Plant Form and Function Learning Goal How are

Plant Form and Function Learning Goal: How are plants structurally adapted for survival? Concept 3: Analyzing how plants detect and defend themselves against herbivores and environmental stresses (Ch 39) r u o y t e G lution Evo stion e u q ady! re Refer to pg 219 -222 in Holtzclaw Ch 39 in Campbell Media resources

Checkpoint Next Class: Concept 1: Analyzing the structure, growth, development and nutrition of plants (Ch 35, 37) Concept 2: Analyzing the reproduction of angiosperms and modifications through biotechnology (Ch 38) Don’t forget Concept 3: Analyzing how plants detect and to defend themselves against herbivores and connect environmental stresses (Ch 39) to the AP Themes!

Try This! Which of the following constitute plant macronutrients? A. B. C. D. E. Potassium, oxygen, hydrogen and zinc Carbon, oxygen, nitrogen and copper Carbon, oxygen, nitrogen, and hydrogen Carbon, boron, nitrogen, and chlorine Phosphorus, oxygen, nitrogen and iron

Try This! Which of the following constitute plant macronutrients? A. Potassium, oxygen, hydrogen and zinc B. Carbon, oxygen, nitrogen and copper C. Carbon, oxygen, nitrogen, and hydrogen D. Carbon, boron, nitrogen, and chlorine E. Phosphorus, oxygen, nitrogen and iron CHNOPS!!

Try This! In double fertilization, how is the endosperm formed? A. B. C. D. E. The fusing of two sperm and an egg From the epidermis From the fertilization of the egg From the zygote during development From the fusing of a sperm with two polar bodies

Try This! In double fertilization, how is the endosperm formed? A. B. C. D. E. The fusing of two sperm and an egg From the epidermis From the fertilization of the egg From the zygote during development From the fusing of a sperm with two polar bodies

From Last Class… Free Response Page 820 in Campbell – Assess next class ◦ # 12 Evolution Connection With respect to sexual reproduction, some plant species are fully self-fertile, others are fully selfincompatible, and some exhibit a “mixed strategy” with partial self-incompatibility. These reproductive strategies differ in their implications for evolutionary potential. How, for example, might a self-incompatible species fare as a small founder population or remnant population in a severe population bottleneck (see Ch 23), as compared with a self-fertile

From Last Class… Free Response – Evolution Connection Small populations of self-incompatible species, whether due to being founding populations or to bottleneck, would be at a disadvantage relative to self-fertile species. Small populations already have significant challenges in avoiding extinction. Adding the fact that they cannot perform sexual reproduction independently of other organisms merely adds to the list of challenges. Beginning Does not demonstrate a basic understanding of concept. Substantial errors throughout. Developing Basic understanding of concepts. Errors and inconsistency reveal some missing elements. Accomplished Solid understanding of concepts. Most answers are correct. Few errors. Exemplary Complete and in depth understanding of concepts. Answers are correct, with elegant connections.

Concept 3: Analyzing how plants detect and defend themselves against herbivores and environmental stresses (Ch 39)

Concept 3: Analyzing how plants detect and defend themselves against herbivores and environmental stresses (Ch 39) You must know: The three steps to a signal transduction pathway The role of auxins in plants The survival benefits of phototropism and gravitropism How photoperiodism determines when flowering occurs

Try This! Both plants and animals respond to environmental stimuli. Which of the following statements are true and which ones are false? A. The processes by which plants and animals perceive environmental changes are equally complex. B. The processes by which plants and animals perceive environmental changes are often homologous. C. Unlike animal hormones, plant hormones act only locally. D. Both plants and animals have physiological cycles called circadian rhythms.

Try This! Both plants and animals respond to environmental stimuli. Which of the following statements are true and which ones are false? The processes by which plants and animals perceive environmental changes are equally complex. TRUE B. The processes by which plants and animals perceive environmental changes are often homologous. TRUE C. Unlike animal hormones, plant hormones act only locally. FLASE D. Both plants and animals have physiological cycles called circadian rhythms. TRUE A.

Try This! What are the morphological differences in dark-grown plants and light-grown plants?

Try This! What are the morphological differences in dark-grown plants and light-grown plants? ◦ Dark- grown have long stems underdeveloped roots unexpanded leaves shoots lack chlorophyll , t Bu ? Y H W

How does this potato change its growth when there is light?

How does this potato change its growth when there is light? Via the Signal Transduction Pathway!

How does this potato change its growth when there is light? Via the Signal Transduction Pathway! ◦ The signal (light) is transduced to a response (greening)

Signal Transduction - Review Reception Transduction Response

Signal Transduction - Review Reception: Receptors undergo changes in shape due to an environmental stimulus ◦ Ex) phytochrome proteins changing in response to light

Signal Transduction - Review Transduction: Amplification of signal through a multistep pathway ◦ Allows small signal to produce large cellular response Uses protein kinases (phosphorylation cascade) and second messengers (Ca 2+ and c. AMP)

Signal Transduction - Review Response: Two ways response is accomplished: 1. Transcriptional Modification: • 2. ↑ or ↓ m. RNA production (turning genes on/off) Post-Translational Modification: • Activates existing enzyme molecules

Signal Transduction For example, affected proteins for this potato exposed to light include: ◦ Photosynthesis enzymes ◦ Plant growth hormones Auxin levels lower to slow stem growth (focus on leaf growth)

So…. What was AUXIN? A plant hormone… Yes, plants have hormones too!

Examples of Plant Hormones Auxins – stimulate elongation of cells within young developing shoots Cytokinins – stimulate cell division Gibberellins – stimulate stem elongation, pollen, fruit, seed development Abscisic acid – promotes stomatal closure during drought stress Ethylene (gas!) – fruit ripening, leaf abscission

Plant Hormones: chemical messengers that coordinate the different parts of a multicellular organism Tropism: Plant growth response toward or away from a stimulus ◦ Phototropism ◦ Gravitropism How does this benefit survival?

Phototropism - Mechanism

Phototropism - Mechanism

Phototropism - Mechanism

Actions of hormones… Photoperiodism – physiological response to a photoperiod (relative lengths of day and night) ◦ Example: Flowering Short day plants Long day plants Day-neutral plants Circadian rhythms – physiological cycles that have a frequency of about 24 hours

Responses to Mechanical Stimuli Mimosa Plant

Herbivore Defense Video Clip

Think: Illustrate this statement with an example: “A plant generally responds to environmental cues by adjusting its pattern of growth and development. ”

How do plants detect and defend themselves against herbivores and environmental stresses? Do you know? The three steps to a signal transduction pathway The role of auxins in plants The survival benefits of phototropism and gravitropism How photoperiodism determines when flowering occurs

Checkpoint Next Class: Concept 1: Analyzing the structure, growth, development and nutrition of plants (Ch 35, 37) # 12, 13, 15, 16, 20, 21, 24 in Holtz Concept 2: Analyzing the reproduction of angiosperms and modifications through biotechnology (Ch 38) #5, 22, 23 in Holtz Don’t forget to connect Concept 3: Analyzing how plants detect and defend themselves against herbivores and to the environmental stresses (Ch 39) AP Themes! # 1, 2, 7, 8, 9, 10, 11, 14, 25 in Holtz