Chapter 24 Plant Development
The development of plants is different from the development of animals because_______.
-in plant embryos, there is no determined germ line -organogenesis continues throughout the plant's life -the arrested development common in plant embryos is rare in animals
Arabidopsis is considered a model organism for studying plant development because it _____.
-is easy to grow -produces large numbers of offspring -has a rapid life cycle
Which of the following statements is true regarding the role of germ cells in plants and animals?
Animals set aside germ cells early in development, whereas plants form their reproductive tissues from cells of the shoot apical meristem.
How are the MADS box of plants and the homeobox of animals functionally similar to one another?
Both contain a sequence of amino acids that code for the DNA-binding regions of regulatory transcription factors.
Basal mutants in Arabidopsis form embryos that are lacking what organ or organs?
Both root and hypocotyl
During embryogenesis, the shape of the plant body depends primarily on which of the following factors?
Both the plane of cell division and the direction of cell expansion
One of the ABC genes is referred to as AGAMOUS because when this gene is disabled, the flower lacks both of the reproductive floral organs. This indicates that AGAMOUS must belong to which class of genes?
C
Which statement concerning genetic control of plant versus animal development is most accurate?
Different genes are involved but the underlying genetic principles for producing a multicellular body are similar. **Different genes are involved in plant versus animal development.
Researchers believe that the gene PHAN may underlie evolutionary changes in leaf size and shape. What process or activity does PHAN regulate?
Expression of genes that regulate the upper-lower axis in leaves
Floral homeotic mutants have which of the following phenotypes?
Floral organs are produced in the wrong location
Choose the correct sequence of developmental events in plants.
Gametogenesis → fertilization → embryogenesis → vegetative development → reproductive development
How does the gene MONOPTEROS affect the development of Arabidopsis?
It is required for the normal development of the apical-basal axis. **MONOPTEROS mutants lack a hypocotyl and root, elements of the apical-basal axis.
Which of the following represents the correct order, from outside to center, of the four whorls of organs that compose flowers?
Sepals → petals → stamens → carpels
Which of the following statements about shoot and root apical meristems is true?
They direct continued development throughout the life of the plant.
Cloning plants is generally easier than cloning animals because _____.
determination in plants either does not occur or is readily reversible in at least some cells
Vegetative development ______.
is finely tuned to the environment
One of the most important differences between plant and animal development is that _____.
plants continue to grow and develop throughout their lives
the Bicoid concentration gradient provides positional information along the anterior-posterior axis in Drosophila. In Arabidopsis, what signaling molecule represents a signaling mechanism analogous to Bicoid?
the concentration gradient of auxin, which provides positional information along the apical-basal axis
In flowering plants, such as Arabidopsis, the apical-basal axis is established during _____.
the first cell division, which forms apical and basal cells
The radial axis in plants is established during _____.
the globular stage of the embryo, when the three tissue systems begin to form
