ch.38 39 - plant reproduction controls
TRANSCRIPT
Plant Reproduction & Controls
Chapters 38-39
Simplified overview of angiosperm life cycle
Review of an idealized flower
Lily
Types of Flowers
• Complete – have all four organs (sepals, petals, stamens, carpels)
• Incomplete – Lack one or more organs• Bisexual – has carpels and stamens• Unisexual – has carpels or stamens
• Monoeicous – stamens and carpels located on same plant
• Dioecious – carpels and stamens located on different plants
Pyrethrum, a composite flower
Sunflower
Pollination modes
The development of angiosperm gametophytes (pollen and embryo sacs)
Growth of the pollen tube and double fertilization
Pollen grains have tough, ornate, and distinctive walls
“Pin” and “thrum” flower types reduce self-fertilization
Genetic basis of self-incompatibility
The development of a dicot plant embryo
Seed structure
Mobilization of nutrients during the germination of a barley seed
Seed germination
Controls
Review of a general model for signal-transduction pathways
An example of signal transduction in plants: the role of phytochrome in the greening response
An Overview of Plant Hormones
Early experiments of phototropism
Cell elongation in response to auxin: the acid growth hypothesis
Apical dominance: with apical bud (left), apical bud removed (right)
Treating pea dwarfism with a growth hormone
The effect of gibberellin treatment on seedless grapes
Experimental evidence for a flowering hormone(s)
A corn leaf recruits a parasitoid wasp as a defensive response to an herbivore, an army-worm caterpillar
Structure of a phytochrome
Phytochrome: a molecular switching mechanism
Phytochrome regulation of lettuce seed germination
Biological clocks: Example - sleep movements of a bean plant
Biological clocks
Photoperiodic control of flowering