Plant Reproduction Flashcards
What are the 3 growth phases and stages?
Vegetative, Reproduction, and Ripening
Explain the plant life cycle.
Plant life cycle > fertilization produces embryo in seed > embryo develops into plant with flowers eventually > flowers produce gametes
What is the phase change?
transition from vegetative to reproductive growth
How does the light-dependent pathway in plants work?
use light as a cue allows plants to flower when abiotic conditions are optimal
How do short-day poinsettias flower in time for the winter holidays?
manipulation of photoperiod in greenhouses
How do temperature-dependent pathway work?
some plants require a period of chilling before flowering
What is the term when plants require a period of chilling before flowering?
vernalization
What do gibberelins do?
hormones that enhance the expression of LFY which is a big impact on flowering
What happens in the molecular regulation of light signaling?
phytochrome and cryptochrome (red and blue-light receptors) regulate flowering via a gene named CONSTANS (CO); CO is a transcription factor that turns on other genes, resulting in the expression of LEAFY (LFY) = flowering gene; LFY is key gene ‘telling’ a meristem to switch over to flowing (associated with phase change)
What happens in the autonomous pathway?
does not depend on external cues except for basic nutrition; allow day-neutral platoons to “count” and “remember”
What is an example of an autonomous plant?
tobacco plant
How does a tobacco plant have an autonomous pathway?
upper axillary buds of flowering tobacco will remember their position when rooted or grafted; terminal shoot tip becomes committed, or determined, to flower about 4 nodes before it initiates a flower
How do plants count and remember?
inhibitory signals are sent from roots
T/F The gametophyte is dominant, green, and nutritionally independent in bryophytes.
True
What are floral organs thought to have evolved from?
leaves
What is an incomplete flower?
missing one or more whorls
What are the 2 types of symmetry in flowers?
radial and bilateral
What is the structure and evolution of flowers?
separate floral parts grouped together or fused, floral parts lost or reduced, symmetry changed from radial to bilateral regulated by pollination
What is the male gametophyte?
pollen grains
What is the female gametophyte?
embryo sac
What is pollination?
transfer of pollen from anthers to the stigma, pollen germinates and produces a tube that carries the sperm to the embryo sac
What is double fertilization?
one sperm fuses with the egg to form a zygote, other sperm fuses with the polar nuclei to form a triploid cell (3n)
After double fertilization what happens?
zygote divides by mitosis to form an embryo, triploid cell divides by mitosis to form the endosperm, which provides nutrients to the embryo and germinating seedling, integuments of ovule become seed coat, ovules become seeds, over becomes fruit
A process unique to angiosperms is what?
double fertilization
