flower development

Question 1

name the 4 parts/whorls of a flower

Answer 1

1- sepals (collectively calyx)
2- petals (collectively corolla)
3- stamen or androecium (male parts)
4- carpel or gynoecium (female parts)

Question 2

complete flowers have ___
incomplete flowers ____

Answer 2

complete have all 4 whorls
incomplete are missing 1 or more whorls (grass does not have sepals or petals)

Question 3

perfect flowers have ___
imperfect flowers have ___

Answer 3

perfect have both male (stamen) and female (carpel) structures within the same flower

imperfect have only stamen or carpels, not both

Question 4

in arabidopsis a screen for flower mutants was performed, it was found that…

Answer 4

most mutants changed the identity of organs in specific whorls (homeotic mutants)

Question 5

what are the flower mutant phenotypes in arabidopsis?

Answer 5

A mutant: carpel, stamen, stamen, carpel
B mutant: sepal, sepal, carpel, carpel
C mutant: sepal, sepal, petal, petal

Question 6

___ transcription factor genes are the major players in the ABC model

they have been called the ___ of flower morphogenesis

Answer 6

MADS box genes

molecular architects

Question 7

nearly every gene involved in the ABC model is a ___ containing gene

Answer 7

MADS box

Question 8

MADS box proteins bind DNA as ___

Answer 8

dimers

Question 9

A class gene controls development of these whorls:

loss of class A function results in…

Answer 9

whorl 1 and 2 (sepals and petals)

stamens and carpels instead

Question 10

B class gene controls development of these whorls

loss of class B function results in…

Answer 10

whorl 2 and 3 (petals & stamens)

sepals and carpels

Question 11

C class gene controls development of whorls…

loss of class C function results in…

Answer 11

whorl 3 and 4 (stamens and carpels)

petals and sepals

Question 12

uniqueness of the C class mutant

Answer 12

this floral meristem is not derminant, so a new flower forms at the center of the flower, but with the same C-mutant phenotype pattern of organs

Question 13

ABC genes are necessary for development of flower organs, but are they sufficient?

Answer 13

no- expression of ABC genes in leaves in not enough to convert leaves into flower organs

Question 14

among the ABC MADS-box genes, ___ position and genetic function correlate

Answer 14

phylogenetic

Question 15

arabidopsis MADS-box genes ___, ___, and ___ group outside of the ABC genes in phylogeny - their triple mutant has all organs in arabidopsis flower develop into ___

Answer 15

AGL2, AGL4, AGL9
sepals

Question 16

AGL2,4,9 were renamed to ____

their function is needed to fulfill both the ___ and ___ function in Arabidopsis

Answer 16

SEPALLATA (SEP1, SEP2, SEP3)
B and C function

Question 17

SEPALLATA genes define the new ___ class of genes

Answer 17

E

Question 18

___ and ___ genes are necessary for development of flower organs

Answer 18

ABC & SEP

Question 19

ubiquitous expression of the quartet results in conversion of…

Answer 19

arabidopsis leaves into petals

Question 20

Scanning electron microscopy was used to define organ identity, why is this impt?

Answer 20

1- evolutionary context- understanding flower shape in many different species
- development of the flower
- male & female flowers

2- genetic engineering perspective
- altering organ types

Question 21

it has been shown in petaloid monocots that ___ is expressed in the outer two whorls, thus the appearance of—

Answer 21

B
two outer whorls of petals (tepals)

Question 22

in gymnosperms, (non-flowering plants such as pines), ___ and ___ function are sufficient to specify ___ cone development, while ___ function alone is sufficient for ___ cones

Answer 22

B & C- males
C- female