BIO1102- Optional homework questions on the article “Genetic Analysis of Floral Symmetry in Van Gogh's Sunflowers Reveals Independent Recruitment of CYCLOIDEA Genes in the Asteraceae.” You can find...

BIO1102-Optional homework:
Due Thursday February 28 Name_________________________________________

BIO1102- Optional homework questions on the article “Genetic Analysis
of Floral Symmetry in Van Gogh's Sunflowers Reveals Independent
Recruitment of CYCLOIDEA Genes in the Asteraceae.”
You can find the full text article at the link below:
http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1002628
Also, a PDF file is posted on Angel. Please type your answers within the text boxes
provided, except when drawing a cross.
1) State what is the general biological question that the authors are asking
by analyzing the double mutant in the sunflower. Briefly explain its
overall importance to plant biology. (2 points)
2) Briefly explain the evolutionary relationship between the two types of
flower morphology described in the paper and how they affect
pollination and plant diversification. (3 points)
Investigators observed that within Asteraceae, CYC-like genes determine the floral
symmetry of different plants of this group. Researchers have investigated several
genes within CYC group including HaCYC2b, HaCYC2c, and HaCYC2e. Also they have
found that different mutant form of this genes affect differently in the floral
symmetry of plants. The biological question that the authors are asking by
analyzing the double mutant is that how subfunctionalization of different paralogs
within CYC- like gene families has been occurred.
According to evolutionary evidence it is considered that actinomorphy is ancestral
while zygomorphy had evolved from actinomorphy. Zygomorph types of floral
symmetry are more beneficial over actinomorphy because it increases pollinator
specificity. Thus it induces the evolution of reproductive isolation which plays an
important role in the diversification of plant life.
http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1002628
BIO1102-Optional homework:
Due Thursday February 28 Name_________________________________________

3) Briefly describe the two different types of florets found in a wild type
sunflower. Explain how florets morphology and distribution is different
in double and tubular mutants. (3 points)
4) To generate F1 hybrid offspring, a wild-type plant was crossed with a
“weak” semi-double mutant (Primrose), which shows an intermediate
Two tyoes of florets in wild type plants are
 Actinomorphy: In this floret types flowers are radially symmetrical.
 Zygomorphy: in this florets type flowers are bilaterally symmetrical.
Zygomorphic clades are more speciose than actinomrphy, because zygomorphy
increases pollination. Thus it is suggested that zygomorphy is evolved from
actinomorphy and this evolution is very important in plant diversification.
Double mutant are normally actinomorphic disc florets but elongated, outside of the
florets different from zygomorphic and the center of the inflorescence has slight
similarity with zygomorphic plants.
Double mutant with ray-like disc...