1. Angiosperm Reproduction
Chapter 38
Angiosperm Reproduction

2. Angiosperms have 3 unique Features:
__lowers
__ ruits
Double __ertilization (by 2 sperm)

3. ____________________________: transfer pollen from anther to stigma

4. “Pin” and “thrum” flower types reduce self-fertilization
Some plants are self-pollinated
Cross-pollinated plants:
___________________________: plant rejects own pollen or closely related plant
Maximize ___________________________
Stigma
Pin flower
Anther
with
pollen
Thrum flower
“Pin” and “thrum” flower types reduce self-fertilization

5. The development of a plant embryo

6. Fruit Egg cell  plant __________________
__________ inside ovary  _________
Ripe _________  _________
Fruit protects enclosed seed(s)
Aids in dispersal by water, wind, or animals

7. Types of Fruit

8. Seeds Mature seed  ____________________ (resting) Low metabolic rate
Growth & development suspended
Resumes growth when environmental conditions suitable for germination

11. Germination
Seed take up water (imbibition)  trigger metabolic changes to begin growth
Root develops  shoot emerges  leaves expand & turn green (photosynthesis)
Very hazardous for plants due to vulnerability
Predators, parasites, wind

12. (__________________________)
Plant Reproduction
Sexual
Asexual
(__________________________)
Flower  Seeds
Runners, bulbs, grafts, cuttings
vegetative (grass), fragmentation, test-tube cloning
Genetic _______________
Clones
More complex & hazardous for seedlings
_______________
(no pollinator needed)
Suited for stable environments

13. Humans Modify Crops ___________________of plants for breeding
Plant Biotechnology:
Genetically modified organisms
“Golden Rice”: engineered to produce beta-carotene (Vit. A)
Bt corn: transgenic – expresses Bt (bacteria) gene  produces protein toxic to insects
________________ – reduce CO2 emissions
Biodiesel: vegetable oils
Bioethanol: convert cellulose into ethanol

14. Plant Responses to Internal and External Signals
Chapter 39
Plant Responses to Internal and External Signals

15. Experiments with Light and the coleoptile
Conclusion: Tip of coleoptile senses light  some signal was sent from tip to elongating region of coleoptile

16. Excised tip placed
on agar block
Growth-promoting
chemical diffuses
into agar block
Agar block
with chemical
stimulates growth
Offset blocks
cause curvature
Control
(agar block
lacking
chemical)
has no
effect
Cells on darker side elongate faster than cells on brighter side ______________ = chemical messenger that stimulates ______ ______________

17. Hormones: chemical messengers that coordinate different parts of a ________________ organism
Important plant hormones:
Auxin – stimulate ____ elongation  phototropism & gravitropism (high concentrations = herbicide)
_________________ – cell division (___________) & differentiation
_________________ – stem elongation, leaf growth, germination, flowering, fruit development
Abscisic Acid – ________ growth; closes stomata during H2O stress; promote _______________
______________ – promote fruit _____________ (__________ feedback!); involved in apoptosis (shed leaves, death of annuals)

18. The effects of gibberellin on stem elongation and fruit growth

19. Ethylene Gas: Fruit Ripening
Canister of ethylene gas to ripen bananas in shipping container
Untreated tomatoes vs. Ethylene treatment

20. Plant Movement Tropisms: _______________ SLOW
Phototropism – __________ (auxin)
Gravitropism – ___________ (auxin)
_____________________ – touch
Turgor movement: allow plant to make relatively rapid & reversible responses
Venus fly trap, mimosa leaves, “sleep” movement

21. Positive gravitropism in roots: the statolith hypothesis.

22. Thigmotropism: rapid turgor movements by Mimosa plant  action potentials

23. Plant Responses to Light
Plants can detect direction, intensity, & wavelenth of light
________________________: light receptors, absorbs mostly red light
Regulate seed germination, shade avoidance

24. __________________ is a critical factor!
Biological Clocks
____________________: biological clocks
Persist w/o environmental cues
Frequency = 24 hours
Phytochrome system + Biological clock = plant can determine time of year based on amount of light/darkness
__________________ is a critical factor!

25. __________________ is a critical factor!
_______________________: physiological response to the relative length of night & day (i.e. flowering)
Short-day plants: flower when nights are long (mums, poinsettia)
Long-day plant: flower when nights are short (spinach, iris, veggies)
Day-neutral plant: unaffected by photoperiod (tomatoes, rice, dandelions)
__________________ is a critical factor!

26. How does interrupting the dark period with a brief exposure to light affect flowering?

28. Plant responses to stress

29. Flooding (______deprivation):
Drought (H2O deficit):
______________ stoma
release ______________to keep stoma closed
Inhibit growth
roll leaves  reduce SA & ________________
deeper roots
Flooding (______deprivation):
release ____________  root cell death  air tubes formed to provide O2 to submerged roots

30. ________________________:
cell membrane – impede salt uptake
produce solutes to ↓ψ - retain ________
__________:
evap. cooling via transpiration
________________proteins – prevent denaturation
Cold:
alter lipid composition of membrane (↑______. fatty acids, _____fluidity)
increase cytoplasmic _____________
___________________ proteins

31. Herbivores: Pathogens: physical (thorns) chemicals (garlic, mint)
recruit predatory animals (parasitoid wasps)
Pathogens:
1st line of defense = ________________
2nd line = pathogen recognition, host-specific