1. Warm-Up
Explain how plants obtain energy from sunlight.

2. UNIT 4D
Yesterday’s Picture

3. Regulation of Response to Abiotic Factors
UNIT 5A
Regulation of Response to Abiotic Factors

4. 2E.2a: In plants, physiological events involve interactions between environmental stimuli and internal molecular signals.
2E.2a.1: Phototropism, or the response to the presence of light.
2E.2a.2: Photoperiodism, or the response to change in the length of the night, that results in flowering in long-day and short-day plants.
2E.2b: In animals, internal and external signals regulate a variety of physiological responses that synchronize with environmental cycles and cues.
Illustrative example: Circadian rhythms
2E.2c: In fungi, protists and bacteria, internal and external signals regulate a variety of physiological responses that synchronize with environmental cycles and cues.
Illustrative example: Fruiting body formation in fungi, slime molds and certain types of bacteria.

5. Regulation of Response to Abiotic Factors
UNIT 5A
Regulation of Response to Abiotic Factors
Plants respond to light through phototropism.

6. Regulation of Response to Abiotic Factors
UNIT 5A
Regulation of Response to Abiotic Factors
Plants respond to light through phototropism.
abiotic factor: LIGHT!

7. Regulation of Response to Abiotic Factors
UNIT 5A
Regulation of Response to Abiotic Factors
Plants respond to light through phototropism.
Photoperiodism:
Plants respond to the length of day differently.
Short-day plants flower when the day is short; long-day plants flower when day is long.

8. Regulation of Response to Abiotic Factors
UNIT 5A
Regulation of Response to Abiotic Factors
Plants respond to light through phototropism.
Photoperiodism:
Plants respond to the length of day differently.
Short-day plants flower when the day is short; long-day plants flower when day is long.

9. 2E.2a: In plants, physiological events involve interactions between environmental stimuli and internal molecular signals.
2E.2a.1: Phototropism, or the response to the presence of light.
2E.2a.2: Photoperiodism, or the response to change in the length of the night, that results in flowering in long-day and short-day plants.
2E.2b: In animals, internal and external signals regulate a variety of physiological responses that synchronize with environmental cycles and cues.
Illustrative example: Circadian rhythms
2E.2c: In fungi, protists and bacteria, internal and external signals regulate a variety of physiological responses that synchronize with environmental cycles and cues.
Illustrative example: Fruiting body formation in fungi, slime molds and certain types of bacteria.

10. Regulation of Response to Abiotic Factors
UNIT 5A
Regulation of Response to Abiotic Factors
Circadian rhythms are an animal’s internal clock.

11. Regulation of Response to Abiotic Factors
UNIT 5A
Regulation of Response to Abiotic Factors
Circadian rhythms are an animal’s internal clock.
The clock runs without external stimuli, but will be re-trained when exposed to new stimuli.

12. Regulation of Response to Abiotic Factors
UNIT 5A
Regulation of Response to Abiotic Factors
Circadian rhythms are an animal’s internal clock.
The clock runs without external stimuli, but will be re-trained when exposed to new stimuli.
Test subjects placed in natural light cycles for 10 days, constant light for 25 days, then returned to natural cycles for 10 days.

13. 2E.2a: In plants, physiological events involve interactions between environmental stimuli and internal molecular signals.
2E.2a.1: Phototropism, or the response to the presence of light.
2E.2a.2: Photoperiodism, or the response to change in the length of the night, that results in flowering in long-day and short-day plants.
2E.2b: In animals, internal and external signals regulate a variety of physiological responses that synchronize with environmental cycles and cues.
Illustrative example: Circadian rhythms
2E.2c: In fungi, protists and bacteria, internal and external signals regulate a variety of physiological responses that synchronize with environmental cycles and cues.
Illustrative example: Fruiting body formation in fungi, slime molds and certain types of bacteria.

14. Regulation of Response to Abiotic Factors
UNIT 5A
Regulation of Response to Abiotic Factors
Fungi, bacteria and protists respond to lack of food by sending out spores.

15. Regulation of Response to Abiotic Factors
UNIT 5A
Regulation of Response to Abiotic Factors
Fungi, bacteria and protists respond to lack of food by sending out spores.
Spores are like asexual seeds – durable and will make a new generation.

16. Regulation of Response to Abiotic Factors
UNIT 5A
Regulation of Response to Abiotic Factors
Fungi, bacteria and protists respond to lack of food by sending out spores.
Spores are like asexual seeds – durable and will make a new generation.
So, I asked this girl out and she turned me down, and I was like, “hey come on, I’m a fungi!”
Fungi Fruiting Bodies

17. Regulation of Response to Abiotic Factors
UNIT 5A
Regulation of Response to Abiotic Factors
Fungi, bacteria and protists respond to lack of food by sending out spores.
Spores are like asexual seeds – durable and will make a new generation.
Protist Fruiting Bodies

18. Regulation of Response to Abiotic Factors
UNIT 5A
Regulation of Response to Abiotic Factors
Fungi, bacteria and protists respond to lack of food by sending out spores.
Spores are like asexual seeds – durable and will make a new generation.
Bacteria Fruiting Bodies

19. UNIT 5A
CTQ #1
The protein auxin is responsible for plant cell growth. When light shines on a plant cell, a pathway is stimulated to degrade auxin; thus, dark cells become larger and light cells become smaller. This results in the plant “bending” toward the source of the light, a phenomenon also referred to as phototropism. Which of the following statements best justifies the claim that auxin levels directly regulate phototropism? (LO 2.36)
A plant evenly illuminated from all sides will grow perfectly vertically.
Seeds lacking auxin never germinate, or sprout from the ground.
Artificial application of auxin to the illuminated surface of a plant prevents phototropism.
Removing a transcription factor which activates the auxin gene results in enhanced phototropism.

20. UNIT 5A
CTQ #2
Circadian rhythms are regulated by the secretion of melatonin, a hormone, from the pineal gland to many different cell types in the body. Activation of the melatonin synthesis in the pineal gland is activated by the suprachiasmatic nucleus (SCN), a region of the brain. Describe the role of melatonin receptors in the regulation of circadian rhythms. (LO 2.37)

21. Closure
Describe the evolutionary advantage to fruiting body formation.