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Quiz 1: BSE652/BSE652A Developmental Biology
Date: 9-2-2016, 10:30 AM
1. Which one among the following model organisms: worm, fruitfly, zebrafish, frog, chick and
mouse would be the most suitable for carrying out a mutagenesis screen to identify all of
the genes required for formation of the neural tube? Justify your answer (2 marks)
2. A gene called Pitx2 is expressed in few cells in the early mouse embryo within the heart field
and its expression is no longer present in these cells after embryonic day 12. Describe how
you will find the structures within the adult heart which were derived from the Pitx2
expressing cells in the embryo. (6 marks)
3. After a large saturation mutagenesis screen was carried out to find the genes involved in
establishment of anterior-posterior polarity in the early Drosophila (fruitfly) embryo in many
of the mutant lines established the homozygous mutant female flies were sterile. Provide an
explanation for this observation. (2 marks)
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4. The image below is that of an early embryo of the nematode worm C.elegans at the twocelled stage where the anterior cell is labelled “A” and the posterior
cell is labelled “P”. Describe the method you would you use to find
out whether the gut of C.elegans adult worms is derived from the
“A” cell or the “P” cell. (4 marks)
5. For each of the following types of proteins state whether it would it be possible to make a
dominant negative version and also justify your answer: 1) a transcription factor 2) a
cytoskeletal protein, 3) a secreted ligand, 4) a receptor protein and 5) a transporter protein
and 6) an enzyme? (6 marks)
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