gymnosperms - are both male and female; that is, each reproductive organ is either male or female
gymnosperms - they are a group of seed-producing plants that includes conifers, cycads, ginkgo, and gnetophytes
angiosperms - a plant that has flowers and produces seeds enclosed within a carpel
angiosperms - a large group and include herbaceous plants, shrubs, grasses, and most trees
seed coat - seed is surrounded with this
aleurone layer - which lies under the seed coat, functions as a kind of digestive organ in seed germination
starchy endosperm - a food storage tissue that forms separately from the embryo while the seed is still attached to the parent plant
coleorhiza - protects the future root as it grows out of the seed into the surrounding soil
plumule - composed of the epicotyl, young leaves, and the shoot apical meristem.
seed germination - the process by which a plant grows from a seed into a seedling.
breakingthedormancy - the embryo emits a hormone called gibberellin, which diffuses through the seed
monocots - the hormone then triggers the production of digestive enzymes by the aleurone
dicots - the digestive enzymes are produced by the cotyledons
early root emergence - this part of the root tip is known as the zone of division. It is an apical meristem, a growing tip of embryonic, differentiating tissue
early root emergence - zone of elongation, which is responsible for most of the lengthwise growth of the root tip. Since new cells are constantly added to this zone by mitosis
early root emergence - the older portions of the zone of elongation cease to grow and become incorporated into the zone of maturation, where tissue differentiation now begins
primary meristems - give rise to differentiated tissues such as phloem and xylem
primary meristems - eventually form differentiated tissues themselves, but in such a way as to produce lateral growth and increase in girth
zygote - a fertilized egg that has the potential to give rise to all the diverse cell types of the complete individual
cleavage - from one cell to many
implantation - begins on the seventh day of embryonic development
implantation - enzymes destroy some tiny maternal capillaries in the wall of the uterus
in the grass seed, the cotyledon is a food-absorbing structure known as a scutellum
the portion of the seedling below the cotyledons is known as hypocotyl. One of the structures included in it is the future root, or radicle
the root hairs form in the zone of maturation of the growing root tip
when the "hook" of a dicot seedling is exposed to light during germination, it reacts by straightening; the receptor substance that initiates this reaction is pigment known as phytochrome
the growing nodes of embryonic tissue found at the shoot and root tips of a plant are its apical meristems
movement of cells to form a tube such as the neural tube is an example of morphogenesis
specialization of cells to form neurons or some other cell types is called cellular differentiation
the rapid series of mitoses that converts the zygote to a morula is referred to as cleavage
the cluster of cells that projects into the cavity of the blastocyst is the inner mass; it gives rise to the cellembryo
the process by which the blastula becomes a three-layered embryo is called gastrulation
the tissue layer that gives rise to the nervous system is the ectoderm
the germ layer that gives rise to the lining of the digestive tract is the endoderm