Developmental Biology Exam #2 TTU
3302 Held Questions & Answers
(Grade A+)
What pattern do hexagonal structures posses and what are some
examples? -
correct answer ✅Perfect crystalline structure: insect eyes, fish
scales, feathers
What is a periodicity pattern? -
correct answer ✅An imperfect pattern that is repeated and
determined by a mechanism
Give examples of a unique element pattern. -
correct answer ✅Eye, nose, mouth, ear
Give examples of a repeated element pattern. -
correct answer ✅Finger spacing, zebra stripes, hexagonal lattices,
finger prints
Define ommatidia -
correct answer ✅unit of eye that has 8 photo receptors and shells
of pigment cells that scatter light.
, Developmental Biology Exam #2 TTU
3302 Held Questions & Answers
(Grade A+)
In the cell lineage model for Drosophila eyes, was the cell lineage
model accurate? Were the ommatidia cell blocks clones and was
the eye half a clone? -
correct answer ✅No because white clones crossed the equator
and many ommatidia were mosaics. The cell lineage model was
disproved. Body parts are generally not clones.
How do you determine if omatidia for Drosophila eyes are clones?
Give experiment outline. What were the results of this experiment?
-
correct answer ✅You first induce white clones in first instar eye
(20 cells) by using an x-ray for mitotic recombination. The result
was that white clones still crossed the equator of the eye and were
a mosaic
In the Oncopeltus optic experiment, did the progress zone imply
the kiss of death or did sequential induction recruit cells? -
correct answer ✅The mosaic ommatidia result disproves PZ model
and confirms that the cells are not cloned.
In the Oncopeltus optic experiment, how was it proven that the
progress zone was not at play? (Give experiment and results). -
3302 Held Questions & Answers
(Grade A+)
What pattern do hexagonal structures posses and what are some
examples? -
correct answer ✅Perfect crystalline structure: insect eyes, fish
scales, feathers
What is a periodicity pattern? -
correct answer ✅An imperfect pattern that is repeated and
determined by a mechanism
Give examples of a unique element pattern. -
correct answer ✅Eye, nose, mouth, ear
Give examples of a repeated element pattern. -
correct answer ✅Finger spacing, zebra stripes, hexagonal lattices,
finger prints
Define ommatidia -
correct answer ✅unit of eye that has 8 photo receptors and shells
of pigment cells that scatter light.
, Developmental Biology Exam #2 TTU
3302 Held Questions & Answers
(Grade A+)
In the cell lineage model for Drosophila eyes, was the cell lineage
model accurate? Were the ommatidia cell blocks clones and was
the eye half a clone? -
correct answer ✅No because white clones crossed the equator
and many ommatidia were mosaics. The cell lineage model was
disproved. Body parts are generally not clones.
How do you determine if omatidia for Drosophila eyes are clones?
Give experiment outline. What were the results of this experiment?
-
correct answer ✅You first induce white clones in first instar eye
(20 cells) by using an x-ray for mitotic recombination. The result
was that white clones still crossed the equator of the eye and were
a mosaic
In the Oncopeltus optic experiment, did the progress zone imply
the kiss of death or did sequential induction recruit cells? -
correct answer ✅The mosaic ommatidia result disproves PZ model
and confirms that the cells are not cloned.
In the Oncopeltus optic experiment, how was it proven that the
progress zone was not at play? (Give experiment and results). -
