1. -Read pg. What is your circadian rhythm?
Fill out circadian rhythm sheet

2. Biological Clocks/Circadian Rhythms
A physiological cycle with a frequency of about 24 hours is called a circadian rhythm
Even without external, environmental cues, circadian rhythms persist in humans and in all eukaryotes
Example: jet lag in humans

4. Photoperiodism
A physiological response to day length (differs in winter, summer, spring, and fall) is known as photoperiodism
Short-day plants
Require a shorter light period
Flower in later summer/fall/winter
Example: poinsettias
Long-day plants
Require a longer light period
Flower in late spring/early summer
Example: spinach
Day-neutral plants
Are unaffected by photoperiod
Example: tomatoes
But it’s actually the night that matters!!

6. Plant Responses to Internal & External Signals

7. Plant Hormones
Hormones are chemical signals that coordinate the various parts of an organism
A hormone is a compound produced in one part of the body which is then transported to other parts of the body, where it triggers responses in target cells and tissues
Examples of human hormones:
Adrenaline, testosterone, estrogen, epinephrine…

8. Plant Hormones
There are 5 major classes of plant hormones, each with specific functions:
Auxin
Cytokinins
Gibberellins
Abscisic acid
Ethylene

9. Auxin Stimulates stem elongation Stimulates development of fruit
Involved in phototropism and gravitropism

10. Cytokinins Stimulate cell division and growth
Stimulate cytokinesis
Stimulate germination and flowering

11. Gibberelins Trigger seed and bud germination
Promote stem elongation and leaf growth
Important in the growth of fruit

12. Ethylene Promotes fruit ripening
Senescence (aging) is a progression of irreversible change that eventually leads to death
Caused, at least in part, by ethylene
“One bad apple spoils the whole bunch”

13. Abscisic Acid Induces seed dormancy Inhibits cell growth
Anti-gibberellin
Inhibits cell growth
Anti-cytokinin
Inhibits fruit ripening
Anti-ethylene
Closes stomata during water stress, allowing many plants to survive droughts

14. Tropisms
Tropisms are growth responses that result in curvatures of whole plant organs toward or away from a stimuli
There are three major stimuli that induce tropisms
Light (Phototropism)
Gravity (Gravitropism)
Touch (Thigmotropism)

15. Phototropism Phototropism is the growth of a shoot towards light
This is primarily due to the action of auxin
Auxin elongates the cells on the non-light side

16. Plant Defenses
Plants defend themselves against herbivores in several ways
Physical defenses, such as thorns
Chemical defenses, such as
producing distasteful/toxic
compounds

17. interactions between root, stem, leaf,
flower color based on pH

18. To do #1
-Make a list of plant hormones and their functions
-Compare circadian rythm, phototropism, and photperiodism

19. Fungi and Plants

20. Fungi

21. Fungi--Nutrition and Habitat
- Decomposers/Absorptive heterotrophs
- saprobic, parasitic, mutualistic

22. Classification of Fungi
Chytridiomycota
- uniflagellated spores
- link to protists?
Zygomycota
- zygosporangia
- black bread mold
(Rhizopus stolonifer)
Asomycota
- spores produced in
asci (sac-like structure)
- truffles
(Tuber melanosporum)
Basidiomycota
- spores formed in
basidiocarps
- mushrooms

23. Structure
- hyphae form mycellium

24. Growth and Reproduction

25. Only fungi form fruiting bodies and spores

26. Above: The common mold Rhizopus
decomposing strawberries
Right: Pilobolus aiming its sporangia.
Pilobolus, the hat thrower. Pilobolus is a
dung-loving (coprophilous) fungus. Spores
are dispersed up to 2 m away and stick to
grass blades in the vicinity. The grass and
caps are eventually eaten by herbivores.

27. Zygomycota

28. Coenocytic and septate hyphae

29. Life cycle of bread mold
WATCH--
Use these 10 terms to explain the life cycle of a bread mold
Hyphae
Sporangia
Spore
Asexual
Sexual
Pheromones
Zygosporangium
Nuclei
Haploid
Diploid

30. Asomycota

31. Clockwise: Scarlet cup; the Yellow morel; truffels

32. Fungal gills, Hypholoma fasciculare (Basidiomycota). The gills
hang down from the cap in a tightly packed array. By producing
gills in this way the mushroom can increase the surface area of
the fertile layer (hymenium) by a factor of 20 or more.

34. Molds, Yeasts, Lichens and Mycorrhizae
- represent unique lifestyles that evolved independently
Molds
Penicillium on an orange, soft rot of citrus. The name Penicillium comes
from penicillus = brush, and this is based on the brush-like appearance of
the fruiting structure under the microscope.

35. Yeasts inhabit moist habitats - Saccharomyces cerevisiae
- unicellular fungi that
inhabit moist habitats
- Saccharomyces
cerevisiae
- baker/brewer yeast
- Candida
- inhabit human
epithelial tissue
- AIDS patients

36. Lichens b/n fungi and algae - mutual exploitation
- symbiotic association
b/n fungi and algae
- mutual exploitation
- tough, resistant; but
sensitive to air pollution

37. Mycorrhizae - increases the absorptive surface area of plant roots
- mutualistic associations with plant roots
- increases the absorptive surface area of plant roots
- exchange of minerals between plant and fungus

38. To do #2
-Watch life cycle of a bread mold
-Write a summary of the life cycle of bread mold