normally expressed?
in the thorax, but the dominant mutation causs it to be expressed in the head as well
35
what type of mutation is Antp?
gain-of-function
36
what do loss-of-function Antennepedia mutations cause?
they disrupt second leg development
37
where is the Antp gene located?
on chromosome 3 in the antennapedia complex
38
what other genes does the antennepedia complex contain?
labial (lab), proboscipedia (pb), Deformed (Dfd) and Sex combs reduced (Scr)
39
which regions do lab, pb and Dfd affect?
progressively more caudal regions of the head
40
which regions does Scr affect?
the first thoracic segment
41
which region does Antp affect?
the second thoracic segment?
42
which genes are transcribed in the head?
lab, pb and Dfd
43
which genes are transcribed in the thorax?
Dfd, Scr, Antp and Ubx
44
which genes are transcribed in the abdomen?
Ubx, abdA and AbdB
45
homeotic genes combine to make what?
a hox code
46
how long is the homeobox?
180bp
47
how long is the homeodomain?
60 amino acids
48
what are homeotic proteins?
transcription factors
49
what do homeotic proteins bind to?
the regulatory regions of different target genes in the genome
50
what are selector genes?
transcription factors that make important cellfate decisions
51
who discovered that there were similar homeobox genes in vertebrates?
walter gehring
52
what was the first vertebrate homeobox to be discovered?
HoxC6
53
how many homeobox genes do most vertebrates have?
39
54
what are vertebrate homeobox genes called?
hox genes
55
what do hox genes encode?
sequence-specific DNA binding proteins - transcription factors
56
where are the 39 vertebrate hox genes found?
in hox complexes
57
how many complexes do vertebrates have?
4 - all on different chromosomes
58
what are vertebrate hox genes called?
HOXA (human chromosome 7), HOXB (human chromosome 17), HOXC (human chromosome 12) and HOXD (human chromosome 2)
59
what are parologues?
genes at the same location in each complex and show the greatest degree of sequence similarity
60
along which axis are hox genes expressed?
rostral-caudal
61
what is the HOX code?
a unique combination of expressed HOX genes in each somite
62
hox genes specify a somites position along the rostral-caudal axis. true or false?
false - they specify the type of vetebrae the somite will differentiate
63
has homeosis been seen in humans?
yes - some people (1/200) have an extra rib attached to the seventh 'cervical' vertebra
64
what can having cervical rib cause?
a form of thoracic outlet syndrome due to compression of the lower trunk of the branchial plexus or subclavian artery
65
which HOX genes are found in all 3 complexes?
HOX4, HOX9 AND HOX13
66
which HOX genes are expressed in cervical somites?
HOX4 AND HOX5
67
which HOX genes are expressed in thoracic vertebrae?
HOX6-9
68
where are HOX9-11 expressed?
in the lumbar region
69
what does a mutation in one of HOX9-11 cause?
a transformation of the first 4 lumbar vertebrae into rib bearing thoracic vertebrae
70
what does the expression of one of HOX9-11 in the thoracic region cause?
a transformation of the thoracic vertebrae into rib-less lumbar vertebrae

ANAT1003 test 2 (8 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions