Nov 15 Flashcards Preview

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Flashcards in Nov 15 Deck (25):
1

Hox gene products ___ genes involved in cellular development
a) regulate expression of
b) express
c) inhibit
d) are not involved with

a) regulate expression of

2

How can we test whether heterochrony has occurred?

1. Characterize the interval of development and
the rate at which features of interest develop
2. Identify sibling lineages characterized by morphologies that can be tied to developmental differences

3

Changes in pattern of expression or regulation of what genes dramatically changes morphology?

homeotic (HOX) genes

4

Eye development is spurred by what master genes?

Paired box transcription factors (PAX) genes

5

What is the relationship btw HOX genes and their expression along the anterior-posterior axis?

co-linear with their 3’-5’ location on the chromosome

6

What is homeotic transformation?

transformation of one body part into another, arising from mutation in homeotic genes

7

TRUE/FALSE
Cnidarians have HOX genes

TRUE

8

What is the HOX code in arthropods?

each segment has a unique identity

9

Evolutionary diversification of arthropods is
controlled by...

changes in Hox gene expression

10

What are the 3 parts of a limb?

stylopod-->arm
zeugopod-->forearm
autopod-->hand

11

What do fibroblast growth factors (FGF) induce in limb development?

formation of AER (Apical Ectodermal Ridge)

12

What does the AER (Apical Ectodermal Ridge) stimulate during limb development?

limb outgrowth to form an undifferentiated paddle

13

What does the ZPA (zone of polarizing activity) do in limb development?

determines anterior-posterior identity by action of SHH (Sonic Hedgehog) protein gradient

14

What type of gene is SHH?

patterning many systems, including limbs, central nervous system, spinal cord, midline structures in the brain, teeth, etc.

15

SHH is controlled by what genes?

HOX genes

16

Snakes lack which region in their hindlimbs?

apical ectodermal ridge (AER)

17

What was the 1st step in snakes losing their limbs?

expansion of thoracic identity in axial skeleton
elimination of forelimb specification

18

What was the 2nd step in snakes losing their limbs?

extire axial skeleton become thorax
expansion of polarizing potential in lateral plate mesoderm
failure to form AER

19

What was the 3rd step in snakes losing their limbs?

increased morphological uniformity in axial skeleton
elimination of hindlimb specification

20

What gene system controls flower growth in plants?

MADS-Box Genes

21

What are the genes in the MADS-Box gene system?

A, B, C

22

In the MADS-Box Genes, what does the A gene alone produce?

sepal

23

In the MADS-Box Genes, what do the A and B genes together produce?

petal

24

In the MADS-Box genes, what do B and C genes together produce?

stamen

25

In the MADS-Box genes, what does the C gene alone produce?

carpel